Optimize --inplace chunck search to avoid a non-aligned search.

diff --git a/match.c b/match.c
index 611035f..229c9dd 100644 (file)
--- a/match.c
+++ b/match.c
@@ -142,7 +142,7 @@ 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, aligned_offset, end;
        int32 k, want_i, backup;
        char sum2[SUM_LENGTH];
        uint32 s1, s2, sum;
@@ -168,7 +168,7 @@ static void hash_search(int f,struct sum_struct *s,
        if (DEBUG_GTE(DELTASUM, 3))
                rprintf(FINFO, "sum=%.8x k=%ld\n", sum, (long)k);
 
-       offset = 0;
+       offset = aligned_offset = 0;
 
        end = len + 1 - s->sums[s->count-1].len;
 
@@ -233,24 +233,27 @@ static void hash_search(int f,struct sum_struct *s,
 
                        /* When updating in-place, the best possible match is
                         * one with an identical offset, so we prefer that over
-                        * the following want_i optimization. */
+                        * the adjacent 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;
+                               /* All the sender's chunks start at blength boundaries. */
+                               while (aligned_offset < offset)
+                                       aligned_offset += s->blength;
+                               if (offset == aligned_offset) {
+                                       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
+                                                        || 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;
+                                               want_i = i;
                                        }
-                                       /* 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;
                                }
                        }
 
@@ -265,7 +268,6 @@ static void hash_search(int f,struct sum_struct *s,
                                 * will be happy */
                                i = want_i;
                        }
-                   set_want_i:
                        want_i = i + 1;
 
                        matched(f,s,buf,offset,i);