- 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++;
- }
- }
- j++;
- } while (j<s->count && 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);
+ OFF_T offset, end;
+ int j,k, last_i;
+ char sum2[SUM_LENGTH];
+ 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;
+
+ if (verbose > 2)
+ rprintf(FINFO,"hash search b=%ld len=%.0f\n",
+ (long) s->blength, (double)len);
+
+ k = MIN(len, (OFF_T)s->blength);
+
+ 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);
+
+ offset = 0;
+
+ end = len + 1 - s->sums[s->count-1].len;
+
+ if (verbose > 3)
+ rprintf(FINFO, "hash search s->blength=%ld len=%.0f count=%ld\n",
+ (long) s->blength, (double) len, (long) s->count);
+
+ do {
+ tag t = gettag2(s1,s2);
+ int done_csum2 = 0;
+
+ j = tag_table[t];
+ if (verbose > 4)
+ rprintf(FINFO,"offset=%.0f sum=%08x\n",(double)offset,sum);
+
+ if (j == NULL_TAG) {
+ goto null_tag;
+ }
+
+ sum = (s1 & 0xffff) | (s2 << 16);
+ tag_hits++;
+ for (; j < (int) s->count && targets[j].t == t; j++) {
+ int l, i = targets[j].i;
+
+ if (sum != s->sums[i].sum1) continue;
+
+ /* also make sure the two blocks are the same length */
+ 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);
+
+ 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;
+ }
+
+ /* we've found a match, but now check to see
+ * if last_i can hint at a better match */
+ for (j++; j < (int) s->count && 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,s->s2length) != 0) break;
+ /* we've found an adjacent match - the RLL coder
+ * will be happy */
+ i = i2;
+ break;
+ }
+ }
+
+ last_i = i;
+
+ matched(f,s,buf,offset,i);
+ offset += s->sums[i].len - 1;
+ k = 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:
+ /* Trim off the first byte from the checksum */
+ 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 {
+ --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 (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);