org.rocksdb.WriteBatchWithIndex 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;
/**
* Similar to {@link org.rocksdb.WriteBatch} but with a binary searchable
* index built for all the keys inserted.
*
* Calling put, merge, remove or putLogData calls the same function
* as with {@link org.rocksdb.WriteBatch} whilst also building an index.
*
* A user can call {@link org.rocksdb.WriteBatchWithIndex#newIterator()} to
* create an iterator over the write batch or
* {@link org.rocksdb.WriteBatchWithIndex#newIteratorWithBase(org.rocksdb.RocksIterator)}
* to get an iterator for the database with Read-Your-Own-Writes like capability
*/
public class WriteBatchWithIndex extends AbstractWriteBatch {
/**
* Creates a WriteBatchWithIndex where no bytes
* are reserved up-front, bytewise comparison is
* used for fallback key comparisons,
* and duplicate keys operations are retained
*/
public WriteBatchWithIndex() {
super(newWriteBatchWithIndex());
}
/**
* Creates a WriteBatchWithIndex where no bytes
* are reserved up-front, bytewise comparison is
* used for fallback key comparisons, and duplicate key
* assignment is determined by the constructor argument
*
* @param overwriteKey if true, overwrite the key in the index when
* inserting a duplicate key, in this way an iterator will never
* show two entries with the same key.
*/
public WriteBatchWithIndex(final boolean overwriteKey) {
super(newWriteBatchWithIndex(overwriteKey));
}
/**
* Creates a WriteBatchWithIndex
*
* @param fallbackIndexComparator We fallback to this comparator
* to compare keys within a column family if we cannot determine
* the column family and so look up it's comparator.
*
* @param reservedBytes reserved bytes in underlying WriteBatch
*
* @param overwriteKey if true, overwrite the key in the index when
* inserting a duplicate key, in this way an iterator will never
* show two entries with the same key.
*/
public WriteBatchWithIndex(
final AbstractComparator>
fallbackIndexComparator, final int reservedBytes,
final boolean overwriteKey) {
super(newWriteBatchWithIndex(fallbackIndexComparator.getNativeHandle(),
reservedBytes, overwriteKey));
}
/**
* Create an iterator of a column family. User can call
* {@link org.rocksdb.RocksIteratorInterface#seek(byte[])} to
* search to the next entry of or after a key. Keys will be iterated in the
* order given by index_comparator. For multiple updates on the same key,
* each update will be returned as a separate entry, in the order of update
* time.
*
* @param columnFamilyHandle The column family to iterate over
* @return An iterator for the Write Batch contents, restricted to the column
* family
*/
public WBWIRocksIterator newIterator(
final ColumnFamilyHandle columnFamilyHandle) {
return new WBWIRocksIterator(this, iterator1(nativeHandle_,
columnFamilyHandle.nativeHandle_));
}
/**
* Create an iterator of the default column family. User can call
* {@link org.rocksdb.RocksIteratorInterface#seek(byte[])} to
* search to the next entry of or after a key. Keys will be iterated in the
* order given by index_comparator. For multiple updates on the same key,
* each update will be returned as a separate entry, in the order of update
* time.
*
* @return An iterator for the Write Batch contents
*/
public WBWIRocksIterator newIterator() {
return new WBWIRocksIterator(this, iterator0(nativeHandle_));
}
/**
* Provides Read-Your-Own-Writes like functionality by
* creating a new Iterator that will use {@link org.rocksdb.WBWIRocksIterator}
* as a delta and baseIterator as a base
*
* @param columnFamilyHandle The column family to iterate over
* @param baseIterator The base iterator,
* e.g. {@link org.rocksdb.RocksDB#newIterator()}
* @return An iterator which shows a view comprised of both the database
* point-in-time from baseIterator and modifications made in this write batch.
*/
public RocksIterator newIteratorWithBase(
final ColumnFamilyHandle columnFamilyHandle,
final RocksIterator baseIterator) {
RocksIterator iterator = new RocksIterator(
baseIterator.parent_,
iteratorWithBase(nativeHandle_,
columnFamilyHandle.nativeHandle_,
baseIterator.nativeHandle_));
//when the iterator is deleted it will also delete the baseIterator
baseIterator.disOwnNativeHandle();
return iterator;
}
/**
* Provides Read-Your-Own-Writes like functionality by
* creating a new Iterator that will use {@link org.rocksdb.WBWIRocksIterator}
* as a delta and baseIterator as a base. Operates on the default column
* family.
*
* @param baseIterator The base iterator,
* e.g. {@link org.rocksdb.RocksDB#newIterator()}
* @return An iterator which shows a view comprised of both the database
* point-in-timefrom baseIterator and modifications made in this write batch.
*/
public RocksIterator newIteratorWithBase(final RocksIterator baseIterator) {
return newIteratorWithBase(baseIterator.parent_.getDefaultColumnFamily(),
baseIterator);
}
/**
* Similar to {@link RocksDB#get(ColumnFamilyHandle, byte[])} but will only
* read the key from this batch.
*
* @param columnFamilyHandle The column family to retrieve the value from
* @param options The database options to use
* @param key The key to read the value for
*
* @return a byte array storing the value associated with the input key if
* any. null if it does not find the specified key.
*
* @throws RocksDBException if the batch does not have enough data to resolve
* Merge operations, MergeInProgress status may be returned.
*/
public byte[] getFromBatch(final ColumnFamilyHandle columnFamilyHandle,
final DBOptions options, final byte[] key) throws RocksDBException {
return getFromBatch(nativeHandle_, options.nativeHandle_,
key, key.length, columnFamilyHandle.nativeHandle_);
}
/**
* Similar to {@link RocksDB#get(byte[])} but will only
* read the key from this batch.
*
* @param options The database options to use
* @param key The key to read the value for
*
* @return a byte array storing the value associated with the input key if
* any. null if it does not find the specified key.
*
* @throws RocksDBException if the batch does not have enough data to resolve
* Merge operations, MergeInProgress status may be returned.
*/
public byte[] getFromBatch(final DBOptions options, final byte[] key)
throws RocksDBException {
return getFromBatch(nativeHandle_, options.nativeHandle_, key, key.length);
}
/**
* Similar to {@link RocksDB#get(ColumnFamilyHandle, byte[])} but will also
* read writes from this batch.
*
* This function will query both this batch and the DB and then merge
* the results using the DB's merge operator (if the batch contains any
* merge requests).
*
* Setting {@link ReadOptions#setSnapshot(long, long)} will affect what is
* read from the DB but will NOT change which keys are read from the batch
* (the keys in this batch do not yet belong to any snapshot and will be
* fetched regardless).
*
* @param db The Rocks database
* @param columnFamilyHandle The column family to retrieve the value from
* @param options The read options to use
* @param key The key to read the value for
*
* @return a byte array storing the value associated with the input key if
* any. null if it does not find the specified key.
*
* @throws RocksDBException if the value for the key cannot be read
*/
public byte[] getFromBatchAndDB(final RocksDB db, final ColumnFamilyHandle columnFamilyHandle,
final ReadOptions options, final byte[] key) throws RocksDBException {
return getFromBatchAndDB(nativeHandle_, db.nativeHandle_,
options.nativeHandle_, key, key.length,
columnFamilyHandle.nativeHandle_);
}
/**
* Similar to {@link RocksDB#get(byte[])} but will also
* read writes from this batch.
*
* This function will query both this batch and the DB and then merge
* the results using the DB's merge operator (if the batch contains any
* merge requests).
*
* Setting {@link ReadOptions#setSnapshot(long, long)} will affect what is
* read from the DB but will NOT change which keys are read from the batch
* (the keys in this batch do not yet belong to any snapshot and will be
* fetched regardless).
*
* @param db The Rocks database
* @param options The read options to use
* @param key The key to read the value for
*
* @return a byte array storing the value associated with the input key if
* any. null if it does not find the specified key.
*
* @throws RocksDBException if the value for the key cannot be read
*/
public byte[] getFromBatchAndDB(final RocksDB db, final ReadOptions options,
final byte[] key) throws RocksDBException {
return getFromBatchAndDB(nativeHandle_, db.nativeHandle_,
options.nativeHandle_, key, key.length);
}
@Override protected final native void disposeInternal(final long handle);
@Override final native int count0(final long handle);
@Override final native void put(final long handle, final byte[] key,
final int keyLen, final byte[] value, final int valueLen);
@Override final native void put(final long handle, final byte[] key,
final int keyLen, final byte[] value, final int valueLen,
final long cfHandle);
@Override final native void merge(final long handle, final byte[] key,
final int keyLen, final byte[] value, final int valueLen);
@Override final native void merge(final long handle, final byte[] key,
final int keyLen, final byte[] value, final int valueLen,
final long cfHandle);
@Override final native void remove(final long handle, final byte[] key,
final int keyLen);
@Override final native void remove(final long handle, final byte[] key,
final int keyLen, final long cfHandle);
@Override
final native void deleteRange(final long handle, final byte[] beginKey, final int beginKeyLen,
final byte[] endKey, final int endKeyLen);
@Override
final native void deleteRange(final long handle, final byte[] beginKey, final int beginKeyLen,
final byte[] endKey, final int endKeyLen, final long cfHandle);
@Override final native void putLogData(final long handle, final byte[] blob,
final int blobLen);
@Override final native void clear0(final long handle);
@Override final native void setSavePoint0(final long handle);
@Override final native void rollbackToSavePoint0(final long handle);
private native static long newWriteBatchWithIndex();
private native static long newWriteBatchWithIndex(final boolean overwriteKey);
private native static long newWriteBatchWithIndex(
final long fallbackIndexComparatorHandle, final int reservedBytes,
final boolean overwriteKey);
private native long iterator0(final long handle);
private native long iterator1(final long handle, final long cfHandle);
private native long iteratorWithBase(final long handle,
final long baseIteratorHandle, final long cfHandle);
private native byte[] getFromBatch(final long handle, final long optHandle,
final byte[] key, final int keyLen);
private native byte[] getFromBatch(final long handle, final long optHandle,
final byte[] key, final int keyLen, final long cfHandle);
private native byte[] getFromBatchAndDB(final long handle,
final long dbHandle, final long readOptHandle, final byte[] key,
final int keyLen);
private native byte[] getFromBatchAndDB(final long handle,
final long dbHandle, final long readOptHandle, final byte[] key,
final int keyLen, final long cfHandle);
}
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