annotate mercurial/mpatch.h @ 33309:69c4493a54f9

changegroup: don't fail on empty changegroup (API)

I don't know why applying an empty changegroup should be an error. It
seems harmless. I suspect the check was there to find code that
creates empty changegroups just because that would be wasteful. Let's
use develwarn() for that instead, so we catch any such cases that run
with our test runner, but we still allow others to generate empty
changegroups if they want to.

We have run into this check at Google once or twice and had to work
around it, but I'm changing this not so much because of that, but
because it seems like it shouldn't be an error.

I also changed the message slightly to be more modern ("changelog
group" -> "changegroup") and more generic ("received" -> "applied").

#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