X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/5e12ce118622705111df38043132b336590604b0..b9f592fbf50b0dc9e3d1d33b8deb2bf9abad9ef6:/match.c diff --git a/match.c b/match.c index c0ae38c8..d731aae7 100644 --- a/match.c +++ b/match.c @@ -1,17 +1,17 @@ -/* +/* 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. @@ -19,17 +19,15 @@ #include "rsync.h" -extern int csum_length; - extern int verbose; extern int am_server; - -extern int remote_version; +extern int do_progress; +extern int checksum_seed; typedef unsigned short tag; #define TABLESIZE (1<<16) -#define NULL_TAG (-1) +#define NULL_TAG ((size_t)-1) static int false_alarms; static int tag_hits; @@ -43,53 +41,64 @@ static int total_matches; extern struct stats stats; struct target { - tag t; - int i; + tag t; + size_t i; }; static struct target *targets; -static int *tag_table; +static size_t *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); + return (int)t1->t - (int)t2->t; } static void build_hash_table(struct sum_struct *s) { - int i; + size_t i; - if (!tag_table) - tag_table = (int *)malloc(sizeof(tag_table[0])*TABLESIZE); + if (!tag_table) + tag_table = new_array(size_t, TABLESIZE); - targets = (struct target *)malloc(sizeof(targets[0])*s->count); - if (!tag_table || !targets) - out_of_memory("build_hash_table"); + targets = new_array(struct target, s->count); + if (!tag_table || !targets) + out_of_memory("build_hash_table"); - for (i=0;icount;i++) { - targets[i].i = i; - targets[i].t = gettag(s->sums[i].sum1); - } + 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); + qsort(targets,s->count,sizeof(targets[0]),(int (*)())compare_targets); - for (i=0;icount-1;i>=0;i--) { - tag_table[targets[i].t] = i; - } + for (i = s->count; i-- > 0; ) + tag_table[targets[i].t] = i; } static OFF_T last_match; +/** + * 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,int i) { @@ -97,7 +106,7 @@ static void matched(int f,struct sum_struct *s,struct map_struct *buf, OFF_T j; if (verbose > 2 && i >= 0) - rprintf(FINFO,"match at %.0f last_match=%.0f j=%d len=%d n=%.0f\n", + rprintf(FINFO,"match at %.0f last_match=%.0f j=%d len=%u n=%.0f\n", (double)offset,(double)last_match,i,s->sums[i].len,(double)n); send_token(f,i,buf,last_match,n,i<0?0:s->sums[i].len); @@ -107,8 +116,8 @@ static void matched(int f,struct sum_struct *s,struct map_struct *buf, stats.matched_data += s->sums[i].len; n += s->sums[i].len; } - - for (j=0;jfile_size); - if (i == -1) end_progress(buf->file_size); + if (i == -1) + end_progress(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, end; - int j,k, last_i; + unsigned int k; + size_t want_i; char sum2[SUM_LENGTH]; - uint32 s1, s2, sum; + uint32 s1, s2, sum; schar *map; - /* last_i is used to encourage adjacent matches, allowing the RLL coding of the - output to work more efficiently */ - last_i = -1; + /* want_i is used to encourage adjacent matches, allowing the RLL + * coding of the output to work more efficiently. */ + want_i = 0; - if (verbose > 2) - rprintf(FINFO,"hash search b=%d len=%.0f\n",s->n,(double)len); + if (verbose > 2) { + rprintf(FINFO,"hash search b=%u len=%.0f\n", + s->blength, (double)len); + } + + k = MIN(len, 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); - + rprintf(FINFO, "sum=%.8x k=%u\n", sum, k); + offset = 0; - + end = len + 1 - s->sums[s->count-1].len; - - if (verbose > 3) - rprintf(FINFO,"hash search s->n=%d len=%.0f count=%d\n", - s->n,(double)len,s->count); - + + if (verbose > 3) { + rprintf(FINFO, "hash search s->blength=%u len=%.0f count=%.0f\n", + s->blength, (double)len, (double)s->count); + } + do { tag t = gettag2(s1,s2); int done_csum2 = 0; - - j = tag_table[t]; + size_t j = tag_table[t]; + if (verbose > 4) rprintf(FINFO,"offset=%.0f sum=%08x\n",(double)offset,sum); - - if (j == NULL_TAG) { + + if (j == NULL_TAG) goto null_tag; - } sum = (s1 & 0xffff) | (s2 << 16); tag_hits++; - for (; jcount && targets[j].t == t; j++) { - int l, i = targets[j].i; - - if (sum != s->sums[i].sum1) continue; - + do { + unsigned int l; + size_t i = targets[j].i; + + if (sum != s->sums[i].sum1) + continue; + /* also make sure the two blocks are the same length */ - l = MIN(s->n,len-offset); - if (l != s->sums[i].len) continue; + l = MIN((OFF_T)s->blength, len-offset); + if (l != s->sums[i].len) + continue; if (verbose > 3) - rprintf(FINFO,"potential match at %.0f target=%d %d sum=%08x\n", - (double)offset,j,i,sum); - + rprintf(FINFO,"potential match at %.0f target=%.0f %.0f sum=%08x\n", + (double)offset,(double)j,(double)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,csum_length) != 0) { + + if (memcmp(sum2,s->sums[i].sum2,s->s2length) != 0) { false_alarms++; continue; } /* we've found a match, but now check to see - if last_i can hint at a better match */ - for (j++; jcount && targets[j].t == t; j++) { - int i2 = targets[j].i; - if (i2 == last_i + 1) { - if (sum != s->sums[i2].sum1) break; - if (memcmp(sum2,s->sums[i2].sum2,csum_length) != 0) break; - /* we've found an adjacent match - the RLL coder - will be happy */ - i = i2; - break; - } + * if want_i can hint at a better match. */ + if (i != want_i && want_i < s->count + && 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; } + want_i = i + 1; - last_i = i; - 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 = MIN(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 (++j < s->count && targets[j].t == t); + null_tag: /* Trim off the first byte from the checksum */ - map = (schar *)map_ptr(buf,offset,k+1); + map = (schar *)map_ptr(buf, offset, k+1); 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); s2 += s1; - } else { + } else --k; - } /* By matching early we avoid re-reading the data 3 times in the case where a token @@ -246,43 +256,58 @@ static void hash_search(int f,struct sum_struct *s, 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 (offset > last_match + && offset-last_match >= CHUNK_SIZE+s->blength + && 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,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 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) { char file_sum[MD4_SUM_LENGTH]; last_match = 0; false_alarms = 0; tag_hits = 0; - matches=0; - data_transfer=0; + matches = 0; + data_transfer = 0; - sum_init(); + sum_init(checksum_seed); if (len > 0 && s->count>0) { build_hash_table(s); - - if (verbose > 2) + + if (verbose > 2) rprintf(FINFO,"built hash table\n"); - + hash_search(f,s,buf,len); - - if (verbose > 2) + + if (verbose > 2) rprintf(FINFO,"done hash search\n"); } else { OFF_T j; /* by doing this in pieces we avoid too many seeks */ - for (j=0;j<(len-CHUNK_SIZE);j+=CHUNK_SIZE) { + for (j = 0; j < len-CHUNK_SIZE; j += CHUNK_SIZE) { int n1 = MIN(CHUNK_SIZE,(len-CHUNK_SIZE)-j); matched(f,s,buf,j+n1,-2); } @@ -290,22 +315,23 @@ void match_sums(int f,struct sum_struct *s,struct map_struct *buf,OFF_T 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 (verbose > 2) + rprintf(FINFO,"sending file_sum\n"); + write_buf(f,file_sum,MD4_SUM_LENGTH); 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; total_false_alarms += false_alarms; total_matches += matches;