Merge branch 'jc/blame' into jc/web-blame

[git.git] / diff-delta.c

diff --git a/diff-delta.c b/diff-delta.c
index 8b9172aa2ef7402b0a847815bb11a26d1c4444fe..51df4608a8186e519bcb3b4e67d421c18efb696a 100644 (file)
--- a/diff-delta.c
+++ b/diff-delta.c
@@ -148,11 +148,11 @@ struct delta_index * create_delta_index(const void *buf, unsigned long bufsize)
                return NULL;
 
        /* Determine index hash size.  Note that indexing skips the
-          first byte to allow for optimizing the rabin polynomial
+          first byte to allow for optimizing the Rabin's polynomial
           initialization in create_delta(). */
        entries = (bufsize - 1)  / RABIN_WINDOW;
        hsize = entries / 4;
-       for (i = 4; (1 << i) < hsize && i < 31; i++);
+       for (i = 4; (1u << i) < hsize && i < 31; i++);
        hsize = 1 << i;
        hmask = hsize - 1;
 
@@ -205,7 +205,7 @@ struct delta_index * create_delta_index(const void *buf, unsigned long bufsize)
 
        /*
         * Determine a limit on the number of entries in the same hash
-        * bucket.  This guard us against patological data sets causing
+        * bucket.  This guards us against pathological data sets causing
         * really bad hash distribution with most entries in the same hash
         * bucket that would bring us to O(m*n) computing costs (m and n
         * corresponding to reference and target buffer sizes).
@@ -240,7 +240,7 @@ void free_delta_index(struct delta_index *index)
 
 /*
  * The maximum size for any opcode sequence, including the initial header
- * plus rabin window plus biggest copy.
+ * plus Rabin window plus biggest copy.
  */
 #define MAX_OP_SIZE    (5 + 5 + 1 + RABIN_WINDOW + 7)
 
@@ -308,8 +308,8 @@ create_delta(const struct delta_index *index,
                                continue;
                        if (ref_size > top - src)
                                ref_size = top - src;
-                       if (ref_size > 0x10000)
-                               ref_size = 0x10000;
+                       if (ref_size > 0xffffff)
+                               ref_size = 0xffffff;
                        if (ref_size <= msize)
                                break;
                        while (ref_size-- && *src++ == *ref)
@@ -318,6 +318,8 @@ create_delta(const struct delta_index *index,
                                /* this is our best match so far */
                                msize = ref - entry->ptr;
                                moff = entry->ptr - ref_data;
+                               if (msize >= 0x10000)
+                                       break;  /* this is good enough */
                        }
                }
 
@@ -381,6 +383,8 @@ create_delta(const struct delta_index *index,
                        if (msize & 0xff) { out[outpos++] = msize; i |= 0x10; }
                        msize >>= 8;
                        if (msize & 0xff) { out[outpos++] = msize; i |= 0x20; }
+                       msize >>= 8;
+                       if (msize & 0xff) { out[outpos++] = msize; i |= 0x40; }
 
                        *op = i;
                }
@@ -392,7 +396,7 @@ create_delta(const struct delta_index *index,
                                outsize = max_size + MAX_OP_SIZE + 1;
                        if (max_size && outpos > max_size)
                                break;
-                       out = realloc(out, outsize);
+                       out = xrealloc(out, outsize);
                        if (!out) {
                                free(tmp);
                                return NULL;