annotate mercurial/mpatch.h @ 32270:218ca8526ec0

scmutil: make simplekeyvaluefile able to have a non-key-value first line

To ease migration from files with version numbers in their first lines,
we want simplekeyvaluefile to support a non-key-value first line. In this
way, old versions of Mercurial will read such files, discover a newer version
than the one they know how to handle and fail gracefully, rather than with
exception. Shelve's shelvestate file is an example.

#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