mercurial/mpatch.h

rust-discovery: takefullsample() core implementation

take_full_sample() browses the undecided set in both directions: from
its roots as well as from its heads.

Following what's done on the Python side, we alter update_sample()
signature to take a closure returning an iterator: either ParentsIterator
or an iterator over the children found in `children_cache`. These constructs
should probably be split off in a separate module.

This is a first concrete example where a more abstract graph notion (probably
 a trait) would be useful, as this is nothing but an operation on the reversed
DAG.

A similar motivation in the context of the discovery
process would be to replace the call to dagops::range in
`add_missing_revisions()` with a simple iteration over descendents, again an
operation on the reversed graph.

Differential Revision: https://phab.mercurial-scm.org/D6424

#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