microlink/cjs/batchcall.js

Comlink Alternative. Built with JSON-RPC.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = batchcall;
var _serialize = _interopRequireDefault(require("./serialize.js"));
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
/**
 *
 * @param {*} it
 * @param {{ params, method }[]} batch
 * @param {*} param2
 * @returns
 */
function batchcall(it, batch, {
  debug_level = 0
} = {}) {
  let all_params_functions = {};

  // pre-process and serialize requests
  const requests = batch.map(({
    id,
    method,
    params
  }) => {
    if (typeof id !== "number") id = Math.random();
    const [params_serialized, params_functions] = (0, _serialize.default)(params || [], "microlink.call:");
    Object.assign(all_params_functions, params_functions);
    return {
      jsonrpc: "2.0",
      id,
      method,
      params: params_serialized
    };
  });
  if (debug_level >= 2) console.log("[microlink.batchcall] requests serialized to ", requests);
  const ids = requests.map(req => req.id);
  return new Promise(resolve => {
    const listener = async function listener(evt) {
      if (debug_level >= 2) {
        console.log("[microlink.batchcall] response listener received message event with data", evt.data);
      }
      let {
        data
      } = evt;
      if (typeof data !== "object" || data === null) return;

      // worker is requesting that the main thread run a function for it
      if (data.jsonrpc === "2.0" && data.method && data.method in all_params_functions) {
        if (!Array.isArray(data.params)) throw Error("[microlink.batchcall] params should be an array");
        const result = await all_params_functions[data.method](...data.params);
        const msg = {
          jsonrpc: "2.0",
          result,
          id: data.id
        };
        if (debug_level >= 2) console.log("[microlink.batchcall] posting message down to worker:", msg);
        return it.postMessage(msg);
      }
      if (Array.isArray(data) && data.every(it => typeof it === "object" && ids.includes(it.id))) {
        if (debug_level >= 2) console.log("[microlink.batchcall] removing exhausted listener");
        it.removeEventListener("message", listener);

        // enable garbage collection of params
        // even if promise is used later
        all_params_functions = null;

        // sort output results by input order
        data.sort((a, b) => Math.sign(ids.indexOf(a.id) - ids.indexOf(b.id)));
        const results = data.map(res => res.result);
        if (debug_level >= 2) console.log("[microlink.batchcall] resolving batch call:", results);
        resolve(results);
      }
    };
    it.addEventListener("message", listener);
    if (debug_level >= 2) console.log("[microlink.batchcall] posting message down to worker:", requests);
    return it.postMessage(requests);
  });
}