| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.lucene.util.packed; |
| |
| |
| import java.io.IOException; |
| |
| import org.apache.lucene.store.DataOutput; |
| |
| /** |
| * A {@link DataOutput} wrapper to write unaligned, variable-length packed |
| * integers. |
| * @see PackedDataInput |
| * @lucene.internal |
| */ |
| public final class PackedDataOutput { |
| |
| final DataOutput out; |
| long current; |
| int remainingBits; |
| |
| /** |
| * Create a new instance that wraps <code>out</code>. |
| */ |
| public PackedDataOutput(DataOutput out) { |
| this.out = out; |
| current = 0; |
| remainingBits = 8; |
| } |
| |
| /** |
| * Write a value using exactly <code>bitsPerValue</code> bits. |
| */ |
| public void writeLong(long value, int bitsPerValue) throws IOException { |
| assert bitsPerValue == 64 || (value >= 0 && value <= PackedInts.maxValue(bitsPerValue)); |
| while (bitsPerValue > 0) { |
| if (remainingBits == 0) { |
| out.writeByte((byte) current); |
| current = 0L; |
| remainingBits = 8; |
| } |
| final int bits = Math.min(remainingBits, bitsPerValue); |
| current = current | (((value >>> (bitsPerValue - bits)) & ((1L << bits) - 1)) << (remainingBits - bits)); |
| bitsPerValue -= bits; |
| remainingBits -= bits; |
| } |
| } |
| |
| /** |
| * Flush pending bits to the underlying {@link DataOutput}. |
| */ |
| public void flush() throws IOException { |
| if (remainingBits < 8) { |
| out.writeByte((byte) current); |
| } |
| remainingBits = 8; |
| current = 0L; |
| } |
| |
| } |