mercurial/bdiff.h

ancestor: use heapreplace() in place of heappop/heappush()

This should be slightly faster.

Overall perfancestors result::

                 cpython           nginx             mercurial
  -------------  ----------------  ----------------  ----------------
  b6db2e80a9ce^  0.103461          0.006303          0.035716
  8eb2145ff0fb   0.192307 (x1.86)  0.012115 (x1.92)  0.052135 (x1.46)
  this patch     0.139986 (x1.35)  0.006389 (x1.01)  0.037176 (x1.04)

#ifndef _HG_BDIFF_H_
#define _HG_BDIFF_H_

#include "compat.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