view mercurial/bdiff.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_BDIFF_H_
#define _HG_BDIFF_H_

#include "compat.h"

struct bdiff_line {
	int hash, n, e;
	ssize_t len;
	const char *l;
};

struct bdiff_hunk;
struct bdiff_hunk {
	int a1, a2, b1, b2;
	struct bdiff_hunk *next;
};

int bdiff_splitlines(const char *a, ssize_t len, struct bdiff_line **lr);
int bdiff_diff(struct bdiff_line *a, int an, struct bdiff_line *b, int bn,
               struct bdiff_hunk *base);
void bdiff_freehunks(struct bdiff_hunk *l);

#endif