Simon Sapin <simon.sapin@octobus.net> [Tue, 27 Apr 2021 17:49:38 +0200] rev 47118
dirstate-tree: Add #[timed] attribute to `status` and `DirstateMap::read`
When running with a `RUST_LOG=trace` environment variable, the `micro_timer`
crate prints the duration taken by each call to functions with that attribute.
Differential Revision: https://phab.mercurial-scm.org/D10552
Simon Sapin <simon.sapin@octobus.net> [Tue, 27 Apr 2021 14:20:48 +0200] rev 47117
dirstate-tree: Paralellize the status algorithm with Rayon
The `rayon` crate exposes "parallel iterators" that work like normal iterators
but dispatch work on different items to an implicit global thread pool.
Differential Revision: https://phab.mercurial-scm.org/D10551
Simon Sapin <simon.sapin@octobus.net> [Tue, 27 Apr 2021 12:42:21 +0200] rev 47116
dirstate-tree: Avoid BTreeMap double-lookup when inserting a dirstate entry
The child nodes of a given node in the tree-shaped dirstate are kept in a
`BTreeMap` where keys are file names as strings. Finding or inserting a value
in the map takes `O(log(n))` string comparisons, which adds up when constructing
the tree.
The `entry` API allows finding a "spot" in the map that may or may not be
occupied and then access that value or insert a new one without doing map
lookup again. However the current API is limited in that calling `entry`
requires an owned key (and so a memory allocation), even if it ends up not
being used in the case where the map already has a value with an equal key.
This is still a win, with 4% better end-to-end time for `hg status` measured
here with hyperfine:
```
Benchmark #1: ../hg2/hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1
Time (mean ± σ): 1.337 s ± 0.018 s [User: 892.9 ms, System: 437.5 ms]
Range (min … max): 1.316 s … 1.373 s 10 runs
Benchmark #2: ./hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1
Time (mean ± σ): 1.291 s ± 0.008 s [User: 853.4 ms, System: 431.1 ms]
Range (min … max): 1.283 s … 1.309 s 10 runs
Summary
'./hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1' ran
1.04 ± 0.02 times faster than '../hg2/hg status -R $REPO --config=experimental.dirstate-tree.in-memory=1'
```
* ./hg is this revision
* ../hg2/hg is its parent
* $REPO is an old snapshot of mozilla-central
Differential Revision: https://phab.mercurial-scm.org/D10550
Simon Sapin <simon.sapin@octobus.net> [Mon, 26 Apr 2021 19:28:56 +0200] rev 47115
dirstate-tree: Handle I/O errors in status
Errors such as insufficient permissions when listing a directory are logged,
and the algorithm continues without considering that directory.
Differential Revision: https://phab.mercurial-scm.org/D10549
Simon Sapin <simon.sapin@octobus.net> [Mon, 26 Apr 2021 19:16:23 +0200] rev 47114
dirstate-tree: Ignore FIFOs etc. in the status algorithm
If a filesystem directory contains anything that is not:
* a "normal" file
* a symbolic link
* or a directory
… act as if that directory entry was not there. For example, if that path was
previously a tracked file, mark it as deleted or removed.
Differential Revision: https://phab.mercurial-scm.org/D10548
Simon Sapin <simon.sapin@octobus.net> [Fri, 16 Apr 2021 12:12:41 +0200] rev 47113
dirstate-tree: Add the new `status()` algorithm
With the dirstate organized in a tree that mirrors the structure of the
filesystem tree, we can traverse both trees at the same time in order to
compare them. This is hopefully more efficient that building multiple
big hashmaps for all of the repository’s contents.
Differential Revision: https://phab.mercurial-scm.org/D10547
Simon Sapin <simon.sapin@octobus.net> [Fri, 16 Apr 2021 12:12:04 +0200] rev 47112
dirstate-tree: Give to `status()` mutable access to the `DirstateMap`
Differential Revision: https://phab.mercurial-scm.org/D10546
Simon Sapin <simon.sapin@octobus.net> [Tue, 06 Apr 2021 15:49:01 +0200] rev 47111
rust: Add doc-comments to DirstateStatus fields
Differential Revision: https://phab.mercurial-scm.org/D10495
Simon Sapin <simon.sapin@octobus.net> [Tue, 06 Apr 2021 15:14:19 +0200] rev 47110
rust: Move "lookup" a.k.a. "unsure" paths into `DirstateStatus` struct
Instead of having `status()` returning a tuple of those paths and
`DirstateStatus`.
Differential Revision: https://phab.mercurial-scm.org/D10494
Simon Sapin <simon.sapin@octobus.net> [Tue, 13 Apr 2021 17:02:58 +0200] rev 47109
rust: Remove DirstateMap::file_fold_map
This was a HashMap constructed on demand and then cached in the DirstateMap
struct to avoid reconstructing at the next access. However the only use is
in Python bindings converting it to a PyDict. That method in turn is wrapped
in a @cachedproperty in Python code.
This was two redudant layers of caching. This changeset removes the Rust-level
one to keep the Python dict cache, and have bindings create a PyDict by
iterating.
Differential Revision: https://phab.mercurial-scm.org/D10493