Reduce size of cachedFixedComponentsLocales#1328
Merged
itingliu merged 2 commits intoswiftlang:mainfrom Jun 4, 2025
Merged
Conversation
Previously we maintain a cache `private var cachedFixedComponentsLocales: [Locale.Components : any _LocaleProtocol]`, and every call to `Locale(components: Locale.Components)` reads and writes to the cache. This results in a cache with non trivial size of keys.
Optimize this by replacing the key with a String instead of the full `Locale.Components` instance.
Using this as the baseline:
```swift
for identifier in Locale.availableIdentifiers {
let locale = Locale(identifier: identifier)
}
```
With the following as the testing code:
```swift
for identifier in Locale.availableIdentifiers {
let components = Locale.Components(identifier: identifier)
let locale = Locale(components: components)
let components2 = Locale.Components(locale: locale)
let locale2 = Locale(components: components2) // cache hit
}
```
Previously, this incurred +2.6 MB of footprint comparing to the above baseline. After the fix, it incurred only +0.9MB increase.
Also benchmarked that we have not regressed the time now that we are using the string-based identifier as the key.
Fixes 144642686
Contributor
Author
|
@swift-ci please test |
parkera
approved these changes
Jun 4, 2025
chloe-yeo
pushed a commit
to chloe-yeo/swift-foundation
that referenced
this pull request
Jun 10, 2025
* Reduce size of `cachedFixedComponentsLocales`
Previously we maintain a cache `private var cachedFixedComponentsLocales: [Locale.Components : any _LocaleProtocol]`, and every call to `Locale(components: Locale.Components)` reads and writes to the cache. This results in a cache with non trivial size of keys.
Optimize this by replacing the key with a String instead of the full `Locale.Components` instance.
Using this as the baseline:
```swift
for identifier in Locale.availableIdentifiers {
let locale = Locale(identifier: identifier)
}
```
With the following as the testing code:
```swift
for identifier in Locale.availableIdentifiers {
let components = Locale.Components(identifier: identifier)
let locale = Locale(components: components)
let components2 = Locale.Components(locale: locale)
let locale2 = Locale(components: components2) // cache hit
}
```
Previously, this incurred +2.6 MB of footprint comparing to the above baseline. After the fix, it incurred only +0.9MB increase.
Also benchmarked that we have not regressed the time now that we are using the string-based identifier as the key.
Fixes 144642686
* Add a comment about using Locale.Components.icuIdentifier as the cache key
chloe-yeo
pushed a commit
to chloe-yeo/swift-foundation
that referenced
this pull request
Jun 16, 2025
* Reduce size of `cachedFixedComponentsLocales`
Previously we maintain a cache `private var cachedFixedComponentsLocales: [Locale.Components : any _LocaleProtocol]`, and every call to `Locale(components: Locale.Components)` reads and writes to the cache. This results in a cache with non trivial size of keys.
Optimize this by replacing the key with a String instead of the full `Locale.Components` instance.
Using this as the baseline:
```swift
for identifier in Locale.availableIdentifiers {
let locale = Locale(identifier: identifier)
}
```
With the following as the testing code:
```swift
for identifier in Locale.availableIdentifiers {
let components = Locale.Components(identifier: identifier)
let locale = Locale(components: components)
let components2 = Locale.Components(locale: locale)
let locale2 = Locale(components: components2) // cache hit
}
```
Previously, this incurred +2.6 MB of footprint comparing to the above baseline. After the fix, it incurred only +0.9MB increase.
Also benchmarked that we have not regressed the time now that we are using the string-based identifier as the key.
Fixes 144642686
* Add a comment about using Locale.Components.icuIdentifier as the cache key
This file contains hidden or 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
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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.
Previously we maintain a cache
private var cachedFixedComponentsLocales: [Locale.Components : any _LocaleProtocol], and every call toLocale(components: Locale.Components)reads and writes to the cache. This results in a cache with non trivial size of keys.
Optimize this by replacing the key with a String instead of the full
Locale.Componentsinstance.Using this as the baseline:
With the following as the testing code:
Previously, this incurred +2.6 MB of footprint comparing to the above baseline. After the fix, it incurred only +0.9MB increase.
Also benchmarked that we have not regressed the time now that we are using the string-based identifier as the key.