Merge remote-tracking branch 'remotes/kraxel/tags/pull-vga-20170103-1' into staging
[qemu.git] / ui / vnc-enc-zlib.c
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 }