qfsfileengine.cpp

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#include "qfsfileengine_p.h"
#include "qfsfileengine_iterator_p.h"
#include "qfilesystemengine_p.h"
#include "qdatetime.h"
#include "qdiriterator.h"
#include "qset.h"
#include <QtCore/qdebug.h>

#ifndef QT_NO_FSFILEENGINE

#if !defined(Q_OS_WINCE)
#include <errno.h>
#endif
#if defined(Q_OS_UNIX)
#include "private/qcore_unix_p.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#if defined(Q_OS_MAC)
# include <private/qcore_mac_p.h>
#endif

QT_BEGIN_NAMESPACE

#ifdef Q_OS_WIN
#  ifndef S_ISREG
#    define S_ISREG(x)   (((x) & S_IFMT) == S_IFREG)
#  endif
#  ifndef S_ISCHR
#    define S_ISCHR(x)   (((x) & S_IFMT) == S_IFCHR)
#  endif
#  ifndef S_ISFIFO
#    define S_ISFIFO(x) false
#  endif
#  ifndef S_ISSOCK
#    define S_ISSOCK(x) false
#  endif
#  ifndef INVALID_FILE_ATTRIBUTES
#    define INVALID_FILE_ATTRIBUTES (DWORD (-1))
#  endif
#endif

//**************** QFSFileEnginePrivate
QFSFileEnginePrivate::QFSFileEnginePrivate() : QAbstractFileEnginePrivate()
{
    init();
}

void QFSFileEnginePrivate::init()
{
    is_sequential = 0;
    tried_stat = 0;
#if !defined(Q_OS_WINCE)
    need_lstat = 1;
    is_link = 0;
#endif
    openMode = QIODevice::NotOpen;
    fd = -1;
    fh = 0;
#if defined (Q_OS_SYMBIAN)
    symbianFilePos = 0;
#if !defined(QT_SYMBIAN_USE_NATIVE_FILEMAP)
    fileHandleForMaps = -1;
#endif
#endif
    lastIOCommand = IOFlushCommand;
    lastFlushFailed = false;
    closeFileHandle = false;
#ifdef Q_OS_WIN
    fileAttrib = INVALID_FILE_ATTRIBUTES;
    fileHandle = INVALID_HANDLE_VALUE;
    mapHandle = NULL;
#ifndef Q_OS_WINCE
    cachedFd = -1;
#endif
#endif
}

QFSFileEngine::QFSFileEngine(const QString &file)
    : QAbstractFileEngine(*new QFSFileEnginePrivate)
{
    Q_D(QFSFileEngine);
    d->fileEntry = QFileSystemEntry(file);
}

QFSFileEngine::QFSFileEngine() : QAbstractFileEngine(*new QFSFileEnginePrivate)
{
}

QFSFileEngine::QFSFileEngine(QFSFileEnginePrivate &dd)
    : QAbstractFileEngine(dd)
{
}

QFSFileEngine::~QFSFileEngine()
{
    Q_D(QFSFileEngine);
    if (d->closeFileHandle) {
        if (d->fh) {
            int ret;
            do {
                ret = fclose(d->fh);
            } while (ret == EOF && errno == EINTR);
        } else if (d->fd != -1) {
            int ret;
            do {
                ret = QT_CLOSE(d->fd);
            } while (ret == -1 && errno == EINTR);
        }
    }
    QList<uchar*> keys = d->maps.keys();
    for (int i = 0; i < keys.count(); ++i)
        unmap(keys.at(i));
}

void QFSFileEngine::setFileName(const QString &file)
{
    Q_D(QFSFileEngine);
    d->init();
    d->fileEntry = QFileSystemEntry(file);
}

bool QFSFileEngine::open(QIODevice::OpenMode openMode)
{
    Q_D(QFSFileEngine);
    if (d->fileEntry.isEmpty()) {
        qWarning("QFSFileEngine::open: No file name specified");
        setError(QFile::OpenError, QLatin1String("No file name specified"));
        return false;
    }

    // Append implies WriteOnly.
    if (openMode & QFile::Append)
        openMode |= QFile::WriteOnly;

    // WriteOnly implies Truncate if neither ReadOnly nor Append are sent.
    if ((openMode & QFile::WriteOnly) && !(openMode & (QFile::ReadOnly | QFile::Append)))
        openMode |= QFile::Truncate;

    d->openMode = openMode;
    d->lastFlushFailed = false;
    d->tried_stat = 0;
    d->fh = 0;
    d->fd = -1;

    return d->nativeOpen(openMode);
}

bool QFSFileEngine::open(QIODevice::OpenMode openMode, FILE *fh)
{
    return open(openMode, fh, QFile::DontCloseHandle);
}

bool QFSFileEngine::open(QIODevice::OpenMode openMode, FILE *fh, QFile::FileHandleFlags handleFlags)
{
    Q_D(QFSFileEngine);

    // Append implies WriteOnly.
    if (openMode & QFile::Append)
        openMode |= QFile::WriteOnly;

    // WriteOnly implies Truncate if neither ReadOnly nor Append are sent.
    if ((openMode & QFile::WriteOnly) && !(openMode & (QFile::ReadOnly | QFile::Append)))
        openMode |= QFile::Truncate;

    d->openMode = openMode;
    d->lastFlushFailed = false;
    d->closeFileHandle = (handleFlags & QFile::AutoCloseHandle);
    d->fileEntry.clear();
    d->tried_stat = 0;
    d->fd = -1;

    return d->openFh(openMode, fh);
}

bool QFSFileEnginePrivate::openFh(QIODevice::OpenMode openMode, FILE *fh)
{
    Q_Q(QFSFileEngine);
    this->fh = fh;
    fd = -1;

    // Seek to the end when in Append mode.
    if (openMode & QIODevice::Append) {
        int ret;
        do {
            ret = QT_FSEEK(fh, 0, SEEK_END);
        } while (ret != 0 && errno == EINTR);

        if (ret != 0) {
            q->setError(errno == EMFILE ? QFile::ResourceError : QFile::OpenError,
                        qt_error_string(int(errno)));

            this->openMode = QIODevice::NotOpen;
            this->fh = 0;

            return false;
        }
    }

    return true;
}

bool QFSFileEngine::open(QIODevice::OpenMode openMode, int fd)
{
    return open(openMode, fd, QFile::DontCloseHandle);
}

bool QFSFileEngine::open(QIODevice::OpenMode openMode, int fd, QFile::FileHandleFlags handleFlags)
{
    Q_D(QFSFileEngine);

    // Append implies WriteOnly.
    if (openMode & QFile::Append)
        openMode |= QFile::WriteOnly;

    // WriteOnly implies Truncate if neither ReadOnly nor Append are sent.
    if ((openMode & QFile::WriteOnly) && !(openMode & (QFile::ReadOnly | QFile::Append)))
        openMode |= QFile::Truncate;

    d->openMode = openMode;
    d->lastFlushFailed = false;
    d->closeFileHandle = (handleFlags & QFile::AutoCloseHandle);
    d->fileEntry.clear();
    d->fh = 0;
    d->fd = -1;
    d->tried_stat = 0;

    return d->openFd(openMode, fd);
}


bool QFSFileEnginePrivate::openFd(QIODevice::OpenMode openMode, int fd)
{
    Q_Q(QFSFileEngine);
    this->fd = fd;
    fh = 0;

    // Seek to the end when in Append mode.
    if (openMode & QFile::Append) {
        int ret;
        do {
            ret = QT_LSEEK(fd, 0, SEEK_END);
        } while (ret == -1 && errno == EINTR);

        if (ret == -1) {
            q->setError(errno == EMFILE ? QFile::ResourceError : QFile::OpenError,
                        qt_error_string(int(errno)));

            this->openMode = QIODevice::NotOpen;
            this->fd = -1;

            return false;
        }
    }

    return true;
}

bool QFSFileEngine::close()
{
    Q_D(QFSFileEngine);
    d->openMode = QIODevice::NotOpen;
    return d->nativeClose();
}

bool QFSFileEnginePrivate::closeFdFh()
{
    Q_Q(QFSFileEngine);
    if (fd == -1 && !fh
#ifdef Q_OS_SYMBIAN
        && !symbianFile.SubSessionHandle()
#ifndef QT_SYMBIAN_USE_NATIVE_FILEMAP
        && fileHandleForMaps == -1
#endif
#endif
        )
        return false;

    // Flush the file if it's buffered, and if the last flush didn't fail.
    bool flushed = !fh || (!lastFlushFailed && q->flush());
    bool closed = true;
    tried_stat = 0;

#if defined(Q_OS_SYMBIAN) && !defined(QT_SYMBIAN_USE_NATIVE_FILEMAP)
    // Map handle is always owned by us so always close it
    if (fileHandleForMaps >= 0) {
        QT_CLOSE(fileHandleForMaps);
        fileHandleForMaps = -1;
    }
#endif

    // Close the file if we created the handle.
    if (closeFileHandle) {
        int ret;
        do {
#ifdef Q_OS_SYMBIAN
            if (symbianFile.SubSessionHandle()) {
                symbianFile.Close();
                ret = 0;
            } else
#endif
            if (fh) {
                // Close buffered file.
                ret = fclose(fh) != 0 ? -1 : 0;
            } else {
                // Close unbuffered file.
                ret = QT_CLOSE(fd);
            }
        } while (ret == -1 && errno == EINTR);

        // We must reset these guys regardless; calling close again after a
        // failed close causes crashes on some systems.
        fh = 0;
        fd = -1;
        closed = (ret == 0);
    }

    // Report errors.
    if (!flushed || !closed) {
        if (flushed) {
            // If not flushed, we want the flush error to fall through.
            q->setError(QFile::UnspecifiedError, qt_error_string(errno));
        }
        return false;
    }

    return true;
}

bool QFSFileEngine::flush()
{
    Q_D(QFSFileEngine);
    if ((d->openMode & QIODevice::WriteOnly) == 0) {
        // Nothing in the write buffers, so flush succeeds in doing
        // nothing.
        return true;
    }
    return d->nativeFlush();
}

bool QFSFileEnginePrivate::flushFh()
{
    Q_Q(QFSFileEngine);

    // Never try to flush again if the last flush failed. Otherwise you can
    // get crashes on some systems (AIX).
    if (lastFlushFailed)
        return false;

    int ret = fflush(fh);

    lastFlushFailed = (ret != 0);
    lastIOCommand = QFSFileEnginePrivate::IOFlushCommand;

    if (ret != 0) {
        q->setError(errno == ENOSPC ? QFile::ResourceError : QFile::WriteError,
                    qt_error_string(errno));
        return false;
    }
    return true;
}

qint64 QFSFileEngine::size() const
{
    Q_D(const QFSFileEngine);
    return d->nativeSize();
}

#ifndef Q_OS_WIN

qint64 QFSFileEnginePrivate::sizeFdFh() const
{
    Q_Q(const QFSFileEngine);
    const_cast<QFSFileEngine *>(q)->flush();

    tried_stat = 0;
    metaData.clearFlags(QFileSystemMetaData::SizeAttribute);
    if (!doStat(QFileSystemMetaData::SizeAttribute))
        return 0;
    return metaData.size();
}
#endif

qint64 QFSFileEngine::pos() const
{
    Q_D(const QFSFileEngine);
    return d->nativePos();
}

qint64 QFSFileEnginePrivate::posFdFh() const
{
    if (fh)
        return qint64(QT_FTELL(fh));
    return QT_LSEEK(fd, 0, SEEK_CUR);
}

bool QFSFileEngine::seek(qint64 pos)
{
    Q_D(QFSFileEngine);
    return d->nativeSeek(pos);
}

bool QFSFileEnginePrivate::seekFdFh(qint64 pos)
{
    Q_Q(QFSFileEngine);

    // On Windows' stdlib implementation, the results of calling fread and
    // fwrite are undefined if not called either in sequence, or if preceded
    // with a call to fflush().
    if (lastIOCommand != QFSFileEnginePrivate::IOFlushCommand && !q->flush())
        return false;

    if (pos < 0 || pos != qint64(QT_OFF_T(pos)))
        return false;

    if (fh) {
        // Buffered stdlib mode.
        int ret;
        do {
            ret = QT_FSEEK(fh, QT_OFF_T(pos), SEEK_SET);
        } while (ret != 0 && errno == EINTR);

        if (ret != 0) {
            q->setError(QFile::ReadError, qt_error_string(int(errno)));
            return false;
        }
    } else {
        // Unbuffered stdio mode.
        if (QT_LSEEK(fd, QT_OFF_T(pos), SEEK_SET) == -1) {
            qWarning() << "QFile::at: Cannot set file position" << pos;
            q->setError(QFile::PositionError, qt_error_string(errno));
            return false;
        }
    }
    return true;
}

int QFSFileEngine::handle() const
{
    Q_D(const QFSFileEngine);
    return d->nativeHandle();
}

qint64 QFSFileEngine::read(char *data, qint64 maxlen)
{
    Q_D(QFSFileEngine);

    // On Windows' stdlib implementation, the results of calling fread and
    // fwrite are undefined if not called either in sequence, or if preceded
    // with a call to fflush().
    if (d->lastIOCommand != QFSFileEnginePrivate::IOReadCommand) {
        flush();
        d->lastIOCommand = QFSFileEnginePrivate::IOReadCommand;
    }

    return d->nativeRead(data, maxlen);
}

qint64 QFSFileEnginePrivate::readFdFh(char *data, qint64 len)
{
    Q_Q(QFSFileEngine);

    if (len < 0 || len != qint64(size_t(len))) {
        q->setError(QFile::ReadError, qt_error_string(EINVAL));
        return -1;
    }

    qint64 readBytes = 0;
    bool eof = false;

    if (fh) {
        // Buffered stdlib mode.

        size_t result;
        bool retry = true;
        do {
            result = fread(data + readBytes, 1, size_t(len - readBytes), fh);
            eof = feof(fh);
            if (retry && eof && result == 0) {
                // On Mac OS, this is needed, e.g., if a file was written to
                // through another stream since our last read. See test
                // tst_QFile::appendAndRead
                QT_FSEEK(fh, QT_FTELL(fh), SEEK_SET); // re-sync stream.
                retry = false;
                continue;
            }
            readBytes += result;
        } while (!eof && (result == 0 ? errno == EINTR : readBytes < len));

    } else if (fd != -1) {
        // Unbuffered stdio mode.

#ifdef Q_OS_WIN
        int result;
#else
        ssize_t result;
#endif
        do {
            result = QT_READ(fd, data + readBytes, size_t(len - readBytes));
        } while ((result == -1 && errno == EINTR)
                || (result > 0 && (readBytes += result) < len));

        eof = !(result == -1);
    }

    if (!eof && readBytes == 0) {
        readBytes = -1;
        q->setError(QFile::ReadError, qt_error_string(errno));
    }

    return readBytes;
}

qint64 QFSFileEngine::readLine(char *data, qint64 maxlen)
{
    Q_D(QFSFileEngine);

    // On Windows' stdlib implementation, the results of calling fread and
    // fwrite are undefined if not called either in sequence, or if preceded
    // with a call to fflush().
    if (d->lastIOCommand != QFSFileEnginePrivate::IOReadCommand) {
        flush();
        d->lastIOCommand = QFSFileEnginePrivate::IOReadCommand;
    }

    return d->nativeReadLine(data, maxlen);
}

qint64 QFSFileEnginePrivate::readLineFdFh(char *data, qint64 maxlen)
{
    Q_Q(QFSFileEngine);
    if (!fh)
        return q->QAbstractFileEngine::readLine(data, maxlen);

    QT_OFF_T oldPos = 0;
#ifdef Q_OS_WIN
    bool seq = q->isSequential();
    if (!seq)
#endif
        oldPos = QT_FTELL(fh);

    // QIODevice::readLine() passes maxlen - 1 to QFile::readLineData()
    // because it has made space for the '\0' at the end of data.  But fgets
    // does the same, so we'd get two '\0' at the end - passing maxlen + 1
    // solves this.
    if (!fgets(data, int(maxlen + 1), fh)) {
        if (!feof(fh))
            q->setError(QFile::ReadError, qt_error_string(int(errno)));
        return -1;              // error
    }

#ifdef Q_OS_WIN
    if (seq)
        return qstrlen(data);
#endif

    qint64 lineLength = QT_FTELL(fh) - oldPos;
    return lineLength > 0 ? lineLength : qstrlen(data);
}

qint64 QFSFileEngine::write(const char *data, qint64 len)
{
    Q_D(QFSFileEngine);

    // On Windows' stdlib implementation, the results of calling fread and
    // fwrite are undefined if not called either in sequence, or if preceded
    // with a call to fflush().
    if (d->lastIOCommand != QFSFileEnginePrivate::IOWriteCommand) {
        flush();
        d->lastIOCommand = QFSFileEnginePrivate::IOWriteCommand;
    }

    return d->nativeWrite(data, len);
}

qint64 QFSFileEnginePrivate::writeFdFh(const char *data, qint64 len)
{
    Q_Q(QFSFileEngine);

    if (len < 0 || len != qint64(size_t(len))) {
        q->setError(QFile::WriteError, qt_error_string(EINVAL));
        return -1;
    }

    qint64 writtenBytes = 0;

    if (fh) {
        // Buffered stdlib mode.

        size_t result;
        do {
            result = fwrite(data + writtenBytes, 1, size_t(len - writtenBytes), fh);
            writtenBytes += result;
        } while (result == 0 ? errno == EINTR : writtenBytes < len);

    } else if (fd != -1) {
        // Unbuffered stdio mode.

#ifdef Q_OS_WIN
        int result;
#else
        ssize_t result;
#endif
        do {
            result = QT_WRITE(fd, data + writtenBytes, size_t(len - writtenBytes));
        } while ((result == -1 && errno == EINTR)
                || (result > 0 && (writtenBytes += result) < len));
    }

    if (len &&  writtenBytes == 0) {
        writtenBytes = -1;
        q->setError(errno == ENOSPC ? QFile::ResourceError : QFile::WriteError, qt_error_string(errno));
    }

    return writtenBytes;
}

#ifndef QT_NO_FILESYSTEMITERATOR

QAbstractFileEngine::Iterator *QFSFileEngine::beginEntryList(QDir::Filters filters, const QStringList &filterNames)
{
    return new QFSFileEngineIterator(filters, filterNames);
}

QAbstractFileEngine::Iterator *QFSFileEngine::endEntryList()
{
    return 0;
}
#endif

QStringList QFSFileEngine::entryList(QDir::Filters filters, const QStringList &filterNames) const
{
    return QAbstractFileEngine::entryList(filters, filterNames);
}

bool QFSFileEngine::isSequential() const
{
    Q_D(const QFSFileEngine);
    if (d->is_sequential == 0)
        d->is_sequential = d->nativeIsSequential() ? 1 : 2;
    return d->is_sequential == 1;
}

#ifdef Q_OS_UNIX
bool QFSFileEnginePrivate::isSequentialFdFh() const
{
    if (doStat(QFileSystemMetaData::SequentialType))
        return metaData.isSequential();
    return true;
}
#endif

bool QFSFileEngine::extension(Extension extension, const ExtensionOption *option, ExtensionReturn *output)
{
    Q_D(QFSFileEngine);
    if (extension == AtEndExtension && d->fh && isSequential())
        return feof(d->fh);

    if (extension == MapExtension) {
        const MapExtensionOption *options = (MapExtensionOption*)(option);
        MapExtensionReturn *returnValue = static_cast<MapExtensionReturn*>(output);
        returnValue->address = d->map(options->offset, options->size, options->flags);
        return (returnValue->address != 0);
    }
    if (extension == UnMapExtension) {
        UnMapExtensionOption *options = (UnMapExtensionOption*)option;
        return d->unmap(options->address);
    }

    return false;
}

bool QFSFileEngine::supportsExtension(Extension extension) const
{
    Q_D(const QFSFileEngine);
    if (extension == AtEndExtension && d->fh && isSequential())
        return true;
    if (extension == FastReadLineExtension && d->fh)
        return true;
    if (extension == FastReadLineExtension && d->fd != -1 && isSequential())
        return true;
    if (extension == UnMapExtension || extension == MapExtension)
        return true;
    return false;
}

QT_END_NAMESPACE

#endif // QT_NO_FSFILEENGINE