public final class

LeastRecentlyUsedCacheEvictor

extends java.lang.Object

implements CacheEvictor

 java.lang.Object

↳androidx.media3.datasource.cache.LeastRecentlyUsedCacheEvictor

Gradle dependencies

compile group: 'androidx.media3', name: 'media3-datasource', version: '1.5.0-alpha01'

  • groupId: androidx.media3
  • artifactId: media3-datasource
  • version: 1.5.0-alpha01

Artifact androidx.media3:media3-datasource:1.5.0-alpha01 it located at Google repository (https://maven.google.com/)

Overview

Evicts least recently used cache files first.

Summary

Constructors
publicLeastRecentlyUsedCacheEvictor(long maxBytes)

Methods
public voidonCacheInitialized()

public voidonSpanAdded(Cache cache, CacheSpan span)

public voidonSpanRemoved(Cache cache, CacheSpan span)

public voidonSpanTouched(Cache cache, CacheSpan oldSpan, CacheSpan newSpan)

public voidonStartFile(Cache cache, java.lang.String key, long position, long length)

public booleanrequiresCacheSpanTouches()

from java.lang.Objectclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructors

public LeastRecentlyUsedCacheEvictor(long maxBytes)

Methods

public boolean requiresCacheSpanTouches()

public void onCacheInitialized()

public void onStartFile(Cache cache, java.lang.String key, long position, long length)

public void onSpanAdded(Cache cache, CacheSpan span)

public void onSpanRemoved(Cache cache, CacheSpan span)

public void onSpanTouched(Cache cache, CacheSpan oldSpan, CacheSpan newSpan)

Source

/*
 * Copyright (C) 2016 The Android Open Source Project
 *
 * 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 androidx.media3.datasource.cache;

import androidx.media3.common.C;
import androidx.media3.common.util.UnstableApi;
import java.util.TreeSet;

/** Evicts least recently used cache files first. */
@UnstableApi
public final class LeastRecentlyUsedCacheEvictor implements CacheEvictor {

  private final long maxBytes;
  private final TreeSet<CacheSpan> leastRecentlyUsed;

  private long currentSize;

  public LeastRecentlyUsedCacheEvictor(long maxBytes) {
    this.maxBytes = maxBytes;
    this.leastRecentlyUsed = new TreeSet<>(LeastRecentlyUsedCacheEvictor::compare);
  }

  @Override
  public boolean requiresCacheSpanTouches() {
    return true;
  }

  @Override
  public void onCacheInitialized() {
    // Do nothing.
  }

  @Override
  public void onStartFile(Cache cache, String key, long position, long length) {
    if (length != C.LENGTH_UNSET) {
      evictCache(cache, length);
    }
  }

  @Override
  public void onSpanAdded(Cache cache, CacheSpan span) {
    leastRecentlyUsed.add(span);
    currentSize += span.length;
    evictCache(cache, 0);
  }

  @Override
  public void onSpanRemoved(Cache cache, CacheSpan span) {
    leastRecentlyUsed.remove(span);
    currentSize -= span.length;
  }

  @Override
  public void onSpanTouched(Cache cache, CacheSpan oldSpan, CacheSpan newSpan) {
    onSpanRemoved(cache, oldSpan);
    onSpanAdded(cache, newSpan);
  }

  private void evictCache(Cache cache, long requiredSpace) {
    while (currentSize + requiredSpace > maxBytes && !leastRecentlyUsed.isEmpty()) {
      cache.removeSpan(leastRecentlyUsed.first());
    }
  }

  private static int compare(CacheSpan lhs, CacheSpan rhs) {
    long lastTouchTimestampDelta = lhs.lastTouchTimestamp - rhs.lastTouchTimestamp;
    if (lastTouchTimestampDelta == 0) {
      // Use the standard compareTo method as a tie-break.
      return lhs.compareTo(rhs);
    }
    return lhs.lastTouchTimestamp < rhs.lastTouchTimestamp ? -1 : 1;
  }
}