perf(ngcc): only create tasks for non-processed formats (#35719)

packages/compiler-cli/ngcc/src/execution/api.ts

@@ -61,7 +61,7 @@ export interface Task extends JsonObject {
 
   /**
    * The list of all format properties (including `task.formatProperty`) that should be marked as
-   * processed once the taksk has been completed, because they point to the format-path that will be
+   * processed once the task has been completed, because they point to the format-path that will be
    * processed as part of the task.
    */
   formatPropertiesToMarkAsProcessed: EntryPointJsonProperty[];
@@ -75,9 +75,6 @@ export type TaskCompletedCallback = (task: Task, outcome: TaskProcessingOutcome)
 
 /** Represents the outcome of processing a `Task`. */
 export const enum TaskProcessingOutcome {
-  /** The target format property was already processed - didn't have to do anything. */
-  AlreadyProcessed,
-
   /** Successfully processed the target format property. */
   Processed,
 }

packages/compiler-cli/ngcc/src/execution/cluster/master.ts

@@ -41,6 +41,10 @@ export class ClusterMaster {
   }
 
   run(): Promise<void> {
+    if (this.taskQueue.allTasksCompleted) {
+      return Promise.resolve();
+    }
+
     // Set up listeners for worker events (emitted on `cluster`).
     cluster.on('online', this.wrapEventHandler(worker => this.onWorkerOnline(worker.id)));
 
@@ -51,10 +55,8 @@ export class ClusterMaster {
         'exit',
         this.wrapEventHandler((worker, code, signal) => this.onWorkerExit(worker, code, signal)));
 
-    // Start the workers.
-    for (let i = 0; i < this.workerCount; i++) {
-      cluster.fork();
-    }
+    // Since we have pending tasks at the very minimum we need a single worker.
+    cluster.fork();
 
     return this.finishedDeferred.promise.then(() => this.stopWorkers(), err => {
       this.stopWorkers();
@@ -98,11 +100,16 @@ export class ClusterMaster {
       isWorkerAvailable = false;
     }
 
-    // If there are no available workers or no available tasks, log (for debugging purposes).
     if (!isWorkerAvailable) {
-      this.logger.debug(
-          `All ${this.taskAssignments.size} workers are currently busy and cannot take on more ` +
-          'work.');
+      if (this.taskAssignments.size < this.workerCount) {
+        this.logger.debug('Spawning another worker process as there is more work to be done.');
+        cluster.fork();
+      } else {
+        // If there are no available workers or no available tasks, log (for debugging purposes).
+        this.logger.debug(
+            `All ${this.taskAssignments.size} workers are currently busy and cannot take on more ` +
+            'work.');
+      }
     } else {
       const busyWorkers = Array.from(this.taskAssignments)
                               .filter(([_workerId, task]) => task !== null)

packages/compiler-cli/ngcc/src/main.ts

@@ -33,7 +33,7 @@ import {ParallelTaskQueue} from './execution/task_selection/parallel_task_queue'
 import {SerialTaskQueue} from './execution/task_selection/serial_task_queue';
 import {ConsoleLogger, LogLevel} from './logging/console_logger';
 import {Logger} from './logging/logger';
-import {hasBeenProcessed, markAsProcessed} from './packages/build_marker';
+import {hasBeenProcessed} from './packages/build_marker';
 import {NgccConfiguration} from './packages/configuration';
 import {EntryPoint, EntryPointJsonProperty, EntryPointPackageJson, SUPPORTED_FORMAT_PROPERTIES, getEntryPointFormat} from './packages/entry_point';
 import {makeEntryPointBundle} from './packages/entry_point_bundle';
@@ -207,6 +207,12 @@ export function mainNgcc(
       }
 
       for (const formatProperty of propertiesToProcess) {
+        if (hasBeenProcessed(entryPoint.packageJson, formatProperty)) {
+          // The format-path which the property maps to is already processed - nothing to do.
+          logger.debug(`Skipping ${entryPoint.name} : ${formatProperty} (already compiled).`);
+          continue;
+        }
+
         const formatPropertiesToMarkAsProcessed = equivalentPropertiesMap.get(formatProperty) !;
         tasks.push({entryPoint, formatProperty, formatPropertiesToMarkAsProcessed, processDts});
 
@@ -256,13 +262,6 @@ export function mainNgcc(
             `${formatProperty} (formatPath: ${formatPath} | format: ${format})`);
       }
 
-      // The format-path which the property maps to is already processed - nothing to do.
-      if (hasBeenProcessed(packageJson, formatProperty)) {
-        logger.debug(`Skipping ${entryPoint.name} : ${formatProperty} (already compiled).`);
-        onTaskCompleted(task, TaskProcessingOutcome.AlreadyProcessed);
-        return;
-      }
-
       const bundle = makeEntryPointBundle(
           fileSystem, entryPoint, formatPath, isCore, format, processDts, pathMappings, true,
           enableI18nLegacyMessageIdFormat);

packages/compiler-cli/ngcc/test/execution/cluster/worker_spec.ts

@@ -58,15 +58,8 @@ describe('ClusterWorker', () => {
         new ClusterWorker(mockLogger, createCompileFnSpy);
         const onTaskCompleted: TaskCompletedCallback = createCompileFnSpy.calls.argsFor(0)[0];
 
-        onTaskCompleted(null as any, TaskProcessingOutcome.AlreadyProcessed);
-        expect(processSendSpy).toHaveBeenCalledTimes(1);
-        expect(processSendSpy).toHaveBeenCalledWith({
-          type: 'task-completed',
-          outcome: TaskProcessingOutcome.AlreadyProcessed,
-        });
-
         onTaskCompleted(null as any, TaskProcessingOutcome.Processed);
-        expect(processSendSpy).toHaveBeenCalledTimes(2);
+        expect(processSendSpy).toHaveBeenCalledTimes(1);
         expect(processSendSpy).toHaveBeenCalledWith({
           type: 'task-completed',
           outcome: TaskProcessingOutcome.Processed,