- Use an int32 for the each block-size variable.

[rsync/rsync.git] / match.c

diff --git a/match.c b/match.c
index 8ddbf92..b9336b8 100644 (file)
--- a/match.c
+++ b/match.c
@@ -23,6 +23,8 @@ extern int verbose;
 extern int am_server;
 extern int do_progress;
 extern int checksum_seed;
+extern int inplace;
+extern int make_backups;
 
 typedef unsigned short tag;
 
@@ -140,16 +142,17 @@ static void matched(int f,struct sum_struct *s,struct map_struct *buf,
 static void hash_search(int f,struct sum_struct *s,
                        struct map_struct *buf, OFF_T len)
 {
-       OFF_T offset, end;
+       OFF_T offset, end, backup;
        unsigned int k;
-       size_t last_i;
+       size_t want_i;
        char sum2[SUM_LENGTH];
        uint32 s1, s2, sum;
+       int more;
        schar *map;
 
-       /* last_i is used to encourage adjacent matches, allowing the RLL coding of the
-          output to work more efficiently */
-       last_i = (size_t)-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=%u len=%.0f\n",
@@ -200,6 +203,12 @@ static void hash_search(int f,struct sum_struct *s,
                        if (l != s->sums[i].len)
                                continue;
 
+                       /* inplace: ensure chunk's offset is either >= our
+                        * offset or that the data didn't move. */
+                       if (inplace && !make_backups && s->sums[i].offset < offset
+                           && !(s->sums[i].flags & SUMFLG_SAME_OFFSET))
+                               continue;
+
                        if (verbose > 3)
                                rprintf(FINFO,"potential match at %.0f target=%.0f %.0f sum=%08x\n",
                                        (double)offset,(double)j,(double)i,sum);
@@ -215,16 +224,42 @@ static void hash_search(int f,struct sum_struct *s,
                                continue;
                        }
 
+                       /* If inplace is enabled, the best possible match is
+                        * one with an identical offset, so we prefer that over
+                        * the following want_i optimization. */
+                       if (inplace && !make_backups) {
+                               do {
+                                       size_t i2 = targets[j].i;
+                                       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;
+                               } while (++j < s->count && targets[j].t == t);
+                       }
+
                        /* we've found a match, but now check to see
-                        * if last_i can hint at a better match */
-                       if (i != last_i + 1 && last_i + 1 < s->count
-                           && sum == s->sums[last_i+1].sum1
-                           && memcmp(sum2, s->sums[last_i+1].sum2, s->s2length) == 0) {
+                        * if want_i can hint at a better match. */
+                       if (i != want_i && want_i < s->count
+                           && (!inplace || make_backups || 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 = last_i + 1;
+                               i = want_i;
                        }
-                       last_i = i;
+                   set_want_i:
+                       want_i = i + 1;
 
                        matched(f,s,buf,offset,i);
                        offset += s->sums[i].len - 1;
@@ -238,14 +273,21 @@ static void hash_search(int f,struct sum_struct *s,
                } while (++j < s->count && targets[j].t == t);
 
        null_tag:
+               backup = 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
                        --k;
@@ -256,9 +298,8 @@ 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
-                && offset-last_match >= CHUNK_SIZE+s->blength
-                && end-offset > CHUNK_SIZE) {
+               if (backup >= CHUNK_SIZE + s->blength
+                   && end - offset > CHUNK_SIZE) {
                        matched(f,s,buf,offset - s->blength, -2);
                }
        } while (++offset < end);
@@ -285,7 +326,6 @@ static void hash_search(int f,struct sum_struct *s,
 void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
 {
        char file_sum[MD4_SUM_LENGTH];
-       extern int write_batch;
 
        last_match = 0;
        false_alarms = 0;
@@ -323,8 +363,6 @@ void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
        if (verbose > 2)
                rprintf(FINFO,"sending file_sum\n");
        write_buf(f,file_sum,MD4_SUM_LENGTH);
-       if (write_batch)
-               write_batch_delta_file(file_sum, MD4_SUM_LENGTH);
 
        if (targets) {
                free(targets);