view setup_mpatch_cffi.py @ 29917:f32f8bf5dc4c

streamclone: force @filecache properties to be reloaded from file

Before this patch, consumev1() invokes repo.invalidate() after closing
transaction, to force @filecache properties to be reloaded from files
at next access, because streamclone writes data into files directly.

But this doesn't work as expected in the case below:

  1. at closing transaction, repo._refreshfilecachestats() refreshes
     file stat of each @filecache properties with streamclone-ed files

     This means that in-memory properties are treated as valid.

  2. but streamclone doesn't changes in-memory properties

     This means that in-memory properties are actually invalid.

  3. repo.invalidate() just forces to examine file stat of @filecache
     properties at the first access after it

     Such examination should concludes that reloading from file isn't
     needed, because file stat was already refreshed at (1).

     Therefore, invalid in-memory cached properties (2) are
     unintentionally treated as valid (1).

This patch invokes repo.invalidate() with clearfilecache=True, to
force @filecache properties to be reloaded from file at next access.

BTW, it is accidental that repo.invalidate() without
clearfilecache=True in streamclone case seems to work as expected
before this patch.

If transaction is started via "filtered repo" object,
repo._refreshfilecachestats() tries to refresh file stat of each
@filecache properties on "filtered repo" object, even though all of
them are stored into "unfiltered repo" object.

In this case, repo._refreshfilecachestats() does nothing
unintentionally, but this unexpected behavior causes reloading
@filecache properties after repo.invalidate().

This is reason why this patch should be applied before making
_refreshfilecachestats() correctly refresh file stat of @filecache
properties.

from __future__ import absolute_import

import cffi
import os

ffi = cffi.FFI()
mpatch_c = os.path.join(os.path.join(os.path.dirname(__file__), 'mercurial',
                                     'mpatch.c'))
ffi.set_source("_mpatch_cffi", open(mpatch_c).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()