--- a/mercurial/bdiff.c Sun Jun 26 17:32:25 2005 +0100
+++ b/mercurial/bdiff.c Sun Jun 26 15:12:51 2005 -0800
@@ -30,6 +30,10 @@
const char *l;
};
+struct pos {
+ int pos, len;
+};
+
struct hunk {
int a1, a2, b1, b2;
};
@@ -87,36 +91,37 @@
static int equatelines(struct line *a, int an, struct line *b, int bn)
{
- int i, j, buckets = 1, t, *h, *l;
+ int i, j, buckets = 1, t;
+ struct pos *h;
/* build a hash table of the next highest power of 2 */
while (buckets < bn + 1)
buckets *= 2;
- h = malloc(buckets * sizeof(int));
- l = calloc(buckets, sizeof(int));
+ h = malloc(buckets * sizeof(struct pos));
buckets = buckets - 1;
- if (!h || !l) {
- free(h);
+ if (!h)
return 0;
- }
/* clear the hash table */
- for (i = 0; i <= buckets; i++)
- h[i] = -1;
+ for (i = 0; i <= buckets; i++) {
+ h[i].pos = -1;
+ h[i].len = 0;
+ }
/* add lines to the hash table chains */
for (i = bn - 1; i >= 0; i--) {
/* find the equivalence class */
- for (j = b[i].h & buckets; h[j] != -1; j = (j + 1) & buckets)
- if (!cmp(b + i, b + h[j]))
+ for (j = b[i].h & buckets; h[j].pos != -1;
+ j = (j + 1) & buckets)
+ if (!cmp(b + i, b + h[j].pos))
break;
/* add to the head of the equivalence class */
- b[i].n = h[j];
+ b[i].n = h[j].pos;
b[i].e = j;
- h[j] = i;
- l[j]++; /* keep track of popularity */
+ h[j].pos = i;
+ h[j].len++; /* keep track of popularity */
}
/* compute popularity threshold */
@@ -125,24 +130,24 @@
/* match items in a to their equivalence class in b */
for (i = 0; i < an; i++) {
/* find the equivalence class */
- for (j = a[i].h & buckets; h[j] != -1; j = (j + 1) & buckets)
- if (!cmp(a + i, b + h[j]))
+ for (j = a[i].h & buckets; h[j].pos != -1;
+ j = (j + 1) & buckets)
+ if (!cmp(a + i, b + h[j].pos))
break;
a[i].e = j; /* use equivalence class for quick compare */
- if(l[j] <= t)
- a[i].n = h[j]; /* point to head of match list */
+ if(h[j].len <= t)
+ a[i].n = h[j].pos; /* point to head of match list */
else
a[i].n = -1; /* too popular */
}
/* discard hash tables */
free(h);
- free(l);
return 1;
}
-static int longest_match(struct line *a, struct line *b, int *jpos, int *jlen,
+static int longest_match(struct line *a, struct line *b, struct pos *pos,
int a1, int a2, int b1, int b2, int *omi, int *omj)
{
int mi = a1, mj = b1, mk = 0, mb = 0, i, j, k;
@@ -155,12 +160,12 @@
/* loop through all lines match a[i] in b */
for (; j != -1 && j < b2; j = b[j].n) {
/* does this extend an earlier match? */
- if (i > a1 && j > b1 && jpos[j - 1] == i - 1)
- k = jlen[j - 1] + 1;
+ if (i > a1 && j > b1 && pos[j - 1].pos == i - 1)
+ k = pos[j - 1].len + 1;
else
k = 1;
- jpos[j] = i;
- jlen[j] = k;
+ pos[j].pos = i;
+ pos[j].len = k;
/* best match so far? */
if (k > mk) {
@@ -189,47 +194,46 @@
return mk + mb;
}
-static void recurse(struct line *a, struct line *b, int *jpos, int *jlen,
+static void recurse(struct line *a, struct line *b, struct pos *pos,
int a1, int a2, int b1, int b2, struct hunklist *l)
{
int i, j, k;
/* find the longest match in this chunk */
- k = longest_match(a, b, jpos, jlen, a1, a2, b1, b2, &i, &j);
+ k = longest_match(a, b, pos, a1, a2, b1, b2, &i, &j);
if (!k)
return;
/* and recurse on the remaining chunks on either side */
- recurse(a, b, jpos, jlen, a1, i, b1, j, l);
+ recurse(a, b, pos, a1, i, b1, j, l);
l->head->a1 = i;
l->head->a2 = i + k;
l->head->b1 = j;
l->head->b2 = j + k;
l->head++;
- recurse(a, b, jpos, jlen, i + k, a2, j + k, b2, l);
+ recurse(a, b, pos, i + k, a2, j + k, b2, l);
}
static struct hunklist diff(struct line *a, int an, struct line *b, int bn)
{
struct hunklist l;
- int *jpos, *jlen, t;
+ struct pos *pos;
+ int t;
/* allocate and fill arrays */
t = equatelines(a, an, b, bn);
- jpos = calloc(bn, sizeof(int));
- jlen = calloc(bn, sizeof(int));
+ pos = calloc(bn, sizeof(struct pos));
l.head = l.base = malloc(sizeof(struct hunk) * ((an + bn) / 4 + 2));
- if (jpos && jlen && l.base && t) {
+ if (pos && l.base && t) {
/* generate the matching block list */
- recurse(a, b, jpos, jlen, 0, an, 0, bn, &l);
+ recurse(a, b, pos, 0, an, 0, bn, &l);
l.head->a1 = an;
l.head->b1 = bn;
l.head++;
}
- free(jpos);
- free(jlen);
+ free(pos);
return l;
}