| // Copyright 2024 The Bazel Authors. All rights reserved. |
| // |
| // 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.devtools.build.lib.util; |
| |
| import com.google.common.collect.ImmutableList; |
| import com.google.devtools.build.lib.util.ObjectGraphTraverser.EdgeType; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.Map; |
| |
| /** An object receiver for {@link ObjectGraphTraverser} that collects statistics about RAM use. */ |
| public class MemoryAccountant implements ObjectGraphTraverser.ObjectReceiver { |
| /** Measures the shallow size of an object. */ |
| public interface Measurer { |
| |
| /** |
| * Return the shallow size of an objet. |
| * |
| * <p>If this instance doesn't know how to compute it, returns -1. |
| */ |
| long maybeGetShallowSize(Object o); |
| } |
| |
| /** Statistics collected about RAM use. */ |
| public static class Stats { |
| private final Map<String, Long> objectCountByClass; |
| private final Map<String, Long> memoryByClass; |
| private long objectCount; |
| private long memory; |
| |
| private Stats(boolean collectDetails) { |
| objectCountByClass = collectDetails ? new HashMap<>() : null; |
| memoryByClass = collectDetails ? new HashMap<>() : null; |
| objectCount = 0L; |
| memory = 0L; |
| } |
| |
| private void addObject(String clazz, long size) { |
| objectCount += 1; |
| memory += size; |
| if (objectCountByClass != null) { |
| objectCountByClass.put(clazz, objectCountByClass.getOrDefault(clazz, 0L) + 1); |
| } |
| |
| if (memoryByClass != null) { |
| memoryByClass.put(clazz, memoryByClass.getOrDefault(clazz, 0L) + size); |
| } |
| } |
| |
| public long getObjectCount() { |
| return objectCount; |
| } |
| |
| public long getMemoryUse() { |
| return memory; |
| } |
| |
| public Map<String, Long> getObjectCountByClass() { |
| return Collections.unmodifiableMap(objectCountByClass); |
| } |
| |
| public Map<String, Long> getMemoryByClass() { |
| return Collections.unmodifiableMap(memoryByClass); |
| } |
| } |
| |
| private final ImmutableList<Measurer> measurers; |
| private final Stats stats; |
| |
| public MemoryAccountant(Iterable<Measurer> measurers, boolean collectDetails) { |
| this.measurers = ImmutableList.copyOf(measurers); |
| stats = new Stats(collectDetails); |
| } |
| |
| @Override |
| public synchronized void objectFound(Object o, String context) { |
| if (context == null) { |
| if (o.getClass().isArray()) { |
| context = "[] " + o.getClass().getComponentType().getName(); |
| } else { |
| context = o.getClass().getName(); |
| } |
| } |
| |
| long size = getShallowSize(o); |
| stats.addObject(context, size); |
| } |
| |
| private long getShallowSize(Object o) { |
| for (Measurer measurer : measurers) { |
| long candidate = measurer.maybeGetShallowSize(o); |
| if (candidate >= 0) { |
| return candidate; |
| } |
| } |
| |
| return ShallowObjectSizeComputer.getShallowSize(o); |
| } |
| |
| @Override |
| public void edgeFound(Object from, Object to, String toContext, EdgeType edgeType) { |
| // Ignored for now. |
| } |
| |
| public Stats getStats() { |
| return stats; |
| } |
| } |