Merge pull request swiftlang#157 from rmaz/filewatching

Add support for file watching in the build server protocol

Author: benlangmuir

Sources/BuildServerProtocol/Messages.swift

@@ -13,12 +13,14 @@ import LanguageServerProtocol
 
 fileprivate let requestTypes: [_RequestType.Type] = [
   InitializeBuild.self,
+  RegisterForChanges.self,
   ShutdownBuild.self,
   SourceKitOptions.self,
 ]
 
 fileprivate let notificationTypes: [NotificationType.Type] = [
   ExitBuildNotification.self,
+  FileOptionsChangedNotification.self,
   InitializedBuildNotification.self,
 ]
 

Sources/BuildServerProtocol/RegisterForChangeNotifications.swift

@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Swift.org open source project
+//
+// Copyright (c) 2014 - 2019 Apple Inc. and the Swift project authors
+// Licensed under Apache License v2.0 with Runtime Library Exception
+//
+// See https://swift.org/LICENSE.txt for license information
+// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
+//
+//===----------------------------------------------------------------------===//
+import LanguageServerProtocol
+
+
+/// The register for changes request is sent from the language
+/// server to the build server to register or unregister for
+/// changes in file options or dependencies. On changes a
+/// FileOptionsChangedNotification is sent.
+public struct RegisterForChanges: RequestType {
+  public static let method: String = "textDocument/registerForChanges"
+  public typealias Response = VoidResponse
+
+  /// The URL of the document to get options for.
+  public var uri: URL
+
+  /// Whether to register or unregister for the file.
+  public var action: RegisterAction
+
+  public init(uri: URL, action: RegisterAction) {
+    self.uri = uri
+    self.action = action
+  }
+}
+
+public enum RegisterAction: String, Hashable, Codable {
+  case register = "register"
+  case unregister = "unregister"
+}
+
+/// The FileOptionsChangedNotification is sent from the
+/// build server to the language server when it detects
+/// changes to a registered files build settings.
+public struct FileOptionsChangedNotification: NotificationType {
+  public static let method: String = "build/sourceKitOptionsChanged"
+
+  /// The URL of the document that has changed settings.
+  public var uri: URL
+
+  /// The updated options for the registered file.
+  public var updatedOptions: SourceKitOptionsResult
+}

Sources/SKCore/BuildServerBuildSystem.swift

@@ -16,6 +16,8 @@ import SKSupport
 import Foundation
 import BuildServerProtocol
 
+typealias Notification = LanguageServerProtocol.Notification
+
 /// A `BuildSystem` based on communicating with a build server
 ///
 /// Provides build settings from a build server launched based on a
@@ -25,19 +27,24 @@ public final class BuildServerBuildSystem {
   let projectRoot: AbsolutePath
   let buildFolder: AbsolutePath?
   let serverConfig: BuildServerConfig
+  let requestQueue: DispatchQueue
 
   var handler: BuildServerHandler?
   var buildServer: Connection?
   public private(set) var indexStorePath: AbsolutePath?
 
   /// Delegate to handle any build system events.
-  public weak var delegate: BuildSystemDelegate? = nil
+  public weak var delegate: BuildSystemDelegate? {
+    get { return self.handler?.delegate }
+    set { self.handler?.delegate = newValue }
+  }
 
   public init(projectRoot: AbsolutePath, buildFolder: AbsolutePath?, fileSystem: FileSystem = localFileSystem) throws {
     let configPath = projectRoot.appending(component: "buildServer.json")
     let config = try loadBuildServerConfig(path: configPath, fileSystem: fileSystem)
     self.buildFolder = buildFolder
     self.projectRoot = projectRoot
+    self.requestQueue = DispatchQueue(label: "build_server_request_queue")
     self.serverConfig = config
     try self.initializeBuildServer()
   }
@@ -114,24 +121,43 @@ private func readReponseDataKey(data: LSPAny?, key: String) -> String? {
 }
 
 final class BuildServerHandler: LanguageServerEndpoint {
-  override func _registerBuiltinHandlers() { }
+
+  public weak var delegate: BuildSystemDelegate? = nil
+
+  override func _registerBuiltinHandlers() {
+    _register(BuildServerHandler.handleFileOptionsChanged)
+  }
+
+  func handleFileOptionsChanged(_ notification: Notification<FileOptionsChangedNotification>) {
+    // TODO: add delegate method to include the changed settings directly
+    self.delegate?.fileBuildSettingsChanged([notification.params.uri])
+  }
 }
 
 extension BuildServerBuildSystem: BuildSystem {
 
   /// Register the given file for build-system level change notifications, such as command
   /// line flag changes, dependency changes, etc.
   public func registerForChangeNotifications(for url: LanguageServerProtocol.URL) {
-    // TODO: Implement via BSP extensions.
+    let request = RegisterForChanges(uri: url, action: .register)
+    _ = self.buildServer?.send(request, queue: requestQueue, reply: { result in
+      if let error = result.failure {
+        log("error registering \(url): \(error)", level: .error)
+      }
+    })
   }
 
   /// Unregister the given file for build-system level change notifications, such as command
   /// line flag changes, dependency changes, etc.
   public func unregisterForChangeNotifications(for url: LanguageServerProtocol.URL) {
-    // TODO: Implement via BSP extensions.
+    let request = RegisterForChanges(uri: url, action: .unregister)
+    _ = self.buildServer?.send(request, queue: requestQueue, reply: { result in
+      if let error = result.failure {
+        log("error unregistering \(url): \(error)", level: .error)
+      }
+    })
   }
 
-
   public var indexDatabasePath: AbsolutePath? {
     return buildFolder?.appending(components: "index", "db")
   }

Tests/INPUTS/BuildServerBuildSystemTests.testFileRegistration/buildServer.json

@@ -0,0 +1,7 @@
+{
+    "name": "client name",
+    "version": "10",
+    "bspVersion": "2.0",
+    "languages": ["a", "b"],
+    "argv": ["server.py"]
+}

Tests/INPUTS/BuildServerBuildSystemTests.testFileRegistration/server.py

@@ -0,0 +1,83 @@
+#!/usr/bin/env python
+
+import json
+import os
+import sys
+
+
+def send(data):
+    dataStr = json.dumps(data)
+    sys.stdout.write("Content-Length: {}\r\n\r\n{}".format(len(dataStr), dataStr))
+    sys.stdout.flush()
+
+
+while True:
+    line = sys.stdin.readline()
+    if len(line) == 0:
+        break
+
+    assert line.startswith('Content-Length:')
+    length = int(line[len('Content-Length:'):])
+    sys.stdin.readline()
+    message = json.loads(sys.stdin.read(length))
+
+    response = None
+    notification = None
+
+    if message["method"] == "build/initialize":
+        response = {
+            "jsonrpc": "2.0",
+            "id": message["id"],
+            "result": {
+                "displayName": "test server",
+                "version": "0.1",
+                "bspVersion": "2.0",
+                "rootUri": "blah",
+                "capabilities": {"languageIds": ["a", "b"]},
+                "data": {
+                    "indexStorePath": "some/index/store/path"
+                }
+            }
+        }
+    elif message["method"] == "build/initialized":
+        continue
+    elif message["method"] == "build/shutdown":
+        response = {
+            "jsonrpc": "2.0",
+            "id": message["id"],
+            "result": None
+        }
+    elif message["method"] == "build/exit":
+        break
+    elif message["method"] == "textDocument/registerForChanges":
+        response = {
+            "jsonrpc": "2.0",
+            "id": message["id"],
+            "result": None
+        }
+        if message["params"]["action"] == "register":
+            notification = {
+                "jsonrpc": "2.0",
+                "method": "build/sourceKitOptionsChanged",
+                "params": {
+                    "uri": message["params"]["uri"],
+                    "updatedOptions": {
+                        "options": ["a", "b"],
+                        "workingDirectory": "/some/dir"
+                    }
+                }
+            }
+
+    # ignore other notifications
+    elif "id" in message:
+        response = {
+            "jsonrpc": "2.0",
+            "id": message["id"],
+            "error": {
+                "code": -32600,
+                "message": "unhandled method {}".format(message["method"]),
+            }
+        }
+
+    if response: send(response)
+    if notification: send(notification)

Tests/SKCoreTests/BuildServerBuildSystemTests.swift

@@ -46,4 +46,38 @@ final class BuildServerBuildSystemTests: XCTestCase {
     XCTAssertNil(buildSystem?.settings(for: missingFileURL, Language.swift))
   }
 
+  func testFileRegistration() {
+    let root = AbsolutePath(
+      inputsDirectory().appendingPathComponent(testDirectoryName, isDirectory: true).path)
+    let buildFolder = AbsolutePath(NSTemporaryDirectory())
+    let buildSystem = try? BuildServerBuildSystem(projectRoot: root, buildFolder: buildFolder)
+    XCTAssertNotNil(buildSystem)
+
+    let fileUrl = URL(fileURLWithPath: "/some/file/path")
+    let expectation = XCTestExpectation(description: "\(fileUrl) settings updated")
+    let buildSystemDelegate = TestDelegate(expectations: [fileUrl: expectation])
+    buildSystem?.delegate = buildSystemDelegate
+    buildSystem?.registerForChangeNotifications(for: fileUrl)
+
+    let result = XCTWaiter.wait(for: [expectation], timeout: 1)
+    if result != .completed {
+      fatalError("error \(result) waiting for settings notification")
+    }
+  }
+
+}
+
+final class TestDelegate: BuildSystemDelegate {
+
+  let expectations: [URL:XCTestExpectation]
+
+  public init(expectations: [URL:XCTestExpectation]) {
+    self.expectations = expectations
+  }
+
+  func fileBuildSettingsChanged(_ changedFiles: Set<URL>) {
+    for url in changedFiles {
+      expectations[url]?.fulfill()
+    }
+  }
 }

Tests/SKCoreTests/XCTestManifests.swift

@@ -6,6 +6,7 @@ extension BuildServerBuildSystemTests {
     //   `swift test --generate-linuxmain`
     // to regenerate.
     static let __allTests__BuildServerBuildSystemTests = [
+        ("testFileRegistration", testFileRegistration),
         ("testServerInitialize", testServerInitialize),
         ("testSettings", testSettings),
     ]