mercurial/mpatch.h

wireprotov2: define response data as CBOR

Previously, response data was defined as a stream of bytes. We had
the option to declare it as CBOR using a frame flag.

We've converged all wire protocol commands exposed on version 2 to
CBOR. I think consistency is important. The overhead to encoding
things with CBOR is minimal. Even a very large bytestring can be
efficiently encoded using an indefinite length bytestring. Now,
there are limitations with consumers not being able to efficiently
stream large CBOR values. But these feel like solvable problems.

This commit removes the "is CBOR" frame flag from command response
frames and defines the frame as always consisting of a stream of
CBOR values.

The framing protocol media type has been bumped to reflect this
BC change.

Differential Revision: https://phab.mercurial-scm.org/D3382

#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