| /* |
| * Copyright 2009-2010 by The Regents of the University of California |
| * 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 from |
| * |
| * 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 edu.uci.ics.pregelix.dataflow.util; |
| |
| import java.nio.ByteBuffer; |
| |
| import edu.uci.ics.hyracks.api.comm.FrameHelper; |
| import edu.uci.ics.hyracks.api.comm.IFrameTupleAccessor; |
| |
| public final class UpdateBufferTupleAccessor implements IFrameTupleAccessor { |
| private final int frameSize; |
| private final int fieldCount; |
| private ByteBuffer buffer; |
| |
| public UpdateBufferTupleAccessor(int frameSize, int fieldCount) { |
| this.frameSize = frameSize; |
| this.fieldCount = fieldCount; |
| } |
| |
| @Override |
| public void reset(ByteBuffer buffer) { |
| this.buffer = buffer; |
| } |
| |
| @Override |
| public ByteBuffer getBuffer() { |
| return buffer; |
| } |
| |
| @Override |
| public int getTupleCount() { |
| return buffer.getInt(FrameHelper.getTupleCountOffset(frameSize)); |
| } |
| |
| @Override |
| public int getTupleStartOffset(int tupleIndex) { |
| return tupleIndex == 0 ? 0 : buffer.getInt(FrameHelper.getTupleCountOffset(frameSize) - 4 * tupleIndex); |
| } |
| |
| @Override |
| public int getTupleEndOffset(int tupleIndex) { |
| return buffer.getInt(FrameHelper.getTupleCountOffset(frameSize) - 4 * (tupleIndex + 1)); |
| } |
| |
| @Override |
| public int getFieldStartOffset(int tupleIndex, int fIdx) { |
| return fIdx == 0 ? 0 : buffer.getInt(getTupleStartOffset(tupleIndex) + (fIdx - 1) * 4); |
| } |
| |
| @Override |
| public int getFieldEndOffset(int tupleIndex, int fIdx) { |
| return buffer.getInt(getTupleStartOffset(tupleIndex) + fIdx * 4); |
| } |
| |
| @Override |
| public int getFieldLength(int tupleIndex, int fIdx) { |
| return getFieldEndOffset(tupleIndex, fIdx) - getFieldStartOffset(tupleIndex, fIdx); |
| } |
| |
| @Override |
| public int getFieldSlotsLength() { |
| return getFieldCount() * 4; |
| } |
| |
| @Override |
| public int getFieldCount() { |
| return fieldCount; |
| } |
| } |