view mercurial/bdiff.h @ 39505:c6b8eab5db19

snapshot: also consider the snapshot chain of one unrelated revision

To maximize the chance of good delta chain reuse, we inject an unrelated delta
chain into our search. To do so, we search for the highest revision unrelated
to the parents of the current revision and use its snapshot chain too.

Adding this extra snapshot into the mix can have a performance impact. We'll
deal with performance impact in a later series.

#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