view mercurial/mpatch.h @ 37174:bb47dc2f71a0

context: move reuse of context object to repo.__getitem__ (API)

As an example of how weird the basectx.__new__ is: whenever you create
a workingctx, basectx.__new__ gets called first. Since our __new__ has
a "changeid" argument as second parameter, when create the
workingctx(repo, text="blah"), the text gets bound to
"changeid". Since a string isn't a basectx, our __new__ ends up not
doing anything funny, but that's still very confusing code.

Another case is metadataonlyctx.__new__(), which I think exists in
order to prevent metadataonlyctx.__init__'s third argument
(originalctx) from being interpreted as a changeid in
basectx.__new__(), thereby getting reused.

Let's move this to repo.__getitem__ instead, where it will be pretty
obvious what the code does.

After this patch, changectx(ctx) will be an error (it will fail when
trying to see if it's a 20-byte string).

Differential Revision: https://phab.mercurial-scm.org/D2969

#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