mercurial/mpatch.h

perf: add perfprogress command

I've noticed that progress bars can add significant overhead to tight
loops. Let's add a perf command that attempts to isolate that overhead.

With a default hgrc, iteration over 1M items appears to take ~3.75s on
my machine. Profiling reveals ~28% of time is spent in ui.configbool()
resolving the value of the progress.debug config option.

Even if I set progress.disable=true, execution still takes ~2.60s, with
~59% of the time spent in ui.configbool().

Differential Revision: https://phab.mercurial-scm.org/D5407

#ifndef _HG_MPATCH_H_
#define _HG_MPATCH_H_

#define MPATCH_ERR_NO_MEM -3
#define MPATCH_ERR_CANNOT_BE_DECODED -2
#define MPATCH_ERR_INVALID_PATCH -1

struct mpatch_frag {
	int start, end, len;
	const char *data;
};

struct mpatch_flist {
	struct mpatch_frag *base, *head, *tail;
};

int mpatch_decode(const char *bin, ssize_t len, struct mpatch_flist **res);
ssize_t mpatch_calcsize(ssize_t len, struct mpatch_flist *l);
void mpatch_lfree(struct mpatch_flist *a);
int mpatch_apply(char *buf, const char *orig, ssize_t len,
                 struct mpatch_flist *l);
struct mpatch_flist *
mpatch_fold(void *bins, struct mpatch_flist *(*get_next_item)(void *, ssize_t),
            ssize_t start, ssize_t end);

#endif