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1 /*
2  * Copyright (C) 2002 RealVNC Ltd.  All Rights Reserved.
3  * Copyright (C) 2003 Sun Microsystems, Inc.
4  *
5  * This is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This software is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this software; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
18  * USA.
19  */
20 
21 #include "zrleoutstream.h"
22 #include <stdlib.h>
23 
24 #define ZRLE_IN_BUFFER_SIZE  16384
25 #define ZRLE_OUT_BUFFER_SIZE 1024
26 #undef  ZRLE_DEBUG
27 
zrleBufferAlloc(zrleBuffer * buffer,int size)28 static rfbBool zrleBufferAlloc(zrleBuffer *buffer, int size)
29 {
30   buffer->ptr = buffer->start = malloc(size);
31   if (buffer->start == NULL) {
32     buffer->end = NULL;
33     return FALSE;
34   }
35 
36   buffer->end = buffer->start + size;
37 
38   return TRUE;
39 }
40 
zrleBufferFree(zrleBuffer * buffer)41 static void zrleBufferFree(zrleBuffer *buffer)
42 {
43   if (buffer->start)
44     free(buffer->start);
45   buffer->start = buffer->ptr = buffer->end = NULL;
46 }
47 
zrleBufferGrow(zrleBuffer * buffer,int size)48 static rfbBool zrleBufferGrow(zrleBuffer *buffer, int size)
49 {
50   int offset;
51 
52   size  += buffer->end - buffer->start;
53   offset = ZRLE_BUFFER_LENGTH (buffer);
54 
55   buffer->start = realloc(buffer->start, size);
56   if (!buffer->start) {
57     return FALSE;
58   }
59 
60   buffer->end = buffer->start + size;
61   buffer->ptr = buffer->start + offset;
62 
63   return TRUE;
64 }
65 
zrleOutStreamNew(void)66 zrleOutStream *zrleOutStreamNew(void)
67 {
68   zrleOutStream *os;
69 
70   os = malloc(sizeof(zrleOutStream));
71   if (os == NULL)
72     return NULL;
73 
74   if (!zrleBufferAlloc(&os->in, ZRLE_IN_BUFFER_SIZE)) {
75     free(os);
76     return NULL;
77   }
78 
79   if (!zrleBufferAlloc(&os->out, ZRLE_OUT_BUFFER_SIZE)) {
80     zrleBufferFree(&os->in);
81     free(os);
82     return NULL;
83   }
84 
85   os->zs.zalloc = Z_NULL;
86   os->zs.zfree  = Z_NULL;
87   os->zs.opaque = Z_NULL;
88   if (deflateInit(&os->zs, Z_DEFAULT_COMPRESSION) != Z_OK) {
89     zrleBufferFree(&os->in);
90     free(os);
91     return NULL;
92   }
93 
94   return os;
95 }
96 
zrleOutStreamFree(zrleOutStream * os)97 void zrleOutStreamFree (zrleOutStream *os)
98 {
99   deflateEnd(&os->zs);
100   zrleBufferFree(&os->in);
101   zrleBufferFree(&os->out);
102   free(os);
103 }
104 
zrleOutStreamFlush(zrleOutStream * os)105 rfbBool zrleOutStreamFlush(zrleOutStream *os)
106 {
107   os->zs.next_in = os->in.start;
108   os->zs.avail_in = ZRLE_BUFFER_LENGTH (&os->in);
109 
110 #ifdef ZRLE_DEBUG
111   rfbLog("zrleOutStreamFlush: avail_in %d\n", os->zs.avail_in);
112 #endif
113 
114   while (os->zs.avail_in != 0) {
115     do {
116       int ret;
117 
118       if (os->out.ptr >= os->out.end &&
119 	  !zrleBufferGrow(&os->out, os->out.end - os->out.start)) {
120 	rfbLog("zrleOutStreamFlush: failed to grow output buffer\n");
121 	return FALSE;
122       }
123 
124       os->zs.next_out = os->out.ptr;
125       os->zs.avail_out = os->out.end - os->out.ptr;
126 
127 #ifdef ZRLE_DEBUG
128       rfbLog("zrleOutStreamFlush: calling deflate, avail_in %d, avail_out %d\n",
129 	     os->zs.avail_in, os->zs.avail_out);
130 #endif
131 
132       if ((ret = deflate(&os->zs, Z_SYNC_FLUSH)) != Z_OK) {
133 	rfbLog("zrleOutStreamFlush: deflate failed with error code %d\n", ret);
134 	return FALSE;
135       }
136 
137 #ifdef ZRLE_DEBUG
138       rfbLog("zrleOutStreamFlush: after deflate: %d bytes\n",
139 	     os->zs.next_out - os->out.ptr);
140 #endif
141 
142       os->out.ptr = os->zs.next_out;
143     } while (os->zs.avail_out == 0);
144   }
145 
146   os->in.ptr = os->in.start;
147 
148   return TRUE;
149 }
150 
zrleOutStreamOverrun(zrleOutStream * os,int size)151 static int zrleOutStreamOverrun(zrleOutStream *os,
152 				int            size)
153 {
154 #ifdef ZRLE_DEBUG
155   rfbLog("zrleOutStreamOverrun\n");
156 #endif
157 
158   while (os->in.end - os->in.ptr < size && os->in.ptr > os->in.start) {
159     os->zs.next_in = os->in.start;
160     os->zs.avail_in = ZRLE_BUFFER_LENGTH (&os->in);
161 
162     do {
163       int ret;
164 
165       if (os->out.ptr >= os->out.end &&
166 	  !zrleBufferGrow(&os->out, os->out.end - os->out.start)) {
167 	rfbLog("zrleOutStreamOverrun: failed to grow output buffer\n");
168 	return FALSE;
169       }
170 
171       os->zs.next_out = os->out.ptr;
172       os->zs.avail_out = os->out.end - os->out.ptr;
173 
174 #ifdef ZRLE_DEBUG
175       rfbLog("zrleOutStreamOverrun: calling deflate, avail_in %d, avail_out %d\n",
176 	     os->zs.avail_in, os->zs.avail_out);
177 #endif
178 
179       if ((ret = deflate(&os->zs, 0)) != Z_OK) {
180 	rfbLog("zrleOutStreamOverrun: deflate failed with error code %d\n", ret);
181 	return 0;
182       }
183 
184 #ifdef ZRLE_DEBUG
185       rfbLog("zrleOutStreamOverrun: after deflate: %d bytes\n",
186 	     os->zs.next_out - os->out.ptr);
187 #endif
188 
189       os->out.ptr = os->zs.next_out;
190     } while (os->zs.avail_out == 0);
191 
192     /* output buffer not full */
193 
194     if (os->zs.avail_in == 0) {
195       os->in.ptr = os->in.start;
196     } else {
197       /* but didn't consume all the data?  try shifting what's left to the
198        * start of the buffer.
199        */
200       rfbLog("zrleOutStreamOverrun: out buf not full, but in data not consumed\n");
201       memmove(os->in.start, os->zs.next_in, os->in.ptr - os->zs.next_in);
202       os->in.ptr -= os->zs.next_in - os->in.start;
203     }
204   }
205 
206   if (size > os->in.end - os->in.ptr)
207     size = os->in.end - os->in.ptr;
208 
209   return size;
210 }
211 
zrleOutStreamCheck(zrleOutStream * os,int size)212 static int zrleOutStreamCheck(zrleOutStream *os, int size)
213 {
214   if (os->in.ptr + size > os->in.end) {
215     return zrleOutStreamOverrun(os, size);
216   }
217   return size;
218 }
219 
zrleOutStreamWriteBytes(zrleOutStream * os,const zrle_U8 * data,int length)220 void zrleOutStreamWriteBytes(zrleOutStream *os,
221 			     const zrle_U8 *data,
222 			     int            length)
223 {
224   const zrle_U8* dataEnd = data + length;
225   while (data < dataEnd) {
226     int n = zrleOutStreamCheck(os, dataEnd - data);
227     memcpy(os->in.ptr, data, n);
228     os->in.ptr += n;
229     data += n;
230   }
231 }
232 
zrleOutStreamWriteU8(zrleOutStream * os,zrle_U8 u)233 void zrleOutStreamWriteU8(zrleOutStream *os, zrle_U8 u)
234 {
235   zrleOutStreamCheck(os, 1);
236   *os->in.ptr++ = u;
237 }
238 
zrleOutStreamWriteOpaque8(zrleOutStream * os,zrle_U8 u)239 void zrleOutStreamWriteOpaque8(zrleOutStream *os, zrle_U8 u)
240 {
241   zrleOutStreamCheck(os, 1);
242   *os->in.ptr++ = u;
243 }
244 
zrleOutStreamWriteOpaque16(zrleOutStream * os,zrle_U16 u)245 void zrleOutStreamWriteOpaque16 (zrleOutStream *os, zrle_U16 u)
246 {
247   zrleOutStreamCheck(os, 2);
248   *os->in.ptr++ = ((zrle_U8*)&u)[0];
249   *os->in.ptr++ = ((zrle_U8*)&u)[1];
250 }
251 
zrleOutStreamWriteOpaque32(zrleOutStream * os,zrle_U32 u)252 void zrleOutStreamWriteOpaque32 (zrleOutStream *os, zrle_U32 u)
253 {
254   zrleOutStreamCheck(os, 4);
255   *os->in.ptr++ = ((zrle_U8*)&u)[0];
256   *os->in.ptr++ = ((zrle_U8*)&u)[1];
257   *os->in.ptr++ = ((zrle_U8*)&u)[2];
258   *os->in.ptr++ = ((zrle_U8*)&u)[3];
259 }
260 
zrleOutStreamWriteOpaque24A(zrleOutStream * os,zrle_U32 u)261 void zrleOutStreamWriteOpaque24A(zrleOutStream *os, zrle_U32 u)
262 {
263   zrleOutStreamCheck(os, 3);
264   *os->in.ptr++ = ((zrle_U8*)&u)[0];
265   *os->in.ptr++ = ((zrle_U8*)&u)[1];
266   *os->in.ptr++ = ((zrle_U8*)&u)[2];
267 }
268 
zrleOutStreamWriteOpaque24B(zrleOutStream * os,zrle_U32 u)269 void zrleOutStreamWriteOpaque24B(zrleOutStream *os, zrle_U32 u)
270 {
271   zrleOutStreamCheck(os, 3);
272   *os->in.ptr++ = ((zrle_U8*)&u)[1];
273   *os->in.ptr++ = ((zrle_U8*)&u)[2];
274   *os->in.ptr++ = ((zrle_U8*)&u)[3];
275 }
276