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/*
 * 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.
 */

/** 
 * Packed integer arrays and streams.
 * 
 * 
 *     The packed package provides
 *     

 *      sequential and random access capable arrays of positive longs,
 *      routines for efficient serialization and deserialization of streams of packed integers.
 *     
 * 
 *     The implementations provide different trade-offs between memory usage and
 *     access speed. The standard usage scenario is replacing large int or long
 *     arrays in order to reduce the memory footprint.
 * 
 *     The main access point is the {@link org.apache.lucene.util.packed.PackedInts} factory.
 * 
 * 
In-memory structures
 * 
 * 
 *     {@link org.apache.lucene.util.packed.PackedInts.Mutable}
 *         Only supports positive longs.
 *         Requires the number of bits per value to be known in advance.
 *         Random-access for both writing and reading.
 *     
 *     {@link org.apache.lucene.util.packed.GrowableWriter}
 *         Same as PackedInts.Mutable but grows the number of bits per values when needed.
 *         Useful to build a PackedInts.Mutable from a read-once stream of longs.
 *     
 *     {@link org.apache.lucene.util.packed.PagedGrowableWriter}
 *         Slices data into fixed-size blocks stored in GrowableWriters.
 *         Supports more than 2B values.
 *         You should use PackedLongValues instead if you don't need random write access.
 *     
 *     {@link org.apache.lucene.util.packed.PackedLongValues#deltaPackedBuilder}
 *         Can store any sequence of longs.
 *         Compression is good when values are close to each other.
 *         Supports random reads, but only sequential writes.
 *         Can address up to 2^42 values.
 *     
 *     {@link org.apache.lucene.util.packed.PackedLongValues#packedBuilder}
 *         Same as deltaPackedBuilder but assumes values are 0-based.
 *     
 *     {@link org.apache.lucene.util.packed.PackedLongValues#monotonicBuilder}
 *         Same as deltaPackedBuilder except that compression is good when the stream is a succession of affine functions.
 *     
 * 
 * 
 * Disk-based structures
 * 
 * 
 *     {@link org.apache.lucene.util.packed.PackedInts.Writer}, {@link org.apache.lucene.util.packed.PackedInts.Reader}, {@link org.apache.lucene.util.packed.PackedInts.ReaderIterator}
 *         Only supports positive longs.
 *         Requires the number of bits per value to be known in advance.
 *         Supports both fast sequential access with low memory footprint with ReaderIterator and random-access by either loading values in memory or leaving them on disk with Reader.
 *     
 *     {@link org.apache.lucene.util.packed.BlockPackedWriter}, {@link org.apache.lucene.util.packed.BlockPackedReader}, {@link org.apache.lucene.util.packed.BlockPackedReaderIterator}
 *         Splits the stream into fixed-size blocks.
 *         Compression is good when values are close to each other.
 *         Can address up to 2B * blockSize values.
 *     
 *     {@link org.apache.lucene.util.packed.MonotonicBlockPackedWriter}, {@link org.apache.lucene.util.packed.MonotonicBlockPackedReader}
 *         Same as the non-monotonic variants except that compression is good when the stream is a succession of affine functions.
 *         The reason why there is no sequential access is that if you need sequential access, you should rather delta-encode and use BlockPackedWriter.
 *     
 *     {@link org.apache.lucene.util.packed.PackedDataOutput}, {@link org.apache.lucene.util.packed.PackedDataInput}
 *         Writes sequences of longs where each long can use any number of bits.
 *     
 * 
 */
package org.apache.lucene.util.packed;