On Wed, Jan 12, 2005 at 03:57:43PM +0000, Colin Watson wrote:
> https://svn.uhulinux.hu/packages/dev/zlib/patches/02-rsync.patch
> ... but I'm afraid I don't know its current state or whether there's a
> newer version available.
Attached in case the URL goes bad. Looks plausible at a first glance.
--
"You grabbed my hand and we fell into it, like a daydream - or a fever."
diff -Naur zlib-1.2.1.orig/deflate.c zlib-1.2.1/deflate.c
--- zlib-1.2.1.orig/deflate.c 2003-11-09 03:33:12.000000000 +0100
+++ zlib-1.2.1/deflate.c 2004-05-04 00:43:27.000000000 +0200
@@ -115,6 +115,17 @@
* See deflate.c for comments about the MIN_MATCH+1.
*/
+#ifndef RSYNC_WIN
+# define RSYNC_WIN 4096
+#endif
+/* Size of rsync window, must be < MAX_DIST */
+
+#define RSYNC_SUM_MATCH(sum) ((sum) % RSYNC_WIN == 0)
+/* Whether window sum matches magic value */
+
+/* Global rsync mode control variable */
+int zlib_rsync = 0;
+
/* Values for max_lazy_match, good_match and max_chain_length, depending on
* the desired pack level (0..9). The values given below have been tuned to
* exclude worst case performance for pathological files. Better values may be
@@ -841,6 +852,10 @@
#ifdef ASMV
match_init(); /* initialize the asm code */
#endif
+
+ /* rsync params */
+ s->rsync_chunk_end = 0xFFFFFFFFUL;
+ s->rsync_sum = 0;
}
#ifndef FASTEST
@@ -1123,6 +1138,8 @@
zmemcpy(s->window, s->window+wsize, (unsigned)wsize);
s->match_start -= wsize;
s->strstart -= wsize; /* we now have strstart >= MAX_DIST */
+ if (s->rsync_chunk_end != 0xFFFFFFFFUL)
+ s->rsync_chunk_end -= wsize;
s->block_start -= (long) wsize;
/* Slide the hash table (could be avoided with 32 bit values
@@ -1184,15 +1201,51 @@
} while (s->lookahead < MIN_LOOKAHEAD && s->strm->avail_in != 0);
}
+local void rsync_roll(s, start, num)
+ deflate_state *s;
+ unsigned start;
+ unsigned num;
+{
+ unsigned i;
+
+ if (start < RSYNC_WIN) {
+ /* before window fills. */
+ for (i = start; i < RSYNC_WIN; i++) {
+ if (i == start + num) return;
+ s->rsync_sum += (ulg)s->window[i];
+ }
+ num -= (RSYNC_WIN - start);
+ start = RSYNC_WIN;
+ }
+
+ /* buffer after window full */
+ for (i = start; i < start+num; i++) {
+ /* New character in */
+ s->rsync_sum += (ulg)s->window[i];
+ /* Old character out */
+ s->rsync_sum -= (ulg)s->window[i - RSYNC_WIN];
+ if (s->rsync_chunk_end == 0xFFFFFFFFUL
+ && RSYNC_SUM_MATCH(s->rsync_sum))
+ s->rsync_chunk_end = i;
+ }
+}
+
+/* ===========================================================================
+ * Set rsync_chunk_end if window sum matches magic value.
+ */
+#define RSYNC_ROLL(s, start, num) \
+ do { if (zlib_rsync) rsync_roll((s), (start), (num)); } while(0)
+
/* ===========================================================================
* Flush the current block, with given end-of-file flag.
* IN assertion: strstart is set to the end of the current match.
*/
-#define FLUSH_BLOCK_ONLY(s, eof) { \
+#define FLUSH_BLOCK_ONLY(s, eof, pad) { \
_tr_flush_block(s, (s->block_start >= 0L ? \
(charf *)&s->window[(unsigned)s->block_start] : \
(charf *)Z_NULL), \
(ulg)((long)s->strstart - s->block_start), \
+ (pad), \
(eof)); \
s->block_start = s->strstart; \
flush_pending(s->strm); \
@@ -1200,8 +1253,8 @@
}
/* Same but force premature exit if necessary. */
-#define FLUSH_BLOCK(s, eof) { \
- FLUSH_BLOCK_ONLY(s, eof); \
+#define FLUSH_BLOCK(s, eof, pad) { \
+ FLUSH_BLOCK_ONLY(s, eof, pad); \
if (s->strm->avail_out == 0) return (eof) ? finish_started : need_more; \
}
@@ -1252,16 +1305,16 @@
/* strstart == 0 is possible when wraparound on 16-bit machine */
s->lookahead = (uInt)(s->strstart - max_start);
s->strstart = (uInt)max_start;
- FLUSH_BLOCK(s, 0);
+ FLUSH_BLOCK(s, 0, 0);
}
/* Flush if we may have to slide, otherwise block_start may become
* negative and the data will be gone:
*/
if (s->strstart - (uInt)s->block_start >= MAX_DIST(s)) {
- FLUSH_BLOCK(s, 0);
+ FLUSH_BLOCK(s, 0, 0);
}
}
- FLUSH_BLOCK(s, flush == Z_FINISH);
+ FLUSH_BLOCK(s, flush == Z_FINISH, 0);
return flush == Z_FINISH ? finish_done : block_done;
}
@@ -1330,6 +1383,7 @@
s->lookahead -= s->match_length;
+ RSYNC_ROLL(s, s->strstart, s->match_length);
/* Insert new strings in the hash table only if the match length
* is not too large. This saves time but degrades compression.
*/
@@ -1363,12 +1417,17 @@
/* No match, output a literal byte */
Tracevv((stderr,"%c", s->window[s->strstart]));
_tr_tally_lit (s, s->window[s->strstart], bflush);
+ RSYNC_ROLL(s, s->strstart, 1);
s->lookahead--;
s->strstart++;
}
- if (bflush) FLUSH_BLOCK(s, 0);
+ if (zlib_rsync && s->strstart > s->rsync_chunk_end) {
+ s->rsync_chunk_end = 0xFFFFFFFFUL;
+ bflush = 2;
+ }
+ if (bflush) FLUSH_BLOCK(s, 0, bflush-1);
}
- FLUSH_BLOCK(s, flush == Z_FINISH);
+ FLUSH_BLOCK(s, flush == Z_FINISH, bflush-1);
return flush == Z_FINISH ? finish_done : block_done;
}
@@ -1457,6 +1516,7 @@
*/
s->lookahead -= s->prev_length-1;
s->prev_length -= 2;
+ RSYNC_ROLL(s, s->strstart, s->prev_length+1);
do {
if (++s->strstart <= max_insert) {
INSERT_STRING(s, s->strstart, hash_head);
@@ -1466,7 +1526,11 @@
s->match_length = MIN_MATCH-1;
s->strstart++;
- if (bflush) FLUSH_BLOCK(s, 0);
+ if (zlib_rsync && s->strstart > s->rsync_chunk_end) {
+ s->rsync_chunk_end = 0xFFFFFFFFUL;
+ bflush = 2;
+ }
+ if (bflush) FLUSH_BLOCK(s, 0, bflush-1);
} else if (s->match_available) {
/* If there was no match at the previous position, output a
@@ -1475,9 +1539,14 @@
*/
Tracevv((stderr,"%c", s->window[s->strstart-1]));
_tr_tally_lit(s, s->window[s->strstart-1], bflush);
+ if (zlib_rsync && s->strstart > s->rsync_chunk_end) {
+ s->rsync_chunk_end = 0xFFFFFFFFUL;
+ bflush = 2;
+ }
if (bflush) {
- FLUSH_BLOCK_ONLY(s, 0);
+ FLUSH_BLOCK_ONLY(s, 0, bflush-1);
}
+ RSYNC_ROLL(s, s->strstart, 1);
s->strstart++;
s->lookahead--;
if (s->strm->avail_out == 0) return need_more;
@@ -1485,7 +1554,14 @@
/* There is no previous match to compare with, wait for
* the next step to decide.
*/
+ if (zlib_rsync && s->strstart > s->rsync_chunk_end) {
+ /* Reset huffman tree */
+ s->rsync_chunk_end = 0xFFFFFFFFUL;
+ bflush = 2;
+ FLUSH_BLOCK(s, 0, bflush-1);
+ }
s->match_available = 1;
+ RSYNC_ROLL(s, s->strstart, 1);
s->strstart++;
s->lookahead--;
}
@@ -1496,7 +1572,7 @@
_tr_tally_lit(s, s->window[s->strstart-1], bflush);
s->match_available = 0;
}
- FLUSH_BLOCK(s, flush == Z_FINISH);
+ FLUSH_BLOCK(s, flush == Z_FINISH, bflush-1);
return flush == Z_FINISH ? finish_done : block_done;
}
#endif /* FASTEST */
diff -Naur zlib-1.2.1.orig/deflate.h zlib-1.2.1/deflate.h
--- zlib-1.2.1.orig/deflate.h 2003-07-24 07:59:56.000000000 +0200
+++ zlib-1.2.1/deflate.h 2004-05-04 00:38:08.000000000 +0200
@@ -255,6 +255,9 @@
* are always zero.
*/
+ ulg rsync_sum; /* rolling sum of rsync window */
+ ulg rsync_chunk_end; /* next rsync sequence point */
+
} FAR deflate_state;
/* Output a byte on the stream.
@@ -277,7 +280,7 @@
void _tr_init OF((deflate_state *s));
int _tr_tally OF((deflate_state *s, unsigned dist, unsigned lc));
void _tr_flush_block OF((deflate_state *s, charf *buf, ulg stored_len,
- int eof));
+ int pad, int eof));
void _tr_align OF((deflate_state *s));
void _tr_stored_block OF((deflate_state *s, charf *buf, ulg stored_len,
int eof));
diff -Naur zlib-1.2.1.orig/trees.c zlib-1.2.1/trees.c
--- zlib-1.2.1.orig/trees.c 2003-09-15 01:48:50.000000000 +0200
+++ zlib-1.2.1/trees.c 2004-05-04 00:37:06.000000000 +0200
@@ -918,10 +918,11 @@
* Determine the best encoding for the current block: dynamic trees, static
* trees or store, and output the encoded block to the zip file.
*/
-void _tr_flush_block(s, buf, stored_len, eof)
+void _tr_flush_block(s, buf, stored_len, pad, eof)
deflate_state *s;
charf *buf; /* input block, or NULL if too old */
ulg stored_len; /* length of input block */
+ int pad; /* pad output to byte boundary */
int eof; /* true if this is the last block for a file */
{
ulg opt_lenb, static_lenb; /* opt_len and static_len in bytes */
@@ -1009,6 +1010,12 @@
#ifdef DEBUG
s->compressed_len += 7; /* align on byte boundary */
#endif
+#ifdef DEBUG
+ } else if (pad && (s->compressed_len % 8) != 0) {
+#else
+ } else if (pad) {
+#endif
+ _tr_stored_block(s, buf, 0, eof);
}
Tracev((stderr,"\ncomprlen %lu(%lu) ", s->compressed_len>>3,
s->compressed_len-7*eof));
diff -Naur zlib-1.2.1.orig/zlib.h zlib-1.2.1/zlib.h
--- zlib-1.2.1.orig/zlib.h 2003-11-17 22:19:11.000000000 +0100
+++ zlib-1.2.1/zlib.h 2004-05-04 00:37:06.000000000 +0200
@@ -1193,6 +1193,10 @@
ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));
ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
+/* Global rsync mode control variable */
+extern int zlib_rsync;
+
+
#ifdef __cplusplus
}
#endif
