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libtdevnc/libvncclient/zlib.c

163 lines
4.7 KiB

/*
* Copyright (C) 2000 Tridia Corporation. All Rights Reserved.
* Copyright (C) 1999 AT&T Laboratories Cambridge. All Rights Reserved.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
#ifdef LIBVNCSERVER_HAVE_LIBZ
/*
* zlib.c - handle zlib encoding.
*
* This file shouldn't be compiled directly. It is included multiple times by
* rfbproto.c, each time with a different definition of the macro BPP. For
* each value of BPP, this file defines a function which handles an zlib
* encoded rectangle with BPP bits per pixel.
*/
#define HandleZlibBPP CONCAT2E(HandleZlib,BPP)
#define CARDBPP CONCAT3E(uint,BPP,_t)
static rfbBool
HandleZlibBPP (rfbClient* client, int rx, int ry, int rw, int rh)
{
rfbZlibHeader hdr;
int remaining;
int inflateResult;
int toRead;
/* First make sure we have a large enough raw buffer to hold the
* decompressed data. In practice, with a fixed BPP, fixed frame
* buffer size and the first update containing the entire frame
* buffer, this buffer allocation should only happen once, on the
* first update.
*/
if ( client->raw_buffer_size < (( rw * rh ) * ( BPP / 8 ))) {
if ( client->raw_buffer != NULL ) {
free( client->raw_buffer );
}
client->raw_buffer_size = (( rw * rh ) * ( BPP / 8 ));
client->raw_buffer = (char*) malloc( client->raw_buffer_size );
}
if (!ReadFromRFBServer(client, (char *)&hdr, sz_rfbZlibHeader))
return FALSE;
remaining = rfbClientSwap32IfLE(hdr.nBytes);
/* Need to initialize the decompressor state. */
client->decompStream.next_in = ( Bytef * )client->buffer;
client->decompStream.avail_in = 0;
client->decompStream.next_out = ( Bytef * )client->raw_buffer;
client->decompStream.avail_out = client->raw_buffer_size;
client->decompStream.data_type = Z_BINARY;
/* Initialize the decompression stream structures on the first invocation. */
if ( client->decompStreamInited == FALSE ) {
inflateResult = inflateInit( &client->decompStream );
if ( inflateResult != Z_OK ) {
rfbClientLog(
"inflateInit returned error: %d, msg: %s\n",
inflateResult,
client->decompStream.msg);
return FALSE;
}
client->decompStreamInited = TRUE;
}
inflateResult = Z_OK;
/* Process buffer full of data until no more to process, or
* some type of inflater error, or Z_STREAM_END.
*/
while (( remaining > 0 ) &&
( inflateResult == Z_OK )) {
if ( remaining > RFB_BUFFER_SIZE ) {
toRead = RFB_BUFFER_SIZE;
}
else {
toRead = remaining;
}
/* Fill the buffer, obtaining data from the server. */
if (!ReadFromRFBServer(client, client->buffer,toRead))
return FALSE;
client->decompStream.next_in = ( Bytef * )client->buffer;
client->decompStream.avail_in = toRead;
/* Need to uncompress buffer full. */
inflateResult = inflate( &client->decompStream, Z_SYNC_FLUSH );
/* We never supply a dictionary for compression. */
if ( inflateResult == Z_NEED_DICT ) {
rfbClientLog("zlib inflate needs a dictionary!\n");
return FALSE;
}
if ( inflateResult < 0 ) {
rfbClientLog(
"zlib inflate returned error: %d, msg: %s\n",
inflateResult,
client->decompStream.msg);
return FALSE;
}
/* Result buffer allocated to be at least large enough. We should
* never run out of space!
*/
if (( client->decompStream.avail_in > 0 ) &&
( client->decompStream.avail_out <= 0 )) {
rfbClientLog("zlib inflate ran out of space!\n");
return FALSE;
}
remaining -= toRead;
} /* while ( remaining > 0 ) */
if ( inflateResult == Z_OK ) {
/* Put the uncompressed contents of the update on the screen. */
CopyRectangle(client, client->raw_buffer, rx, ry, rw, rh);
}
else {
rfbClientLog(
"zlib inflate returned error: %d, msg: %s\n",
inflateResult,
client->decompStream.msg);
return FALSE;
}
return TRUE;
}
#undef CARDBPP
#endif