Remove cancellationToken.js (#60250)

Author: jakebailey

Herebyfile.mjs

@@ -604,14 +604,6 @@ export const knip = task({
     run: () => exec(process.execPath, ["node_modules/knip/bin/knip.js", "--tags=+internal,-knipignore", "--exclude=duplicates,enumMembers", ...(cmdLineOptions.fix ? ["--fix"] : [])]),
 });
 
-const { main: cancellationToken, watch: watchCancellationToken } = entrypointBuildTask({
-    name: "cancellation-token",
-    project: "src/cancellationToken",
-    srcEntrypoint: "./src/cancellationToken/cancellationToken.ts",
-    builtEntrypoint: "./built/local/cancellationToken/cancellationToken.js",
-    output: "./built/local/cancellationToken.js",
-});
-
 const { main: typingsInstaller, watch: watchTypingsInstaller } = entrypointBuildTask({
     name: "typings-installer",
     buildDeps: [generateDiagnostics],
@@ -661,14 +653,14 @@ const copyBuiltLocalDiagnosticMessages = task({
 export const otherOutputs = task({
     name: "other-outputs",
     description: "Builds miscelaneous scripts and documents distributed with the LKG",
-    dependencies: [cancellationToken, typingsInstaller, watchGuard, generateTypesMap, copyBuiltLocalDiagnosticMessages],
+    dependencies: [typingsInstaller, watchGuard, generateTypesMap, copyBuiltLocalDiagnosticMessages],
 });
 
 export const watchOtherOutputs = task({
     name: "watch-other-outputs",
     description: "Builds miscelaneous scripts and documents distributed with the LKG",
     hiddenFromTaskList: true,
-    dependencies: [watchCancellationToken, watchTypingsInstaller, watchWatchGuard, generateTypesMap, copyBuiltLocalDiagnosticMessages],
+    dependencies: [watchTypingsInstaller, watchWatchGuard, generateTypesMap, copyBuiltLocalDiagnosticMessages],
 });
 
 export const local = task({
@@ -916,7 +908,6 @@ export const produceLKG = task({
         }
 
         const expectedFiles = [
-            "built/local/cancellationToken.js",
             "built/local/tsc.js",
             "built/local/_tsc.js",
             "built/local/tsserver.js",

knip.jsonc

@@ -3,7 +3,6 @@
     "includeEntryExports": true,
     "entry": [
         "Herebyfile.mjs",
-        "src/cancellationToken/cancellationToken.ts",
         "src/testRunner/_namespaces/Harness.ts",
         "src/tsc/tsc.ts",
         "src/tsserver/server.ts",

scripts/produceLKG.mjs

@@ -48,7 +48,6 @@ async function copyTypesMap() {
 }
 
 async function copyScriptOutputs() {
-    await copyFromBuiltLocal("cancellationToken.js");
     await copyFromBuiltLocal("tsc.js");
     await copyFromBuiltLocal("_tsc.js");
     await copyFromBuiltLocal("tsserver.js");

src/cancellationToken/cancellationToken.ts

@@ -2,7 +2,6 @@
     "files": [],
     "include": [],
     "references": [
-        { "path": "./cancellationToken" },
         { "path": "./compiler" },
         { "path": "./deprecatedCompat" },
         { "path": "./harness" },

src/cancellationToken/tsconfig.json

@@ -275,14 +275,7 @@ export function initializeNodeSystem(): StartInput {
         sys.gc = () => global.gc?.();
     }
 
-    let cancellationToken: ts.server.ServerCancellationToken;
-    try {
-        const factory = require("./cancellationToken.js");
-        cancellationToken = factory(sys.args);
-    }
-    catch {
-        cancellationToken = ts.server.nullCancellationToken;
-    }
+    const cancellationToken = createCancellationToken(sys.args);
 
     const localeStr = ts.server.findArgument("--locale");
     if (localeStr) {
@@ -668,3 +661,60 @@ function startNodeSession(options: StartSessionOptions, logger: ts.server.Logger
         return combinePaths(normalizeSlashes(homePath), cacheFolder);
     }
 }
+
+function pipeExists(name: string): boolean {
+    // Unlike statSync, existsSync doesn't throw an exception if the target doesn't exist.
+    // A comment in the node code suggests they're stuck with that decision for back compat
+    // (https://github.com/nodejs/node/blob/9da241b600182a9ff400f6efc24f11a6303c27f7/lib/fs.js#L222).
+    // Caveat: If a named pipe does exist, the first call to existsSync will return true, as for
+    // statSync.  Subsequent calls will return false, whereas statSync would throw an exception
+    // indicating that the pipe was busy.  The difference is immaterial, since our statSync
+    // implementation returned false from its catch block.
+    return fs.existsSync(name);
+}
+
+function createCancellationToken(args: string[]): ts.server.ServerCancellationToken {
+    let cancellationPipeName: string | undefined;
+    for (let i = 0; i < args.length - 1; i++) {
+        if (args[i] === "--cancellationPipeName") {
+            cancellationPipeName = args[i + 1];
+            break;
+        }
+    }
+    if (!cancellationPipeName) {
+        return ts.server.nullCancellationToken;
+    }
+    // cancellationPipeName is a string without '*' inside that can optionally end with '*'
+    // when client wants to signal cancellation it should create a named pipe with name=<cancellationPipeName>
+    // server will synchronously check the presence of the pipe and treat its existence as indicator that current request should be canceled.
+    // in case if client prefers to use more fine-grained schema than one name for all request it can add '*' to the end of cancellationPipeName.
+    // in this case pipe name will be build dynamically as <cancellationPipeName><request_seq>.
+    if (cancellationPipeName.charAt(cancellationPipeName.length - 1) === "*") {
+        const namePrefix = cancellationPipeName.slice(0, -1);
+        if (namePrefix.length === 0 || namePrefix.includes("*")) {
+            throw new Error("Invalid name for template cancellation pipe: it should have length greater than 2 characters and contain only one '*'.");
+        }
+        let perRequestPipeName: string | undefined;
+        let currentRequestId: number;
+        return {
+            isCancellationRequested: () => perRequestPipeName !== undefined && pipeExists(perRequestPipeName),
+            setRequest(requestId: number) {
+                currentRequestId = requestId;
+                perRequestPipeName = namePrefix + requestId;
+            },
+            resetRequest(requestId: number) {
+                if (currentRequestId !== requestId) {
+                    throw new Error(`Mismatched request id, expected ${currentRequestId}, actual ${requestId}`);
+                }
+                perRequestPipeName = undefined;
+            },
+        };
+    }
+    else {
+        return {
+            isCancellationRequested: () => pipeExists(cancellationPipeName),
+            setRequest: (_requestId: number): void => void 0,
+            resetRequest: (_requestId: number): void => void 0,
+        };
+    }
+}