mercurial/strutil.py

localrepo: make invalidate avoid invalidating store inside transaction (API)

Before this patch, invalidate() discards in-memory fncache changes,
even inside transaction scope.

Such changes should be written out at closing transaction. Otherwise,
fncache might overlook newly added files. A file overlooked by
fncache isn't accessible via store vfs, even if it actually exists in
store.

On the other hand, a non-existing file in fncache is less harmful,
because fncachestore always examines whether a file actually exists or
not before access. Therefore, discarding in-memory changes can be
safely omitted.

It is typical case that repo.invalidate() in streamclone is executed
inside nested transaction.

This patch makes invalidate() avoid invalidating store inside
transaction.

This patch focuses on describing only how invalidate() changes own
behavior according to activity of transaction. Describing other detail
of invalidate() in docstr will be done in another series, which
refactors invalidate*() functions.

# strutil.py - string utilities for Mercurial
#
# Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

def findall(haystack, needle, start=0, end=None):
    if end is None:
        end = len(haystack)
    if end < 0:
        end += len(haystack)
    if start < 0:
        start += len(haystack)
    while start < end:
        c = haystack.find(needle, start, end)
        if c == -1:
            break
        yield c
        start = c + 1

def rfindall(haystack, needle, start=0, end=None):
    if end is None:
        end = len(haystack)
    if end < 0:
        end += len(haystack)
    if start < 0:
        start += len(haystack)
    while end >= 0:
        c = haystack.rfind(needle, start, end)
        if c == -1:
            break
        yield c
        end = c - 1