My version of Mark Curtis's --inplace option.

1 files changed, 33 insertions, 0 deletions

diff --git a/match.c b/match.c
index d731aae7..f3858e5b 100644
--- a/match.c
+++ b/match.c
@@ -23,6 +23,7 @@ extern int verbose;
 extern int am_server;
 extern int do_progress;
 extern int checksum_seed;
+extern int inplace;
 
 typedef unsigned short tag;
 
@@ -200,6 +201,12 @@ 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 && 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);
@@ -215,15 +222,41 @@ 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) {
+				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 want_i can hint at a better match. */
 			if (i != want_i && want_i < s->count
+			    && (!inplace || 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);