qtextstream.cpp

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

	return 0;

    uint rnum = 0;   // the number of QChars really read

    if ( d && d->ungetcBuf.length() ) {
	while ( rnum < len && rnum < d->ungetcBuf.length() ) {
	    *buf = d->ungetcBuf.constref( rnum );
	    buf++;
	    rnum++;
	}
	d->ungetcBuf = d->ungetcBuf.mid( rnum );
	if ( rnum >= len )
	    return rnum;
    }

    // we use dev->ungetch() for one of the bytes of the unicode
    // byte-order mark, but a local unget hack for the other byte:
    int ungetHack = EOF;

    if ( doUnicodeHeader ) {
	doUnicodeHeader = FALSE; // only at the top
	int c1 = dev->getch();
	if ( c1 == EOF )
	    return rnum;
	int c2 = dev->getch();
	if ( c1 == 0xfe && c2 == 0xff ) {
	    mapper = 0;
	    latin1 = FALSE;
	    internalOrder = QChar::networkOrdered();
	    networkOrder = TRUE;
	} else if ( c1 == 0xff && c2 == 0xfe ) {
	    mapper = 0;
	    latin1 = FALSE;
	    internalOrder = !QChar::networkOrdered();
	    networkOrder = FALSE;
	} else {
	    if ( c2 != EOF ) {
	 	dev->ungetch( c2 );
		ungetHack = c1;
	    } else {
		/*
		  A small bug might hide here. If only the first byte
		  of a file has made it so far, and that first byte
		  is half of the byte-order mark, then the utfness
		  will not be detected.
		*/
	 	dev->ungetch( c1 );
	    }
	}
    }

#ifndef QT_NO_TEXTCODEC
    if ( mapper ) {
	bool shortRead = FALSE;
	if ( !d->decoder )
	    d->decoder = mapper->makeDecoder();
	while( rnum < len ) {
	    QString s;
	    bool readBlock = !( len == 1+rnum );
	    for (;;) {
		// for efficiency: normally read a whole block
		if ( readBlock ) {
		    // guess buffersize; this may be wrong (too small or too
		    // big). But we can handle this (either iterate reading
		    // or use ungetcBuf).
		    // Note that this might cause problems for codecs where
		    // one byte can result in >1 Unicode Characters if bytes
		    // are written to the stream in the meantime (loss of
		    // synchronicity).
		    uint rlen = len - rnum;
		    char *cbuf = new char[ rlen ];
		    if ( ungetHack != EOF ) {
			rlen = 1+dev->readBlock( cbuf+1, rlen-1 );
			cbuf[0] = (char)ungetHack;
			ungetHack = EOF;
		    } else {
			rlen = dev->readBlock( cbuf, rlen );
		    }
		    s  += d->decoder->toUnicode( cbuf, rlen );
		    delete[] cbuf;
		    // use buffered reading only for the first time, because we
		    // have to get the stream synchronous again (this is easier
		    // with single character reading)
		    readBlock = FALSE;
		}
		// get stream (and codec) in sync
		int c;
		if ( ungetHack == EOF ) {
		    c = dev->getch();
		} else {
		    c = ungetHack;
		    ungetHack = EOF;
		}
		if ( c == EOF ) {
		    shortRead = TRUE;
		    break;
		}
		char b = c;
		uint lengthBefore = s.length();
		s += d->decoder->toUnicode( &b, 1 );
		if ( s.length() > lengthBefore )
		    break; // it seems we are in sync now
	    }
	    uint i = 0;
	    uint end = QMIN( len-rnum, s.length() );
	    while( i < end ) {
		*buf = s.constref(i++);
		buf++;
	    }
	    rnum += end;
	    if ( s.length() > i ) {
		// could be = but append is clearer
		d->ungetcBuf.append( s.mid( i ) );
	    }
	    if ( shortRead )
		return rnum;
	}
    } else
#endif
    if ( latin1 ) {
	if ( len == 1+rnum ) {
	    // use this method for one character because it is more efficient
	    // (arnt doubts whether it makes a difference, but lets it stand)
	    int c = (ungetHack == EOF) ? dev->getch() : ungetHack;
	    if ( c != EOF ) {
		*buf = (char)c;
		buf++;
		rnum++;
	    }
	} else {
	    if ( ungetHack != EOF ) {
		*buf = (char)ungetHack;
		buf++;
		rnum++;
		ungetHack = EOF;
	    }
	    char *cbuf = new char[len - rnum];
	    while ( !dev->atEnd() && rnum < len ) {
		uint rlen = len - rnum;
		rlen = dev->readBlock( cbuf, rlen );
		char *it = cbuf;
		char *end = cbuf + rlen;
		while ( it < end ) {
		    *buf = *it;
		    buf++;
		    it++;
		}
		rnum += rlen;
	    }
	    delete[] cbuf;
	}
    } else { // UCS-2 or UTF-16
	if ( len == 1+rnum ) {
	    int c1 = (ungetHack == EOF) ? dev->getch() : ungetHack;
	    if ( c1 == EOF )
		return rnum;
	    int c2 = dev->getch();
	    if ( c2 == EOF )
		return rnum;

	    if ( networkOrder ) {
		*buf = QChar( c2, c1 );
	    } else {
		*buf = QChar( c1, c2 );
	    }
	    buf++;
	    rnum++;
	} else {
	    char *cbuf = new char[ 2*( len - rnum ) ]; // for paranoids: overflow possible
	    while ( !dev->atEnd() && rnum < len ) {
		uint rlen = 2 * ( len-rnum );
		if ( ungetHack != EOF ) {
		    rlen = 1+dev->readBlock( cbuf+1, rlen-1 );
		    cbuf[0] = (char)ungetHack;
		    ungetHack = EOF;
		} else {
		    rlen = dev->readBlock( cbuf, rlen );
		}
		// We can't use an odd number of bytes, so put it back. But
		// do it only if we are capable of reading more -- normally
		// there should not be an odd number, but the file might be
		// truncated or not in UTF-16...
		if ( (rlen & 1) == 1 )
		    if ( !dev->atEnd() )
			dev->ungetch( cbuf[--rlen] );
		uint i = 0;
		if ( networkOrder ) {
		    while( i < rlen ) {
			*buf = QChar( cbuf[i+1], cbuf[i] );
			buf++;
			i+=2;
		    }
		} else {
		    while( i < rlen ) {
			*buf = QChar( cbuf[i], cbuf[i+1] );
			buf++;
			i+=2;
		    }
		}
		rnum += i/2;
	    }
	    delete[] cbuf;
	}
    }
    return rnum;
}

/*!
    Tries to read one line, but at most len characters from the stream
    and stores them in \a buf.

    Returns the number of characters really read. Newlines are not
    stripped.

    There will be a QEOF appended if the read reaches the end of file;
    this is different to ts_getbuf().

    This function works only if a newline (as byte) is also a newline
    (as resulting character) since it uses QIODevice::readLine(). So
    use it only for such codecs where this is true!

    This function is (almost) a no-op for UTF 16. Don't use it if
    doUnicodeHeader is TRUE!
*/
uint QTextStream::ts_getline( QChar* buf )
{
    uint rnum=0;   // the number of QChars really read
    char cbuf[ getline_buf_size+1 ];

    if ( d && d->ungetcBuf.length() ) {
	while( rnum < getline_buf_size && rnum < d->ungetcBuf.length() ) {
	    buf[rnum] = d->ungetcBuf.constref(rnum);
	    rnum++;
	}
	d->ungetcBuf = d->ungetcBuf.mid( rnum );
	if ( rnum >= getline_buf_size )
	    return rnum;
    }

#ifndef QT_NO_TEXTCODEC
    if ( mapper ) {
	if ( !d->decoder )
	    d->decoder = mapper->makeDecoder();
	QString s;
	bool readBlock = TRUE;
	for (;;) {
	    // for efficiency: try to read a line
	    if ( readBlock ) {
		int rlen = getline_buf_size - rnum;
		rlen = dev->readLine( cbuf, rlen+1 );
		if ( rlen == -1 )
		    rlen = 0;
		s  += d->decoder->toUnicode( cbuf, rlen );
		readBlock = FALSE;
	    }
	    if ( dev->atEnd()
		    || s.at( s.length()-1 ) == '\n'
		    || s.at( s.length()-1 ) == '\r'
	       ) {
		break;
	    } else {
		// get stream (and codec) in sync
		int c;
		c = dev->getch();
		if ( c == EOF ) {
		    break;
		}
		char b = c;
		uint lengthBefore = s.length();
		s  += d->decoder->toUnicode( &b, 1 );
		if ( s.length() > lengthBefore )
		    break; // it seems we are in sync now
	    }
	}
	uint i = 0;
	while( rnum < getline_buf_size && i < s.length() )
	    buf[rnum++] = s.constref(i++);
	if ( s.length() > i )
	    // could be = but append is clearer
	    d->ungetcBuf.append( s.mid( i ) );
	if ( rnum < getline_buf_size && dev->atEnd() )
	    buf[rnum++] = QEOF;
    } else
#endif
    if ( latin1 ) {
	int rlen = getline_buf_size - rnum;
	rlen = dev->readLine( cbuf, rlen+1 );
	if ( rlen == -1 )
	    rlen = 0;
	char *end = cbuf+rlen;
	char *it = cbuf;
	buf +=rnum;
	while ( it != end ) {
	    buf->setCell( *(it++) );
	    buf->setRow( 0 );
	    buf++;
	}
	rnum += rlen;
	if ( rnum < getline_buf_size && dev->atEnd() )
	    buf[1] = QEOF;
    }
    return rnum;
}


/*!
    Puts one character into the stream.
*/
void QTextStream::ts_putc( QChar c )
{
#ifndef QT_NO_TEXTCODEC
    if ( mapper ) {
	if ( !d->encoder )
	    d->encoder = mapper->makeEncoder();
	int len = 1;
	QString s = c;
	QCString block = d->encoder->fromUnicode( s, len );
	dev->writeBlock( block, len );
    } else
#endif
    if ( latin1 ) {
	if ( c.row() )
	    dev->putch( '?' ); // unknown character
	else
	    dev->putch( c.cell() );
    } else {
	if ( doUnicodeHeader ) {
	    doUnicodeHeader = FALSE;
	    ts_putc( QChar::byteOrderMark );
	}
	if ( internalOrder ) {
	    // this case is needed by QStringBuffer
	    dev->writeBlock( (char*)&c, sizeof(QChar) );
	} else if ( networkOrder ) {
	    dev->putch( c.row() );
	    dev->putch( c.cell() );
	} else {
	    dev->putch( c.cell() );
	    dev->putch( c.row() );
	}
    }
}

/*!
    Puts one character into the stream.
*/
void QTextStream::ts_putc( int ch )
{
    ts_putc( QChar((ushort)ch) );
}

bool QTextStream::ts_isdigit( QChar c )
{
    return c.isDigit();
}

bool QTextStream::ts_isspace( QChar c )
{
    return c.isSpace();
}

void QTextStream::ts_ungetc( QChar c )
{
    if ( c.unicode() == 0xffff )
	return;

    d->ungetcBuf.prepend( c );
}



/*!
    Reads \a len bytes from the stream into \a s and returns a
    reference to the stream.

    The buffer \a s must be preallocated.

    Note that no encoding is done by this function.

    \warning The behavior of this function is undefined unless the
    stream's encoding is set to Unicode or Latin1.

    \sa QIODevice::readBlock()
*/

QTextStream &QTextStream::readRawBytes( char *s, uint len )
{
    dev->readBlock( s, len );
    return *this;
}

/*!
    Writes the \a len bytes from \a s to the stream and returns a
    reference to the stream.

    Note that no encoding is done by this function.

    \sa QIODevice::writeBlock()
*/

QTextStream &QTextStream::writeRawBytes( const char* s, uint len )
{
    dev->writeBlock( s, len );
    return *this;
}


QTextStream &QTextStream::writeBlock( const char* p, uint len )
{
    if ( doUnicodeHeader ) {
	doUnicodeHeader = FALSE;
	if ( !mapper && !latin1 )
	    ts_putc( QChar::byteOrderMark );
    }
    // QCString and const char * are treated as Latin-1
    if ( !mapper && latin1 ) {
	dev->writeBlock( p, len );
    } else if ( !mapper && internalOrder ) {
	QChar *u = new QChar[len];
	for ( uint i = 0; i < len; i++ )
	    u[i] = p[i];
	dev->writeBlock( (char*)u, len * sizeof(QChar) );
	delete [] u;
    } else {
	for ( uint i = 0; i < len; i++ )
	    ts_putc( (uchar)p[i] );
    }
    return *this;
}

QTextStream &QTextStream::writeBlock( const QChar* p, uint len )
{
#ifndef QT_NO_TEXTCODEC
    if ( mapper ) {
	if ( !d->encoder )
	    d->encoder = mapper->makeEncoder();
	QConstString s( p, len );
	int l = len;
	QCString block = d->encoder->fromUnicode( s.string(), l );
	dev->writeBlock( block, l );
    } else
#endif
    if ( latin1 ) {
	char *str = QString::unicodeToLatin1( p, len );
	dev->writeBlock( str, len );
	delete [] str;
    } else if ( internalOrder ) {
	if ( doUnicodeHeader ) {
	    doUnicodeHeader = FALSE;
	    ts_putc( QChar::byteOrderMark );
	}
	dev->writeBlock( (char*)p, sizeof(QChar)*len );
    } else {
	for (uint i=0; i<len; i++)
	    ts_putc( p[i] );
    }
    return *this;
}

/*!
    Resets the text stream.

    \list
    \i All flags are set to 0.
    \i The field width is set to 0.
    \i The fill character is set to ' ' (Space).
    \i The precision is set to 6.
    \endlist

    \sa setf(), width(), fill(), precision()
*/

void QTextStream::reset()
{
    fflags = 0;
    fwidth = 0;
    fillchar = ' ';
    fprec = 6;
}

/*!
    \fn QIODevice *QTextStream::device() const

    Returns the IO device currently set.

    \sa setDevice(), unsetDevice()
*/

/*!
    Sets the IO device to \a iod.

    \sa device(), unsetDevice()
*/

void QTextStream::setDevice( QIODevice *iod )
{
    if ( owndev ) {
	delete dev;
	owndev = FALSE;
    }
    dev = iod;
    d->sourceType = QTextStreamPrivate::IODevice;
}

/*!
    Unsets the IO device. Equivalent to setDevice( 0 ).

    \sa device(), setDevice()
*/

void QTextStream::unsetDevice()
{
    setDevice( 0 );
    d->sourceType = QTextStreamPrivate::NotSet;
}

/*!
    \fn bool QTextStream::atEnd() const

    Returns TRUE if the IO device has reached the end position (end of
    the stream or file) or if there is no IO device set; otherwise
    returns FALSE.

    \sa QIODevice::atEnd()
*/

/*!\fn bool QTextStream::eof() const

  \obsolete

  This function has been renamed to atEnd().

  \sa QIODevice::atEnd()
*/

/*****************************************************************************
  QTextStream read functions
 *****************************************************************************/


/*!
    \overload

    Reads a char \a c from the stream and returns a reference to the
    stream. Note that whitespace is skipped.
*/

QTextStream &QTextStream::operator>>( char &c )
{
    CHECK_STREAM_PRECOND
    c = eat_ws();
    return *this;
}

/*!
    Reads a char \a c from the stream and returns a reference to the
    stream. Note that whitespace is \e not skipped.
*/

QTextStream &QTextStream::operator>>( QChar &c )
{
    CHECK_STREAM_PRECOND
    c = ts_getc();
    return *this;
}


ulong QTextStream::input_bin()
{
    ulong val = 0;
    QChar ch = eat_ws();
    int dv = ch.digitValue();
    while (  dv == 0 || dv == 1 ) {
	val = ( val << 1 ) + dv;
	ch = ts_getc();
	dv = ch.digitValue();
    }
    if ( ch != QEOF )
	ts_ungetc( ch );
    return val;
}

ulong QTextStream::input_oct()
{
    ulong val = 0;
    QChar ch = eat_ws();
    int dv = ch.digitValue();
    while ( dv >= 0 && dv <= 7 ) {
	val = ( val << 3 ) + dv;
	ch = ts_getc();
	dv = ch.digitValue();
    }
    if ( dv == 8 || dv == 9 ) {
	while ( ts_isdigit(ch) )
	    ch = ts_getc();
    }
    if ( ch != QEOF )
	ts_ungetc( ch );
    return val;
}

ulong QTextStream::input_dec()
{
    ulong val = 0;
    QChar ch = eat_ws();
    int dv = ch.digitValue();
    while ( ts_isdigit(ch) ) {
	val = val * 10 + dv;
	ch = ts_getc();
	dv = ch.digitValue();
    }
    if ( ch != QEOF )
	ts_ungetc( ch );
    return val;
}

ulong QTextStream::input_hex()
{
    ulong val = 0;
    QChar ch = eat_ws();
    char c = ch;
    while ( isxdigit((uchar) c) ) {
	val <<= 4;
	if ( ts_isdigit(c) )
	    val += c - '0';
	else
	    val += 10 + tolower( (uchar) c ) - 'a';
	c = ch = ts_getc();
    }
    if ( ch != QEOF )
	ts_ungetc( ch );
    return val;
}

long QTextStream::input_int()
{
    long val;
    QChar ch;
    char c;
    switch ( flags() & basefield ) {
    case bin:
	val = (long)input_bin();
	break;
    case oct:
	val = (long)input_oct();
	break;
    case dec:
	c = ch = eat_ws();
	if ( ch == QEOF ) {
	    val = 0;