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diff --git a/qtools/qiodevice.cpp b/qtools/qiodevice.cpp new file mode 100644 index 0000000..b2a6751 --- /dev/null +++ b/qtools/qiodevice.cpp @@ -0,0 +1,636 @@ +/**************************************************************************** +** +** +** Implementation of QIODevice class +** +** Created : 940913 +** +** Copyright (C) 1992-2000 Trolltech AS. All rights reserved. +** +** This file is part of the tools module of the Qt GUI Toolkit. +** +** This file may be distributed under the terms of the Q Public License +** as defined by Trolltech AS of Norway and appearing in the file +** LICENSE.QPL included in the packaging of this file. +** +** This file may be distributed and/or modified under the terms of the +** GNU General Public License version 2 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. +** +** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition +** licenses may use this file in accordance with the Qt Commercial License +** Agreement provided with the Software. +** +** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE +** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. +** +** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for +** information about Qt Commercial License Agreements. +** See http://www.trolltech.com/qpl/ for QPL licensing information. +** See http://www.trolltech.com/gpl/ for GPL licensing information. +** +** Contact info@trolltech.com if any conditions of this licensing are +** not clear to you. +** +**********************************************************************/ + +#include "qiodevice.h" + +// NOT REVISED +/*! + \class QIODevice qiodevice.h + + \brief The QIODevice class is the base class of I/O devices. + + \ingroup io + + An I/O device represents a medium that one can read bytes from + and/or write bytes to. The QIODevice class is the abstract + superclass of all such devices; classes like QFile, QBuffer and + QSocket inherit QIODevice and implement virtual functions like + write() appropriately. + + While applications sometimes use QIODevice directly, mostly it is + better to go through QTextStream and QDataStream, which provide + stream operations on any QIODevice subclass. QTextStream provides + text-oriented stream functionality (for human-readable ASCII files, + for example), while QDataStream deals with binary data in a totally + platform-independent manner. + + The public member functions in QIODevice roughly fall into two + groups: The action functions and the state access functions. The + most important action functions are: <ul> + + <li> open() opens a device for reading and/or writing, depending on + the argument to open(). + + <li> close() closes the device and tidies up. + + <li> readBlock() reads a block of data from the device. + + <li> writeBlock() writes a block of data to the device. + + <li> readLine() reads a line (of text, usually) from the device. + + <li> flush() ensures that all buffered data are written to the real device. + + </ul>There are also some other, less used, action functions: <ul> + + <li> getch() reads a single character. + + <li> ungetch() forgets the last call to getch(), if possible. + + <li> putch() writes a single character. + + <li> size() returns the size of the device, if there is one. + + <li> at() returns the current read/write pointer, if there is one + for this device, or it moves the pointer. + + <li> atEnd() says whether there is more to read, if that is a + meaningful question for this device. + + <li> reset() moves the read/write pointer to the start of the + device, if that is possible for this device. + + </ul>The state access are all "get" functions. The QIODevice subclass + calls setState() to update the state, and simple access functions + tell the user of the device what the device's state is. Here are + the settings, and their associated access functions: <ul> + + <li> Access type. Some devices are direct access (it is possible to + read/write anywhere) while others are sequential. QIODevice + provides the access functions isDirectAccess(), isSequentialAccess() + and isCombinedAccess() to tell users what a given I/O device + supports. + + <li> Buffering. Some devices are accessed in raw mode while others + are buffered. Buffering usually provides greater efficiency, + particularly for small read/write operations. isBuffered() tells + the user whether a given device is buffered. (This can often be set + by the application in the call to open().) + + <li> Synchronicity. Synchronous devices work there and then, for + example files. When you read from a file, the file delivers its + data right away. Others, such as a socket connected to a HTTP + server, may not deliver the data until seconds after you ask to read + it. isSynchronous() and isAsynchronous() tells the user how this + device operates. + + <li> CR/LF translation. For simplicity, applications often like to + see just a single CR/LF style, and QIODevice subclasses can provide + that. isTranslated() returns TRUE if this object translates CR/LF + to just LF. (This can often be set by the application in the call + to open().) + + <li> Accessibility. Some files cannot be written, for example. + isReadable(), isWritable and isReadWrite() tells the application + whether it can read from and write to a given device. (This can + often be set by the application in the call to open().) + + <li> Finally, isOpen() returns TRUE if the device is open. This can + quite obviously be set using open() :) + + </ul> + + QIODevice provides numerous pure virtual functions you need to + implement when subclassing it. Here is a skeleton subclass with all + the members you are certain to need, and some it's likely that you + will need: + + \code + class YourDevice : public QIODevice + { + public: + YourDevice(); + ~YourDevice(); + + bool open( int mode ); + void close(); + void flush(); + + uint size() const; + int at() const; // not a pure virtual function + bool at( int ); // not a pure virtual function + bool atEnd() const; // not a pure virtual function + + int readBlock( char *data, uint maxlen ); + int writeBlock( const char *data, uint len ); + int readLine( char *data, uint maxlen ); + + int getch(); + int putch( int ); + int ungetch( int ); + }; + \endcode + + The three non-pure virtual functions can be ignored if your device + is sequential (e.g. an RS-232 port). + + \sa QDataStream, QTextStream +*/ + + +/*! + Constructs an I/O device. +*/ + +QIODevice::QIODevice() +{ + ioMode = 0; // initial mode + ioSt = IO_Ok; + ioIndex = 0; +} + +/*! + Destructs the I/O device. +*/ + +QIODevice::~QIODevice() +{ +} + + +/*! + \fn int QIODevice::flags() const + Returns the current I/O device flags setting. + + Flags consists of mode flags and state flags. + + \sa mode(), state() +*/ + +/*! + \fn int QIODevice::mode() const + Returns bits OR'ed together that specify the current operation mode. + + These are the flags that were given to the open() function. + + The flags are: \c IO_ReadOnly, \c IO_WriteOnly, \c IO_ReadWrite, + \c IO_Append, \c IO_Truncate and \c IO_Translate. +*/ + +/*! + \fn int QIODevice::state() const + Returns bits OR'ed together that specify the current state. + + The flags are: \c IO_Open. + + Subclasses may define more flags. +*/ + +/*! + \fn bool QIODevice::isDirectAccess() const + Returns TRUE if the I/O device is a direct access (not sequential) device, + otherwise FALSE. + \sa isSequentialAccess() +*/ + +/*! + \fn bool QIODevice::isSequentialAccess() const + Returns TRUE if the I/O device is a sequential access (not direct) device, + otherwise FALSE. Operations involving size() and at(int) are not valid + on sequential devices. + \sa isDirectAccess() +*/ + +/*! + \fn bool QIODevice::isCombinedAccess() const + Returns TRUE if the I/O device is a combined access (both direct and + sequential) device, otherwise FALSE. + + This access method is currently not in use. +*/ + +/*! + \fn bool QIODevice::isBuffered() const + Returns TRUE if the I/O device is a buffered (not raw) device, otherwise + FALSE. + \sa isRaw() +*/ + +/*! + \fn bool QIODevice::isRaw() const + Returns TRUE if the I/O device is a raw (not buffered) device, otherwise + FALSE. + \sa isBuffered() +*/ + +/*! + \fn bool QIODevice::isSynchronous() const + Returns TRUE if the I/O device is a synchronous device, otherwise + FALSE. + \sa isAsynchronous() +*/ + +/*! + \fn bool QIODevice::isAsynchronous() const + Returns TRUE if the I/O device is a asynchronous device, otherwise + FALSE. + + This mode is currently not in use. + + \sa isSynchronous() +*/ + +/*! + \fn bool QIODevice::isTranslated() const + Returns TRUE if the I/O device translates carriage-return and linefeed + characters. + + A QFile is translated if it is opened with the \c IO_Translate mode + flag. +*/ + +/*! + \fn bool QIODevice::isReadable() const + Returns TRUE if the I/O device was opened using \c IO_ReadOnly or + \c IO_ReadWrite mode. + \sa isWritable(), isReadWrite() +*/ + +/*! + \fn bool QIODevice::isWritable() const + Returns TRUE if the I/O device was opened using \c IO_WriteOnly or + \c IO_ReadWrite mode. + \sa isReadable(), isReadWrite() +*/ + +/*! + \fn bool QIODevice::isReadWrite() const + Returns TRUE if the I/O device was opened using \c IO_ReadWrite mode. + \sa isReadable(), isWritable() +*/ + +/*! + \fn bool QIODevice::isInactive() const + Returns TRUE if the I/O device state is 0, i.e. the device is not open. + \sa isOpen() +*/ + +/*! + \fn bool QIODevice::isOpen() const + Returns TRUE if the I/O device state has been opened, otherwise FALSE. + \sa isInactive() +*/ + + +/*! + \fn int QIODevice::status() const + Returns the I/O device status. + + The I/O device status returns an error code. If open() returns FALSE + or readBlock() or writeBlock() return -1, this function can be called to + get the reason why the operation did not succeed. + + The status codes are: + <ul> + <li>\c IO_Ok The operation was successful. + <li>\c IO_ReadError Could not read from the device. + <li>\c IO_WriteError Could not write to the device. + <li>\c IO_FatalError A fatal unrecoverable error occurred. + <li>\c IO_OpenError Could not open the device. + <li>\c IO_ConnectError Could not connect to the device. + <li>\c IO_AbortError The operation was unexpectedly aborted. + <li>\c IO_TimeOutError The operation timed out. + <li>\c IO_OnCloseError An unspecified error happened on close. + </ul> + + \sa resetStatus() +*/ + +/*! + \fn void QIODevice::resetStatus() + + Sets the I/O device status to \c IO_Ok. + + \sa status() +*/ + + +/*! + \fn void QIODevice::setFlags( int f ) + \internal + Used by subclasses to set the device flags. +*/ + +/*! + \internal + Used by subclasses to set the device type. +*/ + +void QIODevice::setType( int t ) +{ +#if defined(CHECK_RANGE) + if ( (t & IO_TypeMask) != t ) + qWarning( "QIODevice::setType: Specified type out of range" ); +#endif + ioMode &= ~IO_TypeMask; // reset type bits + ioMode |= t; +} + +/*! + \internal + Used by subclasses to set the device mode. +*/ + +void QIODevice::setMode( int m ) +{ +#if defined(CHECK_RANGE) + if ( (m & IO_ModeMask) != m ) + qWarning( "QIODevice::setMode: Specified mode out of range" ); +#endif + ioMode &= ~IO_ModeMask; // reset mode bits + ioMode |= m; +} + +/*! + \internal + Used by subclasses to set the device state. +*/ + +void QIODevice::setState( int s ) +{ +#if defined(CHECK_RANGE) + if ( ((uint)s & IO_StateMask) != (uint)s ) + qWarning( "QIODevice::setState: Specified state out of range" ); +#endif + ioMode &= ~IO_StateMask; // reset state bits + ioMode |= (uint)s; +} + +/*! + \internal + Used by subclasses to set the device status (not state). +*/ + +void QIODevice::setStatus( int s ) +{ + ioSt = s; +} + + +/*! + \fn bool QIODevice::open( int mode ) + Opens the I/O device using the specified \e mode. + Returns TRUE if successful, or FALSE if the device could not be opened. + + The mode parameter \e m must be a combination of the following flags. + <ul> + <li>\c IO_Raw specified raw (unbuffered) file access. + <li>\c IO_ReadOnly opens a file in read-only mode. + <li>\c IO_WriteOnly opens a file in write-only mode. + <li>\c IO_ReadWrite opens a file in read/write mode. + <li>\c IO_Append sets the file index to the end of the file. + <li>\c IO_Truncate truncates the file. + <li>\c IO_Translate enables carriage returns and linefeed translation + for text files under MS-DOS, Window, OS/2 and Macintosh. Cannot be + combined with \c IO_Raw. + </ul> + + This virtual function must be reimplemented by all subclasses. + + \sa close() +*/ + +/*! + \fn void QIODevice::close() + Closes the I/O device. + + This virtual function must be reimplemented by all subclasses. + + \sa open() +*/ + +/*! + \fn void QIODevice::flush() + + Flushes an open I/O device. + + This virtual function must be reimplemented by all subclasses. +*/ + + +/*! + \fn uint QIODevice::size() const + Virtual function that returns the size of the I/O device. + \sa at() +*/ + +/*! + Virtual function that returns the current I/O device index. + + This index is the data read/write head of the I/O device. + + \sa size() +*/ + +int QIODevice::at() const +{ + return ioIndex; +} + +/*! + Virtual function that sets the I/O device index to \e pos. + \sa size() +*/ + +bool QIODevice::at( int pos ) +{ +#if defined(CHECK_RANGE) + if ( (uint)pos > size() ) { + qWarning( "QIODevice::at: Index %d out of range", pos ); + return FALSE; + } +#endif + ioIndex = pos; + return TRUE; +} + +/*! + Virtual function that returns TRUE if the I/O device index is at the + end of the input. +*/ + +bool QIODevice::atEnd() const +{ + if ( isSequentialAccess() || isTranslated() ) { + QIODevice* that = (QIODevice*)this; + int c = that->getch(); + bool result = c < 0; + that->ungetch(c); + return result; + } else { + return at() == (int)size(); + } +} + +/*! + \fn bool QIODevice::reset() + Sets the device index to 0. + \sa at() +*/ + + +/*! + \fn int QIODevice::readBlock( char *data, uint maxlen ) + Reads at most \e maxlen bytes from the I/O device into \e data and + returns the number of bytes actually read. + + This virtual function must be reimplemented by all subclasses. + + \sa writeBlock() +*/ + +/*! + This convenience function returns all of the remaining data in the + device. Note that this only works for direct access devices, such + as QFile. + + \sa isDirectAccess() +*/ +QByteArray QIODevice::readAll() +{ + int n = size()-at(); + QByteArray ba(size()-at()); + char* c = ba.data(); + while ( n ) { + int r = readBlock( c, n ); + if ( r < 0 ) + return QByteArray(); + n -= r; + c += r; + } + return ba; +} + +/*! + \fn int QIODevice::writeBlock( const char *data, uint len ) + Writes \e len bytes from \e p to the I/O device and returns the number of + bytes actually written. + + This virtual function must be reimplemented by all subclasses. + + \sa readBlock() +*/ + +/*! + This convenience function is the same as calling + writeBlock( data.data(), data.size() ). +*/ +int QIODevice::writeBlock( const QByteArray& data ) +{ + return writeBlock( data.data(), data.size() ); +} + +/*! + Reads a line of text, up to \e maxlen bytes including a terminating + \0. If there is a newline at the end if the line, it is not stripped. + + Returns the number of bytes read, or -1 in case of error. + + This virtual function can be reimplemented much more efficiently by + the most subclasses. + + \sa readBlock(), QTextStream::readLine() +*/ + +int QIODevice::readLine( char *data, uint maxlen ) +{ + if ( maxlen == 0 ) // application bug? + return 0; + int pos = at(); // get current position + int s = (int)size(); // size of I/O device + char *p = data; + if ( pos >= s ) + return 0; + while ( pos++ < s && --maxlen ) { // read one byte at a time + readBlock( p, 1 ); + if ( *p++ == '\n' ) // end of line + break; + } + *p++ = '\0'; + return (int)((long)p - (long)data); +} + + +/*! + \fn int QIODevice::getch() + + Reads a single byte/character from the I/O device. + + Returns the byte/character read, or -1 if the end of the I/O device has been + reached. + + This virtual function must be reimplemented by all subclasses. + + \sa putch(), ungetch() +*/ + +/*! + \fn int QIODevice::putch( int ch ) + + Writes the character \e ch to the I/O device. + + Returns \e ch, or -1 if some error occurred. + + This virtual function must be reimplemented by all subclasses. + + \sa getch(), ungetch() +*/ + +/*! + \fn int QIODevice::ungetch( int ch ) + + Puts the character \e ch back into the I/O device and decrements the + index if it is not zero. + + This function is normally called to "undo" a getch() operation. + + Returns \e ch, or -1 if some error occurred. + + This virtual function must be reimplemented by all subclasses. + + \sa getch(), putch() +*/ |