org.rocksdb.EncodingType Maven / Gradle / Ivy
// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
package org.rocksdb;
/**
* EncodingType
*
* The value will determine how to encode keys
* when writing to a new SST file.
*
* This value will be stored
* inside the SST file which will be used when reading from
* the file, which makes it possible for users to choose
* different encoding type when reopening a DB. Files with
* different encoding types can co-exist in the same DB and
* can be read.
*/
public enum EncodingType {
/**
* Always write full keys without any special encoding.
*/
kPlain((byte) 0),
/**
* Find opportunity to write the same prefix once for multiple rows.
* In some cases, when a key follows a previous key with the same prefix,
* instead of writing out the full key, it just writes out the size of the
* shared prefix, as well as other bytes, to save some bytes.
*
* When using this option, the user is required to use the same prefix
* extractor to make sure the same prefix will be extracted from the same key.
* The Name() value of the prefix extractor will be stored in the file. When
* reopening the file, the name of the options.prefix_extractor given will be
* bitwise compared to the prefix extractors stored in the file. An error
* will be returned if the two don't match.
*/
kPrefix((byte) 1);
/**
* Returns the byte value of the enumerations value
*
* @return byte representation
*/
public byte getValue() {
return value_;
}
private EncodingType(byte value) {
value_ = value;
}
private final byte value_;
}