+++ /dev/null
-package org.apache.lucene.util.encoding;
-
-import java.io.IOException;
-import java.io.OutputStream;
-
-/**
- * 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.
- */
-
-/**
- * Encodes integers to a set {@link OutputStream}. Extending classes need to
- * override {@link #encode(int)} to encode the value using their encoding
- * algorithm. The default implementation of {@link #close()} closes the set
- * {@link OutputStream}.
- * <p>
- * The default {@link #IntEncoder() constructor} is provided for convenience
- * only. One must call {@link #reInit(OutputStream)} before calling
- * {@link #encode(int)} or {@link #close()}.
- * <p>
- * For convenience, each encoder implements {@link #createMatchingDecoder()} for
- * easy access to the matching decoder.
- * <p>
- * <b>NOTE:</b> some implementations may buffer the encoded values in memory
- * (such as {@link IntEncoderFilter} implementations) and encoding will happen
- * only upon calling {@link #close()}. Therefore it is important to always call
- * {@link #close()} on the encoder at hand.
- * <p>
- * <b>NOTE:</b> encoders are usually not thread safe, unless specifically
- * documented otherwise by an implementation.
- *
- * @lucene.experimental
- */
-public abstract class IntEncoder {
-
- protected OutputStream out = null;
-
- /**
- * Default constructor, provided here for robustness: if in the future a
- * constructor with parameters will be added, this might break custom
- * implementations of this class which call this implicit constructor. So we
- * make it explicit to avoid any such issue in the future.
- */
- public IntEncoder() {
- }
-
- /**
- * Instructs the encoder to finish the encoding process. This method closes
- * the output stream which was specified by {@link #reInit(OutputStream)
- * reInit}. An implementation may do here additional cleanup required to
- * complete the encoding, such as flushing internal buffers, etc.<br>
- * Once this method was called, no further calls to {@link #encode(int)
- * encode} should be made before first calling {@link #reInit(OutputStream)
- * reInit}.
- * <p>
- * <b>NOTE:</b> overriding classes should make sure they either call
- * <code>super.close()</code> or close the output stream themselves.
- */
- public void close() throws IOException {
- if (out != null) {
- out.close();
- }
- }
-
- /**
- * Encodes an integer to the output stream given in
- * {@link #reInit(OutputStream) reInit}
- */
- public abstract void encode(int value) throws IOException;
-
- /**
- * Returns an {@link IntDecoder} which matches this encoder. Every encoder
- * must return an {@link IntDecoder} and <code>null</code> is not a valid
- * value. If an encoder is just a filter, it should at least return its
- * wrapped encoder's matching decoder.
- * <p>
- * <b>NOTE:</b> this method should create a new instance of the matching
- * decoder and leave the instance sharing to the caller. Returning the same
- * instance over and over is risky because encoders and decoders are not
- * thread safe.
- */
- public abstract IntDecoder createMatchingDecoder();
-
- /**
- * Reinitializes the encoder with the give {@link OutputStream}. For
- * re-usability it can be changed without the need to reconstruct a new
- * object.
- * <p>
- * <b>NOTE:</b> after calling {@link #close()}, one <u><i>must</i></u> call
- * this method even if the output stream itself hasn't changed. An example
- * case is that the output stream wraps a byte[], and the output stream itself
- * is reset, but its instance hasn't changed. Some implementations of
- * {@link IntEncoder} may write some metadata about themselves to the output
- * stream, and therefore it is imperative that one calls this method before
- * encoding any data.
- */
- public void reInit(OutputStream out) {
- this.out = out;
- }
-
-}
fnp / pylucene.git / blobdiff