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Diffstat (limited to 'src/corelib/io/qfile.cpp')
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diff --git a/src/corelib/io/qfile.cpp b/src/corelib/io/qfile.cpp new file mode 100644 index 0000000000..8926bf3cef --- /dev/null +++ b/src/corelib/io/qfile.cpp @@ -0,0 +1,1641 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qplatformdefs.h" +#include "qdebug.h" +#include "qfile.h" +#include "qfsfileengine.h" +#include "qtemporaryfile.h" +#include "qlist.h" +#include "qfileinfo.h" +#include "private/qiodevice_p.h" +#include "private/qfile_p.h" +#if defined(QT_BUILD_CORE_LIB) +# include "qcoreapplication.h" +#endif + +#if !defined(Q_OS_WINCE) +#include <errno.h> +#endif + +#ifdef QT_NO_QOBJECT +#define tr(X) QString::fromLatin1(X) +#endif + +QT_BEGIN_NAMESPACE + +static const int QFILE_WRITEBUFFER_SIZE = 16384; + +static QByteArray locale_encode(const QString &f) +{ +#ifndef Q_OS_DARWIN + return f.toLocal8Bit(); +#else + // Mac always expects UTF-8... and decomposed... + return f.normalized(QString::NormalizationForm_D).toUtf8(); +#endif +} + +static QString locale_decode(const QByteArray &f) +{ +#ifndef Q_OS_DARWIN + return QString::fromLocal8Bit(f); +#else + // Mac always gives us UTF-8 and decomposed, we want that composed... + return QString::fromUtf8(f).normalized(QString::NormalizationForm_C); +#endif +} + +//************* QFilePrivate +QFile::EncoderFn QFilePrivate::encoder = locale_encode; +QFile::DecoderFn QFilePrivate::decoder = locale_decode; + +QFilePrivate::QFilePrivate() + : fileEngine(0), lastWasWrite(false), + writeBuffer(QFILE_WRITEBUFFER_SIZE), error(QFile::NoError) +{ +} + +QFilePrivate::~QFilePrivate() +{ + delete fileEngine; + fileEngine = 0; +} + +bool +QFilePrivate::openExternalFile(int flags, int fd) +{ +#ifdef QT_NO_FSFILEENGINE + Q_UNUSED(flags); + Q_UNUSED(fd); + return false; +#else + delete fileEngine; + QFSFileEngine *fe = new QFSFileEngine; + fe->setFileName(fileName); + fileEngine = fe; + return fe->open(QIODevice::OpenMode(flags), fd); +#endif +} + +bool +QFilePrivate::openExternalFile(int flags, FILE *fh) +{ +#ifdef QT_NO_FSFILEENGINE + Q_UNUSED(flags); + Q_UNUSED(fh); + return false; +#else + delete fileEngine; + QFSFileEngine *fe = new QFSFileEngine; + fe->setFileName(fileName); + fileEngine = fe; + return fe->open(QIODevice::OpenMode(flags), fh); +#endif +} + +inline bool QFilePrivate::ensureFlushed() const +{ + // This function ensures that the write buffer has been flushed (const + // because certain const functions need to call it. + if (lastWasWrite) { + const_cast<QFilePrivate *>(this)->lastWasWrite = false; + if (!const_cast<QFile *>(q_func())->flush()) + return false; + } + return true; +} + +void +QFilePrivate::setError(QFile::FileError err) +{ + error = err; + errorString.clear(); +} + +void +QFilePrivate::setError(QFile::FileError err, const QString &errStr) +{ + Q_Q(QFile); + error = err; + q->setErrorString(errStr); +} + +void +QFilePrivate::setError(QFile::FileError err, int errNum) +{ + Q_Q(QFile); + error = err; + q->setErrorString(qt_error_string(errNum)); +} + +//************* QFile + +/*! + \class QFile + \brief The QFile class provides an interface for reading from and writing to files. + + \ingroup io + \mainclass + \reentrant + + QFile is an I/O device for reading and writing text and binary + files and \l{The Qt Resource System}{resources}. A QFile may be + used by itself or, more conveniently, with a QTextStream or + QDataStream. + + The file name is usually passed in the constructor, but it can be + set at any time using setFileName(). QFile expects the file + separator to be '/' regardless of operating system. The use of + other separators (e.g., '\\') is not supported. + + You can check for a file's existence using exists(), and remove a + file using remove(). (More advanced file system related operations + are provided by QFileInfo and QDir.) + + The file is opened with open(), closed with close(), and flushed + with flush(). Data is usually read and written using QDataStream + or QTextStream, but you can also call the QIODevice-inherited + functions read(), readLine(), readAll(), write(). QFile also + inherits getChar(), putChar(), and ungetChar(), which work one + character at a time. + + The size of the file is returned by size(). You can get the + current file position using pos(), or move to a new file position + using seek(). If you've reached the end of the file, atEnd() + returns true. + + \section1 Reading Files Directly + + The following example reads a text file line by line: + + \snippet doc/src/snippets/file/file.cpp 0 + + The QIODevice::Text flag passed to open() tells Qt to convert + Windows-style line terminators ("\\r\\n") into C++-style + terminators ("\\n"). By default, QFile assumes binary, i.e. it + doesn't perform any conversion on the bytes stored in the file. + + \section1 Using Streams to Read Files + + The next example uses QTextStream to read a text file + line by line: + + \snippet doc/src/snippets/file/file.cpp 1 + + QTextStream takes care of converting the 8-bit data stored on + disk into a 16-bit Unicode QString. By default, it assumes that + the user system's local 8-bit encoding is used (e.g., ISO 8859-1 + for most of Europe; see QTextCodec::codecForLocale() for + details). This can be changed using setCodec(). + + To write text, we can use operator<<(), which is overloaded to + take a QTextStream on the left and various data types (including + QString) on the right: + + \snippet doc/src/snippets/file/file.cpp 2 + + QDataStream is similar, in that you can use operator<<() to write + data and operator>>() to read it back. See the class + documentation for details. + + When you use QFile, QFileInfo, and QDir to access the file system + with Qt, you can use Unicode file names. On Unix, these file + names are converted to an 8-bit encoding. If you want to use + standard C++ APIs (\c <cstdio> or \c <iostream>) or + platform-specific APIs to access files instead of QFile, you can + use the encodeName() and decodeName() functions to convert + between Unicode file names and 8-bit file names. + + On Unix, there are some special system files (e.g. in \c /proc) for which + size() will always return 0, yet you may still be able to read more data + from such a file; the data is generated in direct response to you calling + read(). In this case, however, you cannot use atEnd() to determine if + there is more data to read (since atEnd() will return true for a file that + claims to have size 0). Instead, you should either call readAll(), or call + read() or readLine() repeatedly until no more data can be read. The next + example uses QTextStream to read \c /proc/modules line by line: + + \snippet doc/src/snippets/file/file.cpp 3 + + \section1 Signals + + Unlike other QIODevice implementations, such as QTcpSocket, QFile does not + emit the aboutToClose(), bytesWritten(), or readyRead() signals. This + implementation detail means that QFile is not suitable for reading and + writing certain types of files, such as device files on Unix platforms. + + \section1 Platform Specific Issues + + File permissions are handled differently on Linux/Mac OS X and + Windows. In a non \l{QIODevice::isWritable()}{writable} + directory on Linux, files cannot be created. This is not always + the case on Windows, where, for instance, the 'My Documents' + directory usually is not writable, but it is still possible to + create files in it. + + \sa QTextStream, QDataStream, QFileInfo, QDir, {The Qt Resource System} +*/ + +/*! + \enum QFile::FileError + + This enum describes the errors that may be returned by the error() + function. + + \value NoError No error occurred. + \value ReadError An error occurred when reading from the file. + \value WriteError An error occurred when writing to the file. + \value FatalError A fatal error occurred. + \value ResourceError + \value OpenError The file could not be opened. + \value AbortError The operation was aborted. + \value TimeOutError A timeout occurred. + \value UnspecifiedError An unspecified error occurred. + \value RemoveError The file could not be removed. + \value RenameError The file could not be renamed. + \value PositionError The position in the file could not be changed. + \value ResizeError The file could not be resized. + \value PermissionsError The file could not be accessed. + \value CopyError The file could not be copied. + + \omitvalue ConnectError +*/ + +/*! + \enum QFile::Permission + + This enum is used by the permission() function to report the + permissions and ownership of a file. The values may be OR-ed + together to test multiple permissions and ownership values. + + \value ReadOwner The file is readable by the owner of the file. + \value WriteOwner The file is writable by the owner of the file. + \value ExeOwner The file is executable by the owner of the file. + \value ReadUser The file is readable by the user. + \value WriteUser The file is writable by the user. + \value ExeUser The file is executable by the user. + \value ReadGroup The file is readable by the group. + \value WriteGroup The file is writable by the group. + \value ExeGroup The file is executable by the group. + \value ReadOther The file is readable by anyone. + \value WriteOther The file is writable by anyone. + \value ExeOther The file is executable by anyone. + + \warning Because of differences in the platforms supported by Qt, + the semantics of ReadUser, WriteUser and ExeUser are + platform-dependent: On Unix, the rights of the owner of the file + are returned and on Windows the rights of the current user are + returned. This behavior might change in a future Qt version. + + Note that Qt does not by default check for permissions on NTFS + file systems, as this may decrease the performance of file + handling considerably. It is possible to force permission checking + on NTFS by including the following code in your source: + + \snippet doc/src/snippets/ntfsp.cpp 0 + + Permission checking is then turned on and off by incrementing and + decrementing \c qt_ntfs_permission_lookup by 1. + + \snippet doc/src/snippets/ntfsp.cpp 1 +*/ + +#ifdef QT3_SUPPORT +/*! + \typedef QFile::PermissionSpec + + Use QFile::Permission instead. +*/ +#endif + +#ifdef QT_NO_QOBJECT +QFile::QFile() + : QIODevice(*new QFilePrivate) +{ +} +QFile::QFile(const QString &name) + : QIODevice(*new QFilePrivate) +{ + d_func()->fileName = name; +} +QFile::QFile(QFilePrivate &dd) + : QIODevice(dd) +{ +} +#else +/*! + \internal +*/ +QFile::QFile() + : QIODevice(*new QFilePrivate, 0) +{ +} +/*! + Constructs a new file object with the given \a parent. +*/ +QFile::QFile(QObject *parent) + : QIODevice(*new QFilePrivate, parent) +{ +} +/*! + Constructs a new file object to represent the file with the given \a name. +*/ +QFile::QFile(const QString &name) + : QIODevice(*new QFilePrivate, 0) +{ + Q_D(QFile); + d->fileName = name; +} +/*! + Constructs a new file object with the given \a parent to represent the + file with the specified \a name. +*/ +QFile::QFile(const QString &name, QObject *parent) + : QIODevice(*new QFilePrivate, parent) +{ + Q_D(QFile); + d->fileName = name; +} +/*! + \internal +*/ +QFile::QFile(QFilePrivate &dd, QObject *parent) + : QIODevice(dd, parent) +{ +} +#endif + +/*! + Destroys the file object, closing it if necessary. +*/ +QFile::~QFile() +{ + close(); +#ifdef QT_NO_QOBJECT + delete d_ptr; +#endif +} + +/*! + Returns the name set by setFileName() or to the QFile + constructors. + + \sa setFileName(), QFileInfo::fileName() +*/ +QString QFile::fileName() const +{ + return fileEngine()->fileName(QAbstractFileEngine::DefaultName); +} + +/*! + Sets the \a name of the file. The name can have no path, a + relative path, or an absolute path. + + Do not call this function if the file has already been opened. + + If the file name has no path or a relative path, the path used + will be the application's current directory path + \e{at the time of the open()} call. + + Example: + \snippet doc/src/snippets/code/src_corelib_io_qfile.cpp 0 + + Note that the directory separator "/" works for all operating + systems supported by Qt. + + \sa fileName(), QFileInfo, QDir +*/ +void +QFile::setFileName(const QString &name) +{ + Q_D(QFile); + if (isOpen()) { + qWarning("QFile::setFileName: File (%s) is already opened", + qPrintable(fileName())); + close(); + } + if(d->fileEngine) { //get a new file engine later + delete d->fileEngine; + d->fileEngine = 0; + } + d->fileName = name; +} + +/*! + \fn QString QFile::decodeName(const char *localFileName) + + \overload + + Returns the Unicode version of the given \a localFileName. See + encodeName() for details. +*/ + +/*! + By default, this function converts \a fileName to the local 8-bit + encoding determined by the user's locale. This is sufficient for + file names that the user chooses. File names hard-coded into the + application should only use 7-bit ASCII filename characters. + + \sa decodeName() setEncodingFunction() +*/ + +QByteArray +QFile::encodeName(const QString &fileName) +{ + return (*QFilePrivate::encoder)(fileName); +} + +/*! + \typedef QFile::EncoderFn + + This is a typedef for a pointer to a function with the following + signature: + + \snippet doc/src/snippets/code/src_corelib_io_qfile.cpp 1 + + \sa setEncodingFunction(), encodeName() +*/ + +/*! + This does the reverse of QFile::encodeName() using \a localFileName. + + \sa setDecodingFunction(), encodeName() +*/ + +QString +QFile::decodeName(const QByteArray &localFileName) +{ + return (*QFilePrivate::decoder)(localFileName); +} + +/*! + \fn void QFile::setEncodingFunction(EncoderFn function) + + \nonreentrant + + Sets the \a function for encoding Unicode file names. The + default encodes in the locale-specific 8-bit encoding. + + \sa encodeName(), setDecodingFunction() +*/ + +void +QFile::setEncodingFunction(EncoderFn f) +{ + if (!f) + f = locale_encode; + QFilePrivate::encoder = f; +} + +/*! + \typedef QFile::DecoderFn + + This is a typedef for a pointer to a function with the following + signature: + + \snippet doc/src/snippets/code/src_corelib_io_qfile.cpp 2 + + \sa setDecodingFunction() +*/ + +/*! + \fn void QFile::setDecodingFunction(DecoderFn function) + + \nonreentrant + + Sets the \a function for decoding 8-bit file names. The + default uses the locale-specific 8-bit encoding. + + \sa setEncodingFunction(), decodeName() +*/ + +void +QFile::setDecodingFunction(DecoderFn f) +{ + if (!f) + f = locale_decode; + QFilePrivate::decoder = f; +} + +/*! + \overload + + Returns true if the file specified by fileName() exists; otherwise + returns false. + + \sa fileName(), setFileName() +*/ + +bool +QFile::exists() const +{ + // 0x1000000 = QAbstractFileEngine::Refresh, forcing an update + return (fileEngine()->fileFlags(QAbstractFileEngine::FlagsMask + | QAbstractFileEngine::FileFlag(0x1000000)) & QAbstractFileEngine::ExistsFlag); +} + +/*! + Returns true if the file specified by \a fileName exists; otherwise + returns false. +*/ + +bool +QFile::exists(const QString &fileName) +{ + return QFileInfo(fileName).exists(); +} + +/*! + \fn QString QFile::symLinkTarget() const + \since 4.2 + \overload + + Returns the absolute path of the file or directory a symlink (or shortcut + on Windows) points to, or a an empty string if the object isn't a symbolic + link. + + This name may not represent an existing file; it is only a string. + QFile::exists() returns true if the symlink points to an existing file. + + \sa fileName() setFileName() +*/ + +/*! + \obsolete + + Use symLinkTarget() instead. +*/ +QString +QFile::readLink() const +{ + return fileEngine()->fileName(QAbstractFileEngine::LinkName); +} + +/*! + \fn static QString QFile::symLinkTarget(const QString &fileName) + \since 4.2 + + Returns the absolute path of the file or directory referred to by the + symlink (or shortcut on Windows) specified by \a fileName, or returns an + empty string if the \a fileName does not correspond to a symbolic link. + + This name may not represent an existing file; it is only a string. + QFile::exists() returns true if the symlink points to an existing file. +*/ + +/*! + \obsolete + + Use symLinkTarget() instead. +*/ +QString +QFile::readLink(const QString &fileName) +{ + return QFileInfo(fileName).readLink(); +} + +/*! + Removes the file specified by fileName(). Returns true if successful; + otherwise returns false. + + The file is closed before it is removed. + + \sa setFileName() +*/ + +bool +QFile::remove() +{ + Q_D(QFile); + if (d->fileName.isEmpty()) { + qWarning("QFile::remove: Empty or null file name"); + return false; + } + close(); + if(error() == QFile::NoError) { + if(fileEngine()->remove()) { + unsetError(); + return true; + } +#if defined(Q_OS_WIN) + d->setError(QFile::RemoveError, GetLastError()); +#else + d->setError(QFile::RemoveError, errno); +#endif + } + return false; +} + +/*! + \overload + + Removes the file specified by the \a fileName given. + + Returns true if successful; otherwise returns false. + + \sa remove() +*/ + +bool +QFile::remove(const QString &fileName) +{ + return QFile(fileName).remove(); +} + +/*! + Renames the file currently specified by fileName() to \a newName. + Returns true if successful; otherwise returns false. + + If a file with the name \a newName already exists, rename() returns false + (i.e., QFile will not overwrite it). + + The file is closed before it is renamed. + + \sa setFileName() +*/ + +bool +QFile::rename(const QString &newName) +{ + Q_D(QFile); + if (d->fileName.isEmpty()) { + qWarning("QFile::rename: Empty or null file name"); + return false; + } + if (QFile(newName).exists()) { + // ### Race condition. If a file is moved in after this, it /will/ be + // overwritten. On Unix, the proper solution is to use hardlinks: + // return ::link(old, new) && ::remove(old); + d->setError(QFile::RenameError, tr("Destination file exists")); + return false; + } + close(); + if(error() == QFile::NoError) { + if (fileEngine()->rename(newName)) { + unsetError(); + return true; + } + + QFile in(fileName()); + QFile out(newName); + if (in.open(QIODevice::ReadOnly)) { + if (out.open(QIODevice::WriteOnly | QIODevice::Truncate)) { + bool error = false; + char block[4096]; + qint64 read; + while ((read = in.read(block, sizeof(block))) > 0) { + if (read != out.write(block, read)) { + d->setError(QFile::RenameError, out.errorString()); + error = true; + break; + } + } + if (read == -1) { + d->setError(QFile::RenameError, in.errorString()); + return true; + } + if(!error) + in.remove(); + return !error; + } + } + d->setError(QFile::RenameError, out.isOpen() ? in.errorString() : out.errorString()); + } + return false; +} + +/*! + \overload + + Renames the file \a oldName to \a newName. Returns true if + successful; otherwise returns false. + + If a file with the name \a newName already exists, rename() returns false + (i.e., QFile will not overwrite it). + + \sa rename() +*/ + +bool +QFile::rename(const QString &oldName, const QString &newName) +{ + return QFile(oldName).rename(newName); +} + +/*! + + Creates a link named \a linkName that points to the file currently specified by + fileName(). What a link is depends on the underlying filesystem (be it a + shortcut on Windows or a symbolic link on Unix). Returns true if successful; + otherwise returns false. + + This function will not overwrite an already existing entity in the file system; + in this case, \c link() will return false and set \l{QFile::}{error()} to + return \l{QFile::}{RenameError}. + + \note To create a valid link on Windows, \a linkName must have a \c{.lnk} file extension. + + \note On Symbian, no link is created and false is returned if fileName() + currently specifies a directory. + + \sa setFileName() +*/ + +bool +QFile::link(const QString &linkName) +{ + Q_D(QFile); + if (d->fileName.isEmpty()) { + qWarning("QFile::link: Empty or null file name"); + return false; + } + QFileInfo fi(linkName); + if(fileEngine()->link(fi.absoluteFilePath())) { + unsetError(); + return true; + } + d->setError(QFile::RenameError, errno); + return false; +} + +/*! + \overload + + Creates a link named \a linkName that points to the file \a fileName. What a link is + depends on the underlying filesystem (be it a shortcut on Windows + or a symbolic link on Unix). Returns true if successful; otherwise + returns false. + + \sa link() +*/ + +bool +QFile::link(const QString &fileName, const QString &linkName) +{ + return QFile(fileName).link(linkName); +} + +/*! + Copies the file currently specified by fileName() to a file called + \a newName. Returns true if successful; otherwise returns false. + + Note that if a file with the name \a newName already exists, + copy() returns false (i.e. QFile will not overwrite it). + + The source file is closed before it is copied. + + \sa setFileName() +*/ + +bool +QFile::copy(const QString &newName) +{ + Q_D(QFile); + if (d->fileName.isEmpty()) { + qWarning("QFile::copy: Empty or null file name"); + return false; + } + if (QFile(newName).exists()) { + // ### Race condition. If a file is moved in after this, it /will/ be + // overwritten. On Unix, the proper solution is to use hardlinks: + // return ::link(old, new) && ::remove(old); See also rename(). + d->setError(QFile::CopyError, tr("Destination file exists")); + return false; + } + close(); + if(error() == QFile::NoError) { + if(fileEngine()->copy(newName)) { + unsetError(); + return true; + } else { + bool error = false; + if(!open(QFile::ReadOnly)) { + error = true; + d->setError(QFile::CopyError, tr("Cannot open %1 for input").arg(d->fileName)); + } else { + QString fileTemplate = QLatin1String("%1/qt_temp.XXXXXX"); +#ifdef QT_NO_TEMPORARYFILE + QFile out(fileTemplate.arg(QFileInfo(newName).path())); + if (!out.open(QIODevice::ReadWrite)) + error = true; +#else + QTemporaryFile out(fileTemplate.arg(QFileInfo(newName).path())); + if (!out.open()) { + out.setFileTemplate(fileTemplate.arg(QDir::tempPath())); + if (!out.open()) + error = true; + } +#endif + if (error) { + out.close(); + d->setError(QFile::CopyError, tr("Cannot open for output")); + } else { + char block[4096]; + qint64 totalRead = 0; + while(!atEnd()) { + qint64 in = read(block, sizeof(block)); + if (in <= 0) + break; + totalRead += in; + if(in != out.write(block, in)) { + d->setError(QFile::CopyError, tr("Failure to write block")); + error = true; + break; + } + } + + if (totalRead != size()) { + // Unable to read from the source. The error string is + // already set from read(). + error = true; + } + if (!error && !out.rename(newName)) { + error = true; + d->setError(QFile::CopyError, tr("Cannot create %1 for output").arg(newName)); + } +#ifndef QT_NO_TEMPORARYFILE + if (!error) + out.setAutoRemove(false); +#endif + } + } + if(!error) { + QFile::setPermissions(newName, permissions()); + unsetError(); + return true; + } + } + } + return false; +} + +/*! + \overload + + Copies the file \a fileName to \a newName. Returns true if successful; + otherwise returns false. + + If a file with the name \a newName already exists, copy() returns false + (i.e., QFile will not overwrite it). + + \sa rename() +*/ + +bool +QFile::copy(const QString &fileName, const QString &newName) +{ + return QFile(fileName).copy(newName); +} + +/*! + Returns true if the file can only be manipulated sequentially; + otherwise returns false. + + Most files support random-access, but some special files may not. + + \sa QIODevice::isSequential() +*/ +bool QFile::isSequential() const +{ + Q_D(const QFile); + return d->fileEngine && d->fileEngine->isSequential(); +} + +/*! + Opens the file using OpenMode \a mode, returning true if successful; + otherwise false. + + The \a mode must be QIODevice::ReadOnly, QIODevice::WriteOnly, or + QIODevice::ReadWrite. It may also have additional flags, such as + QIODevice::Text and QIODevice::Unbuffered. + + \note In \l{QIODevice::}{WriteOnly} or \l{QIODevice::}{ReadWrite} + mode, if the relevant file does not already exist, this function + will try to create a new file before opening it. + + \note Because of limitations in the native API, QFile ignores the + Unbuffered flag on Windows. + + \sa QIODevice::OpenMode, setFileName() +*/ +bool QFile::open(OpenMode mode) +{ + Q_D(QFile); + if (isOpen()) { + qWarning("QFile::open: File (%s) already open", qPrintable(fileName())); + return false; + } + if (mode & Append) + mode |= WriteOnly; + + unsetError(); + if ((mode & (ReadOnly | WriteOnly)) == 0) { + qWarning("QIODevice::open: File access not specified"); + return false; + } + if (fileEngine()->open(mode)) { + QIODevice::open(mode); + if (mode & Append) + seek(size()); + return true; + } + QFile::FileError err = fileEngine()->error(); + if(err == QFile::UnspecifiedError) + err = QFile::OpenError; + d->setError(err, fileEngine()->errorString()); + return false; +} + +/*! \fn QFile::open(OpenMode, FILE*) + + Use open(FILE *, OpenMode) instead. +*/ + +/*! + \overload + + Opens the existing file handle \a fh in the given \a mode. + Returns true if successful; otherwise returns false. + + Example: + \snippet doc/src/snippets/code/src_corelib_io_qfile.cpp 3 + + When a QFile is opened using this function, close() does not actually + close the file, but only flushes it. + + \bold{Warning:} + \list 1 + \o If \a fh is \c stdin, \c stdout, or \c stderr, you may not be able + to seek(). See QIODevice::isSequentialAccess() for more information. + \o Since this function opens the file without specifying the file name, + you cannot use this QFile with a QFileInfo. + \endlist + + \note For Windows CE you may not be able to call seek() and resize(). + Also, size() is set to \c 0. + + \sa close(), {qmake Variable Reference#CONFIG}{qmake Variable Reference} + + \bold{Note for the Windows Platform} + + \a fh must be opened in binary mode (i.e., the mode string must contain + 'b', as in "rb" or "wb") when accessing files and other random-access + devices. Qt will translate the end-of-line characters if you pass + QIODevice::Text to \a mode. Sequential devices, such as stdin and stdout, + are unaffected by this limitation. + + You need to enable support for console applications in order to use the + stdin, stdout and stderr streams at the console. To do this, add the + following declaration to your application's project file: + + \snippet doc/src/snippets/code/src_corelib_io_qfile.cpp 4 +*/ +bool QFile::open(FILE *fh, OpenMode mode) +{ + Q_D(QFile); + if (isOpen()) { + qWarning("QFile::open: File (%s) already open", qPrintable(fileName())); + return false; + } + if (mode & Append) + mode |= WriteOnly; + unsetError(); + if ((mode & (ReadOnly | WriteOnly)) == 0) { + qWarning("QFile::open: File access not specified"); + return false; + } + if(d->openExternalFile(mode, fh)) { + QIODevice::open(mode); + if (mode & Append) { + seek(size()); + } else { + long pos = ftell(fh); + if (pos != -1) + seek(pos); + } + return true; + } + return false; +} + +/*! \fn QFile::open(OpenMode, int) + + Use open(int, OpenMode) instead. +*/ + +/*! + \overload + + Opens the existing file descripter \a fd in the given \a mode. + Returns true if successful; otherwise returns false. + + When a QFile is opened using this function, close() does not + actually close the file. + + The QFile that is opened using this function is automatically set + to be in raw mode; this means that the file input/output functions + are slow. If you run into performance issues, you should try to + use one of the other open functions. + + \warning If \a fd is 0 (\c stdin), 1 (\c stdout), or 2 (\c + stderr), you may not be able to seek(). size() is set to \c + LLONG_MAX (in \c <climits>). + + \warning For Windows CE you may not be able to call seek(), setSize(), + fileTime(). size() is set to \c 0. + + \warning Since this function opens the file without specifying the file name, + you cannot use this QFile with a QFileInfo. + + \sa close() +*/ +bool QFile::open(int fd, OpenMode mode) +{ + Q_D(QFile); + if (isOpen()) { + qWarning("QFile::open: File (%s) already open", qPrintable(fileName())); + return false; + } + if (mode & Append) + mode |= WriteOnly; + unsetError(); + if ((mode & (ReadOnly | WriteOnly)) == 0) { + qWarning("QFile::open: File access not specified"); + return false; + } + if(d->openExternalFile(mode, fd)) { + QIODevice::open(mode); + if (mode & Append) + seek(size()); + return true; + } + return false; +} + +/*! + Returns the file handle of the file. + + This is a small positive integer, suitable for use with C library + functions such as fdopen() and fcntl(). On systems that use file + descriptors for sockets (i.e. Unix systems, but not Windows) the handle + can be used with QSocketNotifier as well. + + If the file is not open, or there is an error, handle() returns -1. + + This function is not supported on Windows CE. + + \sa QSocketNotifier +*/ + +int +QFile::handle() const +{ + if (!isOpen()) + return -1; + + if (QAbstractFileEngine *engine = fileEngine()) + return engine->handle(); + return -1; +} + +/*! + \enum QFile::MemoryMapFlags + \since 4.4 + + This enum describes special options that may be used by the map() + function. + + \value NoOptions No options. +*/ + +/*! + \since 4.4 + Maps \a size bytes of the file into memory starting at \a offset. A file + should be open for a map to succeed but the file does not need to stay + open after the memory has been mapped. When the QFile is destroyed + or a new file is opened with this object, any maps that have not been + unmapped will automatically be unmapped. + + Any mapping options can be passed through \a flags. + + Returns a pointer to the memory or 0 if there is an error. + + \note On Windows CE 5.0 the file will be closed before mapping occurs. + + \sa unmap(), QAbstractFileEngine::supportsExtension() + */ +uchar *QFile::map(qint64 offset, qint64 size, MemoryMapFlags flags) +{ + Q_D(QFile); + QAbstractFileEngine *engine = fileEngine(); + if (engine + && engine->supportsExtension(QAbstractFileEngine::MapExtension)) { + unsetError(); + uchar *address = engine->map(offset, size, flags); + if (address == 0) + d->setError(engine->error(), engine->errorString()); + return address; + } + return 0; +} + +/*! + \since 4.4 + Unmaps the memory \a address. + + Returns true if the unmap succeeds; false otherwise. + + \sa map(), QAbstractFileEngine::supportsExtension() + */ +bool QFile::unmap(uchar *address) +{ + Q_D(QFile); + QAbstractFileEngine *engine = fileEngine(); + if (engine + && engine->supportsExtension(QAbstractFileEngine::UnMapExtension)) { + unsetError(); + bool success = engine->unmap(address); + if (!success) + d->setError(engine->error(), engine->errorString()); + return success; + } + return false; +} + +/*! + \fn QString QFile::name() const + + Use fileName() instead. +*/ + +/*! + \fn void QFile::setName(const QString &name) + + Use setFileName() instead. +*/ + +/*! + Sets the file size (in bytes) \a sz. Returns true if the file if the + resize succeeds; false otherwise. If \a sz is larger than the file + currently is the new bytes will be set to 0, if \a sz is smaller the + file is simply truncated. + + \sa size(), setFileName() +*/ + +bool +QFile::resize(qint64 sz) +{ + Q_D(QFile); + if (!d->ensureFlushed()) + return false; + if (isOpen() && fileEngine()->pos() > sz) + seek(sz); + if(fileEngine()->setSize(sz)) { + unsetError(); + return true; + } + d->setError(QFile::ResizeError, errno); + return false; +} + +/*! + \overload + + Sets \a fileName to size (in bytes) \a sz. Returns true if the file if + the resize succeeds; false otherwise. If \a sz is larger than \a + fileName currently is the new bytes will be set to 0, if \a sz is + smaller the file is simply truncated. + + \sa resize() +*/ + +bool +QFile::resize(const QString &fileName, qint64 sz) +{ + return QFile(fileName).resize(sz); +} + +/*! + Returns the complete OR-ed together combination of + QFile::Permission for the file. + + \sa setPermissions(), setFileName() +*/ + +QFile::Permissions +QFile::permissions() const +{ + QAbstractFileEngine::FileFlags perms = fileEngine()->fileFlags(QAbstractFileEngine::PermsMask) & QAbstractFileEngine::PermsMask; + return QFile::Permissions((int)perms); //ewww +} + +/*! + \overload + + Returns the complete OR-ed together combination of + QFile::Permission for \a fileName. +*/ + +QFile::Permissions +QFile::permissions(const QString &fileName) +{ + return QFile(fileName).permissions(); +} + +/*! + Sets the permissions for the file to the \a permissions specified. + Returns true if successful, or false if the permissions cannot be + modified. + + \sa permissions(), setFileName() +*/ + +bool +QFile::setPermissions(Permissions permissions) +{ + Q_D(QFile); + if(fileEngine()->setPermissions(permissions)) { + unsetError(); + return true; + } + d->setError(QFile::PermissionsError, errno); + return false; +} + +/*! + \overload + + Sets the permissions for \a fileName file to \a permissions. +*/ + +bool +QFile::setPermissions(const QString &fileName, Permissions permissions) +{ + return QFile(fileName).setPermissions(permissions); +} + +static inline qint64 _qfile_writeData(QAbstractFileEngine *engine, QRingBuffer *buffer) +{ + qint64 ret = engine->write(buffer->readPointer(), buffer->size()); + if (ret > 0) + buffer->free(ret); + return ret; +} + +/*! + Flushes any buffered data to the file. Returns true if successful; + otherwise returns false. +*/ + +bool +QFile::flush() +{ + Q_D(QFile); + if (!d->writeBuffer.isEmpty()) { + qint64 size = d->writeBuffer.size(); + if (_qfile_writeData(d->fileEngine ? d->fileEngine : fileEngine(), + &d->writeBuffer) != size) { + QFile::FileError err = fileEngine()->error(); + if(err == QFile::UnspecifiedError) + err = QFile::WriteError; + d->setError(err, fileEngine()->errorString()); + return false; + } + } + + if (!fileEngine()->flush()) { + QFile::FileError err = fileEngine()->error(); + if(err == QFile::UnspecifiedError) + err = QFile::WriteError; + d->setError(err, fileEngine()->errorString()); + return false; + } + return true; +} + +/*! + Flushes the file and then closes it. + + \sa QIODevice::close() +*/ +void +QFile::close() +{ + Q_D(QFile); + if(!isOpen()) + return; + flush(); + QIODevice::close(); + + unsetError(); + if(!fileEngine()->close()) + d->setError(fileEngine()->error(), fileEngine()->errorString()); +} + +/*! + Returns the size of the file. + + For regular empty files on Unix (e.g. those in \c /proc), this function + returns 0; the contents of such a file are generated on demand in response + to you calling read(). +*/ + +qint64 QFile::size() const +{ + Q_D(const QFile); + if (!d->ensureFlushed()) + return 0; + return fileEngine()->size(); +} + +/*! + \reimp +*/ + +qint64 QFile::pos() const +{ + return QIODevice::pos(); +} + +/*! + Returns true if the end of the file has been reached; otherwise returns + false. + + For regular empty files on Unix (e.g. those in \c /proc), this function + returns true, since the file system reports that the size of such a file is + 0. Therefore, you should not depend on atEnd() when reading data from such a + file, but rather call read() until no more data can be read. +*/ + +bool QFile::atEnd() const +{ + Q_D(const QFile); + + if (!isOpen()) + return true; + + if (!d->ensureFlushed()) + return false; + + // If there's buffered data left, we're not at the end. + if (!d->buffer.isEmpty()) + return false; + + // If the file engine knows best, say what it says. + if (fileEngine()->supportsExtension(QAbstractFileEngine::AtEndExtension)) { + // Check if the file engine supports AtEndExtension, and if it does, + // check if the file engine claims to be at the end. + return fileEngine()->atEnd(); + } + + // Fall back to checking how much is available (will stat files). + return bytesAvailable() == 0; +} + +/*! + \reimp +*/ + +bool QFile::seek(qint64 off) +{ + Q_D(QFile); + if (!isOpen()) { + qWarning("QFile::seek: IODevice is not open"); + return false; + } + + if (!d->ensureFlushed()) + return false; + + if (!fileEngine()->seek(off) || !QIODevice::seek(off)) { + QFile::FileError err = fileEngine()->error(); + if(err == QFile::UnspecifiedError) + err = QFile::PositionError; + d->setError(err, fileEngine()->errorString()); + return false; + } + d->error = NoError; + return true; +} + +/*! + \reimp +*/ +qint64 QFile::readLineData(char *data, qint64 maxlen) +{ + Q_D(QFile); + if (!d->ensureFlushed()) + return -1; + + if (fileEngine()->supportsExtension(QAbstractFileEngine::FastReadLineExtension)) + return fileEngine()->readLine(data, maxlen); + + // Fall back to QIODevice's readLine implementation if the engine + // cannot do it faster. + return QIODevice::readLineData(data, maxlen); +} + +/*! + \reimp +*/ + +qint64 QFile::readData(char *data, qint64 len) +{ + Q_D(QFile); + d->error = NoError; + if (!d->ensureFlushed()) + return -1; + + qint64 ret = -1; + qint64 read = fileEngine()->read(data, len); + if (read != -1) + ret = read; + + if(ret < 0) { + QFile::FileError err = fileEngine()->error(); + if(err == QFile::UnspecifiedError) + err = QFile::ReadError; + d->setError(err, fileEngine()->errorString()); + } + return ret; +} + +/*! + \internal +*/ +bool QFilePrivate::putCharHelper(char c) +{ +#ifdef QT_NO_QOBJECT + return QIODevicePrivate::putCharHelper(c); +#else + + // Cutoff for code that doesn't only touch the buffer. + int writeBufferSize = writeBuffer.size(); + if ((openMode & QIODevice::Unbuffered) || writeBufferSize + 1 >= QFILE_WRITEBUFFER_SIZE +#ifdef Q_OS_WIN + || ((openMode & QIODevice::Text) && c == '\n' && writeBufferSize + 2 >= QFILE_WRITEBUFFER_SIZE) +#endif + ) { + return QIODevicePrivate::putCharHelper(c); + } + + if (!(openMode & QIODevice::WriteOnly)) { + if (openMode == QIODevice::NotOpen) + qWarning("QIODevice::putChar: Closed device"); + else + qWarning("QIODevice::putChar: ReadOnly device"); + return false; + } + + // Make sure the device is positioned correctly. + const bool sequential = isSequential(); + if (pos != devicePos && !sequential && !q_func()->seek(pos)) + return false; + + lastWasWrite = true; + + int len = 1; +#ifdef Q_OS_WIN + if ((openMode & QIODevice::Text) && c == '\n') { + ++len; + *writeBuffer.reserve(1) = '\r'; + } +#endif + + // Write to buffer. + *writeBuffer.reserve(1) = c; + + if (!sequential) { + pos += len; + devicePos += len; + if (!buffer.isEmpty()) + buffer.skip(len); + } + + return true; +#endif +} + +/*! + \reimp +*/ + +qint64 +QFile::writeData(const char *data, qint64 len) +{ + Q_D(QFile); + d->error = NoError; + d->lastWasWrite = true; + bool buffered = !(d->openMode & Unbuffered); + + // Flush buffered data if this read will overflow. + if (buffered && (d->writeBuffer.size() + len) > QFILE_WRITEBUFFER_SIZE) { + if (!flush()) + return -1; + } + + // Write directly to the engine if the block size is larger than + // the write buffer size. + if (!buffered || len > QFILE_WRITEBUFFER_SIZE) { + QAbstractFileEngine *fe = d->fileEngine ? d->fileEngine : fileEngine(); + qint64 ret = fe->write(data, len); + if(ret < 0) { + QFile::FileError err = fileEngine()->error(); + if(err == QFile::UnspecifiedError) + err = QFile::WriteError; + d->setError(err, fileEngine()->errorString()); + } + return ret; + } + + // Write to the buffer. + char *writePointer = d->writeBuffer.reserve(len); + if (len == 1) + *writePointer = *data; + else + ::memcpy(writePointer, data, len); + return len; +} + +/*! + \internal + Returns the QIOEngine for this QFile object. +*/ +QAbstractFileEngine *QFile::fileEngine() const +{ + Q_D(const QFile); + if(!d->fileEngine) + d->fileEngine = QAbstractFileEngine::create(d->fileName); + return d->fileEngine; +} + +/*! + Returns the file error status. + + The I/O device status returns an error code. For example, if open() + returns false, or a read/write operation returns -1, this function can + be called to find out the reason why the operation failed. + + \sa unsetError() +*/ + +QFile::FileError +QFile::error() const +{ + Q_D(const QFile); + return d->error; +} + +/*! + Sets the file's error to QFile::NoError. + + \sa error() +*/ +void +QFile::unsetError() +{ + Q_D(QFile); + d->setError(QFile::NoError); +} + +QT_END_NAMESPACE |