CacheVersion class refactoring:
Responsibilities of class CacheVersion are splitted into:
- interface CacheAttributesManager<Attrs>, that should:
- load actual cache attribute values from FS
- provide expected attribute values (that is required for current build)
- checks when the existed cache (with actual attributes) values is suitable for current build (expected atribute values)
- write new values to FS for next build
- CacheAttributesDiff is created by calling CacheAttributesManager.loadDiff extension method. This is just pair of actual and expected cache attributes values, with reference to manager. Result of loadDiff can be saved.
CacheAttributesDiff are designed to be used as facade of attributes operations: CacheAttributesDiff.status are calculated based on actual and expected attribute values. Based on that status system may perform required actions (i.e. rebuild something, clearing caches, etc...).
Methods of CacheAttributesManager other then loadDiff should be used only through CacheAttributesDiff.
Build system should work in this order:
- get implementation of CacheAttributesManager for particular compiler and cache
- call loadDiff __once__ and save it result
- perform actions based on `diff.status`
- save new cache attribute values by calling `diff.saveExpectedIfNeeded()`
There are 2 implementation of CacheAttributesManager:
- CacheVersionManager that simple checks cache version number.
- CompositeLookupsCacheAttributesManager - manager for global lookups cache that may contain lookups for several compilers (jvm, js).
Gradle:
Usages of CacheVersion in gradle are kept as is. For compatibility this methods are added: CacheAttributesManager.saveIfNeeded, CacheAttributesManager.clean. This methods should not be used in new code.
JPS:
All JPS logic that was responsible for cache version checking completely rewritten.
To write proper implementation for version checking, this things also changed:
- KotlinCompileContext introduced. This context lives between first calling build of kotlin target until build finish. As of now all kotlin targets are loaded on KotlinCompileContext initialization. This is required to collect kotlin target types used in this build (jvm/js). Also all build-wide logic are moved from KotlinBuilder to KotlinCompileContext. Chunk dependency calculation also moved to build start which improves performance for big projects #KT-26113
- Kotlin bindings to JPS build targets also stored in KotlinCompileContext, and binding is fixed. Previously it is stored in local Context and reacreated for each chunk, now they stored in KotlinCompileContext which is binded by GlobalContextKey with this exception: source roots are calculated for each round, since temporary source roots with groovy stubs are created at build time and visible only in local compile context.
- KotlinChunk introduced. All chunk-wide logic are moved from KotlinModuleBuildTarget (i.e compiler, language, cache version checking and dependent cache loading)
- Fix legacy MPP common dependent modules
Cache version checking logic now works as following:
- At first chunk building all targets are loaded and used platforms are collected. Lookups cache manger is created based on this set. Actual cache attributes are loaded from FS. Based on CacheAttributesDiff.status this actions are performed: if cache is invalid all kotlin will be rebuilt. If cache is not required anymore it will be cleaned.
- Before build of each chunk local chunk cache attributes will be checked. If cache is invalid, chunk will be rebuilt. If cache is not required anymore it will be cleaned.
#KT-26113 Fixed
#KT-26072 Fixed
Andrey Uskov