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,int offset,int n)
59 int n1 = MIN(CHUNK_SIZE,n-l);
61 write_buf(f,map_ptr(buf,offset+l,n1),n1);
65 write_int(f,-(token+1));
69 /* Memory allocation/freeing routines, called by zlib stuff. */
71 z_alloc(void *opaque, uInt items, uInt size)
73 return malloc(items * size);
77 z_free(void *opaque, void *adrs, uInt nbytes)
82 /* Flag bytes in compressed stream are encoded as follows: */
83 #define END_FLAG 0 /* that's all folks */
84 #define TOKEN_LONG 0x20 /* followed by 32-bit token number */
85 #define TOKENRUN_LONG 0x21 /* ditto with 16-bit run count */
86 #define DEFLATED_DATA 0x40 /* + 6-bit high len, then low len byte */
87 #define TOKEN_REL 0x80 /* + 6-bit relative token number */
88 #define TOKENRUN_REL 0xc0 /* ditto with 16-bit run count */
90 #define MAX_DATA_COUNT 16383 /* fit 14 bit count into 2 bytes with flags */
92 /* For coding runs of tokens */
93 static int last_token = -1;
95 static int last_run_end;
98 static z_stream tx_strm;
103 /* Send a deflated token */
105 send_deflated_token(int f, int token,
106 struct map_struct *buf, int offset, int nb, int toklen)
109 static int init_done;
111 if (last_token == -1) {
114 tx_strm.next_in = NULL;
115 tx_strm.zalloc = z_alloc;
116 tx_strm.zfree = z_free;
117 if (deflateInit2(&tx_strm, Z_DEFAULT_COMPRESSION, 8,
118 -15, 8, Z_DEFAULT_STRATEGY) != Z_OK) {
119 rprintf(FERROR, "compression init failed\n");
122 if ((obuf = malloc(MAX_DATA_COUNT+2)) == NULL)
123 out_of_memory("send_deflated_token");
126 deflateReset(&tx_strm);
130 } else if (nb != 0 || token != last_token + 1
131 || token >= run_start + 65536) {
132 /* output previous run */
133 r = run_start - last_run_end;
134 n = last_token - run_start;
135 if (r >= 0 && r <= 63) {
136 write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
138 write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
139 write_int(f, run_start);
143 write_byte(f, n >> 8);
145 last_run_end = last_token;
152 /* deflate the data starting at offset */
153 tx_strm.avail_in = 0;
154 tx_strm.avail_out = 0;
156 if (tx_strm.avail_in == 0 && nb != 0) {
157 /* give it some more input */
158 n = MIN(nb, CHUNK_SIZE);
159 tx_strm.next_in = (Bytef *)map_ptr(buf, offset, n);
160 tx_strm.avail_in = n;
164 if (tx_strm.avail_out == 0) {
165 tx_strm.next_out = (Bytef *)(obuf + 2);
166 tx_strm.avail_out = MAX_DATA_COUNT;
168 r = deflate(&tx_strm, nb? Z_NO_FLUSH: Z_PACKET_FLUSH);
170 rprintf(FERROR, "deflate returned %d\n", r);
173 if (nb == 0 || tx_strm.avail_out == 0) {
174 n = MAX_DATA_COUNT - tx_strm.avail_out;
176 obuf[0] = DEFLATED_DATA + (n >> 8);
178 write_buf(f, obuf, n+2);
181 } while (nb != 0 || tx_strm.avail_out == 0);
185 /* add the data in the current block to the compressor's
186 history and hash table */
187 tx_strm.next_in = (Bytef *)map_ptr(buf, offset, toklen);
188 tx_strm.avail_in = toklen;
189 tx_strm.next_out = NULL;
190 tx_strm.avail_out = 2 * toklen;
191 r = deflate(&tx_strm, Z_INSERT_ONLY);
192 if (r != Z_OK || tx_strm.avail_in != 0) {
193 rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
194 r, tx_strm.avail_in);
199 /* end of file - clean up */
200 write_byte(f, END_FLAG);
205 /* tells us what the receiver is in the middle of doing */
206 static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;
208 /* for inflating stuff */
209 static z_stream rx_strm;
213 /* for decoding runs of tokens */
217 /* Receive a deflated token and inflate it */
219 recv_deflated_token(int f, char **data)
222 static int init_done;
223 static int saved_flag;
226 switch (recv_state) {
229 rx_strm.next_out = NULL;
230 rx_strm.zalloc = z_alloc;
231 rx_strm.zfree = z_free;
232 if (inflateInit2(&rx_strm, -15) != Z_OK) {
233 rprintf(FERROR, "inflate init failed\n");
236 if ((cbuf = malloc(MAX_DATA_COUNT)) == NULL
237 || (dbuf = malloc(CHUNK_SIZE)) == NULL)
238 out_of_memory("recv_deflated_token");
241 inflateReset(&rx_strm);
250 flag = saved_flag & 0xff;
254 if ((flag & 0xC0) == DEFLATED_DATA) {
255 n = ((flag & 0x3f) << 8) + read_byte(f);
256 read_buf(f, cbuf, n);
257 rx_strm.next_in = (Bytef *)cbuf;
258 rx_strm.avail_in = n;
259 recv_state = r_inflating;
262 if (recv_state == r_inflated) {
263 /* check previous inflated stuff ended correctly */
264 rx_strm.avail_in = 0;
265 rx_strm.next_out = (Bytef *)dbuf;
266 rx_strm.avail_out = CHUNK_SIZE;
267 r = inflate(&rx_strm, Z_PACKET_FLUSH);
268 n = CHUNK_SIZE - rx_strm.avail_out;
270 rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
275 /* have to return some more data and
276 save the flag for later. */
277 saved_flag = flag + 0x10000;
278 if (rx_strm.avail_out != 0)
285 if (flag == END_FLAG) {
286 /* that's all folks */
291 /* here we have a token of some kind */
292 if (flag & TOKEN_REL) {
293 rx_token += flag & 0x3f;
296 rx_token = read_int(f);
298 rx_run = read_byte(f);
299 rx_run += read_byte(f) << 8;
300 recv_state = r_running;
302 return -1 - rx_token;
305 rx_strm.next_out = (Bytef *)dbuf;
306 rx_strm.avail_out = CHUNK_SIZE;
307 r = inflate(&rx_strm, Z_NO_FLUSH);
308 n = CHUNK_SIZE - rx_strm.avail_out;
310 rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
313 if (rx_strm.avail_in == 0)
314 recv_state = r_inflated;
325 return -1 - rx_token;
331 * put the data corresponding to a token that we've just returned
332 * from recv_deflated_token into the decompressor's history buffer.
335 see_deflate_token(char *buf, int len)
339 rx_strm.next_in = (Bytef *)buf;
340 rx_strm.avail_in = len;
341 r = inflateIncomp(&rx_strm);
343 rprintf(FERROR, "inflateIncomp returned %d\n", r);
349 * transmit a verbatim buffer of length n followed by a token
350 * If token == -1 then we have reached EOF
351 * If n == 0 then don't send a buffer
353 void send_token(int f,int token,struct map_struct *buf,int offset,
356 if (!do_compression) {
357 simple_send_token(f,token,buf,offset,n);
359 send_deflated_token(f, token, buf, offset, n, toklen);
365 * receive a token or buffer from the other end. If the reurn value is >0 then
366 * it is a data buffer of that length, and *data will point at the data.
367 * if the return value is -i then it represents token i-1
368 * if the return value is 0 then the end has been reached
370 int recv_token(int f,char **data)
374 if (!do_compression) {
375 tok = simple_recv_token(f,data);
377 tok = recv_deflated_token(f, data);
383 * look at the data corresponding to a token, if necessary
385 void see_token(char *data, int toklen)
388 see_deflate_token(data, toklen);