[BTA tests] Cache compiled modules in scenario DSL tests

^KT-61860 In Progress

compiler/build-tools/kotlin-build-tools-api-tests/src/testCommon/kotlin/compilation/model/AbstractModule.kt

@@ -96,4 +96,23 @@ abstract class AbstractModule(
     ): CompilationResult
 
     override fun toString() = moduleName
+    override fun equals(other: Any?): Boolean {
+        if (this === other) return true
+        if (other !is AbstractModule) return false
+
+        if (moduleName != other.moduleName) return false
+        if (dependencies != other.dependencies) return false
+        if (additionalCompilationArguments != other.additionalCompilationArguments) return false
+
+        return true
+    }
+
+    override fun hashCode(): Int {
+        var result = moduleName.hashCode()
+        result = 31 * result + dependencies.hashCode()
+        result = 31 * result + additionalCompilationArguments.hashCode()
+        return result
+    }
+
+
 }

compiler/build-tools/kotlin-build-tools-api-tests/src/testCommon/kotlin/compilation/scenario/scenarioDsl.kt

@@ -85,16 +85,37 @@ private class ScenarioDsl(
     ): ScenarioModule {
         val transformedDependencies = dependencies.map { (it as ScenarioModuleImpl).module }
         val module = project.module(moduleName, transformedDependencies, additionalCompilationArguments)
+        return GlobalCompiledProjectsCache.getProjectFromCache(module, strategyConfig)
+            ?: GlobalCompiledProjectsCache.putProjectIntoCache(module, strategyConfig)
+    }
+}
+
+fun BaseCompilationTest.scenario(strategyConfig: CompilerExecutionStrategyConfiguration, action: Scenario.() -> Unit) {
+    action(ScenarioDsl(Project(workingDirectory), strategyConfig))
+}
+
+private object GlobalCompiledProjectsCache {
+    private val globalTempDirectory = Files.createTempDirectory("compiled-test-projects-cache").apply {
+        toFile().deleteOnExit()
+    }
+    private val compiledProjectsCache = mutableMapOf<Module, Pair<MutableSet<String>, Path>>()
+
+    fun getProjectFromCache(module: Module, strategyConfig: CompilerExecutionStrategyConfiguration): ScenarioModuleImpl? {
+        val (initialOutputs, cachedBuildDirPath) = compiledProjectsCache[module] ?: return null
+        cachedBuildDirPath.copyToRecursively(module.buildDirectory, followLinks = false, overwrite = true)
+        return ScenarioModuleImpl(module, initialOutputs, strategyConfig)
+    }
+
+    fun putProjectIntoCache(module: Module, strategyConfig: CompilerExecutionStrategyConfiguration): ScenarioModuleImpl {
         module.compileIncrementally(strategyConfig, SourcesChanges.Unknown)
         val initialOutputs = mutableSetOf<String>()
         for (file in module.outputDirectory.walk()) {
             if (!file.isRegularFile()) continue
             initialOutputs.add(file.relativeTo(module.outputDirectory).toString())
         }
+        val moduleCacheDirectory = globalTempDirectory.resolve(UUID.randomUUID().toString())
+        module.buildDirectory.copyToRecursively(moduleCacheDirectory, followLinks = false, overwrite = false)
+        compiledProjectsCache[module] = Pair(initialOutputs, moduleCacheDirectory)
         return ScenarioModuleImpl(module, initialOutputs, strategyConfig)
     }
-}
-
-fun BaseCompilationTest.scenario(strategyConfig: CompilerExecutionStrategyConfiguration, action: Scenario.() -> Unit) {
-    action(ScenarioDsl(Project(workingDirectory), strategyConfig))
 }