qfsfileengine_unix.cpp

奇趣公司比较新的qt/emd版本

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#include "qplatformdefs.h"
#include "qabstractfileengine.h"
#include "private/qfsfileengine_p.h"
#ifndef QT_NO_REGEXP
# include "qregexp.h"
#endif
#include "qfile.h"
#include "qdir.h"
#include "qdatetime.h"
#include "qdebug.h"
#include "qvarlengtharray.h"

#include <stdlib.h>
#include <limits.h>
#include <errno.h>
#if !defined(QWS) && defined(Q_OS_MAC)
# include <private/qcore_mac_p.h>
#endif

/*!
    \internal

    Returns the stdlib open string corresponding to a QIODevice::OpenMode.
*/
static QByteArray openModeToFopenMode(QIODevice::OpenMode flags, const QString &fileName = QString())
{
    QByteArray mode;
    if ((flags & QIODevice::ReadOnly) && !(flags & QIODevice::Truncate)) {
        mode = "rb";
        if (flags & QIODevice::WriteOnly) {
            if (!fileName.isEmpty() &&QFile::exists(fileName))
                mode = "rb+";
            else
                mode = "wb+";
        }
    } else if (flags & QIODevice::WriteOnly) {
        mode = "wb";
        if (flags & QIODevice::ReadOnly)
            mode += "+";
    }
    if (flags & QIODevice::Append) {
        mode = "ab";
        if (flags & QIODevice::ReadOnly)
            mode += "+";
    }
    return mode;
}

/*!
    \internal

    Returns the stdio open flags corresponding to a QIODevice::OpenMode.
*/
static int openModeToOpenFlags(QIODevice::OpenMode mode)
{
    int oflags = QT_OPEN_RDONLY;
#ifdef QT_LARGEFILE_SUPPORT
    oflags |= QT_OPEN_LARGEFILE;
#endif

    if ((mode & QFile::ReadWrite) == QFile::ReadWrite) {
        oflags = QT_OPEN_RDWR | QT_OPEN_CREAT;
    } else if (mode & QFile::WriteOnly) {
        oflags = QT_OPEN_WRONLY | QT_OPEN_CREAT;
    }

    if (mode & QFile::Append) {
        oflags |= QT_OPEN_APPEND;
    } else if (mode & QFile::WriteOnly) {
        if ((mode & QFile::Truncate) || !(mode & QFile::ReadOnly))
            oflags |= QT_OPEN_TRUNC;
    }

    return oflags;
}

/*!
    \internal
*/
void QFSFileEnginePrivate::nativeInitFileName()
{
    nativeFilePath = QFile::encodeName(filePath);
}

/*!
    \internal
*/
bool QFSFileEnginePrivate::nativeOpen(QIODevice::OpenMode openMode)
{
    Q_Q(QFSFileEngine);

    if (openMode & QIODevice::Unbuffered) {
        int flags = openModeToOpenFlags(openMode);

        // Try to open the file in unbuffered mode.
        do {
            fd = QT_OPEN(nativeFilePath.constData(), flags, 0666);
        } while (fd == -1 && errno == EINTR);

        // On failure, return and report the error.
        if (fd == -1) {
            q->setError(errno == EMFILE ? QFile::ResourceError : QFile::OpenError,
                        qt_error_string(errno));
            return false;
        }

        // Seek to the end when in Append mode.
        if (flags & 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)));
                return false;
            }
        }

        fh = 0;
    } else {
        QByteArray fopenMode = openModeToFopenMode(openMode, filePath);

        // Try to open the file in buffered mode.
        do {
            fh = QT_FOPEN(nativeFilePath.constData(), fopenMode.constData());
        } while (!fh && errno == EINTR);

        // On failure, return and report the error.
        if (!fh) {
            q->setError(errno == EMFILE ? QFile::ResourceError : QFile::OpenError,
                        qt_error_string(int(errno)));
            return false;
        }

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

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

        fd = -1;
    }

    closeFileHandle = true;
    return true;
}

/*!
    \internal
*/
bool QFSFileEnginePrivate::nativeClose()
{
    return closeFdFh();
}

/*!
    \internal

*/
bool QFSFileEnginePrivate::nativeFlush()
{
    return fh ? flushFh() : fd != -1;
}

/*!
    \internal
*/
qint64 QFSFileEnginePrivate::nativeRead(char *data, qint64 len)
{
    Q_Q(QFSFileEngine);

    if (fh && nativeIsSequential()) {
        size_t readBytes = 0;
        int oldFlags = fcntl(QT_FILENO(fh), F_GETFL);
        for (int i = 0; i < 2; ++i) {
            // Unix: Make the underlying file descriptor non-blocking
            int v = 1;
            if ((oldFlags & O_NONBLOCK) == 0)
                fcntl(QT_FILENO(fh), F_SETFL, oldFlags | O_NONBLOCK, &v, sizeof(v));

            // Cross platform stdlib read
            size_t read = 0;
            do {
                read = fread(data + readBytes, 1, size_t(len - readBytes), fh);
            } while (read == 0 && !feof(fh) && errno == EINTR);
            if (read > 0) {
                readBytes += read;
                break;
            } else {
                if (readBytes)
                    break;
                readBytes = read;
            }

            // Unix: Restore the blocking state of the underlying socket
            if ((oldFlags & O_NONBLOCK) == 0) {
                int v = 1;
                fcntl(QT_FILENO(fh), F_SETFL, oldFlags, &v, sizeof(v));
                if (readBytes == 0) {
                    int readByte = 0;
                    do {
                        readByte = fgetc(fh);
                    } while (readByte == -1 && errno == EINTR);
                    if (readByte != -1) {
                        *data = uchar(readByte);
                        readBytes += 1;
                    } else {
                        break;
                    }
                }
            }
        }
        // Unix: Restore the blocking state of the underlying socket
        if ((oldFlags & O_NONBLOCK) == 0) {
            int v = 1;
            fcntl(QT_FILENO(fh), F_SETFL, oldFlags, &v, sizeof(v));
        }
        if (readBytes == 0) {
            q->setError(QFile::ReadError, qt_error_string(int(errno)));
            return -1;
        }
        return readBytes;
    }

    return readFdFh(data, len);
}

/*!
    \internal
*/
qint64 QFSFileEnginePrivate::nativeReadLine(char *data, qint64 maxlen)
{
    return readLineFdFh(data, maxlen);
}

/*!
    \internal
*/
qint64 QFSFileEnginePrivate::nativeWrite(const char *data, qint64 len)
{
    return writeFdFh(data, len);
}

/*!
    \internal
*/
qint64 QFSFileEnginePrivate::nativePos() const
{
    return posFdFh();
}

/*!
    \internal
*/
bool QFSFileEnginePrivate::nativeSeek(qint64 pos)
{
    return seekFdFh(pos);
}

/*!
    \internal
*/
int QFSFileEnginePrivate::nativeHandle() const
{
    return fh ? fileno(fh) : fd;
}

/*!
    \internal
*/
bool QFSFileEnginePrivate::nativeIsSequential() const
{
    return isSequentialFdFh();
}

bool QFSFileEngine::remove()
{
    Q_D(QFSFileEngine);
    return unlink(d->nativeFilePath.constData()) == 0;
}

bool QFSFileEngine::copy(const QString &)
{
    // ### Add copy code for Unix here
    return false;
}

bool QFSFileEngine::rename(const QString &newName)
{
    Q_D(QFSFileEngine);
    return ::rename(d->nativeFilePath.constData(), QFile::encodeName(newName).constData()) == 0;
}

bool QFSFileEngine::link(const QString &newName)
{
    Q_D(QFSFileEngine);
    return ::symlink(d->nativeFilePath.constData(), QFile::encodeName(newName).constData()) == 0;
}

qint64 QFSFileEnginePrivate::nativeSize() const
{
    return sizeFdFh();
}

bool QFSFileEngine::mkdir(const QString &name, bool createParentDirectories) const
{
    QString dirName = name;
    if (createParentDirectories) {
        dirName = QDir::cleanPath(dirName);
        for(int oldslash = -1, slash=0; slash != -1; oldslash = slash) {
            slash = dirName.indexOf(QDir::separator(), oldslash+1);
            if (slash == -1) {
                if (oldslash == dirName.length())
                    break;
                slash = dirName.length();
            }
            if (slash) {
                QByteArray chunk = QFile::encodeName(dirName.left(slash));
                QT_STATBUF st;
                if (QT_STAT(chunk, &st) != -1) {
                    if ((st.st_mode & S_IFMT) != S_IFDIR)
                        return false;
                } else if (::mkdir(chunk, 0777) != 0) {
                        return false;
                }
            }
        }
        return true;
    }
#if defined(Q_OS_DARWIN)  // Mac X doesn't support trailing /'s
    if (dirName[dirName.length() - 1] == QLatin1Char('/'))
        dirName = dirName.left(dirName.length() - 1);
#endif
    return (::mkdir(QFile::encodeName(dirName), 0777) == 0);
}

bool QFSFileEngine::rmdir(const QString &name, bool recurseParentDirectories) const
{
    QString dirName = name;
    if (recurseParentDirectories) {
        dirName = QDir::cleanPath(dirName);
        for(int oldslash = 0, slash=dirName.length(); slash > 0; oldslash = slash) {
            QByteArray chunk = QFile::encodeName(dirName.left(slash));
            QT_STATBUF st;
            if (QT_STAT(chunk, &st) != -1) {
                if ((st.st_mode & S_IFMT) != S_IFDIR)
                    return false;
                if (::rmdir(chunk) != 0)
                    return oldslash != 0;
            } else {
                return false;
            }
            slash = dirName.lastIndexOf(QDir::separator(), oldslash-1);
        }
        return true;
    }
    return ::rmdir(QFile::encodeName(dirName)) == 0;
}

bool QFSFileEngine::caseSensitive() const
{
    return true;
}

bool QFSFileEngine::setCurrentPath(const QString &path)
{
    int r;
    r = ::chdir(QFile::encodeName(path));
    return r >= 0;
}

QString QFSFileEngine::currentPath(const QString &)
{
    QString result;
    QT_STATBUF st;
    if (QT_STAT(".", &st) == 0) {
#if defined(__GLIBC__) && !defined(PATH_MAX)
        char *currentName = ::get_current_dir_name();
        if (currentName) {
            result = QFile::decodeName(QByteArray(currentName));
            ::free(currentName);
        }
#else
        char currentName[PATH_MAX+1];
        if (::getcwd(currentName, PATH_MAX))
            result = QFile::decodeName(QByteArray(currentName));
#endif
#if defined(QT_DEBUG)
        if (result.isNull())
            qWarning("QDir::currentPath: getcwd() failed");
#endif
    } else {
#if defined(QT_DEBUG)
        qWarning("QDir::currentPath: stat(\".\") failed");
#endif
    }
    return result;
}

QString QFSFileEngine::homePath()
{
    QString home = QFile::decodeName(qgetenv("HOME"));
    if (home.isNull())
        home = rootPath();
    return home;
}

QString QFSFileEngine::rootPath()
{
    return QString::fromLatin1("/");
}