Commit | Line | Data |
---|---|---|
2d205ad5 | 1 | NOTE: this patch is for _gzip_! |
58bf8889 | 2 | |
2d205ad5 WD |
3 | This is pending for actual inclusion in gzip. It is currently being |
4 | tried out in the default gzip for Debian Sarge, and may go into the | |
5 | upstream gzip at somepoint in the not-too-distant future. | |
83907074 | 6 | |
2d205ad5 WD |
7 | --- gzip-1.3.5/deflate.c 1999-10-07 23:46:28 -0700 |
8 | +++ deflate.c 2005-02-05 09:40:33 -0800 | |
9 | @@ -122,6 +122,14 @@ | |
83907074 MP |
10 | #endif |
11 | /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ | |
12 | ||
13 | +#ifndef RSYNC_WIN | |
14 | +# define RSYNC_WIN 4096 | |
15 | +#endif | |
16 | +/* Size of rsync window, must be < MAX_DIST */ | |
17 | + | |
18 | +#define RSYNC_SUM_MATCH(sum) ((sum) % RSYNC_WIN == 0) | |
19 | +/* Whether window sum matches magic value */ | |
20 | + | |
21 | /* =========================================================================== | |
22 | * Local data used by the "longest match" routines. | |
23 | */ | |
2d205ad5 | 24 | @@ -203,6 +211,8 @@ |
83907074 MP |
25 | unsigned near good_match; |
26 | /* Use a faster search when the previous match is longer than this */ | |
27 | ||
28 | +local ulg rsync_sum; /* rolling sum of rsync window */ | |
29 | +local ulg rsync_chunk_end; /* next rsync sequence point */ | |
30 | ||
31 | /* Values for max_lazy_match, good_match and max_chain_length, depending on | |
32 | * the desired pack level (0..9). The values given below have been tuned to | |
2d205ad5 | 33 | @@ -301,6 +311,10 @@ |
83907074 MP |
34 | #endif |
35 | /* prev will be initialized on the fly */ | |
36 | ||
37 | + /* rsync params */ | |
38 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
39 | + rsync_sum = 0; | |
40 | + | |
41 | /* Set the default configuration parameters: | |
42 | */ | |
43 | max_lazy_match = configuration_table[pack_level].max_lazy; | |
2d205ad5 | 44 | @@ -537,6 +551,8 @@ |
83907074 MP |
45 | memcpy((char*)window, (char*)window+WSIZE, (unsigned)WSIZE); |
46 | match_start -= WSIZE; | |
47 | strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */ | |
48 | + if (rsync_chunk_end != 0xFFFFFFFFUL) | |
49 | + rsync_chunk_end -= WSIZE; | |
50 | ||
51 | block_start -= (long) WSIZE; | |
52 | ||
2d205ad5 | 53 | @@ -564,13 +580,46 @@ |
83907074 MP |
54 | } |
55 | } | |
56 | ||
57 | +local void rsync_roll(start, num) | |
58 | + unsigned start; | |
59 | + unsigned num; | |
60 | +{ | |
61 | + unsigned i; | |
62 | + | |
63 | + if (start < RSYNC_WIN) { | |
64 | + /* before window fills. */ | |
65 | + for (i = start; i < RSYNC_WIN; i++) { | |
66 | + if (i == start + num) return; | |
67 | + rsync_sum += (ulg)window[i]; | |
68 | + } | |
69 | + num -= (RSYNC_WIN - start); | |
70 | + start = RSYNC_WIN; | |
71 | + } | |
72 | + | |
73 | + /* buffer after window full */ | |
74 | + for (i = start; i < start+num; i++) { | |
75 | + /* New character in */ | |
76 | + rsync_sum += (ulg)window[i]; | |
77 | + /* Old character out */ | |
78 | + rsync_sum -= (ulg)window[i - RSYNC_WIN]; | |
79 | + if (rsync_chunk_end == 0xFFFFFFFFUL && RSYNC_SUM_MATCH(rsync_sum)) | |
80 | + rsync_chunk_end = i; | |
81 | + } | |
82 | +} | |
83 | + | |
84 | +/* =========================================================================== | |
85 | + * Set rsync_chunk_end if window sum matches magic value. | |
86 | + */ | |
87 | +#define RSYNC_ROLL(s, n) \ | |
88 | + do { if (rsync) rsync_roll((s), (n)); } while(0) | |
89 | + | |
90 | /* =========================================================================== | |
91 | * Flush the current block, with given end-of-file flag. | |
92 | * IN assertion: strstart is set to the end of the current match. | |
93 | */ | |
94 | #define FLUSH_BLOCK(eof) \ | |
95 | flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \ | |
96 | - (char*)NULL, (long)strstart - block_start, (eof)) | |
97 | + (char*)NULL, (long)strstart - block_start, flush-1, (eof)) | |
98 | ||
99 | /* =========================================================================== | |
100 | * Processes a new input file and return its compressed length. This | |
2d205ad5 WD |
101 | @@ -581,7 +630,7 @@ |
102 | local off_t deflate_fast() | |
83907074 MP |
103 | { |
104 | IPos hash_head; /* head of the hash chain */ | |
105 | - int flush; /* set if current block must be flushed */ | |
106 | + int flush; /* set if current block must be flushed, 2=>and padded */ | |
107 | unsigned match_length = 0; /* length of best match */ | |
108 | ||
109 | prev_length = MIN_MATCH-1; | |
2d205ad5 | 110 | @@ -610,6 +659,7 @@ |
83907074 MP |
111 | |
112 | lookahead -= match_length; | |
113 | ||
114 | + RSYNC_ROLL(strstart, match_length); | |
115 | /* Insert new strings in the hash table only if the match length | |
116 | * is not too large. This saves time but degrades compression. | |
117 | */ | |
2d205ad5 | 118 | @@ -638,9 +688,14 @@ |
83907074 MP |
119 | /* No match, output a literal byte */ |
120 | Tracevv((stderr,"%c",window[strstart])); | |
121 | flush = ct_tally (0, window[strstart]); | |
122 | + RSYNC_ROLL(strstart, 1); | |
123 | lookahead--; | |
124 | strstart++; | |
125 | } | |
126 | + if (rsync && strstart > rsync_chunk_end) { | |
127 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
128 | + flush = 2; | |
129 | + } | |
130 | if (flush) FLUSH_BLOCK(0), block_start = strstart; | |
131 | ||
132 | /* Make sure that we always have enough lookahead, except | |
2d205ad5 | 133 | @@ -713,6 +768,7 @@ |
83907074 MP |
134 | */ |
135 | lookahead -= prev_length-1; | |
136 | prev_length -= 2; | |
137 | + RSYNC_ROLL(strstart, prev_length+1); | |
138 | do { | |
139 | strstart++; | |
140 | INSERT_STRING(strstart, hash_head); | |
2d205ad5 | 141 | @@ -725,24 +781,39 @@ |
83907074 MP |
142 | match_available = 0; |
143 | match_length = MIN_MATCH-1; | |
144 | strstart++; | |
145 | - if (flush) FLUSH_BLOCK(0), block_start = strstart; | |
146 | ||
147 | + if (rsync && strstart > rsync_chunk_end) { | |
148 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
149 | + flush = 2; | |
150 | + } | |
151 | + if (flush) FLUSH_BLOCK(0), block_start = strstart; | |
152 | } else if (match_available) { | |
153 | /* If there was no match at the previous position, output a | |
154 | * single literal. If there was a match but the current match | |
155 | * is longer, truncate the previous match to a single literal. | |
156 | */ | |
157 | Tracevv((stderr,"%c",window[strstart-1])); | |
158 | - if (ct_tally (0, window[strstart-1])) { | |
159 | - FLUSH_BLOCK(0), block_start = strstart; | |
160 | - } | |
161 | + flush = ct_tally (0, window[strstart-1]); | |
162 | + if (rsync && strstart > rsync_chunk_end) { | |
163 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
164 | + flush = 2; | |
165 | + } | |
166 | + if (flush) FLUSH_BLOCK(0), block_start = strstart; | |
167 | + RSYNC_ROLL(strstart, 1); | |
168 | strstart++; | |
169 | lookahead--; | |
170 | } else { | |
171 | /* There is no previous match to compare with, wait for | |
172 | * the next step to decide. | |
173 | */ | |
174 | + if (rsync && strstart > rsync_chunk_end) { | |
175 | + /* Reset huffman tree */ | |
176 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
177 | + flush = 2; | |
178 | + FLUSH_BLOCK(0), block_start = strstart; | |
179 | + } | |
180 | match_available = 1; | |
181 | + RSYNC_ROLL(strstart, 1); | |
182 | strstart++; | |
183 | lookahead--; | |
184 | } | |
2d205ad5 WD |
185 | --- gzip-1.3.5/gzip.c 2002-09-28 00:38:43 -0700 |
186 | +++ gzip.c 2005-02-05 09:40:33 -0800 | |
187 | @@ -256,6 +256,7 @@ | |
83907074 MP |
188 | unsigned insize; /* valid bytes in inbuf */ |
189 | unsigned inptr; /* index of next byte to be processed in inbuf */ | |
190 | unsigned outcnt; /* bytes in output buffer */ | |
191 | +int rsync = 0; /* make ryncable chunks */ | |
192 | ||
193 | struct option longopts[] = | |
194 | { | |
2d205ad5 | 195 | @@ -285,6 +286,7 @@ |
83907074 MP |
196 | {"best", 0, 0, '9'}, /* compress better */ |
197 | {"lzw", 0, 0, 'Z'}, /* make output compatible with old compress */ | |
198 | {"bits", 1, 0, 'b'}, /* max number of bits per code (implies -Z) */ | |
199 | + {"rsyncable", 0, 0, 'R'}, /* make rsync-friendly archive */ | |
200 | { 0, 0, 0, 0 } | |
201 | }; | |
202 | ||
2d205ad5 | 203 | @@ -365,6 +367,7 @@ |
83907074 MP |
204 | " -Z --lzw produce output compatible with old compress", |
205 | " -b --bits maxbits max number of bits per code (implies -Z)", | |
206 | #endif | |
207 | + " --rsyncable Make rsync-friendly archive", | |
208 | " file... files to (de)compress. If none given, use standard input.", | |
2d205ad5 | 209 | "Report bugs to <bug-gzip@gnu.org>.", |
83907074 | 210 | 0}; |
2d205ad5 | 211 | @@ -543,6 +546,9 @@ |
83907074 MP |
212 | #else |
213 | recursive = 1; break; | |
214 | #endif | |
215 | + case 'R': | |
216 | + rsync = 1; break; | |
217 | + | |
218 | case 'S': | |
219 | #ifdef NO_MULTIPLE_DOTS | |
220 | if (*optarg == '.') optarg++; | |
2d205ad5 WD |
221 | --- gzip-1.3.5/gzip.h 2001-09-30 23:53:41 -0700 |
222 | +++ gzip.h 2005-02-05 09:40:33 -0800 | |
223 | @@ -133,6 +133,7 @@ | |
83907074 MP |
224 | extern unsigned insize; /* valid bytes in inbuf */ |
225 | extern unsigned inptr; /* index of next byte to be processed in inbuf */ | |
226 | extern unsigned outcnt; /* bytes in output buffer */ | |
227 | +extern int rsync; /* deflate into rsyncable chunks */ | |
228 | ||
2d205ad5 WD |
229 | extern off_t bytes_in; /* number of input bytes */ |
230 | extern off_t bytes_out; /* number of output bytes */ | |
231 | @@ -281,7 +282,7 @@ | |
83907074 MP |
232 | /* in trees.c */ |
233 | void ct_init OF((ush *attr, int *method)); | |
234 | int ct_tally OF((int dist, int lc)); | |
2d205ad5 WD |
235 | -off_t flush_block OF((char *buf, ulg stored_len, int eof)); |
236 | +off_t flush_block OF((char *buf, ulg stored_len, int pad, int eof)); | |
83907074 MP |
237 | |
238 | /* in bits.c */ | |
239 | void bi_init OF((file_t zipfile)); | |
2d205ad5 WD |
240 | --- gzip-1.3.5/gzip.texi 2002-09-29 23:57:29 -0700 |
241 | +++ gzip.texi 2005-02-05 09:40:33 -0800 | |
242 | @@ -334,6 +334,14 @@ | |
83907074 MP |
243 | into the directory and compress all the files it finds there (or |
244 | decompress them in the case of @code{gunzip}). | |
245 | ||
246 | +@item --rsyncable | |
247 | +While compressing, synchronize the output occasionally based on the | |
2d205ad5 | 248 | +input. This increases size by less than 1 percent most cases, but |
83907074 MP |
249 | +means that the @code{rsync} program can take advantage of similarities |
250 | +in the uncompressed input when syncronizing two files compressed with | |
251 | +this flag. @code{gunzip} cannot tell the difference between a | |
252 | +compressed file created with this option, and one created without it. | |
253 | + | |
254 | @item --suffix @var{suf} | |
255 | @itemx -S @var{suf} | |
256 | Use suffix @samp{@var{suf}} instead of @samp{.gz}. Any suffix can be | |
2d205ad5 WD |
257 | --- gzip-1.3.5/trees.c 1999-10-05 22:00:00 -0700 |
258 | +++ trees.c 2005-02-05 09:40:33 -0800 | |
259 | @@ -46,12 +46,13 @@ | |
260 | * void ct_tally (int dist, int lc); | |
261 | * Save the match info and tally the frequency counts. | |
262 | * | |
263 | - * off_t flush_block (char *buf, ulg stored_len, int eof) | |
264 | + * off_t flush_block (char *buf, ulg stored_len, int pad, int eof) | |
265 | * Determine the best encoding for the current block: dynamic trees, | |
266 | * static trees or store, and output the encoded block to the zip | |
267 | - * file. Returns the total compressed length for the file so far. | |
268 | - * | |
269 | - */ | |
270 | + * file. If pad is set, pads the block to the next | |
271 | + * byte. Returns the total compressed length for the file so | |
272 | + * far. | |
273 | + * */ | |
274 | ||
275 | #include <config.h> | |
276 | #include <ctype.h> | |
277 | @@ -847,9 +848,10 @@ | |
83907074 MP |
278 | * trees or store, and output the encoded block to the zip file. This function |
279 | * returns the total compressed length for the file so far. | |
280 | */ | |
2d205ad5 WD |
281 | -off_t flush_block(buf, stored_len, eof) |
282 | +off_t flush_block(buf, stored_len, pad, eof) | |
83907074 MP |
283 | char *buf; /* input block, or NULL if too old */ |
284 | ulg stored_len; /* length of input block */ | |
285 | + int pad; /* pad output to byte boundary */ | |
286 | int eof; /* true if this is the last block for a file */ | |
287 | { | |
288 | ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ | |
2d205ad5 WD |
289 | @@ -941,6 +943,10 @@ |
290 | Assert (input_len == bytes_in, "bad input size"); | |
83907074 MP |
291 | bi_windup(); |
292 | compressed_len += 7; /* align on byte boundary */ | |
293 | + } else if (pad && (compressed_len % 8) != 0) { | |
294 | + send_bits((STORED_BLOCK<<1)+eof, 3); /* send block type */ | |
295 | + compressed_len = (compressed_len + 3 + 7) & ~7L; | |
296 | + copy_block(buf, 0, 1); /* with header */ | |
297 | } | |
2d205ad5 WD |
298 | |
299 | return compressed_len >> 3; |