/*
* Copyright (C) 2007 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 java.nio;
/**
* This class is used via JNI by code in frameworks/base/.
*/
final class NIOAccess {
/**
* Returns the underlying native pointer to the data of the given
* Buffer starting at the Buffer's current position, or 0 if the
* Buffer is not backed by native heap storage.
*/
static long getBasePointer(Buffer b) {
long address = b.effectiveDirectAddress;
if (address == 0L) {
return 0L;
}
return address + (b.position << b._elementSizeShift);
}
/**
* Returns the underlying Java array containing the data of the
* given Buffer, or null if the Buffer is not backed by a Java array.
*/
static Object getBaseArray(Buffer b) {
return b.hasArray() ? b.array() : null;
}
/**
* Returns the offset in bytes from the start of the underlying
* Java array object containing the data of the given Buffer to
* the actual start of the data. The start of the data takes into
* account the Buffer's current position. This method is only
* meaningful if getBaseArray() returns non-null.
*/
static int getBaseArrayOffset(Buffer b) {
return b.hasArray() ? ((b.arrayOffset() + b.position) << b._elementSizeShift) : 0;
}
}