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1.1 root 1: /*
2: * QEMU VNC display driver: zlib encoding
3: *
4: * Copyright (C) 2006 Anthony Liguori <[email protected]>
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;
1.1.1.2 ! root 106: previous_out = zstream->avail_out;
1.1 root 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;
1.1.1.2 ! root 116: return previous_out - zstream->avail_out;
1.1 root 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: }
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