7f2330a968
When profiling ngcc it is notable that a large amount of time is spent dealing with an exception that is thrown (and handled internally by fs) when checking the existence of a file. We check file existence a lot in both finding entry-points and when TS is compiling code. This commit adds a simple cached `FileSystem`, which wraps a real `FileSystem` delegate. This will reduce the number of calls through to `fs.exists()` and `fs.readFile()` on the delegate. Initial benchmarks indicate that the cache is miss to hit ratio for `exists()` is about 2:1, which means that we save about 1/3 of the calls to `fs.existsSync()`. Note that this implements a "non-expiring" cache, so it is not suitable for a long lived `FileSystem`, where files may be modified externally. The cache will be updated if a file is changed or moved via calls to `FileSystem` methods but it will not be aware of changes to the files system from outside the `FileSystem` service. For ngcc we must create a new `FileSystem` service for each run of `mainNgcc` and ensure that all file operations (including TS compilation) use the `FileSystem` service. This ensures that it is very unlikely that a file will change externally during `mainNgcc` processing. PR Close #30525
30 lines
1.2 KiB
TypeScript
30 lines
1.2 KiB
TypeScript
/**
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* @license
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* Copyright Google Inc. All Rights Reserved.
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*
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* Use of this source code is governed by an MIT-style license that can be
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* found in the LICENSE file at https://angular.io/license
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*/
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import {CachedFileSystem, NodeJSFileSystem, setFileSystem} from '../src/ngtsc/file_system';
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import {mainNgcc} from './src/main';
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import {hasBeenProcessed as _hasBeenProcessed} from './src/packages/build_marker';
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import {EntryPointJsonProperty, EntryPointPackageJson} from './src/packages/entry_point';
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export {ConsoleLogger, LogLevel} from './src/logging/console_logger';
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export {Logger} from './src/logging/logger';
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export {NgccOptions} from './src/main';
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export {PathMappings} from './src/utils';
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export function hasBeenProcessed(packageJson: object, format: string) {
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// Recreate the file system on each call to reset the cache
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setFileSystem(new CachedFileSystem(new NodeJSFileSystem()));
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return _hasBeenProcessed(packageJson as EntryPointPackageJson, format as EntryPointJsonProperty);
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}
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export function process(...args: Parameters<typeof mainNgcc>) {
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// Recreate the file system on each call to reset the cache
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setFileSystem(new CachedFileSystem(new NodeJSFileSystem()));
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return mainNgcc(...args);
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}
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