Mercurial > hg-stable
changeset 44779:18e36ff8b414 stable
rust-dirstatemap: don't read the dirstate when requesting parents
A future patch for issue 6303 reveals a big performance regression in the Rust
`DirstateMap` that reads the entire dirstate when requesting parents instead
of the first 40 bytes.
`perfdiscovery` gets a *significant* speedup (from 0.101 to 0.016) when applied
against said patch.
I'm assuming it has other performance benefits, but this is already a good
enough win.
Differential Revision: https://phab.mercurial-scm.org/D8513
| author | Raphaël Gomès <rgomes@octobus.net> |
|---|---|
| date | Mon, 11 May 2020 16:44:11 +0200 |
| parents | f189c5280d48 |
| children | 35b255e474d9 |
| files | mercurial/dirstate.py |
| diffstat | 1 files changed, 16 insertions(+), 2 deletions(-) [+] |
line wrap: on
line diff
--- a/mercurial/dirstate.py Thu May 14 10:24:52 2020 -0400 +++ b/mercurial/dirstate.py Mon May 11 16:44:11 2020 +0200 @@ -1743,10 +1743,23 @@ @propertycache def _rustmap(self): - self._rustmap = rustmod.DirstateMap(self._root) + """ + Fills the Dirstatemap when called. + Use `self._inner_rustmap` if reading the dirstate is not necessary. + """ + self._rustmap = self._inner_rustmap self.read() return self._rustmap + @propertycache + def _inner_rustmap(self): + """ + Does not fill the Dirstatemap when called. This allows for + optimizations where only setting/getting the parents is needed. + """ + self._inner_rustmap = rustmod.DirstateMap(self._root) + return self._inner_rustmap + @property def copymap(self): return self._rustmap.copymap() @@ -1756,6 +1769,7 @@ def clear(self): self._rustmap.clear() + self._inner_rustmap.clear() self.setparents(nullid, nullid) util.clearcachedproperty(self, b"_dirs") util.clearcachedproperty(self, b"_alldirs") @@ -1812,7 +1826,7 @@ st = b'' try: - self._parents = self._rustmap.parents(st) + self._parents = self._inner_rustmap.parents(st) except ValueError: raise error.Abort( _(b'working directory state appears damaged!')