mirror of
https://invent.kde.org/network/krfb
synced 2024-07-08 20:15:53 +00:00
9f56633c0b
My patches in this local fork have been merged upstream, but they have been merged after 0.9.8 and 0.9.9 hasn't been released yet, so we cannot yet switch back to finding libvncserver externally. So I am syncing now with basically what is 0.9.8 + my patches and a few bugfixes. svn path=/trunk/KDE/kdenetwork/krfb/; revision=1258493
332 lines
9.7 KiB
C
332 lines
9.7 KiB
C
/*
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* zlib.c
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*
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* Routines to implement zlib based encoding (deflate).
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*/
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/*
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* Copyright (C) 2000 Tridia Corporation. All Rights Reserved.
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* Copyright (C) 1999 AT&T Laboratories Cambridge. All Rights Reserved.
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*
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* This is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This software is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this software; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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* USA.
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*
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* For the latest source code, please check:
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*
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* http://www.developVNC.org/
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*
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* or send email to feedback@developvnc.org.
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*/
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#include "rfb/rfb.h"
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/*
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* zlibBeforeBuf contains pixel data in the client's format.
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* zlibAfterBuf contains the zlib (deflated) encoding version.
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* If the zlib compressed/encoded version is
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* larger than the raw data or if it exceeds zlibAfterBufSize then
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* raw encoding is used instead.
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*/
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/*
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* Out of lazyiness, we use thread local storage for zlib as we did for
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* tight. N.B. ZRLE does it the traditional way with per-client storage
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* (and so at least ZRLE will work threaded on older systems.)
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*/
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#if LIBVNCSERVER_HAVE_LIBPTHREAD && LIBVNCSERVER_HAVE_TLS && !defined(TLS) && defined(__linux__)
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#define TLS __thread
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#endif
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#ifndef TLS
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#define TLS
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#endif
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static TLS int zlibBeforeBufSize = 0;
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static TLS char *zlibBeforeBuf = NULL;
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static TLS int zlibAfterBufSize = 0;
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static TLS char *zlibAfterBuf = NULL;
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static TLS int zlibAfterBufLen = 0;
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void rfbZlibCleanup(rfbScreenInfoPtr screen)
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{
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if (zlibBeforeBufSize) {
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free(zlibBeforeBuf);
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zlibBeforeBufSize=0;
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}
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if (zlibAfterBufSize) {
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zlibAfterBufSize=0;
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free(zlibAfterBuf);
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}
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}
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/*
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* rfbSendOneRectEncodingZlib - send a given rectangle using one Zlib
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* rectangle encoding.
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*/
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static rfbBool
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rfbSendOneRectEncodingZlib(rfbClientPtr cl,
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int x,
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int y,
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int w,
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int h)
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{
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rfbFramebufferUpdateRectHeader rect;
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rfbZlibHeader hdr;
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int deflateResult;
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int previousOut;
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int i;
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char *fbptr = (cl->scaledScreen->frameBuffer + (cl->scaledScreen->paddedWidthInBytes * y)
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+ (x * (cl->scaledScreen->bitsPerPixel / 8)));
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int maxRawSize;
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int maxCompSize;
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maxRawSize = (cl->scaledScreen->width * cl->scaledScreen->height
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* (cl->format.bitsPerPixel / 8));
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if (zlibBeforeBufSize < maxRawSize) {
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zlibBeforeBufSize = maxRawSize;
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if (zlibBeforeBuf == NULL)
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zlibBeforeBuf = (char *)malloc(zlibBeforeBufSize);
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else
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zlibBeforeBuf = (char *)realloc(zlibBeforeBuf, zlibBeforeBufSize);
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}
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/* zlib compression is not useful for very small data sets.
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* So, we just send these raw without any compression.
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*/
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if (( w * h * (cl->scaledScreen->bitsPerPixel / 8)) <
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VNC_ENCODE_ZLIB_MIN_COMP_SIZE ) {
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int result;
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/* The translation function (used also by the in raw encoding)
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* requires 4/2/1 byte alignment in the output buffer (which is
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* updateBuf for the raw encoding) based on the bitsPerPixel of
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* the viewer/client. This prevents SIGBUS errors on some
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* architectures like SPARC, PARISC...
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*/
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if (( cl->format.bitsPerPixel > 8 ) &&
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( cl->ublen % ( cl->format.bitsPerPixel / 8 )) != 0 ) {
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if (!rfbSendUpdateBuf(cl))
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return FALSE;
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}
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result = rfbSendRectEncodingRaw(cl, x, y, w, h);
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return result;
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}
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/*
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* zlib requires output buffer to be slightly larger than the input
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* buffer, in the worst case.
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*/
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maxCompSize = maxRawSize + (( maxRawSize + 99 ) / 100 ) + 12;
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if (zlibAfterBufSize < maxCompSize) {
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zlibAfterBufSize = maxCompSize;
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if (zlibAfterBuf == NULL)
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zlibAfterBuf = (char *)malloc(zlibAfterBufSize);
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else
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zlibAfterBuf = (char *)realloc(zlibAfterBuf, zlibAfterBufSize);
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}
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/*
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* Convert pixel data to client format.
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*/
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(*cl->translateFn)(cl->translateLookupTable, &cl->screen->serverFormat,
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&cl->format, fbptr, zlibBeforeBuf,
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cl->scaledScreen->paddedWidthInBytes, w, h);
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cl->compStream.next_in = ( Bytef * )zlibBeforeBuf;
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cl->compStream.avail_in = w * h * (cl->format.bitsPerPixel / 8);
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cl->compStream.next_out = ( Bytef * )zlibAfterBuf;
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cl->compStream.avail_out = maxCompSize;
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cl->compStream.data_type = Z_BINARY;
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/* Initialize the deflation state. */
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if ( cl->compStreamInited == FALSE ) {
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cl->compStream.total_in = 0;
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cl->compStream.total_out = 0;
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cl->compStream.zalloc = Z_NULL;
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cl->compStream.zfree = Z_NULL;
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cl->compStream.opaque = Z_NULL;
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deflateInit2( &(cl->compStream),
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cl->zlibCompressLevel,
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Z_DEFLATED,
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MAX_WBITS,
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MAX_MEM_LEVEL,
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Z_DEFAULT_STRATEGY );
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/* deflateInit( &(cl->compStream), Z_BEST_COMPRESSION ); */
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/* deflateInit( &(cl->compStream), Z_BEST_SPEED ); */
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cl->compStreamInited = TRUE;
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}
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previousOut = cl->compStream.total_out;
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/* Perform the compression here. */
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deflateResult = deflate( &(cl->compStream), Z_SYNC_FLUSH );
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/* Find the total size of the resulting compressed data. */
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zlibAfterBufLen = cl->compStream.total_out - previousOut;
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if ( deflateResult != Z_OK ) {
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rfbErr("zlib deflation error: %s\n", cl->compStream.msg);
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return FALSE;
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}
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/* Note that it is not possible to switch zlib parameters based on
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* the results of the compression pass. The reason is
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* that we rely on the compressor and decompressor states being
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* in sync. Compressing and then discarding the results would
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* cause lose of synchronization.
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*/
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/* Update statics */
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rfbStatRecordEncodingSent(cl, rfbEncodingZlib, sz_rfbFramebufferUpdateRectHeader + sz_rfbZlibHeader + zlibAfterBufLen,
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+ w * (cl->format.bitsPerPixel / 8) * h);
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if (cl->ublen + sz_rfbFramebufferUpdateRectHeader + sz_rfbZlibHeader
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> UPDATE_BUF_SIZE)
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{
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if (!rfbSendUpdateBuf(cl))
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return FALSE;
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}
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rect.r.x = Swap16IfLE(x);
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rect.r.y = Swap16IfLE(y);
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rect.r.w = Swap16IfLE(w);
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rect.r.h = Swap16IfLE(h);
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rect.encoding = Swap32IfLE(rfbEncodingZlib);
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memcpy(&cl->updateBuf[cl->ublen], (char *)&rect,
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sz_rfbFramebufferUpdateRectHeader);
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cl->ublen += sz_rfbFramebufferUpdateRectHeader;
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hdr.nBytes = Swap32IfLE(zlibAfterBufLen);
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memcpy(&cl->updateBuf[cl->ublen], (char *)&hdr, sz_rfbZlibHeader);
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cl->ublen += sz_rfbZlibHeader;
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for (i = 0; i < zlibAfterBufLen;) {
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int bytesToCopy = UPDATE_BUF_SIZE - cl->ublen;
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if (i + bytesToCopy > zlibAfterBufLen) {
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bytesToCopy = zlibAfterBufLen - i;
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}
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memcpy(&cl->updateBuf[cl->ublen], &zlibAfterBuf[i], bytesToCopy);
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cl->ublen += bytesToCopy;
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i += bytesToCopy;
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if (cl->ublen == UPDATE_BUF_SIZE) {
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if (!rfbSendUpdateBuf(cl))
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return FALSE;
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}
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}
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return TRUE;
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}
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/*
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* rfbSendRectEncodingZlib - send a given rectangle using one or more
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* Zlib encoding rectangles.
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*/
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rfbBool
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rfbSendRectEncodingZlib(rfbClientPtr cl,
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int x,
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int y,
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int w,
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int h)
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{
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int maxLines;
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int linesRemaining;
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rfbRectangle partialRect;
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partialRect.x = x;
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partialRect.y = y;
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partialRect.w = w;
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partialRect.h = h;
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/* Determine maximum pixel/scan lines allowed per rectangle. */
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maxLines = ( ZLIB_MAX_SIZE(w) / w );
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/* Initialize number of scan lines left to do. */
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linesRemaining = h;
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/* Loop until all work is done. */
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while ( linesRemaining > 0 ) {
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int linesToComp;
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if ( maxLines < linesRemaining )
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linesToComp = maxLines;
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else
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linesToComp = linesRemaining;
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partialRect.h = linesToComp;
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/* Encode (compress) and send the next rectangle. */
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if ( ! rfbSendOneRectEncodingZlib( cl,
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partialRect.x,
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partialRect.y,
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partialRect.w,
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partialRect.h )) {
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return FALSE;
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}
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/* Technically, flushing the buffer here is not extrememly
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* efficient. However, this improves the overall throughput
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* of the system over very slow networks. By flushing
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* the buffer with every maximum size zlib rectangle, we
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* improve the pipelining usage of the server CPU, network,
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* and viewer CPU components. Insuring that these components
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* are working in parallel actually improves the performance
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* seen by the user.
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* Since, zlib is most useful for slow networks, this flush
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* is appropriate for the desired behavior of the zlib encoding.
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*/
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if (( cl->ublen > 0 ) &&
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( linesToComp == maxLines )) {
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if (!rfbSendUpdateBuf(cl)) {
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return FALSE;
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}
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}
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/* Update remaining and incremental rectangle location. */
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linesRemaining -= linesToComp;
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partialRect.y += linesToComp;
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}
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return TRUE;
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}
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