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import { dirname, join } from "https://deno.land/std@0.54.0/path/mod.ts"import { readJson } from "https://deno.land/std/fs/read_json.ts";import { writeJson } from "https://deno.land/std/fs/write_json.ts";
export interface ConnectOptions {  bailIfNotPresent?: boolean;}
const getNow = Date.now;
export class Connector<Schema = any> {  private _filePath: string = "";  private readonly WRITE_TIMEOUT: number = 10000;  private readonly WRITE_WORKER_PATH: string = join(dirname(import.meta.url), "writeWorker.ts");  private readonly WRITE_WORKER_OPTIONS: { type: "module"; deno: boolean } = {    type: "module",    deno: true,  };
  private _checkConnection() {    if (!this._filePath) {      throw new Error("DB connection not set. Cannot read.");    }  }
  private _createTaskId(): string {    return `casualdb:connector:${getNow()}`;  }
  async read() {    this._checkConnection();    return readJson(this._filePath) as Promise<Schema>;  }
  async connect(fsPath: string, options?: ConnectOptions): Promise<void> {    try {      const fileInfo = await Deno.stat(fsPath);
      if (!fileInfo.isFile) {        throw new Error("Not a file");      }
      this._filePath = fsPath;      this.read();    } catch (err) {      if (        err instanceof Error && err.toString().startsWith("NotFound") &&        !options?.bailIfNotPresent      ) {        await writeJson(fsPath, {});        this._filePath = fsPath;        return;      }      throw err;    }  }
  write(data: Schema) {    return new Promise((resolve, reject) => {      this._checkConnection();      const taskId = this._createTaskId();      let timeout: null | number = null;
      const worker = new Worker(        this.WRITE_WORKER_PATH,        { ...this.WRITE_WORKER_OPTIONS },      );
      worker.onmessage = (e) => {        const { taskId: returnedTaskId, error } = e.data;
        if (          returnedTaskId && returnedTaskId.toString() === taskId &&          error === false        ) {          resolve();        } else if (error) {          reject(error);        } else {          console.debug(            "[casualdb:connector:debug]",            { returnedTaskId, taskId, error },          );          reject(new Error(`[casualdb] unknown error while writing to file`));        }        if (timeout) {          clearTimeout(timeout);        }      };
      timeout = setTimeout(() => {        reject(          new Error(            `[casualdb] timed out while waiting for worker to respond while writing.`,          ),        );      }, this.WRITE_TIMEOUT);
      worker.postMessage({        file: this._filePath,        taskId,        data,      });    });  }}