encoding: fix trim() to be O(n) instead of O(n^2) `encoding.trim()` iterated over the possible lengths smaller than the input and created a slice for each. It then calculated the column width of the result, which is of course O(n), so the overall algorithm was O(n). This patch rewrites it to iterate over the unicode characters, keeping track of the length so far. Also, the old algorithm started from the end of the string, which made it much worse when the input is large and the limit is small (such as the typical 72 we pass to it). You can time it by running something like this: ``` time python3 -c 'from mercurial.utils import stringutil; print(stringutil.ellipsis(b"0123456789" * 1000, 5))' ``` That drops from 4.05 s to 83 ms with this patch (and most of that is of course startup time). Differential Revision: https://phab.mercurial-scm.org/D12089

share-safe: enable by default (BC) The feature have been around for a year (4 version) and is quite important. Lets make it enabled by default. Differential Revision: https://phab.mercurial-scm.org/D11997

share-safe: add support for static-http repository We need to read the second requirements file in the static-http case too. Otherwise, static-http would miss most of the requirements and misbehave. Differential Revision: https://phab.mercurial-scm.org/D11996

legacy-revlog: fix requirement computation when cloning legacy repo The oldest format of repository does not have requirements so we need to treat them differently when cloning such repository. The previous code had issue whenever we start using a working-copy-only requirements. The "legacy" format is signaled using an empty requirements list. If we add working-copy-only requirements to it, this is no longer empty, and no longer legacy. The new code fix this, and will get fully tested in a couple of changeset, once the share-safe become the default. Differential Revision: https://phab.mercurial-scm.org/D11995

requirements: do not warn about dropping share-safe, unless explicitly set If we are just altering the default value, this is "fine". This will get tested once share-safe become the default. Differential Revision: https://phab.mercurial-scm.org/D11994

sparse: take lock before writing requirements with `share-safe`, we will also write file in the store. So we take the `lock` before altering the requirements. Differential Revision: https://phab.mercurial-scm.org/D11993

largefiles: take lock before writing requirements With `share-safe`, we will also write file in the store. We now take the `lock` as needed. Differential Revision: https://phab.mercurial-scm.org/D11992

lfs: take lock before writing requirements With `share-safe`, we will also write file in the store, so we take the store lock before writing requirements. Differential Revision: https://phab.mercurial-scm.org/D11991

test: simpler requirements matching in test-repo-compengines.t We focus on the requirements relevant for this tests. Differential Revision: https://phab.mercurial-scm.org/D11990

test: simpler requirements matching in test-lfs-largefiles.t We focus on the requirements relevant for this tests. Differential Revision: https://phab.mercurial-scm.org/D11989

test: simpler requirements matching in test-sidedata.t We focus on the requirements relevant for this tests. Differential Revision: https://phab.mercurial-scm.org/D11988

test: simpler requirement matching in test-revlog-v2.t We narrow the matching toward the one we actually care about. Differential Revision: https://phab.mercurial-scm.org/D11987

test-copies: narrow the format check in test-copies-in-changeset.t This will reduce the noise when touching unrelated format variants. Differential Revision: https://phab.mercurial-scm.org/D11986

tests: use debugrequires instead of grepping the file directly With `share-safe`, the requirements are stored in multiple files so it seems better to use the command that retrieve the information wherever it is. Differential Revision: https://phab.mercurial-scm.org/D11985