LXR qemu/ui/vnc-enc-zlib.c

   1/*
   2 * QEMU VNC display driver: zlib encoding
   3 *
   4 * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
   5 * Copyright (C) 2006 Fabrice Bellard
   6 * Copyright (C) 2009 Red Hat, Inc
   7 *
   8 * Permission is hereby granted, free of charge, to any person obtaining a copy
   9 * of this software and associated documentation files (the "Software"), to deal
  10 * in the Software without restriction, including without limitation the rights
  11 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12 * copies of the Software, and to permit persons to whom the Software is
  13 * furnished to do so, subject to the following conditions:
  14 *
  15 * The above copyright notice and this permission notice shall be included in
  16 * all copies or substantial portions of the Software.
  17 *
  18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24 * THE SOFTWARE.
  25 */
  26
  27#include "vnc.h"
  28
  29#define ZALLOC_ALIGNMENT 16
  30
  31void *vnc_zlib_zalloc(void *x, unsigned items, unsigned size)
  32{
  33    void *p;
  34
  35    size *= items;
  36    size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1);
  37
  38    p = g_malloc0(size);
  39
  40    return (p);
  41}
  42
  43void vnc_zlib_zfree(void *x, void *addr)
  44{
  45    g_free(addr);
  46}
  47
  48static void vnc_zlib_start(VncState *vs)
  49{
  50    buffer_reset(&vs->zlib.zlib);
  51
  52    // make the output buffer be the zlib buffer, so we can compress it later
  53    vs->zlib.tmp = vs->output;
  54    vs->output = vs->zlib.zlib;
  55}
  56
  57static int vnc_zlib_stop(VncState *vs)
  58{
  59    z_streamp zstream = &vs->zlib.stream;
  60    int previous_out;
  61
  62    // switch back to normal output/zlib buffers
  63    vs->zlib.zlib = vs->output;
  64    vs->output = vs->zlib.tmp;
  65
  66    // compress the zlib buffer
  67
  68    // initialize the stream
  69    // XXX need one stream per session
  70    if (zstream->opaque != vs) {
  71        int err;
  72
  73        VNC_DEBUG("VNC: initializing zlib stream\n");
  74        VNC_DEBUG("VNC: opaque = %p | vs = %p\n", zstream->opaque, vs);
  75        zstream->zalloc = vnc_zlib_zalloc;
  76        zstream->zfree = vnc_zlib_zfree;
  77
  78        err = deflateInit2(zstream, vs->tight.compression, Z_DEFLATED, MAX_WBITS,
  79                           MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
  80
  81        if (err != Z_OK) {
  82            fprintf(stderr, "VNC: error initializing zlib\n");
  83            return -1;
  84        }
  85
  86        vs->zlib.level = vs->tight.compression;
  87        zstream->opaque = vs;
  88    }
  89
  90    if (vs->tight.compression != vs->zlib.level) {
  91        if (deflateParams(zstream, vs->tight.compression,
  92                          Z_DEFAULT_STRATEGY) != Z_OK) {
  93            return -1;
  94        }
  95        vs->zlib.level = vs->tight.compression;
  96    }
  97
  98    // reserve memory in output buffer
  99    buffer_reserve(&vs->output, vs->zlib.zlib.offset + 64);
 100
 101    // set pointers
 102    zstream->next_in = vs->zlib.zlib.buffer;
 103    zstream->avail_in = vs->zlib.zlib.offset;
 104    zstream->next_out = vs->output.buffer + vs->output.offset;
 105    zstream->avail_out = vs->output.capacity - vs->output.offset;
 106    previous_out = zstream->avail_out;
 107    zstream->data_type = Z_BINARY;
 108
 109    // start encoding
 110    if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
 111        fprintf(stderr, "VNC: error during zlib compression\n");
 112        return -1;
 113    }
 114
 115    vs->output.offset = vs->output.capacity - zstream->avail_out;
 116    return previous_out - zstream->avail_out;
 117}
 118
 119int vnc_zlib_send_framebuffer_update(VncState *vs, int x, int y, int w, int h)
 120{
 121    int old_offset, new_offset, bytes_written;
 122
 123    vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_ZLIB);
 124
 125    // remember where we put in the follow-up size
 126    old_offset = vs->output.offset;
 127    vnc_write_s32(vs, 0);
 128
 129    // compress the stream
 130    vnc_zlib_start(vs);
 131    vnc_raw_send_framebuffer_update(vs, x, y, w, h);
 132    bytes_written = vnc_zlib_stop(vs);
 133
 134    if (bytes_written == -1)
 135        return 0;
 136
 137    // hack in the size
 138    new_offset = vs->output.offset;
 139    vs->output.offset = old_offset;
 140    vnc_write_u32(vs, bytes_written);
 141    vs->output.offset = new_offset;
 142
 143    return 1;
 144}
 145
 146void vnc_zlib_clear(VncState *vs)
 147{
 148    if (vs->zlib.stream.opaque) {
 149        deflateEnd(&vs->zlib.stream);
 150    }
 151    buffer_free(&vs->zlib.zlib);
 152}
 153