-/*
- 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) 2003-2008 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"
-extern int csum_length;
+extern int checksum_seed;
+extern int append_mode;
-extern int verbose;
-extern int am_server;
-
-extern int remote_version;
-
-typedef unsigned short tag;
-
-#define TABLESIZE (1<<16)
-#define NULL_TAG ((tag)-1)
+int updating_basis_file;
static int false_alarms;
-static int tag_hits;
+static int hash_hits;
static int matches;
-static int data_transfer;
+static int64 data_transfer;
static int total_false_alarms;
-static int total_tag_hits;
+static int total_hash_hits;
static int total_matches;
-static int64 total_data_transfer;
+extern struct stats stats;
-struct target {
- tag t;
- int i;
-};
+#define TRADITIONAL_TABLESIZE (1<<16)
-static struct target *targets;
+static uint32 tablesize;
+static int32 *hash_table;
-static tag *tag_table;
-
-#define gettag2(s1,s2) (((s1) + (s2)) & 0xFFFF)
-#define gettag(sum) gettag2((sum)&0xFFFF,(sum)>>16)
-
-static int compare_targets(struct target *t1,struct target *t2)
-{
- return((int)t1->t - (int)t2->t);
-}
+#define SUM2HASH2(s1,s2) (((s1) + (s2)) & 0xFFFF)
+#define SUM2HASH(sum) SUM2HASH2((sum)&0xFFFF,(sum)>>16)
+#define BIG_SUM2HASH(sum) ((sum)%tablesize)
static void build_hash_table(struct sum_struct *s)
{
- int i;
-
- if (!tag_table)
- tag_table = (tag *)malloc(sizeof(tag)*TABLESIZE);
-
- targets = (struct target *)malloc(sizeof(targets[0])*s->count);
- if (!tag_table || !targets)
- out_of_memory("build_hash_table");
-
- for (i=0;i<s->count;i++) {
- targets[i].i = i;
- targets[i].t = gettag(s->sums[i].sum1);
- }
-
- qsort(targets,s->count,sizeof(targets[0]),(int (*)())compare_targets);
+ static uint32 alloc_size;
+ int32 i;
+
+ /* Dynamically calculate the hash table size so that the hash load
+ * 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 < 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;
+ }
- for (i=0;i<TABLESIZE;i++)
- tag_table[i] = NULL_TAG;
+ memset(hash_table, 0xFF, tablesize * sizeof hash_table[0]);
- for (i=s->count-1;i>=0;i--) {
- tag_table[targets[i].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;
-static void matched(int f,struct sum_struct *s,struct map_struct *buf,
- OFF_T offset,int i)
+/**
+ * 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,
+ * or when we get bored of accumulating literal data and just need to
+ * 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.
+ **/
+static void matched(int f, struct sum_struct *s, struct map_struct *buf,
+ OFF_T offset, int32 i)
{
- OFF_T n = offset - last_match;
- int j;
-
- if (verbose > 2 && i >= 0)
- rprintf(FINFO,"match at %d last_match=%d j=%d len=%d n=%d\n",
- (int)offset,(int)last_match,i,(int)s->sums[i].len,(int)n);
+ int32 n = (int32)(offset - last_match); /* max value: block_size (int32) */
+ int32 j;
+
+ if (DEBUG_GTE(CHKSUM, 2) && i >= 0) {
+ rprintf(FINFO,
+ "match at %s last_match=%s j=%d len=%ld n=%ld\n",
+ big_num(offset, 0), big_num(last_match, 0), i,
+ (long)s->sums[i].len, (long)n);
+ }
- send_token(f,i,buf,last_match,n,i<0?0:s->sums[i].len);
+ send_token(f, i, buf, last_match, n, i < 0 ? 0 : s->sums[i].len);
data_transfer += n;
- if (n > 0)
- write_flush(f);
-
- if (i >= 0)
+ if (i >= 0) {
+ stats.matched_data += s->sums[i].len;
n += s->sums[i].len;
-
- for (j=0;j<n;j+=CHUNK_SIZE) {
- int n1 = MIN(CHUNK_SIZE,n-j);
- sum_update(map_ptr(buf,last_match+j,n1),n1);
}
+ for (j = 0; j < n; j += CHUNK_SIZE) {
+ int32 n1 = MIN(CHUNK_SIZE, n - j);
+ sum_update(map_ptr(buf, last_match + j, n1), n1);
+ }
if (i >= 0)
last_match = offset + s->sums[i].len;
else
last_match = offset;
+
+ 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)
+ struct map_struct *buf, OFF_T len)
{
- OFF_T offset;
- int j,k;
- int end;
+ OFF_T offset, end;
+ int32 k, want_i, backup;
char sum2[SUM_LENGTH];
- uint32 s1, s2, sum;
+ uint32 s1, s2, sum;
+ int more;
schar *map;
- if (verbose > 2)
- rprintf(FINFO,"hash search b=%d len=%d\n",s->n,(int)len);
+ /* want_i is used to encourage adjacent matches, allowing the RLL
+ * coding of the output to work more efficiently. */
+ want_i = 0;
+
+ if (DEBUG_GTE(CHKSUM, 2)) {
+ rprintf(FINFO, "hash search b=%ld len=%s\n",
+ (long)s->blength, big_num(len, 0));
+ }
+
+ k = (int32)MIN(len, (OFF_T)s->blength);
+
+ map = (schar *)map_ptr(buf, 0, k);
- k = MIN(len, s->n);
-
- map = (schar *)map_ptr(buf,0,k);
-
sum = get_checksum1((char *)map, k);
s1 = sum & 0xFFFF;
s2 = sum >> 16;
- if (verbose > 3)
- rprintf(FINFO, "sum=%.8x k=%d\n", sum, k);
-
+ if (DEBUG_GTE(CHKSUM, 3))
+ rprintf(FINFO, "sum=%.8x k=%ld\n", sum, (long)k);
+
offset = 0;
-
+
end = len + 1 - s->sums[s->count-1].len;
-
- if (verbose > 3)
- rprintf(FINFO,"hash search s->n=%d len=%d count=%d\n",
- s->n,(int)len,s->count);
-
+
+ if (DEBUG_GTE(CHKSUM, 3)) {
+ rprintf(FINFO, "hash search s->blength=%ld len=%s count=%s\n",
+ (long)s->blength, big_num(len, 0), big_num(s->count, 0));
+ }
+
do {
- tag t = gettag2(s1,s2);
int done_csum2 = 0;
-
- j = tag_table[t];
- if (verbose > 4)
- rprintf(FINFO,"offset=%d sum=%08x\n",(int)offset,sum);
-
- if (j == NULL_TAG) {
- goto null_tag;
+ int32 i;
+
+ if (DEBUG_GTE(CHKSUM, 4)) {
+ rprintf(FINFO, "offset=%s sum=%04x%04x\n",
+ big_num(offset, 0), s2 & 0xFFFF, s1 & 0xFFFF);
+ }
+
+ 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;
}
- sum = (s1 & 0xffff) | (s2 << 16);
- tag_hits++;
- for (; j<s->count && targets[j].t == t; j++) {
- int i = targets[j].i;
-
- if (sum != s->sums[i].sum1) continue;
-
- if (verbose > 3)
- rprintf(FINFO,"potential match at %d target=%d %d sum=%08x\n",
- (int)offset,j,i,sum);
-
+ hash_hits++;
+ do {
+ int32 l;
+
+ if (sum != s->sums[i].sum1)
+ continue;
+
+ /* also make sure the two blocks are the same length */
+ l = (int32)MIN((OFF_T)s->blength, len-offset);
+ if (l != s->sums[i].len)
+ continue;
+
+ /* in-place: ensure chunk's offset is either >= our
+ * offset or that the data didn't move. */
+ if (updating_basis_file && s->sums[i].offset < offset
+ && !(s->sums[i].flags & SUMFLG_SAME_OFFSET))
+ continue;
+
+ if (DEBUG_GTE(CHKSUM, 3)) {
+ rprintf(FINFO,
+ "potential match at %s i=%ld sum=%08x\n",
+ big_num(offset, 0), (long)i, sum);
+ }
+
if (!done_csum2) {
- int l = MIN(s->n,len-offset);
map = (schar *)map_ptr(buf,offset,l);
get_checksum2((char *)map,l,sum2);
done_csum2 = 1;
}
-
- if (memcmp(sum2,s->sums[i].sum2,csum_length) != 0) {
+
+ if (memcmp(sum2,s->sums[i].sum2,s->s2length) != 0) {
false_alarms++;
continue;
}
-
+
+ /* When updating in-place, the best possible match is
+ * one with an identical offset, so we prefer that over
+ * the following 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;
+ }
+ /* This chunk was at the same offset on
+ * both the sender and the receiver. */
+ s->sums[i].flags |= SUMFLG_SAME_OFFSET;
+ goto set_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
+ && (!updating_basis_file || s->sums[want_i].offset >= offset
+ || s->sums[want_i].flags & SUMFLG_SAME_OFFSET)
+ && sum == s->sums[want_i].sum1
+ && memcmp(sum2, s->sums[want_i].sum2, s->s2length) == 0) {
+ /* we've found an adjacent match - the RLL coder
+ * will be happy */
+ i = want_i;
+ }
+ set_want_i:
+ want_i = i + 1;
+
matched(f,s,buf,offset,i);
offset += s->sums[i].len - 1;
- k = MIN((len-offset), s->n);
- map = (schar *)map_ptr(buf,offset,k);
+ k = (int32)MIN((OFF_T)s->blength, len-offset);
+ map = (schar *)map_ptr(buf, offset, k);
sum = get_checksum1((char *)map, k);
s1 = sum & 0xFFFF;
s2 = sum >> 16;
matches++;
break;
- }
-
- null_tag:
+ } while ((i = s->sums[i].chain) >= 0);
+
+ null_hash:
+ backup = (int32)(offset - last_match);
+ /* We sometimes read 1 byte prior to last_match... */
+ if (backup < 0)
+ backup = 0;
+
/* Trim off the first byte from the checksum */
- map = (schar *)map_ptr(buf,offset,k+1);
+ more = offset + k < len;
+ map = (schar *)map_ptr(buf, offset - backup, k + more + backup)
+ + backup;
s1 -= map[0] + CHAR_OFFSET;
s2 -= k * (map[0]+CHAR_OFFSET);
-
+
/* Add on the next byte (if there is one) to the checksum */
- if (k < (len-offset)) {
- s1 += (map[k]+CHAR_OFFSET);
+ if (more) {
+ s1 += map[k] + CHAR_OFFSET;
s2 += s1;
- } else {
+ } else
--k;
- }
/* By matching early we avoid re-reading the
data 3 times in the case where a token
match. The 3 reads are caused by the
running match, the checksum update and the
literal send. */
- if (offset-last_match >= CHUNK_SIZE+s->n &&
- (end-offset > CHUNK_SIZE)) {
- matched(f,s,buf,offset - s->n, -2);
- }
+ if (backup >= s->blength+CHUNK_SIZE && end-offset > CHUNK_SIZE)
+ matched(f, s, buf, offset - s->blength, -2);
} while (++offset < end);
-
- matched(f,s,buf,len,-1);
- map_ptr(buf,len-1,1);
+
+ matched(f, s, buf, len, -1);
+ map_ptr(buf, len-1, 1);
}
-void match_sums(int f,struct sum_struct *s,struct map_struct *buf,OFF_T len)
+/**
+ * Scan through a origin file, looking for sections that match
+ * checksums from the generator, and transmit either literal or token
+ * data.
+ *
+ * Also calculates the MD4 checksum of the whole file, using the md
+ * accumulator. This is transmitted with the file as protection
+ * against corruption on the wire.
+ *
+ * @param s Checksums received from the generator. If <tt>s->count ==
+ * 0</tt>, then there are actually no checksums for this file.
+ *
+ * @param len Length of the file to send.
+ **/
+void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
{
- char file_sum[MD4_SUM_LENGTH];
+ char file_sum[MAX_DIGEST_LEN];
+ int sum_len;
last_match = 0;
false_alarms = 0;
- tag_hits = 0;
- matches=0;
- data_transfer=0;
-
- sum_init();
+ hash_hits = 0;
+ matches = 0;
+ data_transfer = 0;
+
+ sum_init(checksum_seed);
+
+ 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) {
+ if (len > 0 && s->count > 0) {
build_hash_table(s);
-
- if (verbose > 2)
+
+ if (DEBUG_GTE(CHKSUM, 2))
rprintf(FINFO,"built hash table\n");
-
- hash_search(f,s,buf,len);
-
- if (verbose > 2)
+
+ hash_search(f, s, buf, len);
+
+ if (DEBUG_GTE(CHKSUM, 2))
rprintf(FINFO,"done hash search\n");
} else {
- matched(f,s,buf,len,-1);
+ OFF_T j;
+ /* by doing this in pieces we avoid too many seeks */
+ for (j = last_match + CHUNK_SIZE; j < len; j += CHUNK_SIZE)
+ matched(f, s, buf, j, -2);
+ matched(f, s, buf, len, -1);
}
- sum_end(file_sum);
+ 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 (remote_version >= 14) {
- if (verbose > 2)
- rprintf(FINFO,"sending file_sum\n");
- write_buf(f,file_sum,MD4_SUM_LENGTH);
- }
+ if (DEBUG_GTE(CHKSUM, 2))
+ rprintf(FINFO,"sending file_sum\n");
+ write_buf(f, file_sum, sum_len);
- if (targets) {
- free(targets);
- targets=NULL;
- }
-
- if (verbose > 2)
- rprintf(FINFO, "false_alarms=%d tag_hits=%d matches=%d\n",
- false_alarms, tag_hits, matches);
-
- total_tag_hits += tag_hits;
+ if (DEBUG_GTE(CHKSUM, 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;
total_matches += matches;
- total_data_transfer += data_transfer;
+ stats.literal_data += data_transfer;
}
void match_report(void)
{
- if (verbose <= 1)
+ if (!DEBUG_GTE(CHKSUM, 1))
return;
rprintf(FINFO,
- "total: matches=%d tag_hits=%d false_alarms=%d data=%ld\n",
- total_matches,total_tag_hits,
- total_false_alarms,(long)total_data_transfer);
+ "total: matches=%d hash_hits=%d false_alarms=%d data=%s\n",
+ total_matches, total_hash_hits, total_false_alarms,
+ big_num(stats.literal_data, 0));
}
git.samba.org / rsync.git / blobdiff