Refactor TaskStore/Task to control mutability when interning stored strings

Author: owenv

Sources/SWBCore/EnvironmentBindings.swift

@@ -16,22 +16,8 @@ public import SWBUtil
 ///
 /// We almost never inspect the environment, so we make a space/size tradeoff by compactly storing the environment.
 public struct EnvironmentBindings: Sendable {
-    private enum BindingsStorage {
-        case direct([(String, String)])
-        case interned([(StringArena.Handle, StringArena.Handle)], StringArena)
-    }
-
     /// The bindings are stored as one contiguous string
-    private var bindingsStorage: BindingsStorage
-
-    public var bindings: [(String, String)] {
-        switch bindingsStorage {
-        case .direct(let bindings):
-            return bindings
-        case .interned(let internedBindings, let arena):
-            return internedBindings.map { (arena.lookup(handle: $0.0), arena.lookup(handle: $0.1)) }
-        }
-    }
+    public let bindings: [(String, String)]
 
     public var bindingsDictionary: [String: String] {
         var dict = [String: String]()
@@ -43,15 +29,15 @@ public struct EnvironmentBindings: Sendable {
 
     /// Create an empty binding map.
     public init() {
-        self.bindingsStorage = .direct([])
+        self.bindings = []
     }
 
     public init(_ bindings: [(String, String)]) {
-        self.bindingsStorage = .direct(bindings)
+        self.bindings = bindings
     }
 
     public init(_ bindings: [String: String]) {
-        self.bindingsStorage = .direct(bindings.map { ($0, $1) }.sorted(by: { $0.0 < $1.0 }))
+        self.bindings = bindings.map { ($0, $1) }.sorted(by: { $0.0 < $1.0 })
     }
 
     /// Add a signature of the bindings into the given context.
@@ -64,13 +50,6 @@ public struct EnvironmentBindings: Sendable {
             ctx.add(number: 0)
         }
     }
-
-    public mutating func intern(in arena: StringArena) {
-        guard case .direct(let bindings) = bindingsStorage else {
-            return
-        }
-        self.bindingsStorage = .interned(bindings.map { (arena.intern($0.0), arena.intern($0.1)) }, arena)
-    }
 }
 
 extension EnvironmentBindings: Equatable {
@@ -90,6 +69,6 @@ extension EnvironmentBindings: Serializable {
 
     public init(from deserializer: any Deserializer) throws {
         try deserializer.beginAggregate(2)
-        self.bindingsStorage = .direct(Array(zip(try deserializer.deserialize(), try deserializer.deserialize())))
+        self.bindings = Array(zip(try deserializer.deserialize(), try deserializer.deserialize()))
     }
 }

Sources/SWBTaskExecution/BuildDescription.swift

@@ -132,7 +132,7 @@ package final class BuildDescription: Serializable, Sendable, Encodable, Cacheab
     }
 
     // rdar://107734664 (Consider passing the task store as a parameter to build description methods rather than as a property of BuildDescription)
-    package let taskStore: TaskStore
+    package let taskStore: FrozenTaskStore
 
     /// The set of all (non-virtual) paths produced by tasks in the build description.
     private let allOutputPaths: Set<Path>
@@ -188,7 +188,7 @@ package final class BuildDescription: Serializable, Sendable, Encodable, Cacheab
     package let targetsBuildInParallel: Bool
 
     /// Load a build description from the given path.
-    fileprivate init(inDir dir: Path, signature: BuildDescriptionSignature, taskStore: TaskStore, allOutputPaths: Set<Path>, rootPathsPerTarget: [ConfiguredTarget: [Path]], moduleCachePathPerTarget: [ConfiguredTarget: Path], settingsPerTarget: [ConfiguredTarget: Settings], enableStaleFileRemoval: Bool = true, taskActionMap: [String: TaskAction.Type], targetTaskCounts: [ConfiguredTarget: Int], moduleSessionFilePath: Path?, diagnostics: [ConfiguredTarget?: [Diagnostic]], fs: any FSProxy, invalidationPaths: [Path], recursiveSearchPathResults: [RecursiveSearchPathResolver.CachedResult], copiedPathMap: [String: String], targetDependencies: [TargetDependencyRelationship], definingTargetsByModuleName: [String: OrderedSet<ConfiguredTarget>], capturedBuildInfo: CapturedBuildInfo?, bypassActualTasks: Bool, targetsBuildInParallel: Bool) throws {
+    fileprivate init(inDir dir: Path, signature: BuildDescriptionSignature, taskStore: FrozenTaskStore, allOutputPaths: Set<Path>, rootPathsPerTarget: [ConfiguredTarget: [Path]], moduleCachePathPerTarget: [ConfiguredTarget: Path], settingsPerTarget: [ConfiguredTarget: Settings], enableStaleFileRemoval: Bool = true, taskActionMap: [String: TaskAction.Type], targetTaskCounts: [ConfiguredTarget: Int], moduleSessionFilePath: Path?, diagnostics: [ConfiguredTarget?: [Diagnostic]], fs: any FSProxy, invalidationPaths: [Path], recursiveSearchPathResults: [RecursiveSearchPathResolver.CachedResult], copiedPathMap: [String: String], targetDependencies: [TargetDependencyRelationship], definingTargetsByModuleName: [String: OrderedSet<ConfiguredTarget>], capturedBuildInfo: CapturedBuildInfo?, bypassActualTasks: Bool, targetsBuildInParallel: Bool) throws {
         self.dir = dir
         self.signature = signature
         self.taskStore = taskStore
@@ -650,9 +650,11 @@ package final class BuildDescriptionBuilder {
             throw StubError.error("unable to record manifest to build description delegate: \(error)")
         }
 
+        let frozenTaskStore = taskStore.freeze()
+
         // Compute the count of tasks by target, which we use to know when a task is complete.
         var targetTaskCounts = [ConfiguredTarget: Int]()
-        taskStore.forEachTask { task in
+        frozenTaskStore.forEachTask { task in
             if let target = task.forTarget, !task.isGate {
                 targetTaskCounts[target] = (targetTaskCounts[target] ?? 0) + 1
             }
@@ -663,7 +665,7 @@ package final class BuildDescriptionBuilder {
         // Create the build description.
         let buildDescription: BuildDescription
         do {
-            buildDescription = try BuildDescription(inDir: path, signature: signature, taskStore: taskStore, allOutputPaths: allOutputPaths, rootPathsPerTarget: rootPathsPerTarget, moduleCachePathPerTarget: moduleCachePathPerTarget, settingsPerTarget: settingsPerTarget, taskActionMap: taskActionMap, targetTaskCounts: targetTaskCounts, moduleSessionFilePath: moduleSessionFilePath, diagnostics: diagnosticsEngines.mapValues { engine in engine.diagnostics }, fs: fs, invalidationPaths: invalidationPaths, recursiveSearchPathResults: recursiveSearchPathResults, copiedPathMap: copiedPathMap, targetDependencies: targetDependencies, definingTargetsByModuleName: definingTargetsByModuleName, capturedBuildInfo: capturedBuildInfo, bypassActualTasks: bypassActualTasks, targetsBuildInParallel: targetsBuildInParallel)
+            buildDescription = try BuildDescription(inDir: path, signature: signature, taskStore: frozenTaskStore, allOutputPaths: allOutputPaths, rootPathsPerTarget: rootPathsPerTarget, moduleCachePathPerTarget: moduleCachePathPerTarget, settingsPerTarget: settingsPerTarget, taskActionMap: taskActionMap, targetTaskCounts: targetTaskCounts, moduleSessionFilePath: moduleSessionFilePath, diagnostics: diagnosticsEngines.mapValues { engine in engine.diagnostics }, fs: fs, invalidationPaths: invalidationPaths, recursiveSearchPathResults: recursiveSearchPathResults, copiedPathMap: copiedPathMap, targetDependencies: targetDependencies, definingTargetsByModuleName: definingTargetsByModuleName, capturedBuildInfo: capturedBuildInfo, bypassActualTasks: bypassActualTasks, targetsBuildInParallel: targetsBuildInParallel)
         }
         catch {
             throw StubError.error("unable to create build description: \(error)")
@@ -1398,7 +1400,7 @@ package final class BuildDescriptionDeserializerDelegate: DeserializerDelegate,
 
     package let uniquingCoordinator = UniquingDeserializationCoordinator()
 
-    package var taskStore: TaskStore? = nil
+    package var taskStore: FrozenTaskStore? = nil
 
     package init(workspace: Workspace, platformRegistry: PlatformRegistry, sdkRegistry: SDKRegistry, specRegistry: SpecRegistry) {
         self.workspace = workspace

Sources/SWBTaskExecution/BuildDescriptionManager.swift

@@ -559,7 +559,7 @@ package final class BuildDescriptionManager: Sendable {
         let delegate = BuildDescriptionDeserializerDelegate(workspace: workspaceContext.workspace, platformRegistry: workspaceContext.core.platformRegistry, sdkRegistry: workspaceContext.core.sdkRegistry, specRegistry: workspaceContext.core.specRegistry)
         let taskStoreContents = try fs.read(path.join("task-store.msgpack"))
         let taskStoreDeserializer = MsgPackDeserializer(taskStoreContents, delegate: delegate)
-        let taskStore: TaskStore = try taskStoreDeserializer.deserialize()
+        let taskStore: FrozenTaskStore = try taskStoreDeserializer.deserialize()
         delegate.taskStore = taskStore
         let byteString = try fs.read(path.join("description.msgpack"))
         let deserializer = MsgPackDeserializer(byteString, delegate: delegate)