Mercurial > zcinema / file diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/bytestream.cpp	Wed Jul 17 18:46:47 2013 +0300
@@ -0,0 +1,225 @@
+#include "bytestream.h"
+#include "misc.h"
+#include <string.h>
+
+union {
+	uint32 i;
+	float f;
+} g_floatunion;
+
+Bytestream::Bytestream( ulong len ) {
+	m_data = null;
+	resize( len );
+	clear();
+}
+
+Bytestream::Bytestream( const char* data, ulong len ) {
+	m_data = null;
+	init( data, len );
+}
+
+void Bytestream::resize( ulong newsize ) {
+	char* olddata = null;
+	ulong oldsize;
+	
+	if( m_data ) {
+		oldsize = m_size;
+		olddata = new char[oldsize];
+		memcpy( olddata, m_data, oldsize );
+	}
+	
+	delete[] m_data;
+	m_data = new uint8[newsize];
+	m_size = newsize;
+	
+	if( olddata )
+		memcpy( m_data, olddata, min<ulong> ( oldsize, newsize ));
+}
+
+void Bytestream::init( const char* data, ulong len ) {
+	resize( len );
+	memcpy( m_data, data, len );
+	m_ptr = &m_data[0];
+	m_len = len;
+}
+
+size_t Bytestream::len() const {
+	return m_len;
+}
+
+void Bytestream::clear() {
+	m_ptr = &m_data[0];
+	m_len = 0;
+}
+
+uint8& Bytestream::subscript( ulong idx ) {
+	return m_data[idx];
+}
+
+const uint8& Bytestream::const_subscript( ulong idx ) const {
+	return m_data[idx];
+}
+
+void Bytestream::seek( ulong pos ) {
+	m_ptr = m_data + pos;
+}
+
+// =============================================================================
+void Bytestream::rewind() {
+	m_ptr = m_data;
+}
+
+ulong Bytestream::bytesLeft() const {
+	return ( m_len - ( m_ptr - &m_data[0] ));
+}
+
+ulong Bytestream::spaceLeft() const {
+	return ( m_size - m_len );
+}
+
+// =============================================================================
+bool Bytestream::readByte( uint8& val ) {
+	if( bytesLeft() < 1 )
+		return false;
+	
+	val = *m_ptr++;
+	return true;
+}
+
+// =============================================================================
+bool Bytestream::readShort( uint16& val ) {
+	if( bytesLeft() < 2 )
+		return false;
+	
+	val = 0;
+	
+	for( int i = 0; i < 2; ++i )
+		val |= *m_ptr++ << ( i * 8 );
+
+	return true;
+}
+
+// =============================================================================
+bool Bytestream::readLong( uint32& val ) {
+	if( bytesLeft() < 4 )
+		return false;
+	
+	val = 0;
+	
+	for( int i = 0; i < 4; ++i )
+		val |= *m_ptr++ << ( i * 8 );
+	
+	return true;
+}
+
+// =============================================================================
+bool Bytestream::readFloat( float& val ) {
+	if( !readLong( g_floatunion.i ))
+		return false;
+
+	val = g_floatunion.f;
+	return true;
+}
+
+// =============================================================================
+bool Bytestream::readString( str& val ) {
+	if( bytesLeft() < 1 ) // need at least the null terminator
+		return false;
+	
+	uint8_t c;
+	
+	while( readByte( c ) && c != '\0' )
+		val += ( char ) c;
+	
+	return true;
+}
+
+// =============================================================================
+void Bytestream::doWrite( uint8_t val ) {
+	*m_ptr++ = val;
+	m_len++;
+}
+
+void Bytestream::growToFit( ulong bytes ) {
+	if( spaceLeft() < bytes )
+		resize( m_size + bytes + 128 );
+}
+
+bool Bytestream::readBytes( uint8 numbytes, uint8* val ) {
+	while( numbytes-- )
+		if( !readByte( *val++ ))
+			return false;
+	
+	return true;
+}
+
+void Bytestream::writeBytes( uint8 numbytes, const uint8* val ) {
+	growToFit( numbytes );
+	
+	while( numbytes-- )
+		writeByte( *val++ );
+}
+
+// =============================================================================
+void Bytestream::writeByte( uint8 val ) {
+	growToFit( 1 );
+	doWrite( val );
+}
+
+// =============================================================================
+void Bytestream::writeShort( uint16 val ) {
+	growToFit( 2 );
+	
+	for( int i = 0; i < 2; ++i )
+		doWrite(( val >> ( i * 8 )) & 0xFF );
+}
+
+// =============================================================================
+void Bytestream::writeLong( uint32 val ) {
+	growToFit( 4 );
+	
+	for( int i = 0; i < 4; ++i )
+		doWrite(( val >> ( i * 8 )) & 0xFF );
+}
+
+// =============================================================================
+void Bytestream::writeFloat( float val ) {
+	g_floatunion.f = val;
+	writeLong( g_floatunion.i );
+}
+
+// =============================================================================
+void Bytestream::writeString( str val ) {
+	growToFit( val.length() + 1 );
+	
+	for( qchar c : val )
+		doWrite( c.toAscii() );
+	
+	doWrite( '\0' );
+}
+
+// =============================================================================
+bool Bytestream::tryMerge( const Bytestream& other ) {
+	if( spaceLeft() < other.len() )
+		return false;
+	
+	for( ulong i = 0; i < other.len(); ++i )
+		writeByte( other[i] );
+	
+	return true;
+}
+
+void Bytestream::merge( const Bytestream& other ) {
+	growToFit( other.len() );
+	
+	if( !tryMerge( other )) {
+		// Shouldn't happen
+		fprint( stderr, "ByteStream: Not enough space for merge (%1 bytes left, need %2)",
+				spaceLeft(), other.len() );
+		abort();
+	}
+}
+
+const uint8* Bytestream::data() const {
+	return m_data;
+}
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