view mercurial/mpatch.h @ 38047:dabc2237963c

crecord: fallback to text mode if diffs are too big for curses mode

crecord uses curses.newpad to create a region that we can then scroll around in
by moving the main 'screen' as a veiwport into the (probably larger than the
actual screen) pad.  Internally, at least in ncurses, pads are implemented using
windows, which have their dimensions limited to a certain size.  Depending on
compilation options for ncurses, this size might be pretty small: (signed)
short, or it might be larger ((signed) int).

crecord wants to have enough room to have all of the contents of the main area
of the chunkselector in the pad; this means that the full size with everything
expanded must be less than these (undocumented, afaict) limits.

It's not easy to write tests for this because the limits are platform- and
installation- dependent and undocumented / unqueryable, as far as I can tell.

Differential Revision: https://phab.mercurial-scm.org/D3577

#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