2 Copyright (C) Andrew Tridgell 1996
3 Copyright (C) Paul Mackerras 1996
5 This program 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.
10 This program 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.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 extern int do_compression;
26 /* non-compressing recv token */
27 static int simple_recv_token(int f,char **data)
34 buf = (char *)malloc(CHUNK_SIZE);
35 if (!buf) out_of_memory("simple_recv_token");
45 n = MIN(CHUNK_SIZE,residue);
52 /* non-compressing send token */
53 static void simple_send_token(int f,int token,
54 struct map_struct *buf,OFF_T offset,int n)
59 int n1 = MIN(CHUNK_SIZE,n-l);
61 write_buf(f,map_ptr(buf,offset+l,n1),n1);
65 /* a -2 token means to send data only and no token */
67 write_int(f,-(token+1));
72 /* Memory allocation/freeing routines, called by zlib stuff. */
74 z_alloc(void *opaque, uInt items, uInt size)
76 return malloc(items * size);
80 z_free(void *opaque, void *adrs, uInt nbytes)
85 /* Flag bytes in compressed stream are encoded as follows: */
86 #define END_FLAG 0 /* that's all folks */
87 #define TOKEN_LONG 0x20 /* followed by 32-bit token number */
88 #define TOKENRUN_LONG 0x21 /* ditto with 16-bit run count */
89 #define DEFLATED_DATA 0x40 /* + 6-bit high len, then low len byte */
90 #define TOKEN_REL 0x80 /* + 6-bit relative token number */
91 #define TOKENRUN_REL 0xc0 /* ditto with 16-bit run count */
93 #define MAX_DATA_COUNT 16383 /* fit 14 bit count into 2 bytes with flags */
95 /* For coding runs of tokens */
96 static int last_token = -1;
98 static int last_run_end;
100 /* Deflation state */
101 static z_stream tx_strm;
106 /* Send a deflated token */
108 send_deflated_token(int f, int token,
109 struct map_struct *buf, OFF_T offset, int nb, int toklen)
112 static int init_done;
114 if (last_token == -1) {
117 tx_strm.next_in = NULL;
118 tx_strm.zalloc = z_alloc;
119 tx_strm.zfree = z_free;
120 if (deflateInit2(&tx_strm, Z_DEFAULT_COMPRESSION, 8,
121 -15, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
122 rprintf(FERROR, "compression init failed\n");
125 if ((obuf = malloc(MAX_DATA_COUNT+2)) == NULL)
126 out_of_memory("send_deflated_token");
129 deflateReset(&tx_strm);
133 } else if (nb != 0 || token != last_token + 1
134 || token >= run_start + 65536) {
135 /* output previous run */
136 r = run_start - last_run_end;
137 n = last_token - run_start;
138 if (r >= 0 && r <= 63) {
139 write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
141 write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
142 write_int(f, run_start);
146 write_byte(f, n >> 8);
148 last_run_end = last_token;
155 /* deflate the data starting at offset */
156 tx_strm.avail_in = 0;
157 tx_strm.avail_out = 0;
159 if (tx_strm.avail_in == 0 && nb != 0) {
160 /* give it some more input */
161 n = MIN(nb, CHUNK_SIZE);
162 tx_strm.next_in = (Bytef *)map_ptr(buf, offset, n);
163 tx_strm.avail_in = n;
167 if (tx_strm.avail_out == 0) {
168 tx_strm.next_out = (Bytef *)(obuf + 2);
169 tx_strm.avail_out = MAX_DATA_COUNT;
171 r = deflate(&tx_strm, nb? Z_NO_FLUSH: Z_PACKET_FLUSH);
173 rprintf(FERROR, "deflate returned %d\n", r);
176 if (nb == 0 || tx_strm.avail_out == 0) {
177 n = MAX_DATA_COUNT - tx_strm.avail_out;
179 obuf[0] = DEFLATED_DATA + (n >> 8);
181 write_buf(f, obuf, n+2);
184 } while (nb != 0 || tx_strm.avail_out == 0);
188 /* add the data in the current block to the compressor's
189 history and hash table */
190 tx_strm.next_in = (Bytef *)map_ptr(buf, offset, toklen);
191 tx_strm.avail_in = toklen;
192 tx_strm.next_out = NULL;
193 tx_strm.avail_out = 2 * toklen;
194 r = deflate(&tx_strm, Z_INSERT_ONLY);
195 if (r != Z_OK || tx_strm.avail_in != 0) {
196 rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
197 r, tx_strm.avail_in);
202 /* end of file - clean up */
203 write_byte(f, END_FLAG);
208 /* tells us what the receiver is in the middle of doing */
209 static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;
211 /* for inflating stuff */
212 static z_stream rx_strm;
216 /* for decoding runs of tokens */
220 /* Receive a deflated token and inflate it */
222 recv_deflated_token(int f, char **data)
225 static int init_done;
226 static int saved_flag;
229 switch (recv_state) {
232 rx_strm.next_out = NULL;
233 rx_strm.zalloc = z_alloc;
234 rx_strm.zfree = z_free;
235 if (inflateInit2(&rx_strm, -15) != Z_OK) {
236 rprintf(FERROR, "inflate init failed\n");
239 if ((cbuf = malloc(MAX_DATA_COUNT)) == NULL
240 || (dbuf = malloc(CHUNK_SIZE)) == NULL)
241 out_of_memory("recv_deflated_token");
244 inflateReset(&rx_strm);
253 flag = saved_flag & 0xff;
257 if ((flag & 0xC0) == DEFLATED_DATA) {
258 n = ((flag & 0x3f) << 8) + read_byte(f);
259 read_buf(f, cbuf, n);
260 rx_strm.next_in = (Bytef *)cbuf;
261 rx_strm.avail_in = n;
262 recv_state = r_inflating;
265 if (recv_state == r_inflated) {
266 /* check previous inflated stuff ended correctly */
267 rx_strm.avail_in = 0;
268 rx_strm.next_out = (Bytef *)dbuf;
269 rx_strm.avail_out = CHUNK_SIZE;
270 r = inflate(&rx_strm, Z_PACKET_FLUSH);
271 n = CHUNK_SIZE - rx_strm.avail_out;
273 rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
278 /* have to return some more data and
279 save the flag for later. */
280 saved_flag = flag + 0x10000;
281 if (rx_strm.avail_out != 0)
288 if (flag == END_FLAG) {
289 /* that's all folks */
294 /* here we have a token of some kind */
295 if (flag & TOKEN_REL) {
296 rx_token += flag & 0x3f;
299 rx_token = read_int(f);
301 rx_run = read_byte(f);
302 rx_run += read_byte(f) << 8;
303 recv_state = r_running;
305 return -1 - rx_token;
308 rx_strm.next_out = (Bytef *)dbuf;
309 rx_strm.avail_out = CHUNK_SIZE;
310 r = inflate(&rx_strm, Z_NO_FLUSH);
311 n = CHUNK_SIZE - rx_strm.avail_out;
313 rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
316 if (rx_strm.avail_in == 0)
317 recv_state = r_inflated;
328 return -1 - rx_token;
334 * put the data corresponding to a token that we've just returned
335 * from recv_deflated_token into the decompressor's history buffer.
338 see_deflate_token(char *buf, int len)
342 rx_strm.next_in = (Bytef *)buf;
343 rx_strm.avail_in = len;
344 r = inflateIncomp(&rx_strm);
346 rprintf(FERROR, "inflateIncomp returned %d\n", r);
352 * transmit a verbatim buffer of length n followed by a token
353 * If token == -1 then we have reached EOF
354 * If n == 0 then don't send a buffer
356 void send_token(int f,int token,struct map_struct *buf,OFF_T offset,
359 if (!do_compression) {
360 simple_send_token(f,token,buf,offset,n);
362 send_deflated_token(f, token, buf, offset, n, toklen);
368 * receive a token or buffer from the other end. If the reurn value is >0 then
369 * it is a data buffer of that length, and *data will point at the data.
370 * if the return value is -i then it represents token i-1
371 * if the return value is 0 then the end has been reached
373 int recv_token(int f,char **data)
377 if (!do_compression) {
378 tok = simple_recv_token(f,data);
380 tok = recv_deflated_token(f, data);
386 * look at the data corresponding to a token, if necessary
388 void see_token(char *data, int toklen)
391 see_deflate_token(data, toklen);