keep the PID file locked for the lifetime of the process
[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 "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 = g_malloc0(size);
39
40 return (p);
41 }
42
43 void vnc_zlib_zfree(void *x, void *addr)
44 {
45 g_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 }