rocksdb/java/org/rocksdb/WriteBatchInterface.java
2015-01-14 21:16:05 +00:00

99 lines
3.4 KiB
Java

// Copyright (c) 2014, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
package org.rocksdb;
/**
* <p>Defines the interface for a Write Batch which
* holds a collection of updates to apply atomically to a DB.</p>
*/
public interface WriteBatchInterface {
/**
* Returns the number of updates in the batch.
*
* @return number of items in WriteBatch
*/
public int count();
/**
* <p>Store the mapping "key-&gt;value" in the database.</p>
*
* @param key the specified key to be inserted.
* @param value the value associated with the specified key.
*/
public void put(byte[] key, byte[] value);
/**
* <p>Store the mapping "key-&gt;value" within given column
* family.</p>
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param key the specified key to be inserted.
* @param value the value associated with the specified key.
*/
public void put(ColumnFamilyHandle columnFamilyHandle,
byte[] key, byte[] value);
/**
* <p>Merge "value" with the existing value of "key" in the database.
* "key-&gt;merge(existing, value)"</p>
*
* @param key the specified key to be merged.
* @param value the value to be merged with the current value for
* the specified key.
*/
public void merge(byte[] key, byte[] value);
/**
* <p>Merge "value" with the existing value of "key" in given column family.
* "key-&gt;merge(existing, value)"</p>
*
* @param columnFamilyHandle {@link ColumnFamilyHandle} instance
* @param key the specified key to be merged.
* @param value the value to be merged with the current value for
* the specified key.
*/
public void merge(ColumnFamilyHandle columnFamilyHandle,
byte[] key, byte[] value);
/**
* <p>If the database contains a mapping for "key", erase it. Else do nothing.</p>
*
* @param key Key to delete within database
*/
public void remove(byte[] key);
/**
* <p>If column family contains a mapping for "key", erase it. Else do nothing.</p>
*
* @param columnFamilyHandle {@link ColumnFamilyHandle} instance
* @param key Key to delete within database
*/
public void remove(ColumnFamilyHandle columnFamilyHandle, byte[] key);
/**
* Append a blob of arbitrary size to the records in this batch. The blob will
* be stored in the transaction log but not in any other file. In particular,
* it will not be persisted to the SST files. When iterating over this
* WriteBatch, WriteBatch::Handler::LogData will be called with the contents
* of the blob as it is encountered. Blobs, puts, deletes, and merges will be
* encountered in the same order in thich they were inserted. The blob will
* NOT consume sequence number(s) and will NOT increase the count of the batch
*
* Example application: add timestamps to the transaction log for use in
* replication.
*
* @param blob binary object to be inserted
*/
public void putLogData(byte[] blob);
/**
* Clear all updates buffered in this batch
*/
public void clear();
}