/******************************************************************************
 *
 * Project:  VSI Virtual File System
 * Purpose:  Implementation VSI*L File API and other file system access
 *           methods going through file virtualization.
 * Author:   Frank Warmerdam, warmerdam@pobox.com
 *
 ******************************************************************************
 * Copyright (c) 2005, Frank Warmerdam <warmerdam@pobox.com>
 * Copyright (c) 2008-2014, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/

#include "cpl_port.h"
#include "cpl_vsi.h"

#include <cassert>
#include <cinttypes>
#include <cstdarg>
#include <cstddef>
#include <cstring>
#if HAVE_FCNTL_H
#include <fcntl.h>
#endif

#include <algorithm>
#include <limits>
#include <map>
#include <memory>
#include <mutex>
#include <set>
#include <string>
#include <utility>
#include <vector>

#include "cpl_conv.h"
#include "cpl_error.h"
#include "cpl_multiproc.h"
#include "cpl_string.h"
#include "cpl_vsi_virtual.h"
#include "cpl_vsil_curl_class.h"

// To avoid aliasing to GetDiskFreeSpace to GetDiskFreeSpaceA on Windows
#ifdef GetDiskFreeSpace
#undef GetDiskFreeSpace
#endif

/************************************************************************/
/*                             VSIReadDir()                             */
/************************************************************************/

/**
 * \brief Read names in a directory.
 *
 * This function abstracts access to directory contains.  It returns a
 * list of strings containing the names of files, and directories in this
 * directory.  The resulting string list becomes the responsibility of the
 * application and should be freed with CSLDestroy() when no longer needed.
 *
 * Note that no error is issued via CPLError() if the directory path is
 * invalid, though NULL is returned.
 *
 * This function used to be known as CPLReadDir(), but the old name is now
 * deprecated.
 *
 * @param pszPath the relative, or absolute path of a directory to read.
 * UTF-8 encoded.
 * @return The list of entries in the directory, or NULL if the directory
 * doesn't exist.  Filenames are returned in UTF-8 encoding.
 */

char **VSIReadDir(const char *pszPath)
{
    return VSIReadDirEx(pszPath, 0);
}

/************************************************************************/
/*                             VSIReadDirEx()                           */
/************************************************************************/

/**
 * \brief Read names in a directory.
 *
 * This function abstracts access to directory contains.  It returns a
 * list of strings containing the names of files, and directories in this
 * directory.  The resulting string list becomes the responsibility of the
 * application and should be freed with CSLDestroy() when no longer needed.
 *
 * Note that no error is issued via CPLError() if the directory path is
 * invalid, though NULL is returned.
 *
 * If nMaxFiles is set to a positive number, directory listing will stop after
 * that limit has been reached. Note that to indicate truncate, at least one
 * element more than the nMaxFiles limit will be returned. If CSLCount() on the
 * result is lesser or equal to nMaxFiles, then no truncation occurred.
 *
 * @param pszPath the relative, or absolute path of a directory to read.
 * UTF-8 encoded.
 * @param nMaxFiles maximum number of files after which to stop, or 0 for no
 * limit.
 * @return The list of entries in the directory, or NULL if the directory
 * doesn't exist.  Filenames are returned in UTF-8 encoding.
 * @since GDAL 2.1
 */

char **VSIReadDirEx(const char *pszPath, int nMaxFiles)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);

    return poFSHandler->ReadDirEx(pszPath, nMaxFiles);
}

/************************************************************************/
/*                             VSISiblingFiles()                        */
/************************************************************************/

/**
 * \brief Return related filenames
 *
 * This function is essentially meant at being used by GDAL internals.
 *
 * @param pszFilename the path of a filename to inspect
 * UTF-8 encoded.
 * @return The list of entries, relative to the directory, of all sidecar
 * files available or NULL if the list is not known.
 * Filenames are returned in UTF-8 encoding.
 * Most implementations will return NULL, and a subsequent ReadDir will
 * list all files available in the file's directory. This function will be
 * overridden by VSI FilesystemHandlers that wish to force e.g. an empty list
 * to avoid opening non-existent files on slow filesystems. The return value
 * shall be destroyed with CSLDestroy()
 * @since GDAL 3.2
 */
char **VSISiblingFiles(const char *pszFilename)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->SiblingFiles(pszFilename);
}

/************************************************************************/
/*                      VSIGetDirectorySeparator()                      */
/************************************************************************/

/** Return the directory separator for the specified path.
 *
 * Default is forward slash. The only exception currently is the Windows
 * file system which returns backslash, unless the specified path is of the
 * form "{drive_letter}:/{rest_of_the_path}".
 *
 * @since 3.9
 */
const char *VSIGetDirectorySeparator(const char *pszPath)
{
    if (STARTS_WITH(pszPath, "http://") || STARTS_WITH(pszPath, "https://"))
        return "/";

    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);
    return poFSHandler->GetDirectorySeparator(pszPath);
}

/************************************************************************/
/*                             VSIReadRecursive()                       */
/************************************************************************/

/**
 * \brief Read names in a directory recursively.
 *
 * This function abstracts access to directory contents and subdirectories.
 * It returns a list of strings containing the names of files and directories
 * in this directory and all subdirectories.  The resulting string list becomes
 * the responsibility of the application and should be freed with CSLDestroy()
 * when no longer needed.
 *
 * Note that no error is issued via CPLError() if the directory path is
 * invalid, though NULL is returned.
 *
 * Note: since GDAL 3.9, for recursive mode, the directory separator will no
 * longer be always forward slash, but will be the one returned by
 * VSIGetDirectorySeparator(pszPathIn), so potentially backslash on Windows
 * file systems.
 *
 * @param pszPathIn the relative, or absolute path of a directory to read.
 * UTF-8 encoded.
 *
 * @return The list of entries in the directory and subdirectories
 * or NULL if the directory doesn't exist.  Filenames are returned in UTF-8
 * encoding.
 * @since GDAL 1.10.0
 *
 */

char **VSIReadDirRecursive(const char *pszPathIn)
{
    const char SEP = VSIGetDirectorySeparator(pszPathIn)[0];

    const char *const apszOptions[] = {"NAME_AND_TYPE_ONLY=YES", nullptr};
    VSIDIR *psDir = VSIOpenDir(pszPathIn, -1, apszOptions);
    if (!psDir)
        return nullptr;
    CPLStringList oFiles;
    while (auto psEntry = VSIGetNextDirEntry(psDir))
    {
        if (VSI_ISDIR(psEntry->nMode) && psEntry->pszName[0] &&
            psEntry->pszName[strlen(psEntry->pszName) - 1] != SEP)
        {
            oFiles.AddString((std::string(psEntry->pszName) + SEP).c_str());
        }
        else
        {
            oFiles.AddString(psEntry->pszName);
        }
    }
    VSICloseDir(psDir);

    return oFiles.StealList();
}

/************************************************************************/
/*                             CPLReadDir()                             */
/*                                                                      */
/*      This is present only to provide ABI compatibility with older    */
/*      versions.                                                       */
/************************************************************************/
#undef CPLReadDir

CPL_C_START
char CPL_DLL **CPLReadDir(const char *pszPath);
CPL_C_END

char **CPLReadDir(const char *pszPath)
{
    return VSIReadDir(pszPath);
}

/************************************************************************/
/*                             VSIOpenDir()                             */
/************************************************************************/

/**
 * \brief Open a directory to read its entries.
 *
 * This function is close to the POSIX opendir() function.
 *
 * For /vsis3/, /vsigs/, /vsioss/, /vsiaz/ and /vsiadls/, this function has an
 * efficient implementation, minimizing the number of network requests, when
 * invoked with nRecurseDepth <= 0.
 *
 * Entries are read by calling VSIGetNextDirEntry() on the handled returned by
 * that function, until it returns NULL. VSICloseDir() must be called once done
 * with the returned directory handle.
 *
 * @param pszPath the relative, or absolute path of a directory to read.
 * UTF-8 encoded.
 * @param nRecurseDepth 0 means do not recurse in subdirectories, 1 means
 * recurse only in the first level of subdirectories, etc. -1 means unlimited
 * recursion level
 * @param papszOptions NULL terminated list of options, or NULL. The following
 * options are implemented:
 * <ul>
 * <li>PREFIX=string: (GDAL >= 3.4) Filter to select filenames only starting
 *     with the specified prefix. Implemented efficiently for /vsis3/, /vsigs/,
 *     and /vsiaz/ (but not /vsiadls/)
 * </li>
 * <li>NAME_AND_TYPE_ONLY=YES/NO: (GDAL >= 3.4) Defaults to NO. If set to YES,
 *     only the pszName and nMode members of VSIDIR are guaranteed to be set.
 *     This is implemented efficiently for the Unix virtual file system.
 * </li>
 * </ul>
 *
 * @return a handle, or NULL in case of error
 * @since GDAL 2.4
 *
 */

VSIDIR *VSIOpenDir(const char *pszPath, int nRecurseDepth,
                   const char *const *papszOptions)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);

    return poFSHandler->OpenDir(pszPath, nRecurseDepth, papszOptions);
}

/************************************************************************/
/*                          VSIGetNextDirEntry()                        */
/************************************************************************/

/**
 * \brief Return the next entry of the directory
 *
 * This function is close to the POSIX readdir() function. It actually returns
 * more information (file size, last modification time), which on 'real' file
 * systems involve one 'stat' call per file.
 *
 * For filesystems that can have both a regular file and a directory name of
 * the same name (typically /vsis3/), when this situation of duplicate happens,
 * the directory name will be suffixed by a slash character. Otherwise directory
 * names are not suffixed by slash.
 *
 * The returned entry remains valid until the next call to VSINextDirEntry()
 * or VSICloseDir() with the same handle.
 *
 * Note: since GDAL 3.9, for recursive mode, the directory separator will no
 * longer be always forward slash, but will be the one returned by
 * VSIGetDirectorySeparator(pszPathIn), so potentially backslash on Windows
 * file systems.
 *
 * @param dir Directory handled returned by VSIOpenDir(). Must not be NULL.
 *
 * @return a entry, or NULL if there is no more entry in the directory. This
 * return value must not be freed.
 * @since GDAL 2.4
 *
 */

const VSIDIREntry *VSIGetNextDirEntry(VSIDIR *dir)
{
    return dir->NextDirEntry();
}

/************************************************************************/
/*                             VSICloseDir()                            */
/************************************************************************/

/**
 * \brief Close a directory
 *
 * This function is close to the POSIX closedir() function.
 *
 * @param dir Directory handled returned by VSIOpenDir().
 *
 * @since GDAL 2.4
 */

void VSICloseDir(VSIDIR *dir)
{
    delete dir;
}

/************************************************************************/
/*                              VSIMkdir()                              */
/************************************************************************/

/**
 * \brief Create a directory.
 *
 * Create a new directory with the indicated mode. For POSIX-style systems,
 * the mode is modified by the file creation mask (umask). However, some
 * file systems and platforms may not use umask, or they may ignore the mode
 * completely. So a reasonable cross-platform default mode value is 0755.
 *
 * Analog of the POSIX mkdir() function.
 *
 * @param pszPathname the path to the directory to create. UTF-8 encoded.
 * @param mode the permissions mode.
 *
 * @return 0 on success or -1 on an error.
 */

int VSIMkdir(const char *pszPathname, long mode)

{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPathname);

    return poFSHandler->Mkdir(pszPathname, mode);
}

/************************************************************************/
/*                       VSIMkdirRecursive()                            */
/************************************************************************/

/**
 * \brief Create a directory and all its ancestors
 *
 * @param pszPathname the path to the directory to create. UTF-8 encoded.
 * @param mode the permissions mode.
 *
 * @return 0 on success or -1 on an error.
 * @since GDAL 2.3
 */

int VSIMkdirRecursive(const char *pszPathname, long mode)
{
    if (pszPathname == nullptr || pszPathname[0] == '\0' ||
        strncmp("/", pszPathname, 2) == 0)
    {
        return -1;
    }

    const CPLString osPathname(pszPathname);
    VSIStatBufL sStat;
    if (VSIStatL(osPathname, &sStat) == 0)
    {
        return VSI_ISDIR(sStat.st_mode) ? 0 : -1;
    }
    const CPLString osParentPath(CPLGetPath(osPathname));

    // Prevent crazy paths from recursing forever.
    if (osParentPath == osPathname ||
        osParentPath.length() >= osPathname.length())
    {
        return -1;
    }

    if (VSIStatL(osParentPath, &sStat) != 0)
    {
        if (VSIMkdirRecursive(osParentPath, mode) != 0)
            return -1;
    }

    return VSIMkdir(osPathname, mode);
}

/************************************************************************/
/*                             VSIUnlink()                              */
/************************************************************************/

/**
 * \brief Delete a file.
 *
 * Deletes a file object from the file system.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX unlink() function.
 *
 * @param pszFilename the path of the file to be deleted. UTF-8 encoded.
 *
 * @return 0 on success or -1 on an error.
 */

int VSIUnlink(const char *pszFilename)

{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->Unlink(pszFilename);
}

/************************************************************************/
/*                           VSIUnlinkBatch()                           */
/************************************************************************/

/**
 * \brief Delete several files, possibly in a batch.
 *
 * All files should belong to the same file system handler.
 *
 * This is implemented efficiently for /vsis3/ and /vsigs/ (provided for /vsigs/
 * that OAuth2 authentication is used).
 *
 * @param papszFiles NULL terminated list of files. UTF-8 encoded.
 *
 * @return an array of size CSLCount(papszFiles), whose values are TRUE or FALSE
 * depending on the success of deletion of the corresponding file. The array
 * should be freed with VSIFree().
 * NULL might be return in case of a more general error (for example,
 * files belonging to different file system handlers)
 *
 * @since GDAL 3.1
 */

int *VSIUnlinkBatch(CSLConstList papszFiles)
{
    VSIFilesystemHandler *poFSHandler = nullptr;
    for (CSLConstList papszIter = papszFiles; papszIter && *papszIter;
         ++papszIter)
    {
        auto poFSHandlerThisFile = VSIFileManager::GetHandler(*papszIter);
        if (poFSHandler == nullptr)
            poFSHandler = poFSHandlerThisFile;
        else if (poFSHandler != poFSHandlerThisFile)
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Files belong to different file system handlers");
            poFSHandler = nullptr;
            break;
        }
    }
    if (poFSHandler == nullptr)
        return nullptr;
    return poFSHandler->UnlinkBatch(papszFiles);
}

/************************************************************************/
/*                             VSIRename()                              */
/************************************************************************/

/**
 * \brief Rename a file.
 *
 * Renames a file object in the file system.  It should be possible
 * to rename a file onto a new filesystem, but it is safest if this
 * function is only used to rename files that remain in the same directory.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX rename() function.
 *
 * @param oldpath the name of the file to be renamed.  UTF-8 encoded.
 * @param newpath the name the file should be given.  UTF-8 encoded.
 *
 * @return 0 on success or -1 on an error.
 */

int VSIRename(const char *oldpath, const char *newpath)

{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(oldpath);

    return poFSHandler->Rename(oldpath, newpath);
}

/************************************************************************/
/*                             VSICopyFile()                            */
/************************************************************************/

/**
 * \brief Copy a source file into a target file.
 *
 * For a /vsizip/foo.zip/bar target, the options available are those of
 * CPLAddFileInZip()
 *
 * The following copies are made fully on the target server, without local
 * download from source and upload to target:
 * - /vsis3/ -> /vsis3/
 * - /vsigs/ -> /vsigs/
 * - /vsiaz/ -> /vsiaz/
 * - /vsiadls/ -> /vsiadls/
 * - any of the above or /vsicurl/ -> /vsiaz/ (starting with GDAL 3.8)
 *
 * @param pszSource Source filename. UTF-8 encoded. May be NULL if fpSource is
 * not NULL.
 * @param pszTarget Target filename.  UTF-8 encoded. Must not be NULL
 * @param fpSource File handle on the source file. May be NULL if pszSource is
 * not NULL.
 * @param nSourceSize Size of the source file. Pass -1 if unknown.
 * If set to -1, and progress callback is used, VSIStatL() will be used on
 * pszSource to retrieve the source size.
 * @param papszOptions Null terminated list of options, or NULL.
 * @param pProgressFunc Progress callback, or NULL.
 * @param pProgressData User data of progress callback, or NULL.
 *
 * @return 0 on success.
 * @since GDAL 3.7
 */

int VSICopyFile(const char *pszSource, const char *pszTarget,
                VSILFILE *fpSource, vsi_l_offset nSourceSize,
                const char *const *papszOptions, GDALProgressFunc pProgressFunc,
                void *pProgressData)

{
    if (!pszSource && !fpSource)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "pszSource == nullptr && fpSource == nullptr");
        return -1;
    }
    if (!pszTarget || pszTarget[0] == '\0')
    {
        return -1;
    }

    VSIFilesystemHandler *poFSHandlerTarget =
        VSIFileManager::GetHandler(pszTarget);
    return poFSHandlerTarget->CopyFile(pszSource, pszTarget, fpSource,
                                       nSourceSize, papszOptions, pProgressFunc,
                                       pProgressData);
}

/************************************************************************/
/*                       VSICopyFileRestartable()                       */
/************************************************************************/

/**
 \brief Copy a source file into a target file in a way that can (potentially)
 be restarted.

 This function provides the possibility of efficiently restarting upload of
 large files to cloud storage that implements upload in a chunked way,
 such as /vsis3/ and /vsigs/.
 For other destination file systems, this function may fallback to
 VSICopyFile() and not provide any smart restartable implementation.

 Example of a potential workflow:

 @code{.cpp}
 char* pszOutputPayload = NULL;
 int ret = VSICopyFileRestartable(pszSource, pszTarget, NULL,
                                  &pszOutputPayload, NULL, NULL, NULL);
 while( ret == 1 ) // add also a limiting counter to avoid potentiall endless looping
 {
     // TODO: wait for some time

     char* pszOutputPayloadNew = NULL;
     const char* pszInputPayload = pszOutputPayload;
     ret = VSICopyFileRestartable(pszSource, pszTarget, pszInputPayload,
                                  &pszOutputPayloadNew, NULL, NULL, NULL);
     VSIFree(pszOutputPayload);
     pszOutputPayload = pszOutputPayloadNew;
 }
 VSIFree(pszOutputPayload);
 @endcode

 @param pszSource Source filename. UTF-8 encoded. Must not be NULL
 @param pszTarget Target filename. UTF-8 encoded. Must not be NULL
 @param pszInputPayload NULL at the first invocation. When doing a retry,
                        should be the content of *ppszOutputPayload from a
                        previous invocation.
 @param[out] ppszOutputPayload Pointer to an output string that will be set to
                               a value that can be provided as pszInputPayload
                               for a next call to VSICopyFileRestartable().
                               ppszOutputPayload must not be NULL.
                               The string set in *ppszOutputPayload, if not NULL,
                               is JSON-encoded, and can be re-used in another
                               process instance. It must be freed with VSIFree()
                               when no longer needed.
 @param papszOptions Null terminated list of options, or NULL.
 Currently accepted options are:
 <ul>
 <li>NUM_THREADS=integer or ALL_CPUS. Number of threads to use for parallel
 file copying. Only use for when /vsis3/, /vsigs/, /vsiaz/ or /vsiadls/ is in
 source or target. The default is 10.
 </li>
 <li>CHUNK_SIZE=integer. Maximum size of chunk (in bytes) to use
 to split large objects. For upload to /vsis3/, this chunk size must be set at
 least to 5 MB. The default is 50 MB.
 </li>
 </ul>
 @param pProgressFunc Progress callback, or NULL.
 @param pProgressData User data of progress callback, or NULL.
 @return 0 on success,
         -1 on (non-restartable) failure,
         1 if VSICopyFileRestartable() can be called again in a restartable way
 @since GDAL 3.10

 @see VSIAbortPendingUploads()
*/

int VSICopyFileRestartable(const char *pszSource, const char *pszTarget,
                           const char *pszInputPayload,
                           char **ppszOutputPayload,
                           const char *const *papszOptions,
                           GDALProgressFunc pProgressFunc, void *pProgressData)

{
    if (!pszSource)
    {
        return -1;
    }
    if (!pszTarget || pszTarget[0] == '\0')
    {
        return -1;
    }
    if (!ppszOutputPayload)
    {
        return -1;
    }

    VSIFilesystemHandler *poFSHandlerTarget =
        VSIFileManager::GetHandler(pszTarget);
    return poFSHandlerTarget->CopyFileRestartable(
        pszSource, pszTarget, pszInputPayload, ppszOutputPayload, papszOptions,
        pProgressFunc, pProgressData);
}

/************************************************************************/
/*                             VSISync()                                */
/************************************************************************/

/**
 * \brief Synchronize a source file/directory with a target file/directory.
 *
 * This is a analog of the 'rsync' utility. In the current implementation,
 * rsync would be more efficient for local file copying, but VSISync() main
 * interest is when the source or target is a remote
 * file system like /vsis3/ or /vsigs/, in which case it can take into account
 * the timestamps of the files (or optionally the ETag/MD5Sum) to avoid
 * unneeded copy operations.
 *
 * This is only implemented efficiently for:
 * <ul>
 * <li> local filesystem <--> remote filesystem.</li>
 * <li> remote filesystem <--> remote filesystem (starting with GDAL 3.1).
 * Where the source and target remote filesystems are the same and one of
 * /vsis3/, /vsigs/ or /vsiaz/. Or when the target is /vsiaz/ and the source
 * is /vsis3/, /vsigs/, /vsiadls/ or /vsicurl/ (starting with GDAL 3.8)</li>
 * </ul>
 *
 * Similarly to rsync behavior, if the source filename ends with a slash,
 * it means that the content of the directory must be copied, but not the
 * directory name. For example, assuming "/home/even/foo" contains a file "bar",
 * VSISync("/home/even/foo/", "/mnt/media", ...) will create a "/mnt/media/bar"
 * file. Whereas VSISync("/home/even/foo", "/mnt/media", ...) will create a
 * "/mnt/media/foo" directory which contains a bar file.
 *
 * @param pszSource Source file or directory.  UTF-8 encoded.
 * @param pszTarget Target file or directory.  UTF-8 encoded.
 * @param papszOptions Null terminated list of options, or NULL.
 * Currently accepted options are:
 * <ul>
 * <li>RECURSIVE=NO (the default is YES)</li>
 * <li>SYNC_STRATEGY=TIMESTAMP/ETAG/OVERWRITE.
 *
 *     Determines which criterion is used to determine if a target file must be
 *     replaced when it already exists and has the same file size as the source.
 *     Only applies for a source or target being a network filesystem.
 *
 *     The default is TIMESTAMP (similarly to how 'aws s3 sync' works), that is
 *     to say that for an upload operation, a remote file is
 *     replaced if it has a different size or if it is older than the source.
 *     For a download operation, a local file is  replaced if it has a different
 *     size or if it is newer than the remote file.
 *
 *     The ETAG strategy assumes that the ETag metadata of the remote file is
 *     the MD5Sum of the file content, which is only true in the case of /vsis3/
 *     for files not using KMS server side encryption and uploaded in a single
 *     PUT operation (so smaller than 50 MB given the default used by GDAL).
 *     Only to be used for /vsis3/, /vsigs/ or other filesystems using a
 *     MD5Sum as ETAG.
 *
 *     The OVERWRITE strategy (GDAL >= 3.2) will always overwrite the target
 *     file with the source one.
 * </li>
 * <li>NUM_THREADS=integer. (GDAL >= 3.1) Number of threads to use for parallel
 * file copying. Only use for when /vsis3/, /vsigs/, /vsiaz/ or /vsiadls/ is in
 * source or target. The default is 10 since GDAL 3.3</li>
 * <li>CHUNK_SIZE=integer. (GDAL >= 3.1) Maximum size of chunk (in bytes) to use
 * to split large objects when downloading them from /vsis3/, /vsigs/, /vsiaz/
 * or /vsiadls/ to local file system, or for upload to /vsis3/, /vsiaz/ or
 * /vsiadls/ from local file system. Only used if NUM_THREADS > 1. For upload to
 * /vsis3/, this chunk size must be set at least to 5 MB. The default is 8 MB
 * since GDAL 3.3</li> <li>x-amz-KEY=value. (GDAL >= 3.5) MIME header to pass
 * during creation of a /vsis3/ object.</li> <li>x-goog-KEY=value. (GDAL >= 3.5)
 * MIME header to pass during creation of a /vsigs/ object.</li>
 * <li>x-ms-KEY=value. (GDAL >= 3.5) MIME header to pass during creation of a
 * /vsiaz/ or /vsiadls/ object.</li>
 * </ul>
 * @param pProgressFunc Progress callback, or NULL.
 * @param pProgressData User data of progress callback, or NULL.
 * @param ppapszOutputs Unused. Should be set to NULL for now.
 *
 * @return TRUE on success or FALSE on an error.
 * @since GDAL 2.4
 */

int VSISync(const char *pszSource, const char *pszTarget,
            const char *const *papszOptions, GDALProgressFunc pProgressFunc,
            void *pProgressData, char ***ppapszOutputs)

{
    if (pszSource[0] == '\0' || pszTarget[0] == '\0')
    {
        return FALSE;
    }

    VSIFilesystemHandler *poFSHandlerSource =
        VSIFileManager::GetHandler(pszSource);
    VSIFilesystemHandler *poFSHandlerTarget =
        VSIFileManager::GetHandler(pszTarget);
    VSIFilesystemHandler *poFSHandlerLocal = VSIFileManager::GetHandler("");
    VSIFilesystemHandler *poFSHandlerMem =
        VSIFileManager::GetHandler("/vsimem/");
    VSIFilesystemHandler *poFSHandler = poFSHandlerSource;
    if (poFSHandlerTarget != poFSHandlerLocal &&
        poFSHandlerTarget != poFSHandlerMem)
    {
        poFSHandler = poFSHandlerTarget;
    }

    return poFSHandler->Sync(pszSource, pszTarget, papszOptions, pProgressFunc,
                             pProgressData, ppapszOutputs)
               ? TRUE
               : FALSE;
}

/************************************************************************/
/*                    VSIMultipartUploadGetCapabilities()               */
/************************************************************************/

/**
 * \brief Return capabilities for multiple part file upload.
 *
 * @param pszFilename Filename, or virtual file system prefix, onto which
 * capabilities should apply.
 * @param[out] pbNonSequentialUploadSupported If not null,
 * the pointed value is set if parts can be uploaded in a non-sequential way.
 * @param[out] pbParallelUploadSupported If not null,
 * the pointed value is set if parts can be uploaded in a parallel way.
 * (implies *pbNonSequentialUploadSupported = true)
 * @param[out] pbAbortSupported If not null,
 * the pointed value is set if VSIMultipartUploadAbort() is implemented.
 * @param[out] pnMinPartSize If not null, the pointed value is set to the minimum
 * size of parts (but the last one), in MiB.
 * @param[out] pnMaxPartSize If not null, the pointed value is set to the maximum
 * size of parts, in MiB.
 * @param[out] pnMaxPartCount  If not null, the pointed value is set to the
 * maximum number of parts that can be uploaded.
 *
 * @return TRUE in case of success, FALSE otherwise.
 *
 * @since 3.10
 */
int VSIMultipartUploadGetCapabilities(
    const char *pszFilename, int *pbNonSequentialUploadSupported,
    int *pbParallelUploadSupported, int *pbAbortSupported,
    size_t *pnMinPartSize, size_t *pnMaxPartSize, int *pnMaxPartCount)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->MultipartUploadGetCapabilities(
        pbNonSequentialUploadSupported, pbParallelUploadSupported,
        pbAbortSupported, pnMinPartSize, pnMaxPartSize, pnMaxPartCount);
}

/************************************************************************/
/*                     VSIMultipartUploadStart()                        */
/************************************************************************/

/**
 * \brief Initiates the upload a (big) file in a piece-wise way.
 *
 * Using this API directly is generally not needed, but in very advanced cases,
 * as VSIFOpenL(..., "wb") + VSIFWriteL(), VSISync(), VSICopyFile() or
 * VSICopyFileRestartable() may be able to leverage it when needed.
 *
 * This is only implemented for the /vsis3/, /vsigs/, /vsiaz/, /vsiadls/ and
 * /vsioss/ virtual file systems.
 *
 * The typical workflow is to do :
 * - VSIMultipartUploadStart()
 * - VSIMultipartUploadAddPart(): several times
 * - VSIMultipartUploadEnd()
 *
 * If VSIMultipartUploadAbort() is supported by the filesystem (VSIMultipartUploadGetCapabilities()
 * can be used to determine it), this function should be called to cancel an
 * upload. This can be needed to avoid extra billing for some cloud storage
 * providers.
 *
 * The following options are supported:
 * <ul>
 * <li>MIME headers such as Content-Type and Content-Encoding
 * are supported for the /vsis3/, /vsigs/, /vsiaz/, /vsiadls/ file systems.</li>
 * </ul>
 *
 * @param pszFilename Filename to create
 * @param papszOptions NULL or null-terminated list of options.
 * @return an upload ID to pass to other VSIMultipartUploadXXXXX() functions,
 * and to free with CPLFree() once done, or nullptr in case of error.
 *
 * @since 3.10
 */
char *VSIMultipartUploadStart(const char *pszFilename,
                              CSLConstList papszOptions)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->MultipartUploadStart(pszFilename, papszOptions);
}

/************************************************************************/
/*                     VSIMultipartUploadAddPart()                      */
/************************************************************************/

/**
 * \brief Uploads a new part to a multi-part uploaded file.
 *
 * Cf VSIMultipartUploadStart().
 *
 * VSIMultipartUploadGetCapabilities() returns hints on the constraints that
 * apply to the upload, in terms of minimum/maximum size of each part, maximum
 * number of parts, and whether non-sequential or parallel uploads are
 * supported.
 *
 * @param pszFilename Filename to which to append the new part. Should be the
 *                    same as the one used for VSIMultipartUploadStart()
 * @param pszUploadId Value returned by VSIMultipartUploadStart()
 * @param nPartNumber Part number, starting at 1.
 * @param nFileOffset Offset within the file at which (starts at 0) the passed
 *                    data starts.
 * @param pData       Pointer to an array of nDataLength bytes.
 * @param nDataLength Size in bytes of pData.
 * @param papszOptions Unused. Should be nullptr.
 *
 * @return a part identifier that must be passed into the apszPartIds[] array of
 * VSIMultipartUploadEnd(), and to free with CPLFree() once done, or nullptr in
 * case of error.
 *
 * @since 3.10
 */
char *VSIMultipartUploadAddPart(const char *pszFilename,
                                const char *pszUploadId, int nPartNumber,
                                vsi_l_offset nFileOffset, const void *pData,
                                size_t nDataLength, CSLConstList papszOptions)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->MultipartUploadAddPart(pszFilename, pszUploadId,
                                               nPartNumber, nFileOffset, pData,
                                               nDataLength, papszOptions);
}

/************************************************************************/
/*                       VSIMultipartUploadEnd()                        */
/************************************************************************/

/**
 * \brief Completes a multi-part file upload.
 *
 * Cf VSIMultipartUploadStart().
 *
 * @param pszFilename Filename for which multipart upload should be completed.
 *                    Should be the same as the one used for
 *                    VSIMultipartUploadStart()
 * @param pszUploadId Value returned by VSIMultipartUploadStart()
 * @param nPartIdsCount Number of parts,  andsize of apszPartIds
 * @param apszPartIds Array of part identifiers (as returned by
 *                    VSIMultipartUploadAddPart()), that must be ordered in
 *                    the sequential order of parts, and of size nPartIdsCount.
 * @param nTotalSize  Total size of the file in bytes (must be equal to the sum
 *                    of nDataLength passed to VSIMultipartUploadAddPart())
 * @param papszOptions Unused. Should be nullptr.
 *
 * @return TRUE in case of success, FALSE in case of failure.
 *
 * @since 3.10
 */
int VSIMultipartUploadEnd(const char *pszFilename, const char *pszUploadId,
                          size_t nPartIdsCount, const char *const *apszPartIds,
                          vsi_l_offset nTotalSize, CSLConstList papszOptions)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->MultipartUploadEnd(pszFilename, pszUploadId,
                                           nPartIdsCount, apszPartIds,
                                           nTotalSize, papszOptions);
}

/************************************************************************/
/*                       VSIMultipartUploadAbort()                      */
/************************************************************************/

/**
 * \brief Aborts a multi-part file upload.
 *
 * Cf VSIMultipartUploadStart().
 *
 * This function is not implemented for all virtual file systems.
 * Use VSIMultipartUploadGetCapabilities() to determine if it is supported.
 *
 * This can be needed to avoid extra billing for some cloud storage providers.
 *
 * @param pszFilename Filename for which multipart upload should be completed.
 *                    Should be the same as the one used for
 *                    VSIMultipartUploadStart()
 * @param pszUploadId Value returned by VSIMultipartUploadStart()
 * @param papszOptions Unused. Should be nullptr.
 *
 * @return TRUE in case of success, FALSE in case of failure.
 *
 * @since 3.10
 */
int VSIMultipartUploadAbort(const char *pszFilename, const char *pszUploadId,
                            CSLConstList papszOptions)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->MultipartUploadAbort(pszFilename, pszUploadId,
                                             papszOptions);
}

#ifndef DOXYGEN_SKIP

/************************************************************************/
/*                     MultipartUploadGetCapabilities()                 */
/************************************************************************/

bool VSIFilesystemHandler::MultipartUploadGetCapabilities(int *, int *, int *,
                                                          size_t *, size_t *,
                                                          int *)
{
    CPLError(
        CE_Failure, CPLE_NotSupported,
        "MultipartUploadGetCapabilities() not supported by this file system");
    return false;
}

/************************************************************************/
/*                         MultipartUploadStart()                       */
/************************************************************************/

char *VSIFilesystemHandler::MultipartUploadStart(const char *, CSLConstList)
{
    CPLError(CE_Failure, CPLE_NotSupported,
             "MultipartUploadStart() not supported by this file system");
    return nullptr;
}

/************************************************************************/
/*                       MultipartUploadAddPart()                       */
/************************************************************************/

char *VSIFilesystemHandler::MultipartUploadAddPart(const char *, const char *,
                                                   int, vsi_l_offset,
                                                   const void *, size_t,
                                                   CSLConstList)
{
    CPLError(CE_Failure, CPLE_NotSupported,
             "MultipartUploadAddPart() not supported by this file system");
    return nullptr;
}

/************************************************************************/
/*                         MultipartUploadEnd()                         */
/************************************************************************/

bool VSIFilesystemHandler::MultipartUploadEnd(const char *, const char *,
                                              size_t, const char *const *,
                                              vsi_l_offset, CSLConstList)
{
    CPLError(CE_Failure, CPLE_NotSupported,
             "MultipartUploadEnd() not supported by this file system");
    return FALSE;
}

/************************************************************************/
/*                         MultipartUploadAbort()                       */
/************************************************************************/

bool VSIFilesystemHandler::MultipartUploadAbort(const char *, const char *,
                                                CSLConstList)
{
    CPLError(CE_Failure, CPLE_NotSupported,
             "MultipartUploadAbort() not supported by this file system");
    return FALSE;
}

#endif

/************************************************************************/
/*                         VSIAbortPendingUploads()                     */
/************************************************************************/

/**
 * \brief Abort all ongoing multi-part uploads.
 *
 * Abort ongoing multi-part uploads on AWS S3 and Google Cloud Storage. This
 * can be used in case a process doing such uploads was killed in a unclean way.
 *
 * This can be needed to avoid extra billing for some cloud storage providers.
 *
 * Without effect on other virtual file systems.
 *
 * VSIMultipartUploadAbort() can also be used to cancel a given upload, if the
 * upload ID is known.
 *
 * @param pszFilename filename or prefix of a directory into which multipart
 * uploads must be aborted. This can be the root directory of a bucket.  UTF-8
 * encoded.
 *
 * @return TRUE on success or FALSE on an error.
 * @since GDAL 3.4
 */

int VSIAbortPendingUploads(const char *pszFilename)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->AbortPendingUploads(pszFilename);
}

/************************************************************************/
/*                              VSIRmdir()                              */
/************************************************************************/

/**
 * \brief Delete a directory.
 *
 * Deletes a directory object from the file system.  On some systems
 * the directory must be empty before it can be deleted.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX rmdir() function.
 *
 * @param pszDirname the path of the directory to be deleted.  UTF-8 encoded.
 *
 * @return 0 on success or -1 on an error.
 */

int VSIRmdir(const char *pszDirname)

{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszDirname);

    return poFSHandler->Rmdir(pszDirname);
}

/************************************************************************/
/*                         VSIRmdirRecursive()                          */
/************************************************************************/

/**
 * \brief Delete a directory recursively
 *
 * Deletes a directory object and its content from the file system.
 *
 * Starting with GDAL 3.1, /vsis3/ has an efficient implementation of this
 * function.
 * Starting with GDAL 3.4, /vsigs/ has an efficient implementation of this
 * function, provided that OAuth2 authentication is used.
 *
 * @return 0 on success or -1 on an error.
 * @since GDAL 2.3
 */

int VSIRmdirRecursive(const char *pszDirname)
{
    if (pszDirname == nullptr || pszDirname[0] == '\0' ||
        strncmp("/", pszDirname, 2) == 0)
    {
        return -1;
    }
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszDirname);
    return poFSHandler->RmdirRecursive(pszDirname);
}

/************************************************************************/
/*                              VSIStatL()                              */
/************************************************************************/

/**
 * \brief Get filesystem object info.
 *
 * Fetches status information about a filesystem object (file, directory, etc).
 * The returned information is placed in the VSIStatBufL structure.   For
 * portability, only use the st_size (size in bytes) and st_mode (file type).
 * This method is similar to VSIStat(), but will work on large files on
 * systems where this requires special calls.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX stat() function.
 *
 * @param pszFilename the path of the filesystem object to be queried.
 * UTF-8 encoded.
 * @param psStatBuf the structure to load with information.
 *
 * @return 0 on success or -1 on an error.
 */

int VSIStatL(const char *pszFilename, VSIStatBufL *psStatBuf)

{
    return VSIStatExL(pszFilename, psStatBuf, 0);
}

/************************************************************************/
/*                            VSIStatExL()                              */
/************************************************************************/

/**
 * \brief Get filesystem object info.
 *
 * Fetches status information about a filesystem object (file, directory, etc).
 * The returned information is placed in the VSIStatBufL structure.   For
 * portability, only use the st_size (size in bytes) and st_mode (file type).
 * This method is similar to VSIStat(), but will work on large files on
 * systems where this requires special calls.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX stat() function, with an extra parameter to
 * specify which information is needed, which offers a potential for
 * speed optimizations on specialized and potentially slow virtual
 * filesystem objects (/vsigzip/, /vsicurl/)
 *
 * @param pszFilename the path of the filesystem object to be queried.
 * UTF-8 encoded.
 * @param psStatBuf the structure to load with information.
 * @param nFlags 0 to get all information, or VSI_STAT_EXISTS_FLAG,
 *                 VSI_STAT_NATURE_FLAG, VSI_STAT_SIZE_FLAG,
 * VSI_STAT_SET_ERROR_FLAG, VSI_STAT_CACHE_ONLY or a combination of those to get
 * partial info.
 *
 * @return 0 on success or -1 on an error.
 *
 * @since GDAL 1.8.0
 */

int VSIStatExL(const char *pszFilename, VSIStatBufL *psStatBuf, int nFlags)

{
    char szAltPath[4] = {'\0'};

    // Enable to work on "C:" as if it were "C:\".
    if (pszFilename[0] != '\0' && pszFilename[1] == ':' &&
        pszFilename[2] == '\0')
    {
        szAltPath[0] = pszFilename[0];
        szAltPath[1] = pszFilename[1];
        szAltPath[2] = '\\';
        szAltPath[3] = '\0';

        pszFilename = szAltPath;
    }

    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    if (nFlags == 0)
        nFlags =
            VSI_STAT_EXISTS_FLAG | VSI_STAT_NATURE_FLAG | VSI_STAT_SIZE_FLAG;

    return poFSHandler->Stat(pszFilename, psStatBuf, nFlags);
}

/************************************************************************/
/*                       VSIGetFileMetadata()                           */
/************************************************************************/

/**
 * \brief Get metadata on files.
 *
 * Implemented currently only for network-like filesystems, or starting
 * with GDAL 3.7 for /vsizip/
 *
 * @param pszFilename the path of the filesystem object to be queried.
 * UTF-8 encoded.
 * @param pszDomain Metadata domain to query. Depends on the file system.
 * The following are supported:
 * <ul>
 * <li>HEADERS: to get HTTP headers for network-like filesystems (/vsicurl/,
 * /vsis3/, /vsgis/, etc)</li> <li>TAGS: <ul> <li>/vsis3/: to get S3 Object
 * tagging information</li> <li>/vsiaz/: to get blob tags. Refer to
 * https://docs.microsoft.com/en-us/rest/api/storageservices/get-blob-tags</li>
 *    </ul>
 * </li>
 * <li>STATUS: specific to /vsiadls/: returns all system defined properties for
 * a path (seems in practice to be a subset of HEADERS)</li> <li>ACL: specific
 * to /vsiadls/ and /vsigs/: returns the access control list for a path. For
 * /vsigs/, a single XML=xml_content string is returned. Refer to
 * https://cloud.google.com/storage/docs/xml-api/get-object-acls
 * </li>
 * <li>METADATA: specific to /vsiaz/: to set blob metadata. Refer to
 * https://docs.microsoft.com/en-us/rest/api/storageservices/get-blob-metadata.
 * Note: this will be a subset of what pszDomain=HEADERS returns</li>
 * <li>ZIP: specific to /vsizip/: to obtain ZIP specific metadata, in particular
 * if a file is SOZIP-enabled (SOZIP_VALID=YES)</li>
 * </ul>
 * @param papszOptions Unused. Should be set to NULL.
 *
 * @return a NULL-terminated list of key=value strings, to be freed with
 * CSLDestroy() or NULL in case of error / empty list.
 *
 * @since GDAL 3.1.0
 */

char **VSIGetFileMetadata(const char *pszFilename, const char *pszDomain,
                          CSLConstList papszOptions)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);
    return poFSHandler->GetFileMetadata(pszFilename, pszDomain, papszOptions);
}

/************************************************************************/
/*                       VSISetFileMetadata()                           */
/************************************************************************/

/**
 * \brief Set metadata on files.
 *
 * Implemented currently only for /vsis3/, /vsigs/, /vsiaz/ and /vsiadls/
 *
 * @param pszFilename the path of the filesystem object to be set.
 * UTF-8 encoded.
 * @param papszMetadata NULL-terminated list of key=value strings.
 * @param pszDomain Metadata domain to set. Depends on the file system.
 * The following are supported:
 * <ul>
 * <li>HEADERS: specific to /vsis3/ and /vsigs/: to set HTTP headers, such as
 * "Content-Type", or other file system specific header.
 * For /vsigs/, this also includes: x-goog-meta-{key}={value}. Note that you
 * should specify all metadata to be set, as existing metadata will be
 * overridden.
 * </li>
 * <li>TAGS: Content of papszMetadata should be KEY=VALUE pairs.
 *    <ul>
 *      <li>/vsis3/: to set S3 Object tagging information</li>
 *      <li>/vsiaz/: to set blob tags. Refer to
 * https://docs.microsoft.com/en-us/rest/api/storageservices/set-blob-tags.
 * Note: storageV2 must be enabled on the account</li>
 *    </ul>
 * </li>
 * <li>PROPERTIES:
 *    <ul>
 *      <li>to /vsiaz/: to set properties. Refer to
 * https://docs.microsoft.com/en-us/rest/api/storageservices/set-blob-properties.</li>
 *      <li>to /vsiadls/: to set properties. Refer to
 * https://docs.microsoft.com/en-us/rest/api/storageservices/datalakestoragegen2/path/update
 * for headers valid for action=setProperties.</li>
 *    </ul>
 * </li>
 * <li>ACL: specific to /vsiadls/ and /vsigs/: to set access control list.
 * For /vsiadls/, refer to
 * https://docs.microsoft.com/en-us/rest/api/storageservices/datalakestoragegen2/path/update
 * for headers valid for action=setAccessControl or setAccessControlRecursive.
 * In setAccessControlRecursive, x-ms-acl must be specified in papszMetadata.
 * For /vsigs/, refer to
 * https://cloud.google.com/storage/docs/xml-api/put-object-acls. A single
 * XML=xml_content string should be specified as in papszMetadata.
 * </li>
 * <li>METADATA: specific to /vsiaz/: to set blob metadata. Refer to
 * https://docs.microsoft.com/en-us/rest/api/storageservices/set-blob-metadata.
 * Content of papszMetadata should be strings in the form
 * x-ms-meta-name=value</li>
 * </ul>
 * @param papszOptions NULL or NULL terminated list of options.
 *                     For /vsiadls/ and pszDomain=ACL, "RECURSIVE=TRUE" can be
 *                     set to set the access control list recursively. When
 *                     RECURSIVE=TRUE is set, MODE should also be set to one of
 *                     "set", "modify" or "remove".
 *
 * @return TRUE in case of success.
 *
 * @since GDAL 3.1.0
 */

int VSISetFileMetadata(const char *pszFilename, CSLConstList papszMetadata,
                       const char *pszDomain, CSLConstList papszOptions)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);
    return poFSHandler->SetFileMetadata(pszFilename, papszMetadata, pszDomain,
                                        papszOptions)
               ? 1
               : 0;
}

/************************************************************************/
/*                       VSIIsCaseSensitiveFS()                         */
/************************************************************************/

/**
 * \brief Returns if the filenames of the filesystem are case sensitive.
 *
 * This method retrieves to which filesystem belongs the passed filename
 * and return TRUE if the filenames of that filesystem are case sensitive.
 *
 * Currently, this will return FALSE only for Windows real filenames. Other
 * VSI virtual filesystems are case sensitive.
 *
 * This methods avoid ugly \#ifndef _WIN32 / \#endif code, that is wrong when
 * dealing with virtual filenames.
 *
 * @param pszFilename the path of the filesystem object to be tested.
 * UTF-8 encoded.
 *
 * @return TRUE if the filenames of the filesystem are case sensitive.
 *
 * @since GDAL 1.8.0
 */

int VSIIsCaseSensitiveFS(const char *pszFilename)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->IsCaseSensitive(pszFilename);
}

/************************************************************************/
/*                       VSISupportsSparseFiles()                       */
/************************************************************************/

/**
 * \brief Returns if the filesystem supports sparse files.
 *
 * Only supported on Linux (and no other Unix derivatives) and
 * Windows.  On Linux, the answer depends on a few hardcoded
 * signatures for common filesystems. Other filesystems will be
 * considered as not supporting sparse files.
 *
 * @param pszPath the path of the filesystem object to be tested.
 * UTF-8 encoded.
 *
 * @return TRUE if the file system is known to support sparse files. FALSE may
 *              be returned both in cases where it is known to not support them,
 *              or when it is unknown.
 *
 * @since GDAL 2.2
 */

int VSISupportsSparseFiles(const char *pszPath)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);

    return poFSHandler->SupportsSparseFiles(pszPath);
}

/************************************************************************/
/*                           VSIIsLocal()                               */
/************************************************************************/

/**
 * \brief Returns if the file/filesystem is "local".
 *
 * The concept of local is mostly by opposition with a network / remote
 * file system whose access time can be long.
 *
 * /vsimem/ is considered to be a local file system, although a non-persistent
 * one.
 *
 * @param pszPath the path of the filesystem object to be tested.
 * UTF-8 encoded.
 *
 * @return TRUE or FALSE
 *
 * @since GDAL 3.6
 */

bool VSIIsLocal(const char *pszPath)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);

    return poFSHandler->IsLocal(pszPath);
}

/************************************************************************/
/*                       VSIGetCanonicalFilename()                      */
/************************************************************************/

/**
 * \brief Returns the canonical filename.
 *
 * May be implemented by case-insensitive filesystems
 * (currently Win32 and MacOSX) to return the filename with its actual case
 * (i.e. the one that would be used when listing the content of the directory).
 *
 * @param pszPath UTF-8 encoded path
 *
 * @return UTF-8 encoded string, to free with VSIFree()
 *
 * @since GDAL 3.8
 */

char *VSIGetCanonicalFilename(const char *pszPath)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);

    return CPLStrdup(poFSHandler->GetCanonicalFilename(pszPath).c_str());
}

/************************************************************************/
/*                      VSISupportsSequentialWrite()                    */
/************************************************************************/

/**
 * \brief Returns if the filesystem supports sequential write.
 *
 * @param pszPath the path of the filesystem object to be tested.
 * UTF-8 encoded.
 * @param bAllowLocalTempFile whether the file system is allowed to use a
 * local temporary file before uploading to the target location.
 *
 * @return TRUE or FALSE
 *
 * @since GDAL 3.6
 */

bool VSISupportsSequentialWrite(const char *pszPath, bool bAllowLocalTempFile)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);

    return poFSHandler->SupportsSequentialWrite(pszPath, bAllowLocalTempFile);
}

/************************************************************************/
/*                      VSISupportsRandomWrite()                        */
/************************************************************************/

/**
 * \brief Returns if the filesystem supports random write.
 *
 * @param pszPath the path of the filesystem object to be tested.
 * UTF-8 encoded.
 * @param bAllowLocalTempFile whether the file system is allowed to use a
 * local temporary file before uploading to the target location.
 *
 * @return TRUE or FALSE
 *
 * @since GDAL 3.6
 */

bool VSISupportsRandomWrite(const char *pszPath, bool bAllowLocalTempFile)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);

    return poFSHandler->SupportsRandomWrite(pszPath, bAllowLocalTempFile);
}

/************************************************************************/
/*                     VSIHasOptimizedReadMultiRange()                  */
/************************************************************************/

/**
 * \brief Returns if the filesystem supports efficient multi-range reading.
 *
 * Currently only returns TRUE for /vsicurl/ and derived file systems.
 *
 * @param pszPath the path of the filesystem object to be tested.
 * UTF-8 encoded.
 *
 * @return TRUE if the file system is known to have an efficient multi-range
 * reading.
 *
 * @since GDAL 2.3
 */

int VSIHasOptimizedReadMultiRange(const char *pszPath)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszPath);

    return poFSHandler->HasOptimizedReadMultiRange(pszPath);
}

/************************************************************************/
/*                        VSIGetActualURL()                             */
/************************************************************************/

/**
 * \brief Returns the actual URL of a supplied filename.
 *
 * Currently only returns a non-NULL value for network-based virtual file
 * systems. For example "/vsis3/bucket/filename" will be expanded as
 * "https://bucket.s3.amazon.com/filename"
 *
 * Note that the lifetime of the returned string, is short, and may be
 * invalidated by any following GDAL functions.
 *
 * @param pszFilename the path of the filesystem object. UTF-8 encoded.
 *
 * @return the actual URL corresponding to the supplied filename, or NULL.
 * Should not be freed.
 *
 * @since GDAL 2.3
 */

const char *VSIGetActualURL(const char *pszFilename)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->GetActualURL(pszFilename);
}

/************************************************************************/
/*                        VSIGetSignedURL()                             */
/************************************************************************/

/**
 * \brief Returns a signed URL of a supplied filename.
 *
 * Currently only returns a non-NULL value for /vsis3/, /vsigs/, /vsiaz/ and
 * /vsioss/ For example "/vsis3/bucket/filename" will be expanded as
 * "https://bucket.s3.amazon.com/filename?X-Amz-Algorithm=AWS4-HMAC-SHA256..."
 * Configuration options that apply for file opening (typically to provide
 * credentials), and are returned by VSIGetFileSystemOptions(), are also valid
 * in that context.
 *
 * @param pszFilename the path of the filesystem object. UTF-8 encoded.
 * @param papszOptions list of options, or NULL. Depend on file system handler.
 * For /vsis3/, /vsigs/, /vsiaz/ and /vsioss/, the following options are
 * supported: <ul> <li>START_DATE=YYMMDDTHHMMSSZ: date and time in UTC following
 * ISO 8601 standard, corresponding to the start of validity of the URL. If not
 * specified, current date time.</li> <li>EXPIRATION_DELAY=number_of_seconds:
 * number between 1 and 604800 (seven days) for the validity of the signed URL.
 * Defaults to 3600 (one hour)</li> <li>VERB=GET/HEAD/DELETE/PUT/POST: HTTP VERB
 * for which the request will be used. Default to GET.</li>
 * </ul>
 *
 * /vsiaz/ supports additional options:
 * <ul>
 * <li>SIGNEDIDENTIFIER=value: to relate the given shared access signature
 * to a corresponding stored access policy.</li>
 * <li>SIGNEDPERMISSIONS=r|w: permissions associated with the shared access
 * signature. Normally deduced from VERB.</li>
 * </ul>
 *
 * @return a signed URL, or NULL. Should be freed with CPLFree().
 * @since GDAL 2.3
 */

char *VSIGetSignedURL(const char *pszFilename, CSLConstList papszOptions)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->GetSignedURL(pszFilename, papszOptions);
}

/************************************************************************/
/*                             VSIFOpenL()                              */
/************************************************************************/

/**
 * \brief Open file.
 *
 * This function opens a file with the desired access.  Large files (larger
 * than 2GB) should be supported.  Binary access is always implied and
 * the "b" does not need to be included in the pszAccess string.
 *
 * Note that the "VSILFILE *" returned since GDAL 1.8.0 by this function is
 * *NOT* a standard C library FILE *, and cannot be used with any functions
 * other than the "VSI*L" family of functions.  They aren't "real" FILE objects.
 *
 * On windows it is possible to define the configuration option
 * GDAL_FILE_IS_UTF8 to have pszFilename treated as being in the local
 * encoding instead of UTF-8, restoring the pre-1.8.0 behavior of VSIFOpenL().
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fopen() function.
 *
 * @param pszFilename the file to open.  UTF-8 encoded.
 * @param pszAccess access requested (i.e. "r", "r+", "w")
 *
 * @return NULL on failure, or the file handle.
 */

VSILFILE *VSIFOpenL(const char *pszFilename, const char *pszAccess)

{
    return VSIFOpenExL(pszFilename, pszAccess, false);
}

/************************************************************************/
/*                               Open()                                 */
/************************************************************************/

#ifndef DOXYGEN_SKIP

VSIVirtualHandle *VSIFilesystemHandler::Open(const char *pszFilename,
                                             const char *pszAccess)
{
    return Open(pszFilename, pszAccess, false, nullptr);
}

/************************************************************************/
/*                             CopyFile()                               */
/************************************************************************/

int VSIFilesystemHandler::CopyFile(const char *pszSource, const char *pszTarget,
                                   VSILFILE *fpSource, vsi_l_offset nSourceSize,
                                   CSLConstList papszOptions,
                                   GDALProgressFunc pProgressFunc,
                                   void *pProgressData)
{
    VSIVirtualHandleUniquePtr poFileHandleAutoClose;
    if (!fpSource)
    {
        CPLAssert(pszSource);
        fpSource = VSIFOpenExL(pszSource, "rb", TRUE);
        if (!fpSource)
        {
            CPLError(CE_Failure, CPLE_FileIO, "Cannot open %s", pszSource);
            return -1;
        }
        poFileHandleAutoClose.reset(fpSource);
    }
    if (nSourceSize == static_cast<vsi_l_offset>(-1) &&
        pProgressFunc != nullptr && pszSource != nullptr)
    {
        VSIStatBufL sStat;
        if (VSIStatL(pszSource, &sStat) == 0)
        {
            nSourceSize = sStat.st_size;
        }
    }

    VSILFILE *fpOut = VSIFOpenEx2L(pszTarget, "wb", TRUE, papszOptions);
    if (!fpOut)
    {
        CPLError(CE_Failure, CPLE_FileIO, "Cannot create %s", pszTarget);
        return -1;
    }

    CPLString osMsg;
    if (pszSource)
        osMsg.Printf("Copying of %s", pszSource);
    else
        pszSource = "(unknown filename)";

    int ret = 0;
    constexpr size_t nBufferSize = 10 * 4096;
    std::vector<GByte> abyBuffer(nBufferSize, 0);
    GUIntBig nOffset = 0;
    while (true)
    {
        const size_t nRead = VSIFReadL(&abyBuffer[0], 1, nBufferSize, fpSource);
        if (nRead < nBufferSize && VSIFErrorL(fpSource))
        {
            CPLError(
                CE_Failure, CPLE_FileIO,
                "Copying of %s to %s failed: error while reading source file",
                pszSource, pszTarget);
            ret = -1;
            break;
        }
        if (nRead > 0)
        {
            const size_t nWritten = VSIFWriteL(&abyBuffer[0], 1, nRead, fpOut);
            if (nWritten != nRead)
            {
                CPLError(CE_Failure, CPLE_FileIO,
                         "Copying of %s to %s failed: error while writing into "
                         "target file",
                         pszSource, pszTarget);
                ret = -1;
                break;
            }
            nOffset += nRead;
            if (pProgressFunc &&
                !pProgressFunc(
                    nSourceSize == 0 ? 1.0
                    : nSourceSize > 0 &&
                            nSourceSize != static_cast<vsi_l_offset>(-1)
                        ? double(nOffset) / nSourceSize
                        : 0.0,
                    !osMsg.empty() ? osMsg.c_str() : nullptr, pProgressData))
            {
                ret = -1;
                break;
            }
        }
        if (nRead < nBufferSize)
        {
            break;
        }
    }

    if (nSourceSize != static_cast<vsi_l_offset>(-1) && nOffset != nSourceSize)
    {
        CPLError(CE_Failure, CPLE_FileIO,
                 "Copying of %s to %s failed: %" PRIu64 " bytes were copied "
                 "whereas %" PRIu64 " were expected",
                 pszSource, pszTarget, static_cast<uint64_t>(nOffset),
                 static_cast<uint64_t>(nSourceSize));
        ret = -1;
    }

    if (VSIFCloseL(fpOut) != 0)
    {
        ret = -1;
    }

    if (ret != 0)
        VSIUnlink(pszTarget);

    return ret;
}

/************************************************************************/
/*                       CopyFileRestartable()                          */
/************************************************************************/

int VSIFilesystemHandler::CopyFileRestartable(
    const char *pszSource, const char *pszTarget,
    const char * /* pszInputPayload */, char **ppszOutputPayload,
    CSLConstList papszOptions, GDALProgressFunc pProgressFunc,
    void *pProgressData)
{
    *ppszOutputPayload = nullptr;
    return CopyFile(pszSource, pszTarget, nullptr,
                    static_cast<vsi_l_offset>(-1), papszOptions, pProgressFunc,
                    pProgressData);
}

/************************************************************************/
/*                               Sync()                                 */
/************************************************************************/

bool VSIFilesystemHandler::Sync(const char *pszSource, const char *pszTarget,
                                const char *const *papszOptions,
                                GDALProgressFunc pProgressFunc,
                                void *pProgressData, char ***ppapszOutputs)
{
    const char SOURCE_SEP = VSIGetDirectorySeparator(pszSource)[0];

    if (ppapszOutputs)
    {
        *ppapszOutputs = nullptr;
    }

    VSIStatBufL sSource;
    CPLString osSource(pszSource);
    CPLString osSourceWithoutSlash(pszSource);
    if (osSourceWithoutSlash.back() == '/' ||
        osSourceWithoutSlash.back() == '\\')
    {
        osSourceWithoutSlash.pop_back();
    }
    if (VSIStatL(osSourceWithoutSlash, &sSource) < 0)
    {
        CPLError(CE_Failure, CPLE_FileIO, "%s does not exist", pszSource);
        return false;
    }

    if (VSI_ISDIR(sSource.st_mode))
    {
        CPLString osTargetDir(pszTarget);
        if (osSource.back() != '/' && osSource.back() != '\\')
        {
            osTargetDir = CPLFormFilename(osTargetDir,
                                          CPLGetFilename(pszSource), nullptr);
        }

        VSIStatBufL sTarget;
        bool ret = true;
        if (VSIStatL(osTargetDir, &sTarget) < 0)
        {
            if (VSIMkdirRecursive(osTargetDir, 0755) < 0)
            {
                CPLError(CE_Failure, CPLE_FileIO, "Cannot create directory %s",
                         osTargetDir.c_str());
                return false;
            }
        }

        if (!CPLFetchBool(papszOptions, "STOP_ON_DIR", false))
        {
            CPLStringList aosChildOptions(CSLDuplicate(papszOptions));
            if (!CPLFetchBool(papszOptions, "RECURSIVE", true))
            {
                aosChildOptions.SetNameValue("RECURSIVE", nullptr);
                aosChildOptions.AddString("STOP_ON_DIR=TRUE");
            }

            char **papszSrcFiles = VSIReadDir(osSourceWithoutSlash);
            int nFileCount = 0;
            for (auto iter = papszSrcFiles; iter && *iter; ++iter)
            {
                if (strcmp(*iter, ".") != 0 && strcmp(*iter, "..") != 0)
                {
                    nFileCount++;
                }
            }
            int iFile = 0;
            for (auto iter = papszSrcFiles; iter && *iter; ++iter, ++iFile)
            {
                if (strcmp(*iter, ".") == 0 || strcmp(*iter, "..") == 0)
                {
                    continue;
                }
                CPLString osSubSource(
                    CPLFormFilename(osSourceWithoutSlash, *iter, nullptr));
                CPLString osSubTarget(
                    CPLFormFilename(osTargetDir, *iter, nullptr));
                // coverity[divide_by_zero]
                void *pScaledProgress = GDALCreateScaledProgress(
                    double(iFile) / nFileCount, double(iFile + 1) / nFileCount,
                    pProgressFunc, pProgressData);
                ret = Sync((osSubSource + SOURCE_SEP).c_str(), osSubTarget,
                           aosChildOptions.List(), GDALScaledProgress,
                           pScaledProgress, nullptr);
                GDALDestroyScaledProgress(pScaledProgress);
                if (!ret)
                {
                    break;
                }
            }
            CSLDestroy(papszSrcFiles);
        }
        return ret;
    }

    VSIStatBufL sTarget;
    CPLString osTarget(pszTarget);
    if (VSIStatL(osTarget, &sTarget) == 0)
    {
        bool bTargetIsFile = true;
        if (VSI_ISDIR(sTarget.st_mode))
        {
            osTarget =
                CPLFormFilename(osTarget, CPLGetFilename(pszSource), nullptr);
            bTargetIsFile = VSIStatL(osTarget, &sTarget) == 0 &&
                            !CPL_TO_BOOL(VSI_ISDIR(sTarget.st_mode));
        }
        if (bTargetIsFile)
        {
            if (sSource.st_size == sTarget.st_size &&
                sSource.st_mtime == sTarget.st_mtime && sSource.st_mtime != 0)
            {
                CPLDebug("VSI",
                         "%s and %s have same size and modification "
                         "date. Skipping copying",
                         osSourceWithoutSlash.c_str(), osTarget.c_str());
                return true;
            }
        }
    }

    VSILFILE *fpIn = VSIFOpenExL(osSourceWithoutSlash, "rb", TRUE);
    if (fpIn == nullptr)
    {
        CPLError(CE_Failure, CPLE_FileIO, "Cannot open %s",
                 osSourceWithoutSlash.c_str());
        return false;
    }

    VSILFILE *fpOut = VSIFOpenExL(osTarget.c_str(), "wb", TRUE);
    if (fpOut == nullptr)
    {
        CPLError(CE_Failure, CPLE_FileIO, "Cannot create %s", osTarget.c_str());
        VSIFCloseL(fpIn);
        return false;
    }

    bool ret = true;
    constexpr size_t nBufferSize = 10 * 4096;
    std::vector<GByte> abyBuffer(nBufferSize, 0);
    GUIntBig nOffset = 0;
    CPLString osMsg;
    osMsg.Printf("Copying of %s", osSourceWithoutSlash.c_str());
    while (true)
    {
        size_t nRead = VSIFReadL(&abyBuffer[0], 1, nBufferSize, fpIn);
        size_t nWritten = VSIFWriteL(&abyBuffer[0], 1, nRead, fpOut);
        if (nWritten != nRead)
        {
            CPLError(CE_Failure, CPLE_FileIO, "Copying of %s to %s failed",
                     osSourceWithoutSlash.c_str(), osTarget.c_str());
            ret = false;
            break;
        }
        nOffset += nRead;
        if (pProgressFunc && !pProgressFunc(double(nOffset) / sSource.st_size,
                                            osMsg.c_str(), pProgressData))
        {
            ret = false;
            break;
        }
        if (nRead < nBufferSize)
        {
            break;
        }
    }

    VSIFCloseL(fpIn);
    if (VSIFCloseL(fpOut) != 0)
    {
        ret = false;
    }
    return ret;
}

/************************************************************************/
/*                            VSIDIREntry()                             */
/************************************************************************/

VSIDIREntry::VSIDIREntry()
    : pszName(nullptr), nMode(0), nSize(0), nMTime(0), bModeKnown(false),
      bSizeKnown(false), bMTimeKnown(false), papszExtra(nullptr)
{
}

/************************************************************************/
/*                            VSIDIREntry()                             */
/************************************************************************/

VSIDIREntry::VSIDIREntry(const VSIDIREntry &other)
    : pszName(VSIStrdup(other.pszName)), nMode(other.nMode), nSize(other.nSize),
      nMTime(other.nMTime), bModeKnown(other.bModeKnown),
      bSizeKnown(other.bSizeKnown), bMTimeKnown(other.bMTimeKnown),
      papszExtra(CSLDuplicate(other.papszExtra))
{
}

/************************************************************************/
/*                           ~VSIDIREntry()                             */
/************************************************************************/

VSIDIREntry::~VSIDIREntry()
{
    CPLFree(pszName);
    CSLDestroy(papszExtra);
}

/************************************************************************/
/*                              ~VSIDIR()                               */
/************************************************************************/

VSIDIR::~VSIDIR()
{
}

/************************************************************************/
/*                            VSIDIRGeneric                             */
/************************************************************************/

namespace
{
struct VSIDIRGeneric : public VSIDIR
{
    CPLString osRootPath{};
    CPLString osBasePath{};
    char **papszContent = nullptr;
    int nRecurseDepth = 0;
    int nPos = 0;
    VSIDIREntry entry{};
    std::vector<VSIDIRGeneric *> aoStackSubDir{};
    VSIFilesystemHandler *poFS = nullptr;
    std::string m_osFilterPrefix{};

    explicit VSIDIRGeneric(VSIFilesystemHandler *poFSIn) : poFS(poFSIn)
    {
    }

    ~VSIDIRGeneric();

    const VSIDIREntry *NextDirEntry() override;

    VSIDIRGeneric(const VSIDIRGeneric &) = delete;
    VSIDIRGeneric &operator=(const VSIDIRGeneric &) = delete;
};

/************************************************************************/
/*                         ~VSIDIRGeneric()                             */
/************************************************************************/

VSIDIRGeneric::~VSIDIRGeneric()
{
    while (!aoStackSubDir.empty())
    {
        delete aoStackSubDir.back();
        aoStackSubDir.pop_back();
    }
    CSLDestroy(papszContent);
}

}  // namespace

/************************************************************************/
/*                            OpenDir()                                 */
/************************************************************************/

VSIDIR *VSIFilesystemHandler::OpenDir(const char *pszPath, int nRecurseDepth,
                                      const char *const *papszOptions)
{
    char **papszContent = VSIReadDir(pszPath);
    VSIStatBufL sStatL;
    if (papszContent == nullptr &&
        (VSIStatL(pszPath, &sStatL) != 0 || !VSI_ISDIR(sStatL.st_mode)))
    {
        return nullptr;
    }
    VSIDIRGeneric *dir = new VSIDIRGeneric(this);
    dir->osRootPath = pszPath;
    if (!dir->osRootPath.empty() &&
        (dir->osRootPath.back() == '/' || dir->osRootPath.back() == '\\'))
        dir->osRootPath.pop_back();
    dir->nRecurseDepth = nRecurseDepth;
    dir->papszContent = papszContent;
    dir->m_osFilterPrefix = CSLFetchNameValueDef(papszOptions, "PREFIX", "");
    return dir;
}

/************************************************************************/
/*                           NextDirEntry()                             */
/************************************************************************/

const VSIDIREntry *VSIDIRGeneric::NextDirEntry()
{
    const char SEP = VSIGetDirectorySeparator(osRootPath.c_str())[0];

begin:
    if (VSI_ISDIR(entry.nMode) && nRecurseDepth != 0)
    {
        CPLString osCurFile(osRootPath);
        if (!osCurFile.empty())
            osCurFile += SEP;
        osCurFile += entry.pszName;
        auto subdir =
            static_cast<VSIDIRGeneric *>(poFS->VSIFilesystemHandler::OpenDir(
                osCurFile, nRecurseDepth - 1, nullptr));
        if (subdir)
        {
            subdir->osRootPath = osRootPath;
            subdir->osBasePath = entry.pszName;
            subdir->m_osFilterPrefix = m_osFilterPrefix;
            aoStackSubDir.push_back(subdir);
        }
        entry.nMode = 0;
    }

    while (!aoStackSubDir.empty())
    {
        auto l_entry = aoStackSubDir.back()->NextDirEntry();
        if (l_entry)
        {
            return l_entry;
        }
        delete aoStackSubDir.back();
        aoStackSubDir.pop_back();
    }

    if (papszContent == nullptr)
    {
        return nullptr;
    }

    while (true)
    {
        if (!papszContent[nPos])
        {
            return nullptr;
        }
        // Skip . and ..entries
        if (papszContent[nPos][0] == '.' &&
            (papszContent[nPos][1] == '\0' ||
             (papszContent[nPos][1] == '.' && papszContent[nPos][2] == '\0')))
        {
            nPos++;
        }
        else
        {
            CPLFree(entry.pszName);
            CPLString osName(osBasePath);
            if (!osName.empty())
                osName += SEP;
            osName += papszContent[nPos];
            nPos++;

            entry.pszName = CPLStrdup(osName);
            entry.nMode = 0;
            CPLString osCurFile(osRootPath);
            if (!osCurFile.empty())
                osCurFile += SEP;
            osCurFile += entry.pszName;

            const auto StatFile = [&osCurFile, this]()
            {
                VSIStatBufL sStatL;
                if (VSIStatL(osCurFile, &sStatL) == 0)
                {
                    entry.nMode = sStatL.st_mode;
                    entry.nSize = sStatL.st_size;
                    entry.nMTime = sStatL.st_mtime;
                    entry.bModeKnown = true;
                    entry.bSizeKnown = true;
                    entry.bMTimeKnown = true;
                }
                else
                {
                    entry.nMode = 0;
                    entry.nSize = 0;
                    entry.nMTime = 0;
                    entry.bModeKnown = false;
                    entry.bSizeKnown = false;
                    entry.bMTimeKnown = false;
                }
            };

            if (!m_osFilterPrefix.empty() &&
                m_osFilterPrefix.size() > osName.size())
            {
                if (STARTS_WITH(m_osFilterPrefix.c_str(), osName.c_str()) &&
                    m_osFilterPrefix[osName.size()] == SEP)
                {
                    StatFile();
                    if (VSI_ISDIR(entry.nMode))
                    {
                        goto begin;
                    }
                }
                continue;
            }
            if (!m_osFilterPrefix.empty() &&
                !STARTS_WITH(osName.c_str(), m_osFilterPrefix.c_str()))
            {
                continue;
            }

            StatFile();

            break;
        }
    }

    return &(entry);
}

/************************************************************************/
/*                           UnlinkBatch()                              */
/************************************************************************/

int *VSIFilesystemHandler::UnlinkBatch(CSLConstList papszFiles)
{
    int *panRet =
        static_cast<int *>(CPLMalloc(sizeof(int) * CSLCount(papszFiles)));
    for (int i = 0; papszFiles && papszFiles[i]; ++i)
    {
        panRet[i] = VSIUnlink(papszFiles[i]) == 0;
    }
    return panRet;
}

/************************************************************************/
/*                          RmdirRecursive()                            */
/************************************************************************/

int VSIFilesystemHandler::RmdirRecursive(const char *pszDirname)
{
    CPLString osDirnameWithoutEndSlash(pszDirname);
    if (!osDirnameWithoutEndSlash.empty() &&
        (osDirnameWithoutEndSlash.back() == '/' ||
         osDirnameWithoutEndSlash.back() == '\\'))
    {
        osDirnameWithoutEndSlash.pop_back();
    }

    const char SEP = VSIGetDirectorySeparator(pszDirname)[0];

    CPLStringList aosOptions;
    auto poDir =
        std::unique_ptr<VSIDIR>(OpenDir(pszDirname, -1, aosOptions.List()));
    if (!poDir)
        return -1;
    std::vector<std::string> aosDirs;
    while (true)
    {
        auto entry = poDir->NextDirEntry();
        if (!entry)
            break;

        const CPLString osFilename(osDirnameWithoutEndSlash + SEP +
                                   entry->pszName);
        if ((entry->nMode & S_IFDIR))
        {
            aosDirs.push_back(osFilename);
        }
        else
        {
            if (VSIUnlink(osFilename) != 0)
                return -1;
        }
    }

    // Sort in reverse order, so that inner-most directories are deleted first
    std::sort(aosDirs.begin(), aosDirs.end(),
              [](const std::string &a, const std::string &b) { return a > b; });

    for (const auto &osDir : aosDirs)
    {
        if (VSIRmdir(osDir.c_str()) != 0)
            return -1;
    }

    return VSIRmdir(pszDirname);
}

/************************************************************************/
/*                          GetFileMetadata()                           */
/************************************************************************/

char **VSIFilesystemHandler::GetFileMetadata(const char * /* pszFilename*/,
                                             const char * /*pszDomain*/,
                                             CSLConstList /*papszOptions*/)
{
    return nullptr;
}

/************************************************************************/
/*                          SetFileMetadata()                           */
/************************************************************************/

bool VSIFilesystemHandler::SetFileMetadata(const char * /* pszFilename*/,
                                           CSLConstList /* papszMetadata */,
                                           const char * /* pszDomain */,
                                           CSLConstList /* papszOptions */)
{
    CPLError(CE_Failure, CPLE_NotSupported, "SetFileMetadata() not supported");
    return false;
}

#endif

/************************************************************************/
/*                             VSIFOpenExL()                            */
/************************************************************************/

/**
 * \brief Open/create file.
 *
 * This function opens (or creates) a file with the desired access.
 * Binary access is always implied and
 * the "b" does not need to be included in the pszAccess string.
 *
 * Note that the "VSILFILE *" returned by this function is
 * *NOT* a standard C library FILE *, and cannot be used with any functions
 * other than the "VSI*L" family of functions.  They aren't "real" FILE objects.
 *
 * On windows it is possible to define the configuration option
 * GDAL_FILE_IS_UTF8 to have pszFilename treated as being in the local
 * encoding instead of UTF-8, restoring the pre-1.8.0 behavior of VSIFOpenL().
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fopen() function.
 *
 * @param pszFilename the file to open.  UTF-8 encoded.
 * @param pszAccess access requested (i.e. "r", "r+", "w")
 * @param bSetError flag determining whether or not this open call
 * should set VSIErrors on failure.
 *
 * @return NULL on failure, or the file handle.
 *
 * @since GDAL 2.1
 */

VSILFILE *VSIFOpenExL(const char *pszFilename, const char *pszAccess,
                      int bSetError)

{
    return VSIFOpenEx2L(pszFilename, pszAccess, bSetError, nullptr);
}

/************************************************************************/
/*                            VSIFOpenEx2L()                            */
/************************************************************************/

/**
 * \brief Open/create file.
 *
 * This function opens (or creates) a file with the desired access.
 * Binary access is always implied and
 * the "b" does not need to be included in the pszAccess string.
 *
 * Note that the "VSILFILE *" returned by this function is
 * *NOT* a standard C library FILE *, and cannot be used with any functions
 * other than the "VSI*L" family of functions.  They aren't "real" FILE objects.
 *
 * On windows it is possible to define the configuration option
 * GDAL_FILE_IS_UTF8 to have pszFilename treated as being in the local
 * encoding instead of UTF-8, restoring the pre-1.8.0 behavior of VSIFOpenL().
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * The following options are supported:
 * <ul>
 * <li>MIME headers such as Content-Type and Content-Encoding
 * are supported for the /vsis3/, /vsigs/, /vsiaz/, /vsiadls/ file systems.</li>
 * <li>DISABLE_READDIR_ON_OPEN=YES/NO (GDAL >= 3.6) for /vsicurl/ and other
 * network-based file systems. By default, directory file listing is done,
 * unless YES is specified.</li>
 * <li>WRITE_THROUGH=YES (GDAL >= 3.8) for the Windows regular files to
 * set the FILE_FLAG_WRITE_THROUGH flag to the CreateFile() function. In that
 * mode, the data is written to the system cache but is flushed to disk without
 * delay.</li>
 * </ul>
 *
 * Options specifics to /vsis3/, /vsigs/, /vsioss/ and /vsiaz/ in "w" mode:
 * <ul>
 * <li>CHUNK_SIZE=val in MiB. (GDAL >= 3.10) Size of a block. Default is 50 MiB.
 * For /vsis3/, /vsigz/, /vsioss/, it can be up to 5000 MiB.
 * For /vsiaz/, only taken into account when BLOB_TYPE=BLOCK. It can be up to 4000 MiB.
 * </li>
 * </ul>
 *
 * Options specifics to /vsiaz/ in "w" mode:
 * <ul>
 * <li>BLOB_TYPE=APPEND/BLOCK. (GDAL >= 3.10) Type of blob. Defaults to APPEND.
 * Append blocks are limited to 195 GiB
 * (however if the file size is below 4 MiB, a block blob will be created in a
 * single PUT operation)
 * </li>
 * </ul>
 *
 * Analog of the POSIX fopen() function.
 *
 * @param pszFilename the file to open.  UTF-8 encoded.
 * @param pszAccess access requested (i.e. "r", "r+", "w")
 * @param bSetError flag determining whether or not this open call
 * should set VSIErrors on failure.
 * @param papszOptions NULL or NULL-terminated list of strings. The content is
 *                     highly file system dependent.
 *
 *
 * @return NULL on failure, or the file handle.
 *
 * @since GDAL 3.3
 */

VSILFILE *VSIFOpenEx2L(const char *pszFilename, const char *pszAccess,
                       int bSetError, CSLConstList papszOptions)

{
    // Too long filenames can cause excessive memory allocation due to
    // recursion in some filesystem handlers
    constexpr size_t knMaxPath = 8192;
    if (CPLStrnlen(pszFilename, knMaxPath) == knMaxPath)
        return nullptr;

    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    VSILFILE *fp = poFSHandler->Open(pszFilename, pszAccess,
                                     CPL_TO_BOOL(bSetError), papszOptions);

    VSIDebug4("VSIFOpenEx2L(%s,%s,%d) = %p", pszFilename, pszAccess, bSetError,
              fp);

    return fp;
}

/************************************************************************/
/*                             VSIFCloseL()                             */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::Close()
 * \brief Close file.
 *
 * This function closes the indicated file.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fclose() function.
 *
 * @return 0 on success or -1 on failure.
 */

/**
 * \brief Close file.
 *
 * This function closes the indicated file.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fclose() function.
 *
 * @param fp file handle opened with VSIFOpenL().  Passing a nullptr produces
 * undefined behavior.
 *
 * @return 0 on success or -1 on failure.
 */

int VSIFCloseL(VSILFILE *fp)

{
    VSIDebug1("VSIFCloseL(%p)", fp);

    const int nResult = fp->Close();

    delete fp;

    return nResult;
}

/************************************************************************/
/*                             VSIFSeekL()                              */
/************************************************************************/

/**
 * \fn int VSIVirtualHandle::Seek( vsi_l_offset nOffset, int nWhence )
 * \brief Seek to requested offset.
 *
 * Seek to the desired offset (nOffset) in the indicated file.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fseek() call.
 *
 * Caution: vsi_l_offset is a unsigned type, so SEEK_CUR can only be used
 * for positive seek. If negative seek is needed, use
 * handle->Seek( handle->Tell() + negative_offset, SEEK_SET ).
 *
 * @param nOffset offset in bytes.
 * @param nWhence one of SEEK_SET, SEEK_CUR or SEEK_END.
 *
 * @return 0 on success or -1 one failure.
 */

/**
 * \brief Seek to requested offset.
 *
 * Seek to the desired offset (nOffset) in the indicated file.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fseek() call.
 *
 * Caution: vsi_l_offset is a unsigned type, so SEEK_CUR can only be used
 * for positive seek. If negative seek is needed, use
 * VSIFSeekL( fp, VSIFTellL(fp) + negative_offset, SEEK_SET ).
 *
 * @param fp file handle opened with VSIFOpenL().
 * @param nOffset offset in bytes.
 * @param nWhence one of SEEK_SET, SEEK_CUR or SEEK_END.
 *
 * @return 0 on success or -1 one failure.
 */

int VSIFSeekL(VSILFILE *fp, vsi_l_offset nOffset, int nWhence)

{
    return fp->Seek(nOffset, nWhence);
}

/************************************************************************/
/*                             VSIFTellL()                              */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::Tell()
 * \brief Tell current file offset.
 *
 * Returns the current file read/write offset in bytes from the beginning of
 * the file.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX ftell() call.
 *
 * @return file offset in bytes.
 */

/**
 * \brief Tell current file offset.
 *
 * Returns the current file read/write offset in bytes from the beginning of
 * the file.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX ftell() call.
 *
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return file offset in bytes.
 */

vsi_l_offset VSIFTellL(VSILFILE *fp)

{
    return fp->Tell();
}

/************************************************************************/
/*                             VSIRewindL()                             */
/************************************************************************/

/**
 * \brief Rewind the file pointer to the beginning of the file.
 *
 * This is equivalent to VSIFSeekL( fp, 0, SEEK_SET )
 *
 * Analog of the POSIX rewind() call.
 *
 * @param fp file handle opened with VSIFOpenL().
 */

void VSIRewindL(VSILFILE *fp)

{
    CPL_IGNORE_RET_VAL(VSIFSeekL(fp, 0, SEEK_SET));
}

/************************************************************************/
/*                             VSIFFlushL()                             */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::Flush()
 * \brief Flush pending writes to disk.
 *
 * For files in write or update mode and on filesystem types where it is
 * applicable, all pending output on the file is flushed to the physical disk.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fflush() call.
 *
 * On Windows regular files, this method does nothing, unless the
 * VSI_FLUSH configuration option is set to YES (and only when the file has
 * *not* been opened with the WRITE_THROUGH option).
 *
 * @return 0 on success or -1 on error.
 */

/**
 * \brief Flush pending writes to disk.
 *
 * For files in write or update mode and on filesystem types where it is
 * applicable, all pending output on the file is flushed to the physical disk.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fflush() call.
 *
 * On Windows regular files, this method does nothing, unless the
 * VSI_FLUSH configuration option is set to YES (and only when the file has
 * *not* been opened with the WRITE_THROUGH option).
 *
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return 0 on success or -1 on error.
 */

int VSIFFlushL(VSILFILE *fp)

{
    return fp->Flush();
}

/************************************************************************/
/*                             VSIFReadL()                              */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::Read( void *pBuffer, size_t nSize, size_t nCount )
 * \brief Read bytes from file.
 *
 * Reads nCount objects of nSize bytes from the indicated file at the
 * current offset into the indicated buffer.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fread() call.
 *
 * @param pBuffer the buffer into which the data should be read (at least
 * nCount * nSize bytes in size.
 * @param nSize size of objects to read in bytes.
 * @param nCount number of objects to read.
 *
 * @return number of objects successfully read. If that number is less than
 * nCount, VSIFEofL() or VSIFErrorL() can be used to determine the reason for
 * the short read.
 */

/**
 * \brief Read bytes from file.
 *
 * Reads nCount objects of nSize bytes from the indicated file at the
 * current offset into the indicated buffer.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fread() call.
 *
 * @param pBuffer the buffer into which the data should be read (at least
 * nCount * nSize bytes in size.
 * @param nSize size of objects to read in bytes.
 * @param nCount number of objects to read.
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return number of objects successfully read. If that number is less than
 * nCount, VSIFEofL() or VSIFErrorL() can be used to determine the reason for
 * the short read.
 */

size_t VSIFReadL(void *pBuffer, size_t nSize, size_t nCount, VSILFILE *fp)

{
    return fp->Read(pBuffer, nSize, nCount);
}

/************************************************************************/
/*                       VSIFReadMultiRangeL()                          */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::ReadMultiRange( int nRanges, void ** ppData,
 *                                       const vsi_l_offset* panOffsets,
 *                                       const size_t* panSizes )
 * \brief Read several ranges of bytes from file.
 *
 * Reads nRanges objects of panSizes[i] bytes from the indicated file at the
 * offset panOffsets[i] into the buffer ppData[i].
 *
 * Ranges must be sorted in ascending start offset, and must not overlap each
 * other.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory or /vsicurl/.
 *
 * @param nRanges number of ranges to read.
 * @param ppData array of nRanges buffer into which the data should be read
 *               (ppData[i] must be at list panSizes[i] bytes).
 * @param panOffsets array of nRanges offsets at which the data should be read.
 * @param panSizes array of nRanges sizes of objects to read (in bytes).
 *
 * @return 0 in case of success, -1 otherwise.
 * @since GDAL 1.9.0
 */

/**
 * \brief Read several ranges of bytes from file.
 *
 * Reads nRanges objects of panSizes[i] bytes from the indicated file at the
 * offset panOffsets[i] into the buffer ppData[i].
 *
 * Ranges must be sorted in ascending start offset, and must not overlap each
 * other.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory or /vsicurl/.
 *
 * @param nRanges number of ranges to read.
 * @param ppData array of nRanges buffer into which the data should be read
 *               (ppData[i] must be at list panSizes[i] bytes).
 * @param panOffsets array of nRanges offsets at which the data should be read.
 * @param panSizes array of nRanges sizes of objects to read (in bytes).
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return 0 in case of success, -1 otherwise.
 * @since GDAL 1.9.0
 */

int VSIFReadMultiRangeL(int nRanges, void **ppData,
                        const vsi_l_offset *panOffsets, const size_t *panSizes,
                        VSILFILE *fp)
{
    return fp->ReadMultiRange(nRanges, ppData, panOffsets, panSizes);
}

/************************************************************************/
/*                             VSIFWriteL()                             */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::Write( const void *pBuffer,
 *                              size_t nSize, size_t nCount )
 * \brief Write bytes to file.
 *
 * Writes nCount objects of nSize bytes to the indicated file at the
 * current offset into the indicated buffer.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fwrite() call.
 *
 * @param pBuffer the buffer from which the data should be written (at least
 * nCount * nSize bytes in size.
 * @param nSize size of objects to write in bytes.
 * @param nCount number of objects to write.
 *
 * @return number of objects successfully written.
 */

/**
 * \brief Write bytes to file.
 *
 * Writes nCount objects of nSize bytes to the indicated file at the
 * current offset into the indicated buffer.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX fwrite() call.
 *
 * @param pBuffer the buffer from which the data should be written (at least
 * nCount * nSize bytes in size.
 * @param nSize size of objects to write in bytes.
 * @param nCount number of objects to write.
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return number of objects successfully written.
 */

size_t VSIFWriteL(const void *pBuffer, size_t nSize, size_t nCount,
                  VSILFILE *fp)

{
    return fp->Write(pBuffer, nSize, nCount);
}

/************************************************************************/
/*                              VSIFEofL()                              */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::Eof()
 * \brief Test for end of file.
 *
 * Returns TRUE (non-zero) if an end-of-file condition occurred during the
 * previous read operation. The end-of-file flag is cleared by a successful
 * VSIFSeekL() call, or a call to VSIFClearErrL().
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX feof() call.
 *
 * @return TRUE if at EOF, else FALSE.
 */

/**
 * \brief Test for end of file.
 *
 * Returns TRUE (non-zero) if an end-of-file condition occurred during the
 * previous read operation. The end-of-file flag is cleared by a successful
 * VSIFSeekL() call, or a call to VSIFClearErrL().
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX feof() call.
 *
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return TRUE if at EOF, else FALSE.
 */

int VSIFEofL(VSILFILE *fp)

{
    return fp->Eof();
}

/************************************************************************/
/*                            VSIFErrorL()                              */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::Error()
 * \brief Test the error indicator.
 *
 * Returns TRUE (non-zero) if an error condition occurred during the
 * previous read operation. The error indicator is cleared by a call to
 * VSIFClearErrL(). Note that a end-of-file situation, reported by VSIFEofL(),
 * is *not* an error reported by VSIFErrorL().
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX ferror() call.
 *
 * @return TRUE if the error indicator is set, else FALSE.
 * @since 3.10
 */

/**
 * \brief Test the error indicator.
 *
 * Returns TRUE (non-zero) if an error condition occurred during the
 * previous read operation. The error indicator is cleared by a call to
 * VSIFClearErrL(). Note that a end-of-file situation, reported by VSIFEofL(),
 * is *not* an error reported by VSIFErrorL().
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX feof() call.
 *
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return TRUE if the error indicator is set, else FALSE.
 * @since 3.10
 */

int VSIFErrorL(VSILFILE *fp)

{
    return fp->Error();
}

/************************************************************************/
/*                           VSIFClearErrL()                            */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::ClearErr()
 * \brief Reset the error and end-of-file indicators.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX clearerr() call.
 *
 * @since 3.10
 */

/**
 * \brief Reset the error and end-of-file indicators.
 *
 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX clearerr() call.
 *
 * @param fp file handle opened with VSIFOpenL().
 *
 * @since 3.10
 */

void VSIFClearErrL(VSILFILE *fp)

{
    fp->ClearErr();
}

/************************************************************************/
/*                            VSIFTruncateL()                           */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::Truncate( vsi_l_offset nNewSize )
 * \brief Truncate/expand the file to the specified size

 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX ftruncate() call.
 *
 * @param nNewSize new size in bytes.
 *
 * @return 0 on success
 * @since GDAL 1.9.0
 */

/**
 * \brief Truncate/expand the file to the specified size

 * This method goes through the VSIFileHandler virtualization and may
 * work on unusual filesystems such as in memory.
 *
 * Analog of the POSIX ftruncate() call.
 *
 * @param fp file handle opened with VSIFOpenL().
 * @param nNewSize new size in bytes.
 *
 * @return 0 on success
 * @since GDAL 1.9.0
 */

int VSIFTruncateL(VSILFILE *fp, vsi_l_offset nNewSize)

{
    return fp->Truncate(nNewSize);
}

/************************************************************************/
/*                            VSIFPrintfL()                             */
/************************************************************************/

/**
 * \brief Formatted write to file.
 *
 * Provides fprintf() style formatted output to a VSI*L file.  This formats
 * an internal buffer which is written using VSIFWriteL().
 *
 * Analog of the POSIX fprintf() call.
 *
 * @param fp file handle opened with VSIFOpenL().
 * @param pszFormat the printf() style format string.
 *
 * @return the number of bytes written or -1 on an error.
 */

int VSIFPrintfL(VSILFILE *fp, CPL_FORMAT_STRING(const char *pszFormat), ...)

{
    va_list args;

    va_start(args, pszFormat);
    CPLString osResult;
    osResult.vPrintf(pszFormat, args);
    va_end(args);

    return static_cast<int>(
        VSIFWriteL(osResult.c_str(), 1, osResult.length(), fp));
}

/************************************************************************/
/*                 VSIVirtualHandle::Printf()                           */
/************************************************************************/

/**
 * \brief Formatted write to file.
 *
 * Provides fprintf() style formatted output to a VSI*L file.  This formats
 * an internal buffer which is written using VSIFWriteL().
 *
 * Analog of the POSIX fprintf() call.
 *
 * @param pszFormat the printf() style format string.
 *
 * @return the number of bytes written or -1 on an error.
 */

int VSIVirtualHandle::Printf(CPL_FORMAT_STRING(const char *pszFormat), ...)
{
    va_list args;

    va_start(args, pszFormat);
    CPLString osResult;
    osResult.vPrintf(pszFormat, args);
    va_end(args);

    return static_cast<int>(Write(osResult.c_str(), 1, osResult.length()));
}

/************************************************************************/
/*                              VSIFPutcL()                              */
/************************************************************************/

// TODO: should we put in conformance with POSIX regarding the return
// value. As of today (2015-08-29), no code in GDAL sources actually
// check the return value.

/**
 * \brief Write a single byte to the file
 *
 * Writes the character nChar, cast to an unsigned char, to file.
 *
 * Almost an analog of the POSIX  fputc() call, except that it returns
 * the  number of  character  written (1  or 0),  and  not the  (cast)
 * character itself or EOF.
 *
 * @param nChar character to write.
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return 1 in case of success, 0 on error.
 */

int VSIFPutcL(int nChar, VSILFILE *fp)

{
    const unsigned char cChar = static_cast<unsigned char>(nChar);
    return static_cast<int>(VSIFWriteL(&cChar, 1, 1, fp));
}

/************************************************************************/
/*                        VSIFGetRangeStatusL()                        */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::GetRangeStatus( vsi_l_offset nOffset,
 *                                       vsi_l_offset nLength )
 * \brief Return if a given file range contains data or holes filled with zeroes
 *
 * This uses the filesystem capabilities of querying which regions of
 * a sparse file are allocated or not. This is currently only
 * implemented for Linux (and no other Unix derivatives) and Windows.
 *
 * Note: A return of VSI_RANGE_STATUS_DATA doesn't exclude that the
 * extent is filled with zeroes! It must be interpreted as "may
 * contain non-zero data".
 *
 * @param nOffset offset of the start of the extent.
 * @param nLength extent length.
 *
 * @return extent status: VSI_RANGE_STATUS_UNKNOWN, VSI_RANGE_STATUS_DATA or
 *         VSI_RANGE_STATUS_HOLE
 * @since GDAL 2.2
 */

/**
 * \brief Return if a given file range contains data or holes filled with zeroes
 *
 * This uses the filesystem capabilities of querying which regions of
 * a sparse file are allocated or not. This is currently only
 * implemented for Linux (and no other Unix derivatives) and Windows.
 *
 * Note: A return of VSI_RANGE_STATUS_DATA doesn't exclude that the
 * extent is filled with zeroes! It must be interpreted as "may
 * contain non-zero data".
 *
 * @param fp file handle opened with VSIFOpenL().
 * @param nOffset offset of the start of the extent.
 * @param nLength extent length.
 *
 * @return extent status: VSI_RANGE_STATUS_UNKNOWN, VSI_RANGE_STATUS_DATA or
 *         VSI_RANGE_STATUS_HOLE
 * @since GDAL 2.2
 */

VSIRangeStatus VSIFGetRangeStatusL(VSILFILE *fp, vsi_l_offset nOffset,
                                   vsi_l_offset nLength)
{
    return fp->GetRangeStatus(nOffset, nLength);
}

/************************************************************************/
/*                           VSIIngestFile()                            */
/************************************************************************/

/**
 * \brief Ingest a file into memory.
 *
 * Read the whole content of a file into a memory buffer.
 *
 * Either fp or pszFilename can be NULL, but not both at the same time.
 *
 * If fp is passed non-NULL, it is the responsibility of the caller to
 * close it.
 *
 * If non-NULL, the returned buffer is guaranteed to be NUL-terminated.
 *
 * @param fp file handle opened with VSIFOpenL().
 * @param pszFilename filename.
 * @param ppabyRet pointer to the target buffer. *ppabyRet must be freed with
 *                 VSIFree()
 * @param pnSize pointer to variable to store the file size. May be NULL.
 * @param nMaxSize maximum size of file allowed. If no limit, set to a negative
 *                 value.
 *
 * @return TRUE in case of success.
 *
 * @since GDAL 1.11
 */

int VSIIngestFile(VSILFILE *fp, const char *pszFilename, GByte **ppabyRet,
                  vsi_l_offset *pnSize, GIntBig nMaxSize)
{
    if (fp == nullptr && pszFilename == nullptr)
        return FALSE;
    if (ppabyRet == nullptr)
        return FALSE;

    *ppabyRet = nullptr;
    if (pnSize != nullptr)
        *pnSize = 0;

    bool bFreeFP = false;
    if (nullptr == fp)
    {
        fp = VSIFOpenL(pszFilename, "rb");
        if (nullptr == fp)
        {
            CPLError(CE_Failure, CPLE_FileIO, "Cannot open file '%s'",
                     pszFilename);
            return FALSE;
        }
        bFreeFP = true;
    }
    else
    {
        if (VSIFSeekL(fp, 0, SEEK_SET) != 0)
            return FALSE;
    }

    vsi_l_offset nDataLen = 0;

    if (pszFilename == nullptr || strcmp(pszFilename, "/vsistdin/") == 0)
    {
        vsi_l_offset nDataAlloc = 0;
        if (VSIFSeekL(fp, 0, SEEK_SET) != 0)
        {
            if (bFreeFP)
                CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
            return FALSE;
        }
        while (true)
        {
            if (nDataLen + 8192 + 1 > nDataAlloc)
            {
                nDataAlloc = (nDataAlloc * 4) / 3 + 8192 + 1;
                if (nDataAlloc >
                    static_cast<vsi_l_offset>(static_cast<size_t>(nDataAlloc)))
                {
                    CPLError(CE_Failure, CPLE_AppDefined,
                             "Input file too large to be opened");
                    VSIFree(*ppabyRet);
                    *ppabyRet = nullptr;
                    if (bFreeFP)
                        CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
                    return FALSE;
                }
                GByte *pabyNew = static_cast<GByte *>(
                    VSIRealloc(*ppabyRet, static_cast<size_t>(nDataAlloc)));
                if (pabyNew == nullptr)
                {
                    CPLError(CE_Failure, CPLE_OutOfMemory,
                             "Cannot allocate " CPL_FRMT_GIB " bytes",
                             nDataAlloc);
                    VSIFree(*ppabyRet);
                    *ppabyRet = nullptr;
                    if (bFreeFP)
                        CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
                    return FALSE;
                }
                *ppabyRet = pabyNew;
            }
            const int nRead =
                static_cast<int>(VSIFReadL(*ppabyRet + nDataLen, 1, 8192, fp));
            nDataLen += nRead;

            if (nMaxSize >= 0 && nDataLen > static_cast<vsi_l_offset>(nMaxSize))
            {
                CPLError(CE_Failure, CPLE_AppDefined,
                         "Input file too large to be opened");
                VSIFree(*ppabyRet);
                *ppabyRet = nullptr;
                if (pnSize != nullptr)
                    *pnSize = 0;
                if (bFreeFP)
                    CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
                return FALSE;
            }

            if (pnSize != nullptr)
                *pnSize += nRead;
            (*ppabyRet)[nDataLen] = '\0';
            if (nRead == 0)
                break;
        }
    }
    else
    {
        if (VSIFSeekL(fp, 0, SEEK_END) != 0)
        {
            if (bFreeFP)
                CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
            return FALSE;
        }
        nDataLen = VSIFTellL(fp);

        // With "large" VSI I/O API we can read data chunks larger than
        // VSIMalloc could allocate. Catch it here.
        if (nDataLen !=
                static_cast<vsi_l_offset>(static_cast<size_t>(nDataLen)) ||
            nDataLen + 1 < nDataLen
            // opening a directory returns nDataLen = INT_MAX (on 32bit) or
            // INT64_MAX (on 64bit)
            || nDataLen + 1 > std::numeric_limits<size_t>::max() / 2 ||
            (nMaxSize >= 0 && nDataLen > static_cast<vsi_l_offset>(nMaxSize)))
        {
            CPLError(CE_Failure, CPLE_AppDefined,
                     "Input file too large to be opened");
            if (bFreeFP)
                CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
            return FALSE;
        }

        if (VSIFSeekL(fp, 0, SEEK_SET) != 0)
        {
            if (bFreeFP)
                CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
            return FALSE;
        }

        *ppabyRet =
            static_cast<GByte *>(VSIMalloc(static_cast<size_t>(nDataLen + 1)));
        if (nullptr == *ppabyRet)
        {
            CPLError(CE_Failure, CPLE_OutOfMemory,
                     "Cannot allocate " CPL_FRMT_GIB " bytes", nDataLen + 1);
            if (bFreeFP)
                CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
            return FALSE;
        }

        (*ppabyRet)[nDataLen] = '\0';
        if (nDataLen !=
            VSIFReadL(*ppabyRet, 1, static_cast<size_t>(nDataLen), fp))
        {
            CPLError(CE_Failure, CPLE_FileIO,
                     "Cannot read " CPL_FRMT_GIB " bytes", nDataLen);
            VSIFree(*ppabyRet);
            *ppabyRet = nullptr;
            if (bFreeFP)
                CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
            return FALSE;
        }
        if (pnSize != nullptr)
            *pnSize = nDataLen;
    }
    if (bFreeFP)
        CPL_IGNORE_RET_VAL(VSIFCloseL(fp));
    return TRUE;
}

/************************************************************************/
/*                         VSIOverwriteFile()                           */
/************************************************************************/

/**
 * \brief Overwrite an existing file with content from another one
 *
 * @param fpTarget file handle opened with VSIFOpenL() with "rb+" flag.
 * @param pszSourceFilename source filename
 *
 * @return TRUE in case of success.
 *
 * @since GDAL 3.1
 */

int VSIOverwriteFile(VSILFILE *fpTarget, const char *pszSourceFilename)
{
    VSILFILE *fpSource = VSIFOpenL(pszSourceFilename, "rb");
    if (fpSource == nullptr)
    {
        CPLError(CE_Failure, CPLE_FileIO, "Cannot open %s", pszSourceFilename);
        return false;
    }

    const size_t nBufferSize = 4096;
    void *pBuffer = CPLMalloc(nBufferSize);
    VSIFSeekL(fpTarget, 0, SEEK_SET);
    bool bRet = true;
    while (true)
    {
        size_t nRead = VSIFReadL(pBuffer, 1, nBufferSize, fpSource);
        size_t nWritten = VSIFWriteL(pBuffer, 1, nRead, fpTarget);
        if (nWritten != nRead)
        {
            bRet = false;
            break;
        }
        if (nRead < nBufferSize)
            break;
    }

    if (bRet)
    {
        bRet = VSIFTruncateL(fpTarget, VSIFTellL(fpTarget)) == 0;
        if (!bRet)
        {
            CPLError(CE_Failure, CPLE_FileIO, "Truncation failed");
        }
    }

    CPLFree(pBuffer);
    VSIFCloseL(fpSource);
    return bRet;
}

/************************************************************************/
/*                        VSIFGetNativeFileDescriptorL()                */
/************************************************************************/

/**
 * \fn VSIVirtualHandle::GetNativeFileDescriptor()
 * \brief Returns the "native" file descriptor for the virtual handle.
 *
 * This will only return a non-NULL value for "real" files handled by the
 * operating system (to be opposed to GDAL virtual file systems).
 *
 * On POSIX systems, this will be a integer value ("fd") cast as a void*.
 * On Windows systems, this will be the HANDLE.
 *
 * @return the native file descriptor, or NULL.
 */

/**
 * \brief Returns the "native" file descriptor for the virtual handle.
 *
 * This will only return a non-NULL value for "real" files handled by the
 * operating system (to be opposed to GDAL virtual file systems).
 *
 * On POSIX systems, this will be a integer value ("fd") cast as a void*.
 * On Windows systems, this will be the HANDLE.
 *
 * @param fp file handle opened with VSIFOpenL().
 *
 * @return the native file descriptor, or NULL.
 */

void *VSIFGetNativeFileDescriptorL(VSILFILE *fp)
{
    return fp->GetNativeFileDescriptor();
}

/************************************************************************/
/*                      VSIGetDiskFreeSpace()                           */
/************************************************************************/

/**
 * \brief Return free disk space available on the filesystem.
 *
 * This function returns the free disk space available on the filesystem.
 *
 * @param pszDirname a directory of the filesystem to query.
 * @return The free space in bytes. Or -1 in case of error.
 * @since GDAL 2.1
 */

GIntBig VSIGetDiskFreeSpace(const char *pszDirname)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszDirname);

    return poFSHandler->GetDiskFreeSpace(pszDirname);
}

/************************************************************************/
/*                    VSIGetFileSystemsPrefixes()                       */
/************************************************************************/

/**
 * \brief Return the list of prefixes for virtual file system handlers
 * currently registered.
 *
 * Typically: "", "/vsimem/", "/vsicurl/", etc
 *
 * @return a NULL terminated list of prefixes. Must be freed with CSLDestroy()
 * @since GDAL 2.3
 */

char **VSIGetFileSystemsPrefixes(void)
{
    return VSIFileManager::GetPrefixes();
}

/************************************************************************/
/*                     VSIGetFileSystemOptions()                        */
/************************************************************************/

/**
 * \brief Return the list of options associated with a virtual file system
 * handler as a serialized XML string.
 *
 * Those options may be set as configuration options with CPLSetConfigOption().
 *
 * @param pszFilename a filename, or prefix of a virtual file system handler.
 * @return a string, which must not be freed, or NULL if no options is declared.
 * @since GDAL 2.3
 */

const char *VSIGetFileSystemOptions(const char *pszFilename)
{
    VSIFilesystemHandler *poFSHandler = VSIFileManager::GetHandler(pszFilename);

    return poFSHandler->GetOptions();
}

/************************************************************************/
/*                       VSISetPathSpecificOption()                     */
/************************************************************************/

static std::mutex oMutexPathSpecificOptions;

// key is a path prefix
// value is a map of key, value pair
static std::map<std::string, std::map<std::string, std::string>>
    oMapPathSpecificOptions;

/**
 * \brief Set a credential (or more generally an option related to a
 *        virtual file system) for a given path prefix.
 * @deprecated in GDAL 3.6 for the better named VSISetPathSpecificOption()
 * @see VSISetPathSpecificOption()
 */
void VSISetCredential(const char *pszPathPrefix, const char *pszKey,
                      const char *pszValue)
{
    VSISetPathSpecificOption(pszPathPrefix, pszKey, pszValue);
}

/**
 * \brief Set a path specific option for a given path prefix.
 *
 * Such option is typically, but not limited to, a credential setting for a
 * virtual file system.
 *
 * That option may also be set as a configuration option with
 * CPLSetConfigOption(), but this function allows to specify them with a
 * granularity at the level of a file path, which makes it easier if using the
 * same virtual file system but with different credentials (e.g. different
 * credentials for bucket "/vsis3/foo" and "/vsis3/bar")
 *
 * This is supported for the following virtual file systems:
 * /vsis3/, /vsigs/, /vsiaz/, /vsioss/, /vsiwebhdfs, /vsiswift.
 * Note: setting them for a path starting with /vsiXXX/ will also apply for
 * /vsiXXX_streaming/ requests.
 *
 * Note that no particular care is taken to store them in RAM in a secure way.
 * So they might accidentally hit persistent storage if swapping occurs, or
 * someone with access to the memory allocated by the process may be able to
 * read them.
 *
 * @param pszPathPrefix a path prefix of a virtual file system handler.
 *                      Typically of the form "/vsiXXX/bucket". Must NOT be
 * NULL. Should not include trailing slashes.
 * @param pszKey        Option name. Must NOT be NULL.
 * @param pszValue      Option value. May be NULL to erase it.
 *
 * @since GDAL 3.6
 */

void VSISetPathSpecificOption(const char *pszPathPrefix, const char *pszKey,
                              const char *pszValue)
{
    std::lock_guard<std::mutex> oLock(oMutexPathSpecificOptions);
    auto oIter = oMapPathSpecificOptions.find(pszPathPrefix);
    CPLString osKey(pszKey);
    osKey.toupper();
    if (oIter == oMapPathSpecificOptions.end())
    {
        if (pszValue != nullptr)
            oMapPathSpecificOptions[pszPathPrefix][osKey] = pszValue;
    }
    else if (pszValue != nullptr)
        oIter->second[osKey] = pszValue;
    else
        oIter->second.erase(osKey);
}

/************************************************************************/
/*                       VSIClearPathSpecificOptions()                  */
/************************************************************************/

/**
 * \brief Clear path specific options set with VSISetPathSpecificOption()
 * @deprecated in GDAL 3.6 for the better named VSIClearPathSpecificOptions()
 * @see VSIClearPathSpecificOptions()
 */
void VSIClearCredentials(const char *pszPathPrefix)
{
    return VSIClearPathSpecificOptions(pszPathPrefix);
}

/**
 * \brief Clear path specific options set with VSISetPathSpecificOption()
 *
 * Note that no particular care is taken to remove them from RAM in a secure
 * way.
 *
 * @param pszPathPrefix If set to NULL, all path specific options are cleared.
 *                      If set to not-NULL, only those set with
 *                      VSISetPathSpecificOption(pszPathPrefix, ...) will be
 * cleared.
 *
 * @since GDAL 3.6
 */
void VSIClearPathSpecificOptions(const char *pszPathPrefix)
{
    std::lock_guard<std::mutex> oLock(oMutexPathSpecificOptions);
    if (pszPathPrefix == nullptr)
    {
        oMapPathSpecificOptions.clear();
    }
    else
    {
        oMapPathSpecificOptions.erase(pszPathPrefix);
    }
}

/************************************************************************/
/*                        VSIGetPathSpecificOption()                    */
/************************************************************************/

/**
 * \brief Get the value of a credential (or more generally an option related to
 * a virtual file system) for a given path.
 * @deprecated in GDAL 3.6 for the better named VSIGetPathSpecificOption()
 * @see VSIGetPathSpecificOption()
 */
const char *VSIGetCredential(const char *pszPath, const char *pszKey,
                             const char *pszDefault)
{
    return VSIGetPathSpecificOption(pszPath, pszKey, pszDefault);
}

/**
 * \brief Get the value a path specific option.
 *
 * Such option is typically, but not limited to, a credential setting for a
 * virtual file system.
 *
 * If no match occurs, CPLGetConfigOption(pszKey, pszDefault) is returned.
 *
 * Mostly to be used by virtual file system implementations.
 *
 * @since GDAL 3.6
 * @see VSISetPathSpecificOption()
 */
const char *VSIGetPathSpecificOption(const char *pszPath, const char *pszKey,
                                     const char *pszDefault)
{
    {
        std::lock_guard<std::mutex> oLock(oMutexPathSpecificOptions);
        for (auto it = oMapPathSpecificOptions.rbegin();
             it != oMapPathSpecificOptions.rend(); ++it)
        {
            if (STARTS_WITH(pszPath, it->first.c_str()))
            {
                auto oIter = it->second.find(CPLString(pszKey).toupper());
                if (oIter != it->second.end())
                    return oIter->second.c_str();
            }
        }
    }
    return CPLGetConfigOption(pszKey, pszDefault);
}

/************************************************************************/
/*                      VSIDuplicateFileSystemHandler()                 */
/************************************************************************/

/**
 * \brief Duplicate an existing file system handler.
 *
 * A number of virtual file system for remote object stores use protocols
 * identical or close to popular ones (typically AWS S3), but with slightly
 * different settings (at the very least the endpoint).
 *
 * This functions allows to duplicate the source virtual file system handler
 * as a new one with a different prefix (when the source virtual file system
 * handler supports the duplication operation).
 *
 * VSISetPathSpecificOption() will typically be called afterwards to change
 * configurable settings on the cloned file system handler (e.g. AWS_S3_ENDPOINT
 * for a clone of /vsis3/).
 *
 * @since GDAL 3.7
 */
bool VSIDuplicateFileSystemHandler(const char *pszSourceFSName,
                                   const char *pszNewFSName)
{
    VSIFilesystemHandler *poTargetFSHandler =
        VSIFileManager::GetHandler(pszNewFSName);
    if (poTargetFSHandler != VSIFileManager::GetHandler("/"))
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "%s is already a known virtual file system", pszNewFSName);
        return false;
    }

    VSIFilesystemHandler *poSourceFSHandler =
        VSIFileManager::GetHandler(pszSourceFSName);
    if (!poSourceFSHandler)
    {
        CPLError(CE_Failure, CPLE_AppDefined,
                 "%s is not a known virtual file system", pszSourceFSName);
        return false;
    }

    poTargetFSHandler = poSourceFSHandler->Duplicate(pszNewFSName);
    if (!poTargetFSHandler)
        return false;

    VSIFileManager::InstallHandler(pszNewFSName, poTargetFSHandler);
    return true;
}

/************************************************************************/
/* ==================================================================== */
/*                           VSIFileManager()                           */
/* ==================================================================== */
/************************************************************************/

#ifndef DOXYGEN_SKIP

/*
** Notes on Multithreading:
**
** The VSIFileManager maintains a list of file type handlers (mem, large
** file, etc).  It should be thread safe.
**/

/************************************************************************/
/*                           VSIFileManager()                           */
/************************************************************************/

VSIFileManager::VSIFileManager() : poDefaultHandler(nullptr)
{
}

/************************************************************************/
/*                          ~VSIFileManager()                           */
/************************************************************************/

VSIFileManager::~VSIFileManager()
{
    std::set<VSIFilesystemHandler *> oSetAlreadyDeleted;
    for (std::map<std::string, VSIFilesystemHandler *>::const_iterator iter =
             oHandlers.begin();
         iter != oHandlers.end(); ++iter)
    {
        if (oSetAlreadyDeleted.find(iter->second) == oSetAlreadyDeleted.end())
        {
            oSetAlreadyDeleted.insert(iter->second);
            delete iter->second;
        }
    }

    delete poDefaultHandler;
}

/************************************************************************/
/*                                Get()                                 */
/************************************************************************/

static VSIFileManager *poManager = nullptr;
static CPLMutex *hVSIFileManagerMutex = nullptr;

VSIFileManager *VSIFileManager::Get()
{
    CPLMutexHolder oHolder(&hVSIFileManagerMutex);
    if (poManager != nullptr)
    {
        return poManager;
    }

    poManager = new VSIFileManager;
    VSIInstallLargeFileHandler();
    VSIInstallSubFileHandler();
    VSIInstallMemFileHandler();
#ifdef HAVE_LIBZ
    VSIInstallGZipFileHandler();
    VSIInstallZipFileHandler();
#endif
#ifdef HAVE_LIBARCHIVE
    VSIInstall7zFileHandler();
    VSIInstallRarFileHandler();
#endif
#ifdef HAVE_CURL
    VSIInstallCurlFileHandler();
    VSIInstallCurlStreamingFileHandler();
    VSIInstallS3FileHandler();
    VSIInstallS3StreamingFileHandler();
    VSIInstallGSFileHandler();
    VSIInstallGSStreamingFileHandler();
    VSIInstallAzureFileHandler();
    VSIInstallAzureStreamingFileHandler();
    VSIInstallADLSFileHandler();
    VSIInstallOSSFileHandler();
    VSIInstallOSSStreamingFileHandler();
    VSIInstallSwiftFileHandler();
    VSIInstallSwiftStreamingFileHandler();
    VSIInstallWebHdfsHandler();
#endif
    VSIInstallStdinHandler();
    VSIInstallHdfsHandler();
    VSIInstallStdoutHandler();
    VSIInstallSparseFileHandler();
    VSIInstallTarFileHandler();
    VSIInstallCachedFileHandler();
    VSIInstallCryptFileHandler();

    return poManager;
}

/************************************************************************/
/*                           GetPrefixes()                              */
/************************************************************************/

char **VSIFileManager::GetPrefixes()
{
    CPLMutexHolder oHolder(&hVSIFileManagerMutex);
    CPLStringList aosList;
    for (const auto &oIter : Get()->oHandlers)
    {
        if (oIter.first != "/vsicurl?")
        {
            aosList.AddString(oIter.first.c_str());
        }
    }
    return aosList.StealList();
}

/************************************************************************/
/*                             GetHandler()                             */
/************************************************************************/

VSIFilesystemHandler *VSIFileManager::GetHandler(const char *pszPath)

{
    VSIFileManager *poThis = Get();
    const size_t nPathLen = strlen(pszPath);

    for (std::map<std::string, VSIFilesystemHandler *>::const_iterator iter =
             poThis->oHandlers.begin();
         iter != poThis->oHandlers.end(); ++iter)
    {
        const char *pszIterKey = iter->first.c_str();
        const size_t nIterKeyLen = iter->first.size();
        if (strncmp(pszPath, pszIterKey, nIterKeyLen) == 0)
            return iter->second;

        // "/vsimem\foo" should be handled as "/vsimem/foo".
        if (nIterKeyLen && nPathLen > nIterKeyLen &&
            pszIterKey[nIterKeyLen - 1] == '/' &&
            pszPath[nIterKeyLen - 1] == '\\' &&
            strncmp(pszPath, pszIterKey, nIterKeyLen - 1) == 0)
            return iter->second;

        // /vsimem should be treated as a match for /vsimem/.
        if (nPathLen + 1 == nIterKeyLen &&
            strncmp(pszPath, pszIterKey, nPathLen) == 0)
            return iter->second;
    }

    return poThis->poDefaultHandler;
}

/************************************************************************/
/*                           InstallHandler()                           */
/************************************************************************/

void VSIFileManager::InstallHandler(const std::string &osPrefix,
                                    VSIFilesystemHandler *poHandler)

{
    if (osPrefix == "")
        Get()->poDefaultHandler = poHandler;
    else
        Get()->oHandlers[osPrefix] = poHandler;
}

/************************************************************************/
/*                          RemoveHandler()                             */
/************************************************************************/

void VSIFileManager::RemoveHandler(const std::string &osPrefix)
{
    if (osPrefix == "")
        Get()->poDefaultHandler = nullptr;
    else
        Get()->oHandlers.erase(osPrefix);
}

/************************************************************************/
/*                       VSICleanupFileManager()                        */
/************************************************************************/

void VSICleanupFileManager()

{
    if (poManager)
    {
        delete poManager;
        poManager = nullptr;
    }

    if (hVSIFileManagerMutex != nullptr)
    {
        CPLDestroyMutex(hVSIFileManagerMutex);
        hVSIFileManagerMutex = nullptr;
    }

#ifdef HAVE_CURL
    VSICURLDestroyCacheFileProp();
#endif
}

/************************************************************************/
/*                            Truncate()                                */
/************************************************************************/

int VSIVirtualHandle::Truncate(vsi_l_offset nNewSize)
{
    const vsi_l_offset nOriginalPos = Tell();
    if (Seek(0, SEEK_END) == 0 && nNewSize >= Tell())
    {
        // Fill with zeroes
        std::vector<GByte> aoBytes(4096, 0);
        vsi_l_offset nCurOffset = nOriginalPos;
        while (nCurOffset < nNewSize)
        {
            constexpr vsi_l_offset nMaxOffset = 4096;
            const int nSize =
                static_cast<int>(std::min(nMaxOffset, nNewSize - nCurOffset));
            if (Write(&aoBytes[0], nSize, 1) != 1)
            {
                Seek(nOriginalPos, SEEK_SET);
                return -1;
            }
            nCurOffset += nSize;
        }
        return Seek(nOriginalPos, SEEK_SET) == 0 ? 0 : -1;
    }

    CPLDebug("VSI", "Truncation is not supported in generic implementation "
                    "of Truncate()");
    Seek(nOriginalPos, SEEK_SET);
    return -1;
}

/************************************************************************/
/*                           ReadMultiRange()                           */
/************************************************************************/

int VSIVirtualHandle::ReadMultiRange(int nRanges, void **ppData,
                                     const vsi_l_offset *panOffsets,
                                     const size_t *panSizes)
{
    int nRet = 0;
    const vsi_l_offset nCurOffset = Tell();
    for (int i = 0; i < nRanges; i++)
    {
        if (Seek(panOffsets[i], SEEK_SET) < 0)
        {
            nRet = -1;
            break;
        }

        const size_t nRead = Read(ppData[i], 1, panSizes[i]);
        if (panSizes[i] != nRead)
        {
            nRet = -1;
            break;
        }
    }

    Seek(nCurOffset, SEEK_SET);

    return nRet;
}

#endif  // #ifndef DOXYGEN_SKIP

/************************************************************************/
/*                            HasPRead()                                */
/************************************************************************/

/** Returns whether this file handle supports the PRead() method.
 *
 * @since GDAL 3.6
 */
bool VSIVirtualHandle::HasPRead() const
{
    return false;
}

/************************************************************************/
/*                             PRead()                                  */
/************************************************************************/

/** Do a parallel-compatible read operation.
 *
 * This methods reads into pBuffer up to nSize bytes starting at offset nOffset
 * in the file. The current file offset is not affected by this method.
 *
 * The implementation is thread-safe: several threads can issue PRead()
 * concurrently on the same VSIVirtualHandle object.
 *
 * This method has the same semantics as pread() Linux operation. It is only
 * available if HasPRead() returns true.
 *
 * @param pBuffer output buffer (must be at least nSize bytes large).
 * @param nSize   number of bytes to read in the file.
 * @param nOffset file offset from which to read.
 * @return number of bytes read.
 * @since GDAL 3.6
 */
size_t VSIVirtualHandle::PRead(CPL_UNUSED void *pBuffer,
                               CPL_UNUSED size_t nSize,
                               CPL_UNUSED vsi_l_offset nOffset) const
{
    return 0;
}
