X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/d5ee1f8e7a370884aa9c5353de5129728ed9a37b..6d56efa6ea66afa2e6f4eb79d9dd5f3b54b723c3:/match.c diff --git a/match.c b/match.c index 2c807279..a3659fc6 100644 --- a/match.c +++ b/match.c @@ -1,257 +1,408 @@ -/* - 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; - -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=0; -static int total_tag_hits=0; -static int total_matches=0; -static int total_data_transfer=0; +static int total_false_alarms; +static int total_hash_hits; +static int total_matches; +extern struct stats stats; -struct target { - tag t; - int i; -}; +#define TRADITIONAL_TABLESIZE (1<<16) -static struct target *targets=NULL; +static uint32 tablesize; +static int32 *hash_table; -static tag *tag_table = NULL; +#define SUM2HASH2(s1,s2) (((s1) + (s2)) & 0xFFFF) +#define SUM2HASH(sum) SUM2HASH2((sum)&0xFFFF,(sum)>>16) -#define gettag2(s1,s2) (((s1) + (s2)) & 0xFFFF) -#define gettag(sum) gettag2((sum)&0xFFFF,(sum)>>16) +#define BIG_SUM2HASH(sum) ((sum)%tablesize) -static int compare_targets(struct target *t1,struct target *t2) +static void build_hash_table(struct sum_struct *s) { - return(t1->t - t2->t); + 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; + } + + memset(hash_table, 0xFF, tablesize * sizeof hash_table[0]); + + 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 void build_hash_table(struct sum_struct *s) -{ - int i; +static OFF_T last_match; - 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"); +/** + * 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) +{ + 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); + } - for (i=0;icount;i++) { - targets[i].i = i; - targets[i].t = gettag(s->sums[i].sum1); - } + send_token(f, i, buf, last_match, n, i < 0 ? 0 : s->sums[i].len); + data_transfer += n; + + if (i >= 0) { + stats.matched_data += s->sums[i].len; + n += s->sums[i].len; + } - qsort(targets,s->count,sizeof(targets[0]),(int (*)())compare_targets); + 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); + } - for (i=0;i= 0) + last_match = offset + s->sums[i].len; + else + last_match = offset; - for (i=s->count-1;i>=0;i--) { - tag_table[targets[i].t] = i; - } + if (buf && INFO_GTE(PROGRESS, 1)) + show_progress(last_match, buf->file_size); } -static off_t last_match; +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; + char sum2[SUM_LENGTH]; + uint32 s1, s2, sum; + int more; + schar *map; + + /* 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); -static void matched(int f,struct sum_struct *s,char *buf,off_t len, - int offset,int i) -{ - int n = offset - last_match; - - if (verbose > 2) - if (i != -1) - fprintf(stderr,"match at %d last_match=%d j=%d len=%d n=%d\n", - (int)offset,(int)last_match,i,(int)s->sums[i].len,n); - - if (n > 0) { - int l = 0; - write_int(f,n); - while (l < n) { - int n1 = MIN(CHUNK_SIZE,n-l); - write_buf(f,map_ptr(buf,last_match+l,n1),n1); - l += n1; - } - data_transfer += n; - } - write_int(f,-(i+1)); - if (i != -1) - last_match = offset + s->sums[i].len; - if (n > 0) - write_flush(f); -} + map = (schar *)map_ptr(buf, 0, k); + sum = get_checksum1((char *)map, k); + s1 = sum & 0xFFFF; + s2 = sum >> 16; + if (DEBUG_GTE(CHKSUM, 3)) + rprintf(FINFO, "sum=%.8x k=%ld\n", sum, (long)k); -static void hash_search(int f,struct sum_struct *s,char *buf,off_t len) -{ - int offset,j,k; - int end; - char sum2[SUM_LENGTH]; - uint32 s1, s2, sum; - char *map; - - if (verbose > 2) - fprintf(stderr,"hash search b=%d len=%d\n",s->n,(int)len); - - k = MIN(len, s->n); - - map = map_ptr(buf,0,k); - - sum = get_checksum1(map, k); - s1 = sum & 0xFFFF; - s2 = sum >> 16; - if (verbose > 3) - fprintf(stderr, "sum=%.8x k=%d\n", sum, k); - - offset = 0; - - end = len + 1 - s->sums[s->count-1].len; - - if (verbose > 3) - fprintf(stderr,"hash search s->n=%d len=%d count=%d\n", - s->n,(int)len,s->count); - - do { - tag t = gettag2(s1,s2); - j = tag_table[t]; - if (verbose > 4) - fprintf(stderr,"offset=%d sum=%08x\n", - offset,sum); - - if (j != NULL_TAG) { - int done_csum2 = 0; - - sum = (s1 & 0xffff) | (s2 << 16); - tag_hits++; - do { - int i = targets[j].i; - - if (sum == s->sums[i].sum1) { - if (verbose > 3) - fprintf(stderr,"potential match at %d target=%d %d sum=%08x\n", - offset,j,i,sum); - - if (!done_csum2) { - int l = MIN(s->n,len-offset); - map = map_ptr(buf,offset,l); - get_checksum2(map,l,sum2); - done_csum2 = 1; - } - if (memcmp(sum2,s->sums[i].sum2,csum_length) == 0) { - matched(f,s,buf,len,offset,i); - offset += s->sums[i].len - 1; - k = MIN((len-offset), s->n); - map = map_ptr(buf,offset,k); - sum = get_checksum1(map, k); - s1 = sum & 0xFFFF; - s2 = sum >> 16; - ++matches; - break; - } else { - false_alarms++; - } + offset = 0; + + end = len + 1 - s->sums[s->count-1].len; + + 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)); } - j++; - } while (jcount && targets[j].t == t); - } - - /* Trim off the first byte from the checksum */ - map = map_ptr(buf,offset,k+1); - s1 -= map[0]; - s2 -= k * map[0]; - - /* Add on the next byte (if there is one) to the checksum */ - if (k < (len-offset)) { - s1 += map[k]; - s2 += s1; - } else { - --k; - } - - } while (++offset < end); - - matched(f,s,buf,len,len,-1); + + do { + int done_csum2 = 0; + 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; + } + + 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) { + map = (schar *)map_ptr(buf,offset,l); + get_checksum2((char *)map,l,sum2); + done_csum2 = 1; + } + + 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 = (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; + } 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 */ + 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 (more) { + s1 += map[k] + CHAR_OFFSET; + s2 += s1; + } else + --k; + + /* By matching early we avoid re-reading the + data 3 times in the case where a token + match comes a long way after last + match. The 3 reads are caused by the + running match, the checksum update and the + literal send. */ + 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); } -void match_sums(int f,struct sum_struct *s,char *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 s->count == + * 0, 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) { - last_match = 0; - false_alarms = 0; - tag_hits = 0; - matches=0; - data_transfer=0; - - if (len > 0 && s->count>0) { - build_hash_table(s); - - if (verbose > 2) - fprintf(stderr,"built hash table\n"); - - hash_search(f,s,buf,len); - - if (verbose > 2) - fprintf(stderr,"done hash search\n"); - } else { - matched(f,s,buf,len,len,-1); - } - - if (targets) { - free(targets); - targets=NULL; - } - - if (verbose > 2) - fprintf(stderr, "false_alarms=%d tag_hits=%d matches=%d\n", - false_alarms, tag_hits, matches); - - total_tag_hits += tag_hits; - total_false_alarms += false_alarms; - total_matches += matches; - total_data_transfer += data_transfer; + char file_sum[MAX_DIGEST_LEN]; + int sum_len; + + last_match = 0; + false_alarms = 0; + 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) { + build_hash_table(s); + + if (DEBUG_GTE(CHKSUM, 2)) + rprintf(FINFO,"built hash table\n"); + + hash_search(f, s, buf, len); + + if (DEBUG_GTE(CHKSUM, 2)) + rprintf(FINFO,"done hash search\n"); + } else { + 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_len = sum_end(file_sum); + /* If we had a read error, send a bad checksum. */ + if (buf && buf->status != 0) + file_sum[0]++; + + if (DEBUG_GTE(CHKSUM, 2)) + rprintf(FINFO,"sending file_sum\n"); + write_buf(f, file_sum, sum_len); + + 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; + stats.literal_data += data_transfer; } void match_report(void) { - if (verbose <= 1) - return; + if (!DEBUG_GTE(CHKSUM, 1)) + return; - fprintf(am_server?stderr:stdout, - "total: matches=%d tag_hits=%d false_alarms=%d data=%d\n", - total_matches,total_tag_hits, - total_false_alarms,total_data_transfer); + rprintf(FINFO, + "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)); }