gecko/mobile/android/base/mozglue/DirectBufferAllocator.java

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/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko.mozglue;
import java.nio.ByteBuffer;
//
// We must manually allocate direct buffers in JNI to work around a bug where Honeycomb's
// ByteBuffer.allocateDirect() grossly overallocates the direct buffer size.
// https://code.google.com/p/android/issues/detail?id=16941
//
public final class DirectBufferAllocator {
private DirectBufferAllocator() {}
public static ByteBuffer allocate(int size) {
if (size <= 0 || (size % 4) != 0) {
throw new IllegalArgumentException("Invalid size " + size);
}
ByteBuffer directBuffer = nativeAllocateDirectBuffer(size);
if (directBuffer == null) {
throw new OutOfMemoryError("allocateDirectBuffer() returned null");
} else if (!directBuffer.isDirect()) {
throw new AssertionError("allocateDirectBuffer() did not return a direct buffer");
}
return directBuffer;
}
public static ByteBuffer free(ByteBuffer buffer) {
if (buffer == null) {
return null;
}
if (!buffer.isDirect()) {
throw new IllegalArgumentException("buffer must be direct");
}
nativeFreeDirectBuffer(buffer);
return null;
}
// These JNI methods are implemented in mozglue/android/nsGeckoUtils.cpp.
private static native ByteBuffer nativeAllocateDirectBuffer(long size);
private static native void nativeFreeDirectBuffer(ByteBuffer buf);
}