DefaultBitmapPoolParams.java

/*
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

package com.facebook.imagepipeline.memory;

import android.util.SparseIntArray;

import com.facebook.common.util.ByteConstants;

/**
 * Provides pool parameters for {@link BitmapPool}
 */
public class DefaultBitmapPoolParams {
  /**
   * We are not reusing Bitmaps and want to free them as soon as possible.
   */
  private static final int MAX_SIZE_SOFT_CAP = 0;

  private DefaultBitmapPoolParams() {
  }

  /**
   * Our Bitmaps live in ashmem, meaning that they are pinned in androids' shared native memory.
   * Therefore, we are not constrained by the max heap size of the dalvik heap, but we want to make
   * sure we don't use too much memory on low end devices, so that we don't force other background
   * process to be evicted.
   */
  private static int getMaxSizeHardCap() {
    final int maxMemory = (int)Math.min(Runtime.getRuntime().maxMemory(), Integer.MAX_VALUE);
    if (maxMemory > 16 * ByteConstants.MB) {
      return maxMemory / 4 * 3;
    } else {
      return maxMemory / 2;
    }
  }

  /**
   * This will cause all get/release calls to behave like alloc/free calls i.e. no pooling.
   */
  private static final SparseIntArray DEFAULT_BUCKETS = new SparseIntArray(0);

  public static PoolParams get() {
    return new PoolParams(
        MAX_SIZE_SOFT_CAP,
        getMaxSizeHardCap(),
        DEFAULT_BUCKETS
    );
  }
}