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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 = qemu_mallocz(size); | |
39 | ||
40 | return (p); | |
41 | } | |
42 | ||
43 | void vnc_zlib_zfree(void *x, void *addr) | |
44 | { | |
45 | qemu_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 | } |