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, 80 MAX_WBITS, 81 MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY); 82 83 if (err != Z_OK) { 84 fprintf(stderr, "VNC: error initializing zlib\n"); 85 return -1; 86 } 87 88 vs->zlib.level = vs->tight->compression; 89 zstream->opaque = vs; 90 } 91 92 if (vs->tight->compression != vs->zlib.level) { 93 if (deflateParams(zstream, vs->tight->compression, 94 Z_DEFAULT_STRATEGY) != Z_OK) { 95 return -1; 96 } 97 vs->zlib.level = vs->tight->compression; 98 } 99 100 // reserve memory in output buffer 101 buffer_reserve(&vs->output, vs->zlib.zlib.offset + 64); 102 103 // set pointers 104 zstream->next_in = vs->zlib.zlib.buffer; 105 zstream->avail_in = vs->zlib.zlib.offset; 106 zstream->next_out = vs->output.buffer + vs->output.offset; 107 zstream->avail_out = vs->output.capacity - vs->output.offset; 108 previous_out = zstream->avail_out; 109 zstream->data_type = Z_BINARY; 110 111 // start encoding 112 if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) { 113 fprintf(stderr, "VNC: error during zlib compression\n"); 114 return -1; 115 } 116 117 vs->output.offset = vs->output.capacity - zstream->avail_out; 118 return previous_out - zstream->avail_out; 119 } 120 121 int vnc_zlib_send_framebuffer_update(VncState *vs, int x, int y, int w, int h) 122 { 123 int old_offset, new_offset, bytes_written; 124 125 vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_ZLIB); 126 127 // remember where we put in the follow-up size 128 old_offset = vs->output.offset; 129 vnc_write_s32(vs, 0); 130 131 // compress the stream 132 vnc_zlib_start(vs); 133 vnc_raw_send_framebuffer_update(vs, x, y, w, h); 134 bytes_written = vnc_zlib_stop(vs); 135 136 if (bytes_written == -1) 137 return 0; 138 139 // hack in the size 140 new_offset = vs->output.offset; 141 vs->output.offset = old_offset; 142 vnc_write_u32(vs, bytes_written); 143 vs->output.offset = new_offset; 144 145 return 1; 146 } 147 148 void vnc_zlib_clear(VncState *vs) 149 { 150 if (vs->zlib.stream.opaque) { 151 deflateEnd(&vs->zlib.stream); 152 } 153 buffer_free(&vs->zlib.zlib); 154 } 155