+++ /dev/null
-package org.apache.lucene.util.encoding;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-/**
- * 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.
- */
-
-/**
- * Decodes data which was encoded by {@link FourFlagsIntEncoder}. Scans
- * the <code>indicator</code>, one flag (1-bits) at a time, and decodes extra
- * data using {@link VInt8IntDecoder}.
- *
- * @see FourFlagsIntEncoder
- * @lucene.experimental
- */
-public class FourFlagsIntDecoder extends IntDecoder {
-
- /**
- * Holds all combinations of <i>indicator</i> for fast decoding (saves time
- * on real-time bit manipulation)
- */
- private final static byte[][] decodeTable = new byte[256][4];
-
- /** Generating all combinations of <i>indicator</i> into separate flags. */
- static {
- for (int i = 256; i != 0;) {
- --i;
- for (int j = 4; j != 0;) {
- --j;
- decodeTable[i][j] = (byte) ((i >>> (j << 1)) & 0x3);
- }
- }
- }
-
- private final IntDecoder decoder = new VInt8IntDecoder();
-
- /** The indicator for decoding a chunk of 4 integers. */
- private int indicator;
-
- /** Used as an ordinal of 0 - 3, as the decoder decodes chunks of 4 integers. */
- private int ordinal = 0;
-
- @Override
- public long decode() throws IOException {
- // If we've decoded 8 integers, read the next indicator.
- if ((ordinal & 0x3) == 0) {
- indicator = in.read();
- if (indicator < 0) {
- return EOS;
- }
- ordinal = 0;
- }
-
- byte decodeVal = decodeTable[indicator][ordinal++];
- if (decodeVal == 0) {
- // decode the value from the stream.
- long decode = decoder.decode();
- return decode == EOS ? EOS : decode + 4;
- }
-
- return decodeVal;
- }
-
- @Override
- public void reInit(InputStream in) {
- super.reInit(in);
- decoder.reInit(in);
- ordinal = 0;
- indicator = 0;
- }
-
- @Override
- public String toString() {
- return "FourFlags (VInt8)";
- }
-
-}