view mercurial/cffi/bdiffbuild.py @ 45059:79f6f9fa18c1

documentation: add some internals documentation about bid merge

This is an important algorithm that was only documented on the wiki so far.

Some update to the algorithm (and associated doc) is to expected in the future
since the bid merge algorithm is bug-ridden when it comes to file deletion comes
to play.

Differential Revision: https://phab.mercurial-scm.org/D8711

from __future__ import absolute_import

import cffi
import os

ffi = cffi.FFI()
with open(
    os.path.join(os.path.join(os.path.dirname(__file__), '..'), 'bdiff.c')
) as f:
    ffi.set_source(
        "mercurial.cffi._bdiff", f.read(), include_dirs=['mercurial']
    )
ffi.cdef(
    """
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);
void free(void*);
"""
)

if __name__ == '__main__':
    ffi.compile()