/**
 * Copyright (c) 2011-2025 Bill Greiman
 * This file is part of the SdFat library for SD memory cards.
 *
 * MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
#define DBG_FILE "ExFatFile.cpp"
#include "../common/DebugMacros.h"
#include "../common/FsUtf.h"
#include "ExFatLib.h"
//------------------------------------------------------------------------------
/** test for legal character.
 *
 * \param[in] c character to be tested.
 *
 * \return true for legal character else false.
 */
inline bool lfnLegalChar(uint8_t c)
{
#if USE_UTF8_LONG_NAMES
    return !lfnReservedChar(c);
#else  // USE_UTF8_LONG_NAMES
    return !(lfnReservedChar(c) || c & 0X80);
#endif // USE_UTF8_LONG_NAMES
}
//------------------------------------------------------------------------------
bool ExFatFile::attrib(uint8_t bits)
{
    if (!isFileOrSubDir() || (bits & FS_ATTRIB_USER_SETTABLE) != bits)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    // Don't allow read-only to be set if the file is open for write.
    if ((bits & FS_ATTRIB_READ_ONLY) && isWritable())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    m_attributes = (m_attributes & ~FS_ATTRIB_USER_SETTABLE) | bits;
    // insure sync() will update dir entry
    m_flags |= FILE_FLAG_DIR_DIRTY;
    if (!sync())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
uint8_t *ExFatFile::dirCache(uint8_t set, uint8_t options)
{
    DirPos_t pos = m_dirPos;
    if (m_vol->dirSeek(&pos, FS_DIR_SIZE * set) != 1)
    {
        return nullptr;
    }
    return m_vol->dirCache(&pos, options);
}
//------------------------------------------------------------------------------
bool ExFatFile::close()
{
    bool rtn = sync();
    m_attributes = FILE_ATTR_CLOSED;
    m_flags = 0;
    return rtn;
}
//------------------------------------------------------------------------------
bool ExFatFile::contiguousRange(Sector_t *bgnSector, Sector_t *endSector)
{
    if (!isContiguous())
    {
        return false;
    }
    if (bgnSector)
    {
        *bgnSector = firstSector();
    }
    if (endSector)
    {
        *endSector = firstSector() + ((m_dataLength - 1) >> m_vol->bytesPerSectorShift());
    }
    return true;
}
//------------------------------------------------------------------------------
void ExFatFile::fgetpos(fspos_t *pos) const
{
    pos->position = m_curPosition;
    pos->cluster = m_curCluster;
}
//------------------------------------------------------------------------------
int ExFatFile::fgets(char *str, int num, const char *delim)
{
    char ch;
    int n = 0;
    int r = -1;
    while ((n + 1) < num && (r = read(&ch, 1)) == 1)
    {
        // delete CR
        if (ch == '\r')
        {
            continue;
        }
        str[n++] = ch;
        if (!delim)
        {
            if (ch == '\n')
            {
                break;
            }
        }
        else
        {
            if (strchr(delim, ch))
            {
                break;
            }
        }
    }
    if (r < 0)
    {
        // read error
        return -1;
    }
    str[n] = '\0';
    return n;
}
//------------------------------------------------------------------------------
Sector_t ExFatFile::firstSector() const
{
    return m_firstCluster ? m_vol->clusterStartSector(m_firstCluster) : 0;
}
//------------------------------------------------------------------------------
void ExFatFile::fsetpos(const fspos_t *pos)
{
    m_curPosition = pos->position;
    m_curCluster = pos->cluster;
}
//------------------------------------------------------------------------------
bool ExFatFile::getAccessDateTime(uint16_t *pdate, uint16_t *ptime)
{
    const DirFile_t *df = reinterpret_cast<DirFile_t *>(m_vol->dirCache(&m_dirPos, FsCache::CACHE_FOR_READ));
    if (!df)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    *pdate = getLe16(df->accessDate);
    *ptime = getLe16(df->accessTime);
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::getCreateDateTime(uint16_t *pdate, uint16_t *ptime)
{
    const DirFile_t *df = reinterpret_cast<DirFile_t *>(m_vol->dirCache(&m_dirPos, FsCache::CACHE_FOR_READ));
    if (!df)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    *pdate = getLe16(df->createDate);
    *ptime = getLe16(df->createTime);
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::getModifyDateTime(uint16_t *pdate, uint16_t *ptime)
{
    const DirFile_t *df = reinterpret_cast<DirFile_t *>(m_vol->dirCache(&m_dirPos, FsCache::CACHE_FOR_READ));
    if (!df)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    *pdate = getLe16(df->modifyDate);
    *ptime = getLe16(df->modifyTime);
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::isBusy()
{
    return m_vol->isBusy();
}
//------------------------------------------------------------------------------
bool ExFatFile::open(const char *path, oflag_t oflag)
{
    return open(ExFatVolume::cwv(), path, oflag);
}
//------------------------------------------------------------------------------
bool ExFatFile::open(ExFatVolume *vol, const char *path, oflag_t oflag)
{
    return vol && open(vol->vwd(), path, oflag);
}
//------------------------------------------------------------------------------
bool ExFatFile::open(ExFatFile *dirFile, const char *path, oflag_t oflag)
{
    ExFatFile tmpDir;
    ExName_t fname;
    // error if already open
    if (isOpen() || !dirFile->isDir())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    if (isDirSeparator(*path))
    {
        while (isDirSeparator(*path))
        {
            path++;
        }
        if (*path == 0)
        {
            return openRoot(dirFile->m_vol);
        }
        if (!tmpDir.openRoot(dirFile->m_vol))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        dirFile = &tmpDir;
    }
    while (1)
    {
        if (!parsePathName(path, &fname, &path))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        if (*path == 0)
        {
            break;
        }
        if (!openPrivate(dirFile, &fname, O_RDONLY))
        {
            DBG_WARN_MACRO;
            goto fail;
        }
        tmpDir.copy(this);
        dirFile = &tmpDir;
        close();
    }
    return openPrivate(dirFile, &fname, oflag);

fail:
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::open(uint32_t index, oflag_t oflag)
{
    ExFatVolume *vol = ExFatVolume::cwv();
    return vol ? open(vol->vwd(), index, oflag) : false;
}
//------------------------------------------------------------------------------
bool ExFatFile::open(ExFatFile *dirFile, uint32_t index, oflag_t oflag)
{
    if (dirFile->seekSet(FS_DIR_SIZE * index) && openNext(dirFile, oflag))
    {
        if (dirIndex() == index)
        {
            return true;
        }
        close();
        DBG_FAIL_MACRO;
    }
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::openCwd()
{
    if (isOpen() || !ExFatVolume::cwv())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    this->copy(ExFatVolume::cwv()->vwd());
    rewind();
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::openNext(ExFatFile *dir, oflag_t oflag)
{
    if (isOpen() || !dir->isDir() || (dir->curPosition() & 0X1F))
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    return openPrivate(dir, nullptr, oflag);

fail:
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::openPrivate(ExFatFile *dir, ExName_t *fname, oflag_t oflag)
{
    int n;
    uint8_t modeFlags;
    uint8_t *cache __attribute__((unused));
    DirPos_t freePos __attribute__((unused));
    DirFile_t *dirFile;
    DirStream_t *dirStream;
    DirName_t *dirName;
    uint8_t buf[FS_DIR_SIZE];
    uint8_t freeCount = 0;
    uint8_t freeNeed = 3;
    bool inSet = false;

    // error if already open, no access mode, or no directory.
    if (isOpen() || !dir->isDir())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }

    switch (oflag & O_ACCMODE)
    {
    case O_RDONLY:
        modeFlags = FILE_FLAG_READ;
        break;
    case O_WRONLY:
        modeFlags = FILE_FLAG_WRITE;
        break;
    case O_RDWR:
        modeFlags = FILE_FLAG_READ | FILE_FLAG_WRITE;
        break;
    default:
        DBG_FAIL_MACRO;
        goto fail;
    }
    modeFlags |= (oflag & O_APPEND) ? FILE_FLAG_APPEND : 0;

    if (fname)
    {
        freeNeed = 2 + (fname->nameLength + 14) / 15;
        dir->rewind();
    }

    while (1)
    {
        n = dir->read(buf, FS_DIR_SIZE);
        if (n == 0)
        {
            goto create;
        }
        if (n != FS_DIR_SIZE)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        if (!(buf[0] & EXFAT_TYPE_USED))
        {
            // Unused entry.
            if (freeCount == 0)
            {
                freePos.position = dir->curPosition() - FS_DIR_SIZE;
                freePos.cluster = dir->curCluster();
            }
            if (freeCount < freeNeed)
            {
                freeCount++;
            }
            if (buf[0] == EXFAT_TYPE_END_DIR)
            {
                if (fname)
                {
                    goto create;
                }
                // Likely openNext call.
                DBG_WARN_MACRO;
                goto fail;
            }
            inSet = false;
        }
        else if (!inSet)
        {
            if (freeCount < freeNeed)
            {
                freeCount = 0;
            }
            if (buf[0] != EXFAT_TYPE_FILE)
            {
                continue;
            }
            inSet = true;
            memset(this, 0, sizeof(ExFatFile));
            dirFile = reinterpret_cast<DirFile_t *>(buf);
            m_setCount = dirFile->setCount;
            m_attributes = getLe16(dirFile->attributes) & FS_ATTRIB_COPY;
            if (!(m_attributes & FS_ATTRIB_DIRECTORY))
            {
                m_attributes |= FILE_ATTR_FILE;
            }
            m_vol = dir->volume();
            m_dirPos.cluster = dir->curCluster();
            m_dirPos.position = dir->curPosition() - FS_DIR_SIZE;
            m_dirPos.isContiguous = dir->isContiguous();
        }
        else if (buf[0] == EXFAT_TYPE_STREAM)
        {
            dirStream = reinterpret_cast<DirStream_t *>(buf);
            m_flags = modeFlags;
            if (dirStream->flags & EXFAT_FLAG_CONTIGUOUS)
            {
                m_flags |= FILE_FLAG_CONTIGUOUS;
            }
            m_validLength = getLe64(dirStream->validLength);
            m_firstCluster = getLe32(dirStream->firstCluster);
            m_dataLength = getLe64(dirStream->dataLength);
            if (!fname)
            {
                goto found;
            }
            fname->reset();
            if (fname->nameLength != dirStream->nameLength || fname->nameHash != getLe16(dirStream->nameHash))
            {
                inSet = false;
            }
        }
        else if (buf[0] == EXFAT_TYPE_NAME)
        {
            dirName = reinterpret_cast<DirName_t *>(buf);
            if (!cmpName(dirName, fname))
            {
                inSet = false;
                continue;
            }
            if (fname->atEnd())
            {
                goto found;
            }
        }
        else
        {
            inSet = false;
        }
    }

found:
    // Don't open if create only.
    if (oflag & O_EXCL)
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    // Write, truncate, or at end is an error for a directory or read-only file.
    if ((oflag & (O_TRUNC | O_AT_END)) || (m_flags & FILE_FLAG_WRITE))
    {
        if (isSubDir() || isReadOnly() || EXFAT_READ_ONLY)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }

#if !EXFAT_READ_ONLY
    if (oflag & O_TRUNC)
    {
        if (!(m_flags & FILE_FLAG_WRITE))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        if (!truncate(0))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }
    else if ((oflag & O_AT_END) && !seekSet(fileSize()))
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    if (isWritable())
    {
        m_attributes |= FS_ATTRIB_ARCHIVE;
    }
#endif // !EXFAT_READ_ONLY
    return true;

create:
#if EXFAT_READ_ONLY
    DBG_FAIL_MACRO;
    goto fail;
#else  // EXFAT_READ_ONLY
    // don't create unless O_CREAT and write
    if (!(oflag & O_CREAT) || !(modeFlags & FILE_FLAG_WRITE) || !fname)
    {
        DBG_WARN_MACRO;
        goto fail;
    }
    while (freeCount < freeNeed)
    {
        n = dir->read(buf, FS_DIR_SIZE);
        if (n == 0)
        {
            Cluster_t saveCurCluster = dir->m_curCluster;
            if (!dir->addDirCluster())
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
            dir->m_curCluster = saveCurCluster;
            continue;
        }
        if (n != FS_DIR_SIZE)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        if (freeCount == 0)
        {
            freePos.position = dir->curPosition() - FS_DIR_SIZE;
            freePos.cluster = dir->curCluster();
        }
        freeCount++;
    }
    freePos.isContiguous = dir->isContiguous();
    memset(this, 0, sizeof(ExFatFile));
    m_vol = dir->volume();
    m_attributes = FILE_ATTR_FILE | FS_ATTRIB_ARCHIVE;
    m_dirPos = freePos;
    fname->reset();
    for (uint8_t i = 0; i < freeNeed; i++)
    {
        cache = dirCache(i, FsCache::CACHE_FOR_WRITE);
        if (!cache || (cache[0] & 0x80))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        memset(cache, 0, FS_DIR_SIZE);
        if (i == 0)
        {
            dirFile = reinterpret_cast<DirFile_t *>(cache);
            dirFile->type = EXFAT_TYPE_FILE;
            m_setCount = freeNeed - 1;
            dirFile->setCount = m_setCount;

            if (FsDateTime::callback)
            {
                uint16_t date, time;
                uint8_t ms10;
                FsDateTime::callback(&date, &time, &ms10);
                setLe16(dirFile->createDate, date);
                setLe16(dirFile->createTime, time);
                dirFile->createTimeMs = ms10;
            }
            else
            {
                setLe16(dirFile->createDate, FS_DEFAULT_DATE);
                setLe16(dirFile->modifyDate, FS_DEFAULT_DATE);
                setLe16(dirFile->accessDate, FS_DEFAULT_DATE);
                if (FS_DEFAULT_TIME)
                {
                    setLe16(dirFile->createTime, FS_DEFAULT_TIME);
                    setLe16(dirFile->modifyTime, FS_DEFAULT_TIME);
                    setLe16(dirFile->accessTime, FS_DEFAULT_TIME);
                }
            }
        }
        else if (i == 1)
        {
            dirStream = reinterpret_cast<DirStream_t *>(cache);
            dirStream->type = EXFAT_TYPE_STREAM;
            dirStream->flags = EXFAT_FLAG_ALWAYS1;
            m_flags = modeFlags | FILE_FLAG_DIR_DIRTY;
            dirStream->nameLength = fname->nameLength;
            setLe16(dirStream->nameHash, fname->nameHash);
        }
        else
        {
            dirName = reinterpret_cast<DirName_t *>(cache);
            dirName->type = EXFAT_TYPE_NAME;
            for (size_t k = 0; k < 15; k++)
            {
                if (fname->atEnd())
                {
                    break;
                }
                uint16_t u = fname->get16();
                setLe16(dirName->unicode + 2 * k, u);
            }
        }
    }
    return sync();
#endif // EXFAT_READ_ONLY

fail:
    // close file
    m_attributes = FILE_ATTR_CLOSED;
    m_flags = 0;
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::openRoot(ExFatVolume *vol)
{
    if (isOpen())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    memset(this, 0, sizeof(ExFatFile));
    m_attributes = FILE_ATTR_ROOT;
    m_vol = vol;
    m_flags = FILE_FLAG_READ;
    return true;

fail:
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::parsePathName(const char *path, ExName_t *fname, const char **ptr)
{
    // Skip leading spaces.
    while (*path == ' ')
    {
        path++;
    }
    fname->begin = path;
    fname->end = path;
    while (*path && !isDirSeparator(*path))
    {
        uint8_t c = *path++;
        if (!lfnLegalChar(c))
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
        if (c != '.' && c != ' ')
        {
            // Need to trim trailing dots spaces.
            fname->end = path;
        }
    }
    // Advance to next path component.
    for (; *path == ' ' || isDirSeparator(*path); path++)
    {
    }
    *ptr = path;
    return hashName(fname);

fail:
    return false;
}
//------------------------------------------------------------------------------
int ExFatFile::peek()
{
    uint64_t saveCurPosition = m_curPosition;
    Cluster_t saveCurCluster = m_curCluster;
    int c = read();
    m_curPosition = saveCurPosition;
    m_curCluster = saveCurCluster;
    return c;
}
//------------------------------------------------------------------------------
int ExFatFile::read(void *buf, size_t count)
{
    uint8_t *dst = reinterpret_cast<uint8_t *>(buf);
    int8_t fg;
    uint64_t maxRead;
    size_t toRead;
    size_t toFill;
    size_t rtn = 0;
    size_t n;
    uint8_t *cache;
    uint16_t sectorOffset;
    Sector_t sector;
    uint32_t clusterOffset;

    if (!isReadable())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    if (isContiguous() || isFile())
    {
        if (count > (m_dataLength - m_curPosition))
        {
            count = m_dataLength - m_curPosition;
        }
        maxRead = m_curPosition < m_validLength ? m_validLength - m_curPosition : 0;
        toRead = count < maxRead ? count : maxRead;
        toFill = count > toRead ? count - toRead : 0;
    }
    else
    {
        toRead = count;
        toFill = 0;
    }
    while (toRead)
    {
        clusterOffset = m_curPosition & m_vol->clusterMask();
        sectorOffset = clusterOffset & m_vol->sectorMask();
        if (clusterOffset == 0)
        {
            if (m_curPosition == 0)
            {
                m_curCluster = isRoot() ? m_vol->rootDirectoryCluster() : m_firstCluster;
            }
            else if (isContiguous())
            {
                m_curCluster++;
            }
            else
            {
                fg = m_vol->fatGet(m_curCluster, &m_curCluster);
                if (fg < 0)
                {
                    DBG_FAIL_MACRO;
                    goto fail;
                }
                if (fg == 0)
                {
                    // EOF if directory.
                    if (isDir())
                    {
                        break;
                    }
                    DBG_FAIL_MACRO;
                    goto fail;
                }
            }
        }
        sector = m_vol->clusterStartSector(m_curCluster) + (clusterOffset >> m_vol->bytesPerSectorShift());
        if (sectorOffset != 0 || toRead < m_vol->bytesPerSector() || sector == m_vol->dataCacheSector())
        {
            n = m_vol->bytesPerSector() - sectorOffset;
            if (n > toRead)
            {
                n = toRead;
            }
            // read sector to cache and copy data to caller
            cache = m_vol->dataCachePrepare(sector, FsCache::CACHE_FOR_READ);
            if (!cache)
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
            const uint8_t *src = cache + sectorOffset;
            memcpy(dst, src, n);
#if USE_MULTI_SECTOR_IO
        }
        else if (toRead >= 2 * m_vol->bytesPerSector())
        {
            uint32_t ns = toRead >> m_vol->bytesPerSectorShift();
            // Limit reads to current cluster.
            uint32_t maxNs = m_vol->sectorsPerCluster() - (clusterOffset >> m_vol->bytesPerSectorShift());
            if (ns > maxNs)
            {
                ns = maxNs;
            }
            n = ns << m_vol->bytesPerSectorShift();
            if (!m_vol->cacheSafeRead(sector, dst, ns))
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
#endif // USE_MULTI_SECTOR_IO
        }
        else
        {
            // read single sector
            n = m_vol->bytesPerSector();
            if (!m_vol->cacheSafeRead(sector, dst))
            {
                DBG_FAIL_MACRO;
                goto fail;
            }
        }
        dst += n;
        rtn += n;
        m_curPosition += n;
        toRead -= n;
    }
    if (toFill)
    {
        memset(dst, 0, toFill);
        seekCur(toFill);
        rtn += toFill;
    }
    return rtn;

fail:
    m_error |= READ_ERROR;
    return -1;
}
//------------------------------------------------------------------------------
bool ExFatFile::remove(const char *path)
{
    ExFatFile file;
    if (!file.open(this, path, O_WRONLY))
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    return file.remove();

fail:
    return false;
}
//------------------------------------------------------------------------------
bool ExFatFile::seekSet(uint64_t pos)
{
    uint32_t nCur;
    uint32_t nNew;
    Cluster_t tmp = m_curCluster;
    // error if file not open
    if (!isOpen())
    {
        DBG_FAIL_MACRO;
        goto fail;
    }
    // Optimize O_APPEND writes.
    if (pos == m_curPosition)
    {
        return true;
    }
    if (pos == 0)
    {
        // set position to start of file
        m_curCluster = 0;
        goto done;
    }
    if (isFile())
    {
        if (pos > m_dataLength)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }
    // calculate cluster index for new position
    nNew = (pos - 1) >> m_vol->bytesPerClusterShift();
    if (isContiguous())
    {
        m_curCluster = m_firstCluster + nNew;
        goto done;
    }
    // calculate cluster index for current position
    nCur = (m_curPosition - 1) >> m_vol->bytesPerClusterShift();
    if (nNew < nCur || m_curPosition == 0)
    {
        // must follow chain from first cluster
        m_curCluster = isRoot() ? m_vol->rootDirectoryCluster() : m_firstCluster;
    }
    else
    {
        // advance from curPosition
        nNew -= nCur;
    }
    while (nNew--)
    {
        if (m_vol->fatGet(m_curCluster, &m_curCluster) <= 0)
        {
            DBG_FAIL_MACRO;
            goto fail;
        }
    }

done:
    m_curPosition = pos;
    return true;

fail:
    m_curCluster = tmp;
    return false;
}
