com.google.javascript.jscomp.disambiguate.ClusterPropagator Maven / Gradle / Ivy

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/*
 * Copyright 2019 The Closure Compiler Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.javascript.jscomp.disambiguate;

import com.google.javascript.jscomp.graph.FixedPointGraphTraversal;

/** A callback to propagate clusterings across a type graph. */
final class ClusterPropagator implements FixedPointGraphTraversal.EdgeCallback {

  ClusterPropagator() {}

  @Override
  public boolean traverseEdge(FlatType src, Object unused, FlatType dest) {
    int startDestPropCount = dest.getAssociatedProps().size();

    /**
     * We make sure to check invalidation on the source first to preempt property propagation.
     * There's no point in porpagating any properties in that case. Clearing them eagerly saves time
     * and memory.
     */
    invalidatePropertiesIfInvalidating(src);

    for (PropertyClustering prop : src.getAssociatedProps()) {
      if (prop.isInvalidated()) {
        continue;
      }

      dest.getAssociatedProps().add(prop);
      prop.getClusters().union(src, dest);
    }

    invalidatePropertiesIfInvalidating(dest);

    // Were any properties added to dest?
    return startDestPropCount < dest.getAssociatedProps().size();
  }

  private static void invalidatePropertiesIfInvalidating(FlatType flat) {
    if (flat.isInvalidating()) {
      flat.getAssociatedProps().forEach(PropertyClustering::invalidate);
      flat.getAssociatedProps().clear();
    }
  }
}