@quick-game/cli/dist/cli-server/client/front_end/models/source_map_scopes/ScopeTreeCache.js

Command line interface for rapid qg development

// Copyright 2023 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import * as Formatter from '../formatter/formatter.js';
/**
 * Caches scope trees for whole scripts.
 *
 * We use `SDK.Script` as a key to uniquely identify scripts.
 * `SDK.Script` boils down to "target" + "script ID". This duplicates work in case of
 * identitical script running on multiple targets (e.g. workers).
 */
export class ScopeTreeCache {
    /** If a script failed to parse, we stash null in order to prevent unnecessary re-parsing */
    #scopeTrees = new WeakMap();
    #pendingScopeTrees = new Map();
    static #instance;
    static instance() {
        if (!ScopeTreeCache.#instance) {
            ScopeTreeCache.#instance = new ScopeTreeCache();
        }
        return ScopeTreeCache.#instance;
    }
    async scopeTreeForScript(script) {
        const maybeCachedTree = this.#scopeTrees.get(script);
        if (maybeCachedTree !== undefined) {
            // We intentionally return `null` here if the script already failed to parse once.
            return maybeCachedTree;
        }
        const { content } = await script.requestContent();
        if (content === null) {
            return null;
        }
        // We check for pending requests for this script AFTER we load the script content.
        // There must not be any suspension point between checking #pendingScopeTrees and
        // the actual call to the worker.
        // This is fine, since #requestContent does similar request de-duplication.
        const maybePromise = this.#pendingScopeTrees.get(script);
        if (maybePromise) {
            return maybePromise;
        }
        const sourceType = script.isModule ? 'module' : 'script';
        const scopeTreePromise = Formatter.FormatterWorkerPool.formatterWorkerPool().javaScriptScopeTree(content, sourceType);
        this.#pendingScopeTrees.set(script, scopeTreePromise);
        const scopeTree = await scopeTreePromise;
        this.#pendingScopeTrees.delete(script);
        this.#scopeTrees.set(script, scopeTree);
        return scopeTree;
    }
}
//# sourceMappingURL=ScopeTreeCache.js.map