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83907074 MP |
1 | In message <20020403094739.GA5434@samba.org> you write: |
2 | > On 3 Apr 2002, Rusty Russell <rusty@rustcorp.com.au> wrote: | |
3 | > > In message <20020403020455.GC18851@samba.org> you write: | |
4 | > > > Hi, | |
5 | > > > | |
6 | > > > I think you said the other day that you had a working --rsyncable | |
7 | > > > patch for gzip. Could I have it please? | |
8 | > | |
9 | > Thanks for that. I'll put it in with our contrib patches and probably | |
10 | > merge it soon. | |
11 | > | |
12 | > I was actually after the patch to gzip, rather than the fuzzy patch | |
13 | > for rsync. I'd like to try it myself and also distribute it along | |
14 | > with rsync. | |
15 | ||
16 | It's pending for actual gzip inclusion! The maintainer was dug up and | |
17 | everything: it'll even be on by default. | |
18 | ||
19 | But here's the old patch, | |
20 | Rusty. | |
21 | -- | |
22 | Anyone who quotes me in their sig is an idiot. -- Rusty Russell. | |
23 | ||
24 | diff -ur gzip-1.2.4.orig/deflate.c gzip-1.2.4-rsync/deflate.c | |
25 | --- gzip-1.2.4.orig/deflate.c Fri Aug 13 22:35:31 1993 | |
26 | +++ gzip-1.2.4-rsync/deflate.c Sat Dec 30 15:33:25 2000 | |
27 | @@ -121,6 +121,14 @@ | |
28 | #endif | |
29 | /* Matches of length 3 are discarded if their distance exceeds TOO_FAR */ | |
30 | ||
31 | +#ifndef RSYNC_WIN | |
32 | +# define RSYNC_WIN 4096 | |
33 | +#endif | |
34 | +/* Size of rsync window, must be < MAX_DIST */ | |
35 | + | |
36 | +#define RSYNC_SUM_MATCH(sum) ((sum) % RSYNC_WIN == 0) | |
37 | +/* Whether window sum matches magic value */ | |
38 | + | |
39 | /* =========================================================================== | |
40 | * Local data used by the "longest match" routines. | |
41 | */ | |
42 | @@ -202,6 +210,8 @@ | |
43 | unsigned near good_match; | |
44 | /* Use a faster search when the previous match is longer than this */ | |
45 | ||
46 | +local ulg rsync_sum; /* rolling sum of rsync window */ | |
47 | +local ulg rsync_chunk_end; /* next rsync sequence point */ | |
48 | ||
49 | /* Values for max_lazy_match, good_match and max_chain_length, depending on | |
50 | * the desired pack level (0..9). The values given below have been tuned to | |
51 | @@ -300,6 +310,10 @@ | |
52 | #endif | |
53 | /* prev will be initialized on the fly */ | |
54 | ||
55 | + /* rsync params */ | |
56 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
57 | + rsync_sum = 0; | |
58 | + | |
59 | /* Set the default configuration parameters: | |
60 | */ | |
61 | max_lazy_match = configuration_table[pack_level].max_lazy; | |
62 | @@ -536,6 +550,8 @@ | |
63 | memcpy((char*)window, (char*)window+WSIZE, (unsigned)WSIZE); | |
64 | match_start -= WSIZE; | |
65 | strstart -= WSIZE; /* we now have strstart >= MAX_DIST: */ | |
66 | + if (rsync_chunk_end != 0xFFFFFFFFUL) | |
67 | + rsync_chunk_end -= WSIZE; | |
68 | ||
69 | block_start -= (long) WSIZE; | |
70 | ||
71 | @@ -563,13 +579,46 @@ | |
72 | } | |
73 | } | |
74 | ||
75 | +local void rsync_roll(start, num) | |
76 | + unsigned start; | |
77 | + unsigned num; | |
78 | +{ | |
79 | + unsigned i; | |
80 | + | |
81 | + if (start < RSYNC_WIN) { | |
82 | + /* before window fills. */ | |
83 | + for (i = start; i < RSYNC_WIN; i++) { | |
84 | + if (i == start + num) return; | |
85 | + rsync_sum += (ulg)window[i]; | |
86 | + } | |
87 | + num -= (RSYNC_WIN - start); | |
88 | + start = RSYNC_WIN; | |
89 | + } | |
90 | + | |
91 | + /* buffer after window full */ | |
92 | + for (i = start; i < start+num; i++) { | |
93 | + /* New character in */ | |
94 | + rsync_sum += (ulg)window[i]; | |
95 | + /* Old character out */ | |
96 | + rsync_sum -= (ulg)window[i - RSYNC_WIN]; | |
97 | + if (rsync_chunk_end == 0xFFFFFFFFUL && RSYNC_SUM_MATCH(rsync_sum)) | |
98 | + rsync_chunk_end = i; | |
99 | + } | |
100 | +} | |
101 | + | |
102 | +/* =========================================================================== | |
103 | + * Set rsync_chunk_end if window sum matches magic value. | |
104 | + */ | |
105 | +#define RSYNC_ROLL(s, n) \ | |
106 | + do { if (rsync) rsync_roll((s), (n)); } while(0) | |
107 | + | |
108 | /* =========================================================================== | |
109 | * Flush the current block, with given end-of-file flag. | |
110 | * IN assertion: strstart is set to the end of the current match. | |
111 | */ | |
112 | #define FLUSH_BLOCK(eof) \ | |
113 | flush_block(block_start >= 0L ? (char*)&window[(unsigned)block_start] : \ | |
114 | - (char*)NULL, (long)strstart - block_start, (eof)) | |
115 | + (char*)NULL, (long)strstart - block_start, flush-1, (eof)) | |
116 | ||
117 | /* =========================================================================== | |
118 | * Processes a new input file and return its compressed length. This | |
119 | @@ -580,7 +629,7 @@ | |
120 | local ulg deflate_fast() | |
121 | { | |
122 | IPos hash_head; /* head of the hash chain */ | |
123 | - int flush; /* set if current block must be flushed */ | |
124 | + int flush; /* set if current block must be flushed, 2=>and padded */ | |
125 | unsigned match_length = 0; /* length of best match */ | |
126 | ||
127 | prev_length = MIN_MATCH-1; | |
128 | @@ -609,6 +658,7 @@ | |
129 | ||
130 | lookahead -= match_length; | |
131 | ||
132 | + RSYNC_ROLL(strstart, match_length); | |
133 | /* Insert new strings in the hash table only if the match length | |
134 | * is not too large. This saves time but degrades compression. | |
135 | */ | |
136 | @@ -637,9 +687,14 @@ | |
137 | /* No match, output a literal byte */ | |
138 | Tracevv((stderr,"%c",window[strstart])); | |
139 | flush = ct_tally (0, window[strstart]); | |
140 | + RSYNC_ROLL(strstart, 1); | |
141 | lookahead--; | |
142 | strstart++; | |
143 | } | |
144 | + if (rsync && strstart > rsync_chunk_end) { | |
145 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
146 | + flush = 2; | |
147 | + } | |
148 | if (flush) FLUSH_BLOCK(0), block_start = strstart; | |
149 | ||
150 | /* Make sure that we always have enough lookahead, except | |
151 | @@ -715,6 +770,7 @@ | |
152 | */ | |
153 | lookahead -= prev_length-1; | |
154 | prev_length -= 2; | |
155 | + RSYNC_ROLL(strstart, prev_length+1); | |
156 | do { | |
157 | strstart++; | |
158 | INSERT_STRING(strstart, hash_head); | |
159 | @@ -727,24 +783,39 @@ | |
160 | match_available = 0; | |
161 | match_length = MIN_MATCH-1; | |
162 | strstart++; | |
163 | - if (flush) FLUSH_BLOCK(0), block_start = strstart; | |
164 | ||
165 | + if (rsync && strstart > rsync_chunk_end) { | |
166 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
167 | + flush = 2; | |
168 | + } | |
169 | + if (flush) FLUSH_BLOCK(0), block_start = strstart; | |
170 | } else if (match_available) { | |
171 | /* If there was no match at the previous position, output a | |
172 | * single literal. If there was a match but the current match | |
173 | * is longer, truncate the previous match to a single literal. | |
174 | */ | |
175 | Tracevv((stderr,"%c",window[strstart-1])); | |
176 | - if (ct_tally (0, window[strstart-1])) { | |
177 | - FLUSH_BLOCK(0), block_start = strstart; | |
178 | - } | |
179 | + flush = ct_tally (0, window[strstart-1]); | |
180 | + if (rsync && strstart > rsync_chunk_end) { | |
181 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
182 | + flush = 2; | |
183 | + } | |
184 | + if (flush) FLUSH_BLOCK(0), block_start = strstart; | |
185 | + RSYNC_ROLL(strstart, 1); | |
186 | strstart++; | |
187 | lookahead--; | |
188 | } else { | |
189 | /* There is no previous match to compare with, wait for | |
190 | * the next step to decide. | |
191 | */ | |
192 | + if (rsync && strstart > rsync_chunk_end) { | |
193 | + /* Reset huffman tree */ | |
194 | + rsync_chunk_end = 0xFFFFFFFFUL; | |
195 | + flush = 2; | |
196 | + FLUSH_BLOCK(0), block_start = strstart; | |
197 | + } | |
198 | match_available = 1; | |
199 | + RSYNC_ROLL(strstart, 1); | |
200 | strstart++; | |
201 | lookahead--; | |
202 | } | |
203 | diff -ur gzip-1.2.4.orig/gzip.c gzip-1.2.4-rsync/gzip.c | |
204 | --- gzip-1.2.4.orig/gzip.c Thu Aug 19 23:39:43 1993 | |
205 | +++ gzip-1.2.4-rsync/gzip.c Fri Dec 29 21:20:54 2000 | |
206 | @@ -239,6 +239,7 @@ | |
207 | unsigned insize; /* valid bytes in inbuf */ | |
208 | unsigned inptr; /* index of next byte to be processed in inbuf */ | |
209 | unsigned outcnt; /* bytes in output buffer */ | |
210 | +int rsync = 0; /* make ryncable chunks */ | |
211 | ||
212 | struct option longopts[] = | |
213 | { | |
214 | @@ -268,6 +269,7 @@ | |
215 | {"best", 0, 0, '9'}, /* compress better */ | |
216 | {"lzw", 0, 0, 'Z'}, /* make output compatible with old compress */ | |
217 | {"bits", 1, 0, 'b'}, /* max number of bits per code (implies -Z) */ | |
218 | + {"rsyncable", 0, 0, 'R'}, /* make rsync-friendly archive */ | |
219 | { 0, 0, 0, 0 } | |
220 | }; | |
221 | ||
222 | @@ -357,6 +359,7 @@ | |
223 | " -Z --lzw produce output compatible with old compress", | |
224 | " -b --bits maxbits max number of bits per code (implies -Z)", | |
225 | #endif | |
226 | + " --rsyncable Make rsync-friendly archive", | |
227 | " file... files to (de)compress. If none given, use standard input.", | |
228 | 0}; | |
229 | char **p = help_msg; | |
230 | @@ -516,6 +519,9 @@ | |
231 | #else | |
232 | recursive = 1; break; | |
233 | #endif | |
234 | + case 'R': | |
235 | + rsync = 1; break; | |
236 | + | |
237 | case 'S': | |
238 | #ifdef NO_MULTIPLE_DOTS | |
239 | if (*optarg == '.') optarg++; | |
240 | diff -ur gzip-1.2.4.orig/gzip.h gzip-1.2.4-rsync/gzip.h | |
241 | --- gzip-1.2.4.orig/gzip.h Fri Aug 13 22:35:33 1993 | |
242 | +++ gzip-1.2.4-rsync/gzip.h Sat Dec 30 15:26:56 2000 | |
243 | @@ -131,6 +131,7 @@ | |
244 | extern unsigned insize; /* valid bytes in inbuf */ | |
245 | extern unsigned inptr; /* index of next byte to be processed in inbuf */ | |
246 | extern unsigned outcnt; /* bytes in output buffer */ | |
247 | +extern int rsync; /* deflate into rsyncable chunks */ | |
248 | ||
249 | extern long bytes_in; /* number of input bytes */ | |
250 | extern long bytes_out; /* number of output bytes */ | |
251 | @@ -282,7 +283,7 @@ | |
252 | /* in trees.c */ | |
253 | void ct_init OF((ush *attr, int *method)); | |
254 | int ct_tally OF((int dist, int lc)); | |
255 | -ulg flush_block OF((char *buf, ulg stored_len, int eof)); | |
256 | +ulg flush_block OF((char *buf, ulg stored_len, int pad, int eof)); | |
257 | ||
258 | /* in bits.c */ | |
259 | void bi_init OF((file_t zipfile)); | |
260 | diff -ur gzip-1.2.4.orig/gzip.texi gzip-1.2.4-rsync/gzip.texi | |
261 | --- gzip-1.2.4.orig/gzip.texi Thu Aug 19 06:42:50 1993 | |
262 | +++ gzip-1.2.4-rsync/gzip.texi Fri Dec 29 21:20:54 2000 | |
263 | @@ -316,6 +316,14 @@ | |
264 | into the directory and compress all the files it finds there (or | |
265 | decompress them in the case of @code{gunzip}). | |
266 | ||
267 | +@item --rsyncable | |
268 | +While compressing, synchronize the output occasionally based on the | |
269 | +input. This reduces compression by about 1 percent most cases, but | |
270 | +means that the @code{rsync} program can take advantage of similarities | |
271 | +in the uncompressed input when syncronizing two files compressed with | |
272 | +this flag. @code{gunzip} cannot tell the difference between a | |
273 | +compressed file created with this option, and one created without it. | |
274 | + | |
275 | @item --suffix @var{suf} | |
276 | @itemx -S @var{suf} | |
277 | Use suffix @samp{@var{suf}} instead of @samp{.gz}. Any suffix can be | |
278 | diff -ur gzip-1.2.4.orig/trees.c gzip-1.2.4-rsync/trees.c | |
279 | --- gzip-1.2.4.orig/trees.c Wed Aug 18 03:36:32 1993 | |
280 | +++ gzip-1.2.4-rsync/trees.c Sat Dec 30 15:37:00 2000 | |
281 | @@ -850,9 +850,10 @@ | |
282 | * trees or store, and output the encoded block to the zip file. This function | |
283 | * returns the total compressed length for the file so far. | |
284 | */ | |
285 | -ulg flush_block(buf, stored_len, eof) | |
286 | +ulg flush_block(buf, stored_len, pad, eof) | |
287 | char *buf; /* input block, or NULL if too old */ | |
288 | ulg stored_len; /* length of input block */ | |
289 | + int pad; /* pad output to byte boundary */ | |
290 | int eof; /* true if this is the last block for a file */ | |
291 | { | |
292 | ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */ | |
293 | @@ -944,6 +967,10 @@ | |
294 | Assert (input_len == isize, "bad input size"); | |
295 | bi_windup(); | |
296 | compressed_len += 7; /* align on byte boundary */ | |
297 | + } else if (pad && (compressed_len % 8) != 0) { | |
298 | + send_bits((STORED_BLOCK<<1)+eof, 3); /* send block type */ | |
299 | + compressed_len = (compressed_len + 3 + 7) & ~7L; | |
300 | + copy_block(buf, 0, 1); /* with header */ | |
301 | } | |
302 | Tracev((stderr,"\ncomprlen %lu(%lu) ", compressed_len>>3, | |
303 | compressed_len-7*eof)); |