Chunk a really large file to avoid sender-side hash-table

[rsync/rsync.git] / match.c

diff --git a/match.c b/match.c
index 8367d15..01e9117 100644 (file)
--- a/match.c
+++ b/match.c
@@ -46,9 +46,9 @@ static int32 *hash_table;
 #define SUM2HASH2(s1,s2) (((s1) + (s2)) & 0xFFFF)
 #define SUM2HASH(sum) SUM2HASH2((sum)&0xFFFF,(sum)>>16)
 
-static void build_hash_table(struct sum_struct *s)
+static int32 build_hash_table(struct sum_struct *s, int32 start)
 {
-       int32 i;
+       int32 i, end = s->count;
 
        if (!hash_table) {
                hash_table = new_array(int32, TABLESIZE);
@@ -58,11 +58,21 @@ static void build_hash_table(struct sum_struct *s)
 
        memset(hash_table, 0xFF, TABLESIZE * sizeof hash_table[0]);
 
-       for (i = 0; i < s->count; i++) {
+       if (end - start > TABLESIZE*8/10)
+               end = start + TABLESIZE*8/10;
+
+       for (i = start; i < end; i++) {
                uint32 t = SUM2HASH(s->sums[i].sum1);
                s->sums[i].chain = hash_table[t];
                hash_table[t] = i;
        }
+
+       if (verbose > 2) {
+               rprintf(FINFO, "built hash table for entries %ld - %ld\n",
+                       (long)start, (long)end - 1);
+       }
+
+       return end;
 }
 
 
@@ -120,8 +130,8 @@ 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;
-       int32 k, want_i, backup;
+       OFF_T offset, end, reset = 0;
+       int32 k, want_i, backup, sum_pos = 0;
        char sum2[SUM_LENGTH];
        uint32 s1, s2, sum;
        int more;
@@ -159,6 +169,11 @@ static void hash_search(int f,struct sum_struct *s,
                int done_csum2 = 0;
                int32 i;
 
+               if (offset >= reset) {
+                       sum_pos = build_hash_table(s, sum_pos);
+                       reset = sum_pos * s->blength;
+               }
+
                if (verbose > 4) {
                        rprintf(FINFO, "offset=%.0f sum=%04x%04x\n",
                                (double)offset, s2 & 0xFFFF, s1 & 0xFFFF);
@@ -336,11 +351,6 @@ void match_sums(int f, struct sum_struct *s, struct map_struct *buf, OFF_T len)
        }
 
        if (len > 0 && s->count > 0) {
-               build_hash_table(s);
-
-               if (verbose > 2)
-                       rprintf(FINFO,"built hash table\n");
-
                hash_search(f, s, buf, len);
 
                if (verbose > 2)