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+/****************************************************************************
+**
+**
+** Implementation of QBuffer class
+**
+** Created : 930812
+**
+** 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 "qbuffer.h"
+#include <stdlib.h>
+
+// REVISED: paul
+/*!
+ \class QBuffer qbuffer.h
+ \brief The QBuffer class is an I/O device that operates on a QByteArray
+
+ \ingroup io
+
+ QBuffer allows reading and writing a memory buffer. It is normally
+ used together with a QTextStream or a QDataStream. QBuffer has an
+ associated QByteArray which holds the buffer data. The size() of the
+ buffer is automatically adjusted as data is written.
+
+ The constructor \c QBuffer(QByteArray) creates a QBuffer with an
+ existing byte array. The byte array can also be set with setBuffer().
+ Writing to the QBuffer will modify the original byte array, since
+ QByteArray is \link shclass.html explicitly shared.\endlink
+
+ Use open() to open the buffer before use, and to set the mode
+ (read-only,write-only, etc.). close() closes the buffer. The buffer
+ must be closed before reopening or calling setBuffer().
+
+ The common way to use QBuffer is through \l QDataStream or \l QTextStream
+ which have constructors that take a QBuffer parameter. For
+ convenience, there are also QDataStream and QTextStream constructors
+ that take a QByteArray parameter. These constructors create and open
+ an internal QBuffer.
+
+ Note that QTextStream can also operate on a QString (a Unicode
+ string); a QBuffer cannot.
+
+ You can also use QBuffer directly through the standard QIODevice
+ functions readBlock(), writeBlock() readLine(), at(), getch(), putch() and
+ ungetch().
+
+ \sa QFile, QDataStream, QTextStream, QByteArray, \link shclass.html Shared Classes\endlink
+*/
+
+
+/*!
+ Constructs an empty buffer.
+*/
+
+QBuffer::QBuffer()
+{
+ setFlags( IO_Direct );
+ a_inc = 16; // initial increment
+ a_len = 0;
+ ioIndex = 0;
+}
+
+
+/*!
+ Constructs a buffer that operates on \a buf.
+ If you open the buffer in write mode (\c IO_WriteOnly or
+ \c IO_ReadWrite) and write something into the buffer, \a buf
+ will be modified.
+
+
+ Example:
+ \code
+ QCString str = "abc";
+ QBuffer b( str );
+ b.open( IO_WriteOnly );
+ b.at( 3 ); // position at \0
+ b.writeBlock( "def", 4 ); // write including \0
+ b.close();
+ // Now, str == "abcdef"
+ \endcode
+
+
+ \sa setBuffer()
+*/
+
+QBuffer::QBuffer( QByteArray buf ) : a(buf)
+{
+ setFlags( IO_Direct );
+ a_len = a.size();
+ a_inc = (a_len > 512) ? 512 : a_len; // initial increment
+ if ( a_inc < 16 )
+ a_inc = 16;
+ ioIndex = 0;
+}
+
+/*!
+ Destructs the buffer.
+*/
+
+QBuffer::~QBuffer()
+{
+}
+
+
+/*!
+ Replaces the buffer's contents with \a buf.
+
+ This may not be done when isOpen() is TRUE.
+
+ Note that if you open the buffer in write mode (\c IO_WriteOnly or
+ IO_ReadWrite) and write something into the buffer, \a buf is also
+ modified because QByteArray is an explicitly shared class.
+
+ \sa buffer(), open(), close()
+*/
+
+bool QBuffer::setBuffer( QByteArray buf )
+{
+ if ( isOpen() ) {
+#if defined(CHECK_STATE)
+ qWarning( "QBuffer::setBuffer: Buffer is open");
+#endif
+ return FALSE;
+ }
+ a = buf;
+ a_len = a.size();
+ a_inc = (a_len > 512) ? 512 : a_len; // initial increment
+ if ( a_inc < 16 )
+ a_inc = 16;
+ ioIndex = 0;
+ return TRUE;
+}
+
+/*!
+ \fn QByteArray QBuffer::buffer() const
+
+ Returns this buffer's byte array.
+
+ \sa setBuffer()
+*/
+
+/*!
+ \reimp
+ Opens the buffer in the mode \a m. Returns TRUE if successful,
+ otherwise FALSE. The buffer must be opened before use.
+
+ The mode parameter \a m must be a combination of the following flags.
+ <ul>
+ <li>\c IO_ReadOnly opens a buffer in read-only mode.
+ <li>\c IO_WriteOnly opens a buffer in write-only mode.
+ <li>\c IO_ReadWrite opens a buffer in read/write mode.
+ <li>\c IO_Append sets the buffer index to the end of the buffer.
+ <li>\c IO_Truncate truncates the buffer.
+ </ul>
+
+ \sa close(), isOpen()
+*/
+
+bool QBuffer::open( int m )
+{
+ if ( isOpen() ) { // buffer already open
+#if defined(CHECK_STATE)
+ qWarning( "QBuffer::open: Buffer already open" );
+#endif
+ return FALSE;
+ }
+ setMode( m );
+ if ( m & IO_Truncate ) { // truncate buffer
+ a.resize( 0 );
+ a_len = 0;
+ }
+ if ( m & IO_Append ) { // append to end of buffer
+ ioIndex = a.size();
+ } else {
+ ioIndex = 0;
+ }
+ a_inc = 16;
+ setState( IO_Open );
+ setStatus( 0 );
+ return TRUE;
+}
+
+/*!
+ \reimp
+ Closes an open buffer.
+ \sa open()
+*/
+
+void QBuffer::close()
+{
+ if ( isOpen() ) {
+ setFlags( IO_Direct );
+ ioIndex = 0;
+ a_inc = 16;
+ }
+}
+
+/*!
+ \reimp
+ The flush function does nothing for a QBuffer.
+*/
+
+void QBuffer::flush()
+{
+ return;
+}
+
+
+/*!
+ \fn int QBuffer::at() const
+ \reimp
+*/
+
+/*!
+ \fn uint QBuffer::size() const
+ \reimp
+*/
+
+/*!
+ \reimp
+*/
+
+bool QBuffer::at( int pos )
+{
+#if defined(CHECK_STATE)
+ if ( !isOpen() ) {
+ qWarning( "QBuffer::at: Buffer is not open" );
+ return FALSE;
+ }
+#endif
+ if ( (uint)pos > a_len ) {
+#if defined(CHECK_RANGE)
+ qWarning( "QBuffer::at: Index %d out of range", pos );
+#endif
+ return FALSE;
+ }
+ ioIndex = pos;
+ return TRUE;
+}
+
+
+/*!
+ \reimp
+*/
+
+int QBuffer::readBlock( char *p, uint len )
+{
+#if defined(CHECK_STATE)
+ CHECK_PTR( p );
+ if ( !isOpen() ) { // buffer not open
+ qWarning( "QBuffer::readBlock: Buffer not open" );
+ return -1;
+ }
+ if ( !isReadable() ) { // reading not permitted
+ qWarning( "QBuffer::readBlock: Read operation not permitted" );
+ return -1;
+ }
+#endif
+ if ( (uint)ioIndex + len > a.size() ) { // overflow
+ if ( (uint)ioIndex >= a.size() ) {
+ setStatus( IO_ReadError );
+ return -1;
+ } else {
+ len = a.size() - (uint)ioIndex;
+ }
+ }
+ memcpy( p, a.data()+ioIndex, len );
+ ioIndex += len;
+ return len;
+}
+
+/*!
+ \reimp
+
+ Writes \a len bytes from \a p into the buffer at the current index,
+ overwriting any characters there and extending the buffer if necessary.
+ Returns the number of bytes actually written.
+
+ Returns -1 if a serious error occurred.
+
+ \sa readBlock()
+*/
+
+int QBuffer::writeBlock( const char *p, uint len )
+{
+#if defined(CHECK_NULL)
+ if ( p == 0 && len != 0 )
+ qWarning( "QBuffer::writeBlock: Null pointer error" );
+#endif
+#if defined(CHECK_STATE)
+ if ( !isOpen() ) { // buffer not open
+ qWarning( "QBuffer::writeBlock: Buffer not open" );
+ return -1;
+ }
+ if ( !isWritable() ) { // writing not permitted
+ qWarning( "QBuffer::writeBlock: Write operation not permitted" );
+ return -1;
+ }
+#endif
+ if ( (uint)ioIndex + len >= a_len ) { // overflow
+ uint new_len = a_len + a_inc*(((uint)ioIndex+len-a_len)/a_inc+1);
+ if ( !a.resize( new_len ) ) { // could not resize
+#if defined(CHECK_NULL)
+ qWarning( "QBuffer::writeBlock: Memory allocation error" );
+#endif
+ setStatus( IO_ResourceError );
+ return -1;
+ }
+ a_inc *= 2; // double increment
+ a_len = new_len;
+ a.shd->len = (uint)ioIndex + len;
+ }
+ memcpy( a.data()+ioIndex, p, len );
+ ioIndex += len;
+ if ( a.shd->len < (uint)ioIndex )
+ a.shd->len = (uint)ioIndex; // fake (not alloc'd) length
+ return len;
+}
+
+
+/*!
+ \reimp
+*/
+
+int QBuffer::readLine( char *p, uint maxlen )
+{
+#if defined(CHECK_STATE)
+ CHECK_PTR( p );
+ if ( !isOpen() ) { // buffer not open
+ qWarning( "QBuffer::readLine: Buffer not open" );
+ return -1;
+ }
+ if ( !isReadable() ) { // reading not permitted
+ qWarning( "QBuffer::readLine: Read operation not permitted" );
+ return -1;
+ }
+#endif
+ if ( maxlen == 0 )
+ return 0;
+ uint start = (uint)ioIndex;
+ char *d = a.data() + ioIndex;
+ maxlen--; // make room for 0-terminator
+ if ( a.size() - (uint)ioIndex < maxlen )
+ maxlen = a.size() - (uint)ioIndex;
+ while ( maxlen-- ) {
+ if ( (*p++ = *d++) == '\n' )
+ break;
+ }
+ *p = '\0';
+ ioIndex = d - a.data();
+ return (uint)ioIndex - start;
+}
+
+
+/*!
+ \reimp
+*/
+
+int QBuffer::getch()
+{
+#if defined(CHECK_STATE)
+ if ( !isOpen() ) { // buffer not open
+ qWarning( "QBuffer::getch: Buffer not open" );
+ return -1;
+ }
+ if ( !isReadable() ) { // reading not permitted
+ qWarning( "QBuffer::getch: Read operation not permitted" );
+ return -1;
+ }
+#endif
+ if ( (uint)ioIndex+1 > a.size() ) { // overflow
+ setStatus( IO_ReadError );
+ return -1;
+ }
+ return uchar(*(a.data()+ioIndex++));
+}
+
+/*!
+ \reimp
+ Writes the character \a ch into the buffer, overwriting
+ the character at the current index, extending the buffer
+ if necessary.
+
+ Returns \a ch, or -1 if some error occurred.
+
+ \sa getch(), ungetch()
+*/
+
+int QBuffer::putch( int ch )
+{
+#if defined(CHECK_STATE)
+ if ( !isOpen() ) { // buffer not open
+ qWarning( "QBuffer::putch: Buffer not open" );
+ return -1;
+ }
+ if ( !isWritable() ) { // writing not permitted
+ qWarning( "QBuffer::putch: Write operation not permitted" );
+ return -1;
+ }
+#endif
+ if ( (uint)ioIndex + 1 >= a_len ) { // overflow
+ char buf[1];
+ buf[0] = (char)ch;
+ if ( writeBlock(buf,1) != 1 )
+ return -1; // write error
+ } else {
+ *(a.data() + ioIndex++) = (char)ch;
+ if ( a.shd->len < (uint)ioIndex )
+ a.shd->len = (uint)ioIndex;
+ }
+ return ch;
+}
+
+/*!
+ \reimp
+*/
+
+int QBuffer::ungetch( int ch )
+{
+#if defined(CHECK_STATE)
+ if ( !isOpen() ) { // buffer not open
+ qWarning( "QBuffer::ungetch: Buffer not open" );
+ return -1;
+ }
+ if ( !isReadable() ) { // reading not permitted
+ qWarning( "QBuffer::ungetch: Read operation not permitted" );
+ return -1;
+ }
+#endif
+ if ( ch != -1 ) {
+ if ( ioIndex )
+ ioIndex--;
+ else
+ ch = -1;
+ }
+ return ch;
+}