mercurial/bdiff.h

revset: use phasecache.getrevset to calculate public()

Other revsets like secret(), draft(), _nonpublic() are using
phasescache.getrevset already. The latter is more efficient after D1606.
So let's migrate the public() revset function too.

Tested using:

  $ hg debugshell --hidden --cwd hg-committed`
  In [1]: %timeit len(repo.revs('public()'))

* Before D1606: 10 loops, best of 3: 22.5 ms per loop
* Before this change, after D1606: 10 loops, best of 3: 28.6 ms per loop
* After this change: 10 loops, best of 3: 20.2 ms per loop

Therefore `public()` revset becomes even slightly faster after the data
structure change by D1606. A similar performance win could also be observed
on a large repo.

A side effect is `phasecache.getrevset` needs to take a `subset` parameter.
That was added with a default value so it won't cause BC issues.

Differential Revision: https://phab.mercurial-scm.org/D1620

#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