InitializeHandler: Add batch requests support

.github/workflows/ci.yaml

@@ -11,7 +11,7 @@ jobs:
     name: Build and test
     runs-on: macos-15
     env:
-      XCODE_VERSION: ${{ '16.4' }}
+      XCODE_VERSION: ${{ '26.0' }}
     steps:
       - name: Select Xcode
         run: "sudo xcode-select -s /Applications/Xcode_$XCODE_VERSION.app"

BUILD.bazel

@@ -7,6 +7,7 @@ setup_sourcekit_bsp(
     bazel_wrapper = "bazel",
     files_to_watch = ["Sources/**/*.swift"],
     index_flags = [],
+    index_build_batch_size = 7,
     targets = [
         "//Sources/sourcekit-bazel-bsp",
         "//Sources/SourceKitBazelBSP",

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 6.1
+// swift-tools-version: 6.2
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
@@ -14,8 +14,8 @@ let package = Package(
             revision: "1.5.0"
         ),
         .package(
-            url: "https://github.com/apple/sourcekit-lsp",
-            revision: "1aae2a4c329035163db85d64ae7bc81ee80aaa3c"
+            url: "https://github.com/rockbruno/sourcekit-lsp",
+            revision: "c052baae81ec6532bb2f939a21acc4650fb1dc86"
         ),
         .package(
             url: "https://github.com/apple/swift-protobuf.git",

Sources/SourceKitBazelBSP/RequestHandlers/BuildTargets/BuildTargetsHandler.swift

@@ -41,7 +41,7 @@ final class BuildTargetsHandler {
         _ id: RequestID
     ) throws -> WorkspaceBuildTargetsResponse {
         let taskId = TaskId(id: "buildTargets-\(id.description)")
-        connection?.startWorkTask(id: taskId, title: "sourcekit-bazel-bsp: Processing updates to the build graph...")
+        connection?.startWorkTask(id: taskId, title: "sourcekit-bazel-bsp: Processing the build graph...")
         do {
             let result = try targetStore.stateLock.withLockUnchecked {
                 return try targetStore.fetchTargets()

Sources/SourceKitBazelBSP/RequestHandlers/InitializeHandler.swift

@@ -172,6 +172,7 @@ final class InitializeHandler {
         } else {
             watchers = nil
         }
+        let batchSize: Int? = initializedConfig.baseConfig.indexBuildBatchSize
         return InitializeBuildResponse(
             displayName: "sourcekit-bazel-bsp",
             version: sourcekitBazelBSPVersion,
@@ -192,6 +193,10 @@ final class InitializeHandler {
             data: SourceKitInitializeBuildResponseData(
                 indexDatabasePath: initializedConfig.indexDatabasePath,
                 indexStorePath: initializedConfig.indexStorePath,
+                multiTargetPreparation: MultiTargetPreparationSupport(
+                    supported: true,
+                    batchSize: batchSize
+                ),
                 outputPathsProvider: nil,  // FIXME: Not sure if we need this or not
                 prepareProvider: true,
                 sourceKitOptionsProvider: true,

Sources/SourceKitBazelBSP/RequestHandlers/PrepareHandler.swift

@@ -70,12 +70,9 @@ final class PrepareHandler {
 
         let taskId = TaskId(id: "buildPrepare-\(id.description)")
         let taskTitle: String = {
-            guard targetsToBuild.count == 1 else {
-                return "sourcekit-bazel-bsp: Building \(targetsToBuild.count) targets..."
-            }
-            let targetUrl = targetsToBuild[0].uri.fileURL
-            let targetName = targetUrl?.lastPathComponent ?? targetsToBuild[0].uri.stringValue
-            return "sourcekit-bazel-bsp: Building \(targetName)..."
+            let targetUrls = targetsToBuild.compactMap { $0.uri.fileURL }
+            let targetNames = targetUrls.map { $0.lastPathComponent }.joined(separator: ", ")
+            return "sourcekit-bazel-bsp: Building \(targetNames)..."
         }()
         connection?.startWorkTask(
             id: taskId,

Sources/SourceKitBazelBSP/Server/BaseServerConfig.swift

@@ -32,6 +32,7 @@ package struct BaseServerConfig: Equatable {
     let buildTestPlatformPlaceholder: String
     let filesToWatch: String?
     let useSeparateOutputBaseForAquery: Bool
+    let indexBuildBatchSize: Int?
 
     package init(
         bazelWrapper: String,
@@ -40,7 +41,8 @@ package struct BaseServerConfig: Equatable {
         buildTestSuffix: String,
         buildTestPlatformPlaceholder: String,
         filesToWatch: String?,
-        useSeparateOutputBaseForAquery: Bool = false
+        useSeparateOutputBaseForAquery: Bool = false,
+        indexBuildBatchSize: Int? = nil
     ) {
         self.bazelWrapper = bazelWrapper
         self.targets = targets
@@ -49,5 +51,6 @@ package struct BaseServerConfig: Equatable {
         self.buildTestPlatformPlaceholder = buildTestPlatformPlaceholder
         self.filesToWatch = filesToWatch
         self.useSeparateOutputBaseForAquery = useSeparateOutputBaseForAquery
+        self.indexBuildBatchSize = indexBuildBatchSize
     }
 }

Sources/sourcekit-bazel-bsp/Commands/Serve.swift

@@ -73,6 +73,12 @@ struct Serve: ParsableCommand {
     )
     var topLevelRuleToDiscover: [TopLevelRuleType] = []
 
+    @Option(
+        help:
+            "The number of targets to prepare in parallel. If not specified, SourceKit-LSP will calculate an appropriate value based on the environment. Requires using the pre-built SourceKit-LSP binary from the release archive.",
+    )
+    var indexBuildBatchSize: Int? = nil
+
     func run() throws {
         logger.info("`serve` invoked, initializing BSP server...")
 
@@ -111,7 +117,8 @@ struct Serve: ParsableCommand {
             buildTestSuffix: buildTestSuffix,
             buildTestPlatformPlaceholder: buildTestPlatformPlaceholder,
             filesToWatch: filesToWatch,
-            useSeparateOutputBaseForAquery: separateAqueryOutput
+            useSeparateOutputBaseForAquery: separateAqueryOutput,
+            indexBuildBatchSize: indexBuildBatchSize
         )
         let server = SourceKitBazelBSPServer(baseConfig: config)
         server.run()

rules/setup_sourcekit_bsp.bzl

@@ -15,6 +15,9 @@ def _setup_sourcekit_bsp_impl(ctx):
     bsp_config_argv.append(ctx.attr.build_test_platform_placeholder)
     if ctx.attr.separate_aquery_output:
         bsp_config_argv.append("--separate-aquery-output")
+    if ctx.attr.index_build_batch_size:
+        bsp_config_argv.append("--index-build-batch-size")
+        bsp_config_argv.append(ctx.attr.index_build_batch_size)
     for index_flag in ctx.attr.index_flags:
         bsp_config_argv.append("--index-flag")
         bsp_config_argv.append(index_flag)
@@ -107,5 +110,9 @@ setup_sourcekit_bsp = rule(
             doc = "Whether to use a separate output base for compiler arguments requests. This greatly increases the performance of the server at the cost of more disk usage.",
             default = False,
         ),
+        "index_build_batch_size": attr.int(
+            doc = "The number of targets to prepare in parallel. If not specified, SourceKit-LSP will calculate an appropriate value based on the environment. Requires using the pre-built SourceKit-LSP binary from the release archive.",
+            mandatory = False,
+        )
     },
 )