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 "qemu/osdep.h" 28 #include "vnc.h" 29 30 #define ZALLOC_ALIGNMENT 16 31 32 void *vnc_zlib_zalloc(void *x, unsigned items, unsigned size) 33 { 34 void *p; 35 36 size *= items; 37 size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1); 38 39 p = g_malloc0(size); 40 41 return (p); 42 } 43 44 void vnc_zlib_zfree(void *x, void *addr) 45 { 46 g_free(addr); 47 } 48 49 static void vnc_zlib_start(VncState *vs) 50 { 51 buffer_reset(&vs->zlib.zlib); 52 53 // make the output buffer be the zlib buffer, so we can compress it later 54 vs->zlib.tmp = vs->output; 55 vs->output = vs->zlib.zlib; 56 } 57 58 static int vnc_zlib_stop(VncState *vs) 59 { 60 z_streamp zstream = &vs->zlib.stream; 61 int previous_out; 62 63 // switch back to normal output/zlib buffers 64 vs->zlib.zlib = vs->output; 65 vs->output = vs->zlib.tmp; 66 67 // compress the zlib buffer 68 69 // initialize the stream 70 // XXX need one stream per session 71 if (zstream->opaque != vs) { 72 int err; 73 74 VNC_DEBUG("VNC: initializing zlib stream\n"); 75 VNC_DEBUG("VNC: opaque = %p | vs = %p\n", zstream->opaque, vs); 76 zstream->zalloc = vnc_zlib_zalloc; 77 zstream->zfree = vnc_zlib_zfree; 78 79 err = deflateInit2(zstream, vs->tight.compression, Z_DEFLATED, MAX_WBITS, 80 MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY); 81 82 if (err != Z_OK) { 83 fprintf(stderr, "VNC: error initializing zlib\n"); 84 return -1; 85 } 86 87 vs->zlib.level = vs->tight.compression; 88 zstream->opaque = vs; 89 } 90 91 if (vs->tight.compression != vs->zlib.level) { 92 if (deflateParams(zstream, vs->tight.compression, 93 Z_DEFAULT_STRATEGY) != Z_OK) { 94 return -1; 95 } 96 vs->zlib.level = vs->tight.compression; 97 } 98 99 // reserve memory in output buffer 100 buffer_reserve(&vs->output, vs->zlib.zlib.offset + 64); 101 102 // set pointers 103 zstream->next_in = vs->zlib.zlib.buffer; 104 zstream->avail_in = vs->zlib.zlib.offset; 105 zstream->next_out = vs->output.buffer + vs->output.offset; 106 zstream->avail_out = vs->output.capacity - vs->output.offset; 107 previous_out = zstream->avail_out; 108 zstream->data_type = Z_BINARY; 109 110 // start encoding 111 if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) { 112 fprintf(stderr, "VNC: error during zlib compression\n"); 113 return -1; 114 } 115 116 vs->output.offset = vs->output.capacity - zstream->avail_out; 117 return previous_out - zstream->avail_out; 118 } 119 120 int vnc_zlib_send_framebuffer_update(VncState *vs, int x, int y, int w, int h) 121 { 122 int old_offset, new_offset, bytes_written; 123 124 vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_ZLIB); 125 126 // remember where we put in the follow-up size 127 old_offset = vs->output.offset; 128 vnc_write_s32(vs, 0); 129 130 // compress the stream 131 vnc_zlib_start(vs); 132 vnc_raw_send_framebuffer_update(vs, x, y, w, h); 133 bytes_written = vnc_zlib_stop(vs); 134 135 if (bytes_written == -1) 136 return 0; 137 138 // hack in the size 139 new_offset = vs->output.offset; 140 vs->output.offset = old_offset; 141 vnc_write_u32(vs, bytes_written); 142 vs->output.offset = new_offset; 143 144 return 1; 145 } 146 147 void vnc_zlib_clear(VncState *vs) 148 { 149 if (vs->zlib.stream.opaque) { 150 deflateEnd(&vs->zlib.stream); 151 } 152 buffer_free(&vs->zlib.zlib); 153 } 154