@atlaskit/editor-plugin-limited-mode/dist/esm/pm-plugins/utils/latch-detector.js

LimitedMode plugin for @atlaskit/editor-core

function _createForOfIteratorHelper(r, e) { var t = "undefined" != typeof Symbol && r[Symbol.iterator] || r["@@iterator"]; if (!t) { if (Array.isArray(r) || (t = _unsupportedIterableToArray(r)) || e && r && "number" == typeof r.length) { t && (r = t); var _n = 0, F = function F() {}; return { s: F, n: function n() { return _n >= r.length ? { done: !0 } : { done: !1, value: r[_n++] }; }, e: function e(r) { throw r; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var o, a = !0, u = !1; return { s: function s() { t = t.call(r); }, n: function n() { var r = t.next(); return a = r.done, r; }, e: function e(r) { u = !0, o = r; }, f: function f() { try { a || null == t.return || t.return(); } finally { if (u) throw o; } } }; }
function _unsupportedIterableToArray(r, a) { if (r) { if ("string" == typeof r) return _arrayLikeToArray(r, a); var t = {}.toString.call(r).slice(8, -1); return "Object" === t && r.constructor && (t = r.constructor.name), "Map" === t || "Set" === t ? Array.from(r) : "Arguments" === t || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(t) ? _arrayLikeToArray(r, a) : void 0; } }
function _arrayLikeToArray(r, a) { (null == a || a > r.length) && (a = r.length); for (var e = 0, n = Array(a); e < a; e++) n[e] = r[e]; return n; }
import { isPerformanceAPIAvailable, isPerformanceObserverLongTaskAvailable } from '@atlaskit/editor-common/is-performance-api-available';
/**
 * Wires browser performance signals into the supplied {@link LatchPolicy}.
 *
 * Holds no configuration and makes no decisions: it measures, and forwards. Everything tunable lives
 * on the policy, including the clock it reads.
 *
 * The measurement mirrors `editor-plugin-base/src/pm-plugins/frozen-editor.ts`, which already runs an
 * identical `longtask` observer and per-keystroke rAF measurement for every session to feed
 * `ACTION.SLOW_INPUT` / `ACTION.BROWSER_FREEZE`. It is duplicated rather than shared so that this
 * experiment stays self-contained inside the limited-mode plugin — no new cross-plugin dependency,
 * and deleting it is a single-directory revert if the experiment does not ship. The marginal cost is
 * one `performance.now()` and one `requestAnimationFrame` per keystroke.
 */
export var createLatchDetector = function createLatchDetector(_ref) {
  var onLatchCriteriaMet = _ref.onLatchCriteriaMet,
    policy = _ref.policy;
  // One clock for the whole subsystem, so measured durations and the policy's windows agree.
  var now = policy.now;
  var observer;
  var destroyed = false;
  var handleEvaluation = function handleEvaluation(evaluation) {
    if (evaluation !== 'latched') {
      return;
    }

    // One-way latch: the policy will never evaluate again, so stop paying for the observers.
    teardownObservers();
    var details = policy.getLatchDetails();
    if (details) {
      onLatchCriteriaMet(details);
    }
  };
  function teardownObservers() {
    var _observer;
    (_observer = observer) === null || _observer === void 0 || _observer.disconnect();
    observer = undefined;
  }
  if (isPerformanceObserverLongTaskAvailable()) {
    try {
      observer = new PerformanceObserver(function (list) {
        var _iterator = _createForOfIteratorHelper(list.getEntries()),
          _step;
        try {
          for (_iterator.s(); !(_step = _iterator.n()).done;) {
            var entry = _step.value;
            if (policy.isLatched()) {
              return;
            }
            handleEvaluation(policy.recordLongTask(entry.duration));
          }
        } catch (err) {
          _iterator.e(err);
        } finally {
          _iterator.f();
        }
      });
      observer.observe({
        entryTypes: ['longtask']
      });
    } catch (_unused) {
      // `longtask` is unsupported in some browsers even when PerformanceObserver exists. The
      // latency criterion alone is still a valid trigger, so carry on without freeze detection.
      observer = undefined;
    }
  }
  return {
    noteDocumentChange: function noteDocumentChange(_ref2) {
      var nodeSizeDelta = _ref2.nodeSizeDelta,
        isDocumentReplaced = _ref2.isDocumentReplaced;
      if (destroyed || policy.isLatched()) {
        return;
      }
      if (isDocumentReplaced || policy.isBulkChange(nodeSizeDelta)) {
        policy.suppress();
      }
    },
    measureInput: function measureInput() {
      if (destroyed || policy.isLatched() || !isPerformanceAPIAvailable()) {
        return;
      }
      var start = now();

      // Runs after every handleTextInput and all resulting plugin work, but before paint — the
      // same measurement point frozen-editor uses, so the numbers are comparable to existing
      // SLOW_INPUT telemetry.
      requestAnimationFrame(function () {
        if (destroyed || policy.isLatched()) {
          return;
        }
        handleEvaluation(policy.recordInputLatency(now() - start));
      });
    },
    destroy: function destroy() {
      destroyed = true;
      teardownObservers();
    }
  };
};