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 | |