LKG update

Author: RyanCavanaugh

lib/cancellationToken.js

@@ -15,6 +15,15 @@ and limitations under the License.
 
 "use strict";
 var fs = require("fs");
+function pipeExists(name) {
+    try {
+        fs.statSync(name);
+        return true;
+    }
+    catch (e) {
+        return false;
+    }
+}
 function createCancellationToken(args) {
     var cancellationPipeName;
     for (var i = 0; i < args.length - 1; i++) {
@@ -24,18 +33,39 @@ function createCancellationToken(args) {
         }
     }
     if (!cancellationPipeName) {
-        return { isCancellationRequested: function () { return false; } };
+        return {
+            isCancellationRequested: function () { return false; },
+            setRequest: function (_requestId) { return void 0; },
+            resetRequest: function (_requestId) { return void 0; }
+        };
     }
-    return {
-        isCancellationRequested: function () {
-            try {
-                fs.statSync(cancellationPipeName);
-                return true;
-            }
-            catch (e) {
-                return false;
-            }
+    if (cancellationPipeName.charAt(cancellationPipeName.length - 1) === "*") {
+        var namePrefix_1 = cancellationPipeName.slice(0, -1);
+        if (namePrefix_1.length === 0 || namePrefix_1.indexOf("*") >= 0) {
+            throw new Error("Invalid name for template cancellation pipe: it should have length greater than 2 characters and contain only one '*'.");
         }
-    };
+        var perRequestPipeName_1;
+        var currentRequestId_1;
+        return {
+            isCancellationRequested: function () { return perRequestPipeName_1 !== undefined && pipeExists(perRequestPipeName_1); },
+            setRequest: function (requestId) {
+                currentRequestId_1 = currentRequestId_1;
+                perRequestPipeName_1 = namePrefix_1 + requestId;
+            },
+            resetRequest: function (requestId) {
+                if (currentRequestId_1 !== requestId) {
+                    throw new Error("Mismatched request id, expected " + currentRequestId_1 + ", actual " + requestId);
+                }
+                perRequestPipeName_1 = undefined;
+            }
+        };
+    }
+    else {
+        return {
+            isCancellationRequested: function () { return pipeExists(cancellationPipeName); },
+            setRequest: function (_requestId) { return void 0; },
+            resetRequest: function (_requestId) { return void 0; }
+        };
+    }
 }
 module.exports = createCancellationToken;