/*
- Copyright (C) Andrew Tridgell 1996
- Copyright (C) Paul Mackerras 1996
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
+ * Block matching used by the file-transfer code.
+ *
+ * Copyright (C) 1996 Andrew Tridgell
+ * Copyright (C) 1996 Paul Mackerras
+ * Copyright (C) 2003-2009 Wayne Davison
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, visit the http://fsf.org website.
+ */
#include "rsync.h"
+#include "inums.h"
-extern int verbose;
-extern int do_progress;
extern int checksum_seed;
extern int append_mode;
+extern int checksum_len;
int updating_basis_file;
+char sender_file_sum[MAX_DIGEST_LEN];
static int false_alarms;
static int hash_hits;
extern struct stats stats;
+#define TRADITIONAL_TABLESIZE (1<<16)
+
static uint32 tablesize;
-static int32 *sum_table;
+static int32 *hash_table;
+
+#define SUM2HASH2(s1,s2) (((s1) + (s2)) & 0xFFFF)
+#define SUM2HASH(sum) SUM2HASH2((sum)&0xFFFF,(sum)>>16)
-#define GETTAG(sum) ((sum)%tablesize)
+#define BIG_SUM2HASH(sum) ((sum)%tablesize)
static void build_hash_table(struct sum_struct *s)
{
+ static uint32 alloc_size;
int32 i;
- uint32 prior_size = tablesize;
/* Dynamically calculate the hash table size so that the hash load
- * for big files is about 80%. This number must be odd or s2 will
- * not be able to span the entire set. */
+ * for big files is about 80%. A number greater than the traditional
+ * size must be odd or s2 will not be able to span the entire set. */
tablesize = (uint32)(s->count/8) * 10 + 11;
- if (tablesize < 65537)
- tablesize = 65537; /* a prime number */
- if (tablesize != prior_size) {
- free(sum_table);
- sum_table = new_array(int32, tablesize);
- if (!sum_table)
+ if (tablesize < TRADITIONAL_TABLESIZE)
+ tablesize = TRADITIONAL_TABLESIZE;
+ if (tablesize > alloc_size || tablesize < alloc_size - 16*1024) {
+ if (hash_table)
+ free(hash_table);
+ hash_table = new_array(int32, tablesize);
+ if (!hash_table)
out_of_memory("build_hash_table");
+ alloc_size = tablesize;
}
- memset(sum_table, 0xFF, tablesize * sizeof sum_table[0]);
+ memset(hash_table, 0xFF, tablesize * sizeof hash_table[0]);
- for (i = 0; i < s->count; i++) {
- uint32 t = GETTAG(s->sums[i].sum1);
- s->sums[i].chain = sum_table[t];
- sum_table[t] = i;
+ if (tablesize == TRADITIONAL_TABLESIZE) {
+ for (i = 0; i < s->count; i++) {
+ uint32 t = SUM2HASH(s->sums[i].sum1);
+ s->sums[i].chain = hash_table[t];
+ hash_table[t] = i;
+ }
+ } else {
+ for (i = 0; i < s->count; i++) {
+ uint32 t = BIG_SUM2HASH(s->sums[i].sum1);
+ s->sums[i].chain = hash_table[t];
+ hash_table[t] = i;
+ }
}
}
static OFF_T last_match;
-/**
- * Transmit a literal and/or match token.
+/* Transmit a literal and/or match token.
*
* This delightfully-named function is called either when we find a
* match and need to transmit all the unmatched data leading up to it,
* transmit it. As a result of this second case, it is called even if
* we have not matched at all!
*
- * @param i If >0, the number of a matched token. If 0, indicates we
- * have only literal data.
- **/
+ * If i >= 0, the number of a matched token. If < 0, indicates we have
+ * only literal data. A -1 will send a 0-token-int too, and a -2 sends
+ * only literal data, w/o any token-int. */
static void matched(int f, struct sum_struct *s, struct map_struct *buf,
OFF_T offset, int32 i)
{
- int32 n = offset - last_match; /* max value: block_size (int32) */
+ int32 n = (int32)(offset - last_match); /* max value: block_size (int32) */
int32 j;
- if (verbose > 2 && i >= 0) {
+ if (DEBUG_GTE(DELTASUM, 2) && i >= 0) {
rprintf(FINFO,
- "match at %.0f last_match=%.0f j=%d len=%ld n=%ld\n",
- (double)offset, (double)last_match, i,
+ "match at %s last_match=%s j=%d len=%ld n=%ld\n",
+ big_num(offset), big_num(last_match), i,
(long)s->sums[i].len, (long)n);
}
else
last_match = offset;
- if (buf && do_progress)
+ if (buf && INFO_GTE(PROGRESS, 1))
show_progress(last_match, buf->file_size);
}
static void hash_search(int f,struct sum_struct *s,
struct map_struct *buf, OFF_T len)
{
- OFF_T offset, end, backup;
- int32 k, want_i;
+ OFF_T offset, aligned_offset, end;
+ int32 k, want_i, aligned_i, backup;
char sum2[SUM_LENGTH];
uint32 s1, s2, sum;
int more;
* coding of the output to work more efficiently. */
want_i = 0;
- if (verbose > 2) {
- rprintf(FINFO, "hash search b=%ld len=%.0f\n",
- (long)s->blength, (double)len);
+ if (DEBUG_GTE(DELTASUM, 2)) {
+ rprintf(FINFO, "hash search b=%ld len=%s\n",
+ (long)s->blength, big_num(len));
}
k = (int32)MIN(len, (OFF_T)s->blength);
sum = get_checksum1((char *)map, k);
s1 = sum & 0xFFFF;
s2 = sum >> 16;
- if (verbose > 3)
+ if (DEBUG_GTE(DELTASUM, 3))
rprintf(FINFO, "sum=%.8x k=%ld\n", sum, (long)k);
- offset = 0;
+ offset = aligned_offset = aligned_i = 0;
end = len + 1 - s->sums[s->count-1].len;
- if (verbose > 3) {
- rprintf(FINFO, "hash search s->blength=%ld len=%.0f count=%.0f\n",
- (long)s->blength, (double)len, (double)s->count);
+ if (DEBUG_GTE(DELTASUM, 3)) {
+ rprintf(FINFO, "hash search s->blength=%ld len=%s count=%s\n",
+ (long)s->blength, big_num(len), big_num(s->count));
}
do {
int done_csum2 = 0;
int32 i;
- if (verbose > 4)
- rprintf(FINFO,"offset=%.0f sum=%08x\n",(double)offset,sum);
+ if (DEBUG_GTE(DELTASUM, 4)) {
+ rprintf(FINFO, "offset=%s sum=%04x%04x\n",
+ big_num(offset), s2 & 0xFFFF, s1 & 0xFFFF);
+ }
- i = sum_table[GETTAG(sum)];
- if (i < 0)
- goto null_hash;
+ if (tablesize == TRADITIONAL_TABLESIZE) {
+ if ((i = hash_table[SUM2HASH2(s1,s2)]) < 0)
+ goto null_hash;
+ sum = (s1 & 0xffff) | (s2 << 16);
+ } else {
+ sum = (s1 & 0xffff) | (s2 << 16);
+ if ((i = hash_table[BIG_SUM2HASH(sum)]) < 0)
+ goto null_hash;
+ }
hash_hits++;
do {
&& !(s->sums[i].flags & SUMFLG_SAME_OFFSET))
continue;
- if (verbose > 3) {
+ if (DEBUG_GTE(DELTASUM, 3)) {
rprintf(FINFO,
- "potential match at %.0f i=%ld sum=%08x\n",
- (double)offset, (long)i, sum);
+ "potential match at %s i=%ld sum=%08x\n",
+ big_num(offset), (long)i, sum);
}
if (!done_csum2) {
/* When updating in-place, the best possible match is
* one with an identical offset, so we prefer that over
- * the following want_i optimization. */
+ * the adjacent want_i optimization. */
if (updating_basis_file) {
- int32 i2;
- for (i2 = i; i2 >= 0; i2 = s->sums[i2].chain) {
- if (s->sums[i2].offset != offset)
- continue;
- if (i2 != i) {
- if (sum != s->sums[i2].sum1)
- break;
- if (memcmp(sum2, s->sums[i2].sum2,
- s->s2length) != 0)
- break;
- i = i2;
+ /* All the generator's chunks start at blength boundaries. */
+ while (aligned_offset < offset) {
+ aligned_offset += s->blength;
+ aligned_i++;
+ }
+ if (offset == aligned_offset
+ || (sum == 0 && l == s->blength && aligned_offset + l <= len)) {
+ if (i != aligned_i) {
+ if (sum != s->sums[aligned_i].sum1
+ || l != s->sums[aligned_i].len
+ || memcmp(sum2, s->sums[aligned_i].sum2, s->s2length) != 0)
+ goto check_want_i;
+ i = aligned_i;
+ }
+ if (offset != aligned_offset) {
+ /* We've matched some zeros in a spot that is also zeros
+ * further along in the basis file, if we find zeros ahead
+ * in the sender's file, we'll output enough literal data
+ * to re-align with the basis file, and get back to seeking
+ * instead of writing. */
+ backup = (int32)(aligned_offset - last_match);
+ if (backup < 0)
+ backup = 0;
+ map = (schar *)map_ptr(buf, aligned_offset - backup, l + backup)
+ + backup;
+ sum = get_checksum1((char *)map, l);
+ if (sum != s->sums[i].sum1)
+ goto check_want_i;
+ get_checksum2((char *)map, l, sum2);
+ if (memcmp(sum2, s->sums[i].sum2, s->s2length) != 0)
+ goto check_want_i;
+ /* OK, we have a re-alignment match. Bump the offset
+ * forward to the new match point. */
+ offset = aligned_offset;
}
- /* This chunk was at the same offset on
- * both the sender and the receiver. */
+ /* This identical chunk is in the same spot in the old and new file. */
s->sums[i].flags |= SUMFLG_SAME_OFFSET;
- goto set_want_i;
+ want_i = i;
}
}
+ check_want_i:
/* we've found a match, but now check to see
* if want_i can hint at a better match. */
if (i != want_i && want_i < s->count
* will be happy */
i = want_i;
}
- set_want_i:
want_i = i + 1;
matched(f,s,buf,offset,i);
} while ((i = s->sums[i].chain) >= 0);
null_hash:
- backup = offset - last_match;
+ backup = (int32)(offset - last_match);
/* We sometimes read 1 byte prior to last_match... */
if (backup < 0)
backup = 0;
s2 += s1;
} else
--k;
- sum = (s1 & 0xffff) | (s2 << 16);
/* By matching early we avoid re-reading the
data 3 times in the case where a token
**/
void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
{
- char file_sum[MD4_SUM_LENGTH];
-
last_match = 0;
false_alarms = 0;
hash_hits = 0;
sum_init(checksum_seed);
- if (append_mode) {
- OFF_T j = 0;
- for (j = CHUNK_SIZE; j < s->flength; j += CHUNK_SIZE) {
- if (buf && do_progress)
- show_progress(last_match, buf->file_size);
- sum_update(map_ptr(buf, last_match, CHUNK_SIZE),
- CHUNK_SIZE);
- last_match = j;
- }
- if (last_match < s->flength) {
- int32 len = s->flength - last_match;
- if (buf && do_progress)
- show_progress(last_match, buf->file_size);
- sum_update(map_ptr(buf, last_match, len), len);
- last_match = s->flength;
+ if (append_mode > 0) {
+ if (append_mode == 2) {
+ OFF_T j = 0;
+ for (j = CHUNK_SIZE; j < s->flength; j += CHUNK_SIZE) {
+ if (buf && INFO_GTE(PROGRESS, 1))
+ show_progress(last_match, buf->file_size);
+ sum_update(map_ptr(buf, last_match, CHUNK_SIZE),
+ CHUNK_SIZE);
+ last_match = j;
+ }
+ if (last_match < s->flength) {
+ int32 n = (int32)(s->flength - last_match);
+ if (buf && INFO_GTE(PROGRESS, 1))
+ show_progress(last_match, buf->file_size);
+ sum_update(map_ptr(buf, last_match, n), n);
+ }
}
+ last_match = s->flength;
s->count = 0;
}
if (len > 0 && s->count > 0) {
build_hash_table(s);
- if (verbose > 2)
+ if (DEBUG_GTE(DELTASUM, 2))
rprintf(FINFO,"built hash table\n");
- hash_search(f,s,buf,len);
+ hash_search(f, s, buf, len);
- if (verbose > 2)
+ if (DEBUG_GTE(DELTASUM, 2))
rprintf(FINFO,"done hash search\n");
} else {
OFF_T j;
matched(f, s, buf, len, -1);
}
- sum_end(file_sum);
- /* If we had a read error, send a bad checksum. */
- if (buf && buf->status != 0)
- file_sum[0]++;
+ if (sum_end(sender_file_sum) != checksum_len)
+ overflow_exit("checksum_len"); /* Impossible... */
+
+ /* If we had a read error, send a bad checksum. We use all bits
+ * off as long as the checksum doesn't happen to be that, in
+ * which case we turn the last 0 bit into a 1. */
+ if (buf && buf->status != 0) {
+ int i;
+ for (i = 0; i < checksum_len && sender_file_sum[i] == 0; i++) {}
+ memset(sender_file_sum, 0, checksum_len);
+ if (i == checksum_len)
+ sender_file_sum[i-1]++;
+ }
- if (verbose > 2)
+ if (DEBUG_GTE(DELTASUM, 2))
rprintf(FINFO,"sending file_sum\n");
- write_buf(f,file_sum,MD4_SUM_LENGTH);
+ write_buf(f, sender_file_sum, checksum_len);
- if (verbose > 2)
+ if (DEBUG_GTE(DELTASUM, 2)) {
rprintf(FINFO, "false_alarms=%d hash_hits=%d matches=%d\n",
false_alarms, hash_hits, matches);
+ }
total_hash_hits += hash_hits;
total_false_alarms += false_alarms;
void match_report(void)
{
- if (verbose <= 1)
+ if (!DEBUG_GTE(DELTASUM, 1))
return;
rprintf(FINFO,
- "total: matches=%d hash_hits=%d false_alarms=%d data=%.0f\n",
+ "total: matches=%d hash_hits=%d false_alarms=%d data=%s\n",
total_matches, total_hash_hits, total_false_alarms,
- (double)stats.literal_data);
+ big_num(stats.literal_data));
}
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