mercurial/mpatch.h

rust-index: add a function to convert PyObject index for hg-core

Function in hg-core need something implementing the `Graph` trait. Right now,
the `hg-cpython` entry points directly turn the PyObject passed as argument
into a `cindex::Index`. However, if we start having the option to use an Index
in Rust, we need to dispatch between the different possible PyObject we could
receive.

So move the "duplicate" call into a unified function. When time come. It will be
easy to update the logic of all interface when the time come.

Differential Revision: https://phab.mercurial-scm.org/D7653

#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