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 31 void *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 43 void vnc_zlib_zfree(void *x, void *addr) 44 { 45 g_free(addr); 46 } 47 48 static 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 57 static 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 } 118 119 int 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 } 145 146 void 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