Fix poor performance of to_tracking_manifest #1047
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
jrray
force-pushed
the
to-tracking-manifest-perf
branch
from
d195019
to
e6fb537
Compare
jrray
force-pushed
the
to-tracking-manifest-perf
branch
from
e6fb537
to
ff99801
Compare
This method had something like O(n^3) complexity because it would for every tree in a manifest iterate over every tree in a manifest and calculate the digest for every tree in the manifest (modulo short circuiting). `Manifest::get_tree` is the culprit and an alternative technique of caching the mapping of digest to tree was added. Both uses of this method have been updated but this method was left in place with a new warning. It would be cheaper to call `get_tree` in a contrived case where the cache is only accessed once and not reused for multiple lookups. Fixes #1043. Signed-off-by: J Robert Ray <jrray@imageworks.com>
jrray
force-pushed
the
to-tracking-manifest-perf
branch
from
ff99801
to
4b80569
Compare
rydrman
approved these changes
Jun 14, 2024
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
This method had something like O(n^3) complexity because it would for
every tree in a manifest iterate over every tree in a manifest and
calculate the digest for every tree in the manifest (modulo short
circuiting).
Manifest::get_treeis the culprit and an alternative technique ofcaching the mapping of digest to tree was added. Both uses of this
method have been updated but this method was left in place with a new
warning. It would be cheaper to call
get_treein a contrived casewhere the cache is only accessed once and not reused for multiple
lookups.
Fixes #1043.