mercurial/bdiff.h

dagop: just compare with the last value to deduplicate input of revancestors()

Since we're using a max heap, the current rev should be a duplicate only
if it equals to the previous one. We don't have to maintain the whole seen
set.

  # reverse(ancestors(tip)) using hg repo
  0) 0.086420
  1) 0.081051

#ifndef _HG_BDIFF_H_
#define _HG_BDIFF_H_

struct bdiff_line {
	int hash, n, e;
	ssize_t len;
	const char *l;
};

struct bdiff_hunk;
struct bdiff_hunk {
	int a1, a2, b1, b2;
	struct bdiff_hunk *next;
};

int bdiff_splitlines(const char *a, ssize_t len, struct bdiff_line **lr);
int bdiff_diff(struct bdiff_line *a, int an, struct bdiff_line *b, int bn,
	struct bdiff_hunk *base);
void bdiff_freehunks(struct bdiff_hunk *l);

#endif