respond-framework/dist/proxy/useMemo.js

create as fast you think

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;
var _react = require("react");
var _createSnapProxy = require("./createSnapProxy.js");
var _isChanged = require("./helpers/isChanged.js");
const useMemo0 = (func, respond, dependencies = []) => {
  const last = (0, _react.useRef)();
  const subscribe = (0, _react.useCallback)(cb => respond.listen(cb), [respond]); // standard listening to all proxy state changes

  const createSnapshot = () => respond.snapshot();
  const getSnapshot = () => {
    const next = createSnapshot();
    const {
      snapshot,
      affected
    } = last.current ?? {};
    const changed = inRender || !last.current || (0, _isChanged.default)(snapshot, next, affected);
    return changed ? next : snapshot; // not changed -- referentially equal
  };
  let inRender = true;
  const snapshot = (0, _react.useSyncExternalStore)(subscribe, getSnapshot, createSnapshot);
  inRender = false;
  const deps = (0, _react.useMemo)(() => dependencies, dependencies);
  const cache = (0, _react.useMemo)(() => new WeakMap(), []);
  const affected = (0, _react.useMemo)(() => new WeakMap(), [snapshot, deps]);
  const changed = affected !== last.current?.affected; // changes when either snapshot or deps changes
  const memoized = changed ? func((0, _createSnapProxy.default)(snapshot, {
    affected,
    cache
  }), ...deps) : last.current.memoized;
  (0, _react.useLayoutEffect)(() => {
    last.current = {
      snapshot,
      affected,
      memoized,
      deps
    };
  });
  return memoized;
};
var _default = exports.default = useMemo0;