perf(ivy): let ngcc first check marker file before assembling bundle (#27438)

With the bundle info being assembled into a single object before the
transform is started, we now greedily create a TypeScript program up-front.
If a marker file exists that indicates that the bundle could be skipped
the program creation has already taken place which takes a significant
amount of time. This commit moves the marker check to occur before the
bundle is assembled.

PR Close #27438

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

@@ -8,6 +8,7 @@
 import * as path from 'canonical-path';
 import * as yargs from 'yargs';
 
+import {checkMarkerFile, writeMarkerFile} from './packages/build_marker';
 import {DependencyHost} from './packages/dependency_host';
 import {DependencyResolver} from './packages/dependency_resolver';
 import {EntryPointFormat} from './packages/entry_point';
@@ -59,6 +60,11 @@ export function mainNgcc(args: string[]): number {
       const dtsTransformFormat: EntryPointFormat = entryPoint.fesm2015 ? 'fesm2015' : 'esm2015';
 
       formats.forEach(format => {
+        if (checkMarkerFile(entryPoint, format)) {
+          console.warn(`Skipping ${entryPoint.name} : ${format} (already built).`);
+          return;
+        }
+
         const bundle =
             makeEntryPointBundle(entryPoint, isCore, format, format === dtsTransformFormat);
         if (bundle === null) {
@@ -67,6 +73,9 @@ export function mainNgcc(args: string[]): number {
         } else {
           transformer.transform(entryPoint, isCore, bundle);
         }
+
+        // Write the built-with-ngcc marker
+        writeMarkerFile(entryPoint, format);
       });
     });
   } catch (e) {

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

@@ -20,7 +20,6 @@ import {Esm5Renderer} from '../rendering/esm5_renderer';
 import {EsmRenderer} from '../rendering/esm_renderer';
 import {FileInfo, Renderer} from '../rendering/renderer';
 
-import {checkMarkerFile, writeMarkerFile} from './build_marker';
 import {EntryPoint} from './entry_point';
 import {EntryPointBundle} from './entry_point_bundle';
 
@@ -53,11 +52,6 @@ export class Transformer {
    * @param bundle the bundle to transform.
    */
   transform(entryPoint: EntryPoint, isCore: boolean, bundle: EntryPointBundle): void {
-    if (checkMarkerFile(entryPoint, bundle.format)) {
-      console.warn(`Skipping ${entryPoint.name} : ${bundle.format} (already built).`);
-      return;
-    }
-
     console.warn(`Compiling ${entryPoint.name} - ${bundle.format}`);
 
     const reflectionHost = this.getHost(isCore, bundle);
@@ -73,9 +67,6 @@ export class Transformer {
 
     // Write out all the transformed files.
     renderedFiles.forEach(file => this.writeFile(file));
-
-    // Write the built-with-ngcc marker
-    writeMarkerFile(entryPoint, bundle.format);
   }
 
   getHost(isCore: boolean, bundle: EntryPointBundle): NgccReflectionHost {