*
* Copyright (C) 1996 Andrew Tridgell
* Copyright (C) 1996 Paul Mackerras
- * Copyright (C) 2003-2008 Wayne Davison
+ * 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
*/
#include "rsync.h"
+#include "inums.h"
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;
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 = (int32)(offset - last_match); /* max value: block_size (int32) */
int32 j;
- if (DEBUG_GTE(CHKSUM, 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);
}
static void hash_search(int f,struct sum_struct *s,
struct map_struct *buf, OFF_T len)
{
- OFF_T offset, end;
- int32 k, want_i, backup;
+ 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 (DEBUG_GTE(CHKSUM, 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 (DEBUG_GTE(CHKSUM, 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 (DEBUG_GTE(CHKSUM, 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 (DEBUG_GTE(CHKSUM, 4)) {
- rprintf(FINFO, "offset=%.0f sum=%04x%04x\n",
- (double)offset, s2 & 0xFFFF, s1 & 0xFFFF);
+ if (DEBUG_GTE(DELTASUM, 4)) {
+ rprintf(FINFO, "offset=%s sum=%04x%04x\n",
+ big_num(offset), s2 & 0xFFFF, s1 & 0xFFFF);
}
if (tablesize == TRADITIONAL_TABLESIZE) {
&& !(s->sums[i].flags & SUMFLG_SAME_OFFSET))
continue;
- if (DEBUG_GTE(CHKSUM, 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);
**/
void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
{
- char file_sum[MAX_DIGEST_LEN];
- int sum_len;
-
last_match = 0;
false_alarms = 0;
hash_hits = 0;
if (len > 0 && s->count > 0) {
build_hash_table(s);
- if (DEBUG_GTE(CHKSUM, 2))
+ if (DEBUG_GTE(DELTASUM, 2))
rprintf(FINFO,"built hash table\n");
hash_search(f, s, buf, len);
- if (DEBUG_GTE(CHKSUM, 2))
+ if (DEBUG_GTE(DELTASUM, 2))
rprintf(FINFO,"done hash search\n");
} else {
OFF_T j;
matched(f, s, buf, len, -1);
}
- sum_len = 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 (DEBUG_GTE(CHKSUM, 2))
+ if (DEBUG_GTE(DELTASUM, 2))
rprintf(FINFO,"sending file_sum\n");
- write_buf(f, file_sum, sum_len);
+ write_buf(f, sender_file_sum, checksum_len);
- if (DEBUG_GTE(CHKSUM, 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 (!DEBUG_GTE(CHKSUM, 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));
}
Matt McCutchen's Web Site / rsync / rsync.git / blobdiff