Class VsCodeBasedParserCache

packages/foam-vscode/src/vscode/services/cache.ts:21–99

 * discarded automatically on the next startup.
 */
export default class VsCodeBasedParserCache implements ParserCache {
  static CACHE_NAME = 'foam-cache';
  static CACHE_VERSION = 5;
  static CACHE_VERSION_KEY = 'foam-cache-version';
  private _cache: LRUCache<string, ParserCacheEntry>;

  constructor(private context: ExtensionContext, size = 10000) {
    this._cache = new LRUCache({
      max: size,
      updateAgeOnGet: true,
      updateAgeOnHas: false,
    });

    const storedVersion = context.workspaceState.get<number>(
      VsCodeBasedParserCache.CACHE_VERSION_KEY,
      0
    );
    if (storedVersion !== VsCodeBasedParserCache.CACHE_VERSION) {
      Logger.debug(
        `Cache version mismatch (stored: ${storedVersion}, current: ${VsCodeBasedParserCache.CACHE_VERSION}) — clearing cache`
      );
      this.clear();
      context.workspaceState.update(
        VsCodeBasedParserCache.CACHE_VERSION_KEY,
        VsCodeBasedParserCache.CACHE_VERSION
      );
    } else {
      const source = context.workspaceState.get(
        VsCodeBasedParserCache.CACHE_NAME,
        []
      );
      try {
        this._cache.load(source);
      } catch (e) {
        Logger.warn(`Failed to load cache: ${e}`);
        this.clear();
      }
    }
    Logger.debug('Cache size: ' + this._cache.size);
  }

  clear(): void {
    this._cache.clear();
    this.context.workspaceState.update(VsCodeBasedParserCache.CACHE_NAME, []);
  }

  get(uri: URI): ParserCacheEntry {
    const result = this._cache.get(uri.toString());
    if (result) {
      // The cache returns a plain object, but we need an actual
      // instance of URI in the resource (we check instanceof in the code),
      // so to be sure we convert it here.
      const { checksum, resource } = result;
      const rehydrated = {
        ...resource,
        uri: new URI(resource.uri),
      };
      return {