root / vnc-encoding-zlib.c @ b3e5e3e6
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1 | 70a4568f | Corentin Chary | /*
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2 | 70a4568f | Corentin Chary | * QEMU VNC display driver: zlib encoding
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3 | 70a4568f | Corentin Chary | *
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4 | 70a4568f | Corentin Chary | * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
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5 | 70a4568f | Corentin Chary | * Copyright (C) 2006 Fabrice Bellard
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6 | 70a4568f | Corentin Chary | * Copyright (C) 2009 Red Hat, Inc
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7 | 70a4568f | Corentin Chary | *
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8 | 70a4568f | Corentin Chary | * Permission is hereby granted, free of charge, to any person obtaining a copy
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9 | 70a4568f | Corentin Chary | * of this software and associated documentation files (the "Software"), to deal
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10 | 70a4568f | Corentin Chary | * in the Software without restriction, including without limitation the rights
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11 | 70a4568f | Corentin Chary | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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12 | 70a4568f | Corentin Chary | * copies of the Software, and to permit persons to whom the Software is
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13 | 70a4568f | Corentin Chary | * furnished to do so, subject to the following conditions:
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14 | 70a4568f | Corentin Chary | *
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15 | 70a4568f | Corentin Chary | * The above copyright notice and this permission notice shall be included in
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16 | 70a4568f | Corentin Chary | * all copies or substantial portions of the Software.
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17 | 70a4568f | Corentin Chary | *
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18 | 70a4568f | Corentin Chary | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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19 | 70a4568f | Corentin Chary | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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20 | 70a4568f | Corentin Chary | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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21 | 70a4568f | Corentin Chary | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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22 | 70a4568f | Corentin Chary | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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23 | 70a4568f | Corentin Chary | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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24 | 70a4568f | Corentin Chary | * THE SOFTWARE.
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25 | 70a4568f | Corentin Chary | */
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26 | 70a4568f | Corentin Chary | |
27 | 70a4568f | Corentin Chary | #include "vnc.h" |
28 | 70a4568f | Corentin Chary | |
29 | 70a4568f | Corentin Chary | #define ZALLOC_ALIGNMENT 16 |
30 | 70a4568f | Corentin Chary | |
31 | 70a4568f | Corentin Chary | static void *zalloc(void *x, unsigned items, unsigned size) |
32 | 70a4568f | Corentin Chary | { |
33 | 70a4568f | Corentin Chary | void *p;
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34 | 70a4568f | Corentin Chary | |
35 | 70a4568f | Corentin Chary | size *= items; |
36 | 70a4568f | Corentin Chary | size = (size + ZALLOC_ALIGNMENT - 1) & ~(ZALLOC_ALIGNMENT - 1); |
37 | 70a4568f | Corentin Chary | |
38 | 70a4568f | Corentin Chary | p = qemu_mallocz(size); |
39 | 70a4568f | Corentin Chary | |
40 | 70a4568f | Corentin Chary | return (p);
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41 | 70a4568f | Corentin Chary | } |
42 | 70a4568f | Corentin Chary | |
43 | 70a4568f | Corentin Chary | static void zfree(void *x, void *addr) |
44 | 70a4568f | Corentin Chary | { |
45 | 70a4568f | Corentin Chary | qemu_free(addr); |
46 | 70a4568f | Corentin Chary | } |
47 | 70a4568f | Corentin Chary | |
48 | 70a4568f | Corentin Chary | static void vnc_zlib_start(VncState *vs) |
49 | 70a4568f | Corentin Chary | { |
50 | 70a4568f | Corentin Chary | buffer_reset(&vs->zlib); |
51 | 70a4568f | Corentin Chary | |
52 | 70a4568f | Corentin Chary | // make the output buffer be the zlib buffer, so we can compress it later
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53 | 70a4568f | Corentin Chary | vs->zlib_tmp = vs->output; |
54 | 70a4568f | Corentin Chary | vs->output = vs->zlib; |
55 | 70a4568f | Corentin Chary | } |
56 | 70a4568f | Corentin Chary | |
57 | 70a4568f | Corentin Chary | static int vnc_zlib_stop(VncState *vs, int stream_id) |
58 | 70a4568f | Corentin Chary | { |
59 | 70a4568f | Corentin Chary | z_streamp zstream = &vs->zlib_stream[stream_id]; |
60 | 70a4568f | Corentin Chary | int previous_out;
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61 | 70a4568f | Corentin Chary | |
62 | 70a4568f | Corentin Chary | // switch back to normal output/zlib buffers
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63 | 70a4568f | Corentin Chary | vs->zlib = vs->output; |
64 | 70a4568f | Corentin Chary | vs->output = vs->zlib_tmp; |
65 | 70a4568f | Corentin Chary | |
66 | 70a4568f | Corentin Chary | // compress the zlib buffer
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67 | 70a4568f | Corentin Chary | |
68 | 70a4568f | Corentin Chary | // initialize the stream
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69 | 70a4568f | Corentin Chary | // XXX need one stream per session
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70 | 70a4568f | Corentin Chary | if (zstream->opaque != vs) {
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71 | 70a4568f | Corentin Chary | int err;
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72 | 70a4568f | Corentin Chary | |
73 | 70a4568f | Corentin Chary | VNC_DEBUG("VNC: initializing zlib stream %d\n", stream_id);
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74 | 70a4568f | Corentin Chary | VNC_DEBUG("VNC: opaque = %p | vs = %p\n", zstream->opaque, vs);
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75 | 70a4568f | Corentin Chary | zstream->zalloc = zalloc; |
76 | 70a4568f | Corentin Chary | zstream->zfree = zfree; |
77 | 70a4568f | Corentin Chary | |
78 | 70a4568f | Corentin Chary | err = deflateInit2(zstream, vs->tight_compression, Z_DEFLATED, MAX_WBITS, |
79 | 70a4568f | Corentin Chary | MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY); |
80 | 70a4568f | Corentin Chary | |
81 | 70a4568f | Corentin Chary | if (err != Z_OK) {
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82 | 70a4568f | Corentin Chary | fprintf(stderr, "VNC: error initializing zlib\n");
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83 | 70a4568f | Corentin Chary | return -1; |
84 | 70a4568f | Corentin Chary | } |
85 | 70a4568f | Corentin Chary | |
86 | 70a4568f | Corentin Chary | zstream->opaque = vs; |
87 | 70a4568f | Corentin Chary | } |
88 | 70a4568f | Corentin Chary | |
89 | 70a4568f | Corentin Chary | // XXX what to do if tight_compression changed in between?
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90 | 70a4568f | Corentin Chary | |
91 | 70a4568f | Corentin Chary | // reserve memory in output buffer
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92 | 70a4568f | Corentin Chary | buffer_reserve(&vs->output, vs->zlib.offset + 64);
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93 | 70a4568f | Corentin Chary | |
94 | 70a4568f | Corentin Chary | // set pointers
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95 | 70a4568f | Corentin Chary | zstream->next_in = vs->zlib.buffer; |
96 | 70a4568f | Corentin Chary | zstream->avail_in = vs->zlib.offset; |
97 | 70a4568f | Corentin Chary | zstream->next_out = vs->output.buffer + vs->output.offset; |
98 | 70a4568f | Corentin Chary | zstream->avail_out = vs->output.capacity - vs->output.offset; |
99 | 70a4568f | Corentin Chary | zstream->data_type = Z_BINARY; |
100 | 70a4568f | Corentin Chary | previous_out = zstream->total_out; |
101 | 70a4568f | Corentin Chary | |
102 | 70a4568f | Corentin Chary | // start encoding
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103 | 70a4568f | Corentin Chary | if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
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104 | 70a4568f | Corentin Chary | fprintf(stderr, "VNC: error during zlib compression\n");
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105 | 70a4568f | Corentin Chary | return -1; |
106 | 70a4568f | Corentin Chary | } |
107 | 70a4568f | Corentin Chary | |
108 | 70a4568f | Corentin Chary | vs->output.offset = vs->output.capacity - zstream->avail_out; |
109 | 70a4568f | Corentin Chary | return zstream->total_out - previous_out;
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110 | 70a4568f | Corentin Chary | } |
111 | 70a4568f | Corentin Chary | |
112 | 70a4568f | Corentin Chary | void vnc_zlib_send_framebuffer_update(VncState *vs, int x, int y, int w, int h) |
113 | 70a4568f | Corentin Chary | { |
114 | 70a4568f | Corentin Chary | int old_offset, new_offset, bytes_written;
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115 | 70a4568f | Corentin Chary | |
116 | 70a4568f | Corentin Chary | vnc_framebuffer_update(vs, x, y, w, h, VNC_ENCODING_ZLIB); |
117 | 70a4568f | Corentin Chary | |
118 | 70a4568f | Corentin Chary | // remember where we put in the follow-up size
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119 | 70a4568f | Corentin Chary | old_offset = vs->output.offset; |
120 | 70a4568f | Corentin Chary | vnc_write_s32(vs, 0);
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121 | 70a4568f | Corentin Chary | |
122 | 70a4568f | Corentin Chary | // compress the stream
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123 | 70a4568f | Corentin Chary | vnc_zlib_start(vs); |
124 | 70a4568f | Corentin Chary | vnc_raw_send_framebuffer_update(vs, x, y, w, h); |
125 | 70a4568f | Corentin Chary | bytes_written = vnc_zlib_stop(vs, 0);
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126 | 70a4568f | Corentin Chary | |
127 | 70a4568f | Corentin Chary | if (bytes_written == -1) |
128 | 70a4568f | Corentin Chary | return;
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129 | 70a4568f | Corentin Chary | |
130 | 70a4568f | Corentin Chary | // hack in the size
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131 | 70a4568f | Corentin Chary | new_offset = vs->output.offset; |
132 | 70a4568f | Corentin Chary | vs->output.offset = old_offset; |
133 | 70a4568f | Corentin Chary | vnc_write_u32(vs, bytes_written); |
134 | 70a4568f | Corentin Chary | vs->output.offset = new_offset; |
135 | 70a4568f | Corentin Chary | } |
136 | 70a4568f | Corentin Chary | |
137 | 70a4568f | Corentin Chary | void vnc_zlib_init(VncState *vs)
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138 | 70a4568f | Corentin Chary | { |
139 | 70a4568f | Corentin Chary | int i;
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140 | 70a4568f | Corentin Chary | for (i=0; i<(sizeof(vs->zlib_stream) / sizeof(z_stream)); i++) |
141 | 70a4568f | Corentin Chary | vs->zlib_stream[i].opaque = NULL;
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142 | 70a4568f | Corentin Chary | } |