view mercurial/cffi/mpatchbuild.py @ 46734:1a036d33bc18

rhg: Add an allow-list of ignored extensions

Because rhg doesn’t know how a Python extension would affect
behavior it implements in Rust, when an unsupported extension
is enabled it conservatively falls back to Python-based hg.

However many users will have unsupported extensions enabled in practice.
Maybe they don’t actually affect rhg behavior, but we don’t know.
This adds a `rhg.ignored-extensions` configuration that lets
users list extensions that rhg can safely ignore and proceed even
if they’re not supported in Rust.

Differential Revision: https://phab.mercurial-scm.org/D10188

from __future__ import absolute_import

import cffi
import os

ffi = cffi.FFI()
mpatch_c = os.path.join(
    os.path.join(os.path.dirname(__file__), '..', 'mpatch.c')
)
with open(mpatch_c) as f:
    ffi.set_source(
        "mercurial.cffi._mpatch", f.read(), include_dirs=["mercurial"]
    )
ffi.cdef(
    """

struct mpatch_frag {
       int start, end, len;
       const char *data;
};

struct mpatch_flist {
       struct mpatch_frag *base, *head, *tail;
};

extern "Python" struct mpatch_flist* cffi_get_next_item(void*, ssize_t);

int mpatch_decode(const char *bin, ssize_t len, struct mpatch_flist** res);
ssize_t mpatch_calcsize(size_t len, struct mpatch_flist *l);
void mpatch_lfree(struct mpatch_flist *a);
static int mpatch_apply(char *buf, const char *orig, size_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);
"""
)

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