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rocksdb/java/org/rocksdb/RocksDB.java

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// 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;
import java.util.*;
import java.io.IOException;
import org.rocksdb.util.Environment;
/**
* A RocksDB is a persistent ordered map from keys to values. It is safe for
* concurrent access from multiple threads without any external synchronization.
* All methods of this class could potentially throw RocksDBException, which
* indicates sth wrong at the RocksDB library side and the call failed.
*/
public class RocksDB extends RocksObject {
public static final int NOT_FOUND = -1;
private static final String[] compressionLibs_ = {
"snappy", "z", "bzip2", "lz4", "lz4hc"};
static {
RocksDB.loadLibrary();
}
/**
* Loads the necessary library files.
* Calling this method twice will have no effect.
* By default the method extracts the shared library for loading at
* java.io.tmpdir, however, you can override this temporary location by
* setting the environment variable ROCKSDB_SHAREDLIB_DIR.
*/
public static synchronized void loadLibrary() {
String tmpDir = System.getenv("ROCKSDB_SHAREDLIB_DIR");
// loading possibly necessary libraries.
for (String lib : compressionLibs_) {
try {
System.loadLibrary(lib);
} catch (UnsatisfiedLinkError e) {
// since it may be optional, we ignore its loading failure here.
}
}
try
{
NativeLibraryLoader.loadLibraryFromJar(tmpDir);
}
catch (IOException e)
{
throw new RuntimeException("Unable to load the RocksDB shared library" + e);
}
}
/**
* Tries to load the necessary library files from the given list of
* directories.
*
* @param paths a list of strings where each describes a directory
* of a library.
*/
public static synchronized void loadLibrary(List<String> paths) {
for (String lib : compressionLibs_) {
for (String path : paths) {
try {
System.load(path + "/" + Environment.getSharedLibraryName(lib));
break;
} catch (UnsatisfiedLinkError e) {
// since they are optional, we ignore loading fails.
}
}
}
boolean success = false;
UnsatisfiedLinkError err = null;
for (String path : paths) {
try {
System.load(path + "/" + Environment.getJniLibraryName("rocksdbjni"));
success = true;
break;
} catch (UnsatisfiedLinkError e) {
err = e;
}
}
if (!success) {
throw err;
}
}
/**
* The factory constructor of RocksDB that opens a RocksDB instance given
* the path to the database using the default options w/ createIfMissing
* set to true.
*
* @param path the path to the rocksdb.
* @return a {@link RocksDB} instance on success, null if the specified
* {@link RocksDB} can not be opened.
*
* @throws org.rocksdb.RocksDBException
* @see Options#setCreateIfMissing(boolean)
*/
public static RocksDB open(String path) throws RocksDBException {
// This allows to use the rocksjni default Options instead of
// the c++ one.
Options options = new Options();
return open(options, path);
}
/**
* The factory constructor of RocksDB that opens a RocksDB instance given
* the path to the database using the specified options and db path and a list
* of column family names.
* <p>
* If opened in read write mode every existing column family name must be passed
* within the list to this method.</p>
* <p>
* If opened in read-only mode only a subset of existing column families must
* be passed to this method.</p>
* <p>
* Options instance *should* not be disposed before all DBs using this options
* instance have been closed. If user doesn't call options dispose explicitly,
* then this options instance will be GC'd automatically</p>
* <p>
* ColumnFamily handles are disposed when the RocksDB instance is disposed.
* </p>
*
* @param path the path to the rocksdb.
* @param columnFamilyNames list of column family names
* @param columnFamilyHandles will be filled with ColumnFamilyHandle instances
* on open.
* @return a {@link RocksDB} instance on success, null if the specified
* {@link RocksDB} can not be opened.
*
* @throws org.rocksdb.RocksDBException
* @see Options#setCreateIfMissing(boolean)
*/
public static RocksDB open(String path, List<String> columnFamilyNames,
List<ColumnFamilyHandle> columnFamilyHandles) throws RocksDBException {
// This allows to use the rocksjni default Options instead of
// the c++ one.
Options options = new Options();
return open(options, path, columnFamilyNames, columnFamilyHandles);
}
/**
* The factory constructor of RocksDB that opens a RocksDB instance given
* the path to the database using the specified options and db path.
*
* <p>
* Options instance *should* not be disposed before all DBs using this options
* instance have been closed. If user doesn't call options dispose explicitly,
* then this options instance will be GC'd automatically.</p>
* <p>
* Options instance can be re-used to open multiple DBs if DB statistics is
* not used. If DB statistics are required, then its recommended to open DB
* with new Options instance as underlying native statistics instance does not
* use any locks to prevent concurrent updates.</p>
*
* @param options {@link org.rocksdb.Options} instance.
* @param path the path to the rocksdb.
* @return a {@link RocksDB} instance on success, null if the specified
* {@link RocksDB} can not be opened.
*
* @throws org.rocksdb.RocksDBException
* @see Options#setCreateIfMissing(boolean)
*/
public static RocksDB open(Options options, String path)
throws RocksDBException {
// when non-default Options is used, keeping an Options reference
// in RocksDB can prevent Java to GC during the life-time of
// the currently-created RocksDB.
RocksDB db = new RocksDB();
db.open(options.nativeHandle_, path);
db.storeOptionsInstance(options);
return db;
}
/**
* The factory constructor of RocksDB that opens a RocksDB instance given
* the path to the database using the specified options and db path and a list
* of column family names.
* <p>
* If opened in read write mode every existing column family name must be passed
* within the list to this method.</p>
* <p>
* If opened in read-only mode only a subset of existing column families must
* be passed to this method.</p>
* <p>
* Options instance *should* not be disposed before all DBs using this options
* instance have been closed. If user doesn't call options dispose explicitly,
* then this options instance will be GC'd automatically.</p>
* <p>
* Options instance can be re-used to open multiple DBs if DB statistics is
* not used. If DB statistics are required, then its recommended to open DB
* with new Options instance as underlying native statistics instance does not
* use any locks to prevent concurrent updates.</p>
* <p>
* ColumnFamily handles are disposed when the RocksDB instance is disposed.</p>
*
* @param options {@link org.rocksdb.Options} instance.
* @param path the path to the rocksdb.
* @param columnFamilyNames list of column family names
* @param columnFamilyHandles will be filled with ColumnFamilyHandle instances
* on open.
* @return a {@link RocksDB} instance on success, null if the specified
* {@link RocksDB} can not be opened.
*
* @throws org.rocksdb.RocksDBException
* @see Options#setCreateIfMissing(boolean)
*/
public static RocksDB open(Options options, String path, List<String> columnFamilyNames,
List<ColumnFamilyHandle> columnFamilyHandles)
throws RocksDBException {
RocksDB db = new RocksDB();
List<Long> cfReferences = db.open(options.nativeHandle_, path,
columnFamilyNames, columnFamilyNames.size());
for (int i=0; i<columnFamilyNames.size(); i++) {
columnFamilyHandles.add(new ColumnFamilyHandle(db, cfReferences.get(i)));
}
db.storeOptionsInstance(options);
return db;
}
/**
* The factory constructor of RocksDB that opens a RocksDB instance in
* Read-Only mode given the path to the database using the default
* options.
*
* @param path the path to the RocksDB.
* @return a {@link RocksDB} instance on success, null if the specified
* {@link RocksDB} can not be opened.
* @throws RocksDBException
*/
public static RocksDB openReadOnly(String path)
throws RocksDBException {
// This allows to use the rocksjni default Options instead of
// the c++ one.
Options options = new Options();
return openReadOnly(options, path);
}
/**
* The factory constructor of RocksDB that opens a RocksDB instance in
* Read-Only mode given the path to the database using the default
* options.
*
* @param path the path to the RocksDB.
* @param columnFamilyNames list of column family names
* @param columnFamilyHandles will be filled with ColumnFamilyHandle instances
* on open.
* @return a {@link RocksDB} instance on success, null if the specified
* {@link RocksDB} can not be opened.
* @throws RocksDBException
*/
public static RocksDB openReadOnly(String path, List<String> columnFamilyNames,
List<ColumnFamilyHandle> columnFamilyHandles) throws RocksDBException {
// This allows to use the rocksjni default Options instead of
// the c++ one.
Options options = new Options();
return openReadOnly(options, path, columnFamilyNames, columnFamilyHandles);
}
/**
* The factory constructor of RocksDB that opens a RocksDB instance in
* Read-Only mode given the path to the database using the specified
* options and db path.
*
* Options instance *should* not be disposed before all DBs using this options
* instance have been closed. If user doesn't call options dispose explicitly,
* then this options instance will be GC'd automatically.
*
* @param options {@link Options} instance.
* @param path the path to the RocksDB.
* @return a {@link RocksDB} instance on success, null if the specified
* {@link RocksDB} can not be opened.
* @throws RocksDBException
*/
public static RocksDB openReadOnly(Options options, String path)
throws RocksDBException {
// when non-default Options is used, keeping an Options reference
// in RocksDB can prevent Java to GC during the life-time of
// the currently-created RocksDB.
RocksDB db = new RocksDB();
db.openROnly(options.nativeHandle_, path);
db.storeOptionsInstance(options);
return db;
}
/**
* The factory constructor of RocksDB that opens a RocksDB instance in
* Read-Only mode given the path to the database using the specified
* options and db path.
*
* <p>This open method allows to open RocksDB using a subset of available
* column families</p>
* <p>Options instance *should* not be disposed before all DBs using this
* options instance have been closed. If user doesn't call options dispose
* explicitly,then this options instance will be GC'd automatically.</p>
*
* @param options {@link Options} instance.
* @param path the path to the RocksDB.
* @param columnFamilyNames list of column family names
* @param columnFamilyHandles will be filled with ColumnFamilyHandle instances
* on open.
* @return a {@link RocksDB} instance on success, null if the specified
* {@link RocksDB} can not be opened.
* @throws RocksDBException
*/
public static RocksDB openReadOnly(Options options, String path,
List<String> columnFamilyNames, List<ColumnFamilyHandle> columnFamilyHandles)
throws RocksDBException {
// when non-default Options is used, keeping an Options reference
// in RocksDB can prevent Java to GC during the life-time of
// the currently-created RocksDB.
RocksDB db = new RocksDB();
List<Long> cfReferences = db.openROnly(options.nativeHandle_, path,
columnFamilyNames, columnFamilyNames.size());
for (int i=0; i<columnFamilyNames.size(); i++) {
columnFamilyHandles.add(new ColumnFamilyHandle(db, cfReferences.get(i)));
}
db.storeOptionsInstance(options);
return db;
}
/**
* Static method to determine all available column families for a
* rocksdb database identified by path
*
* @param options Options for opening the database
* @param path Absolute path to rocksdb database
* @return List<byte[]> List containing the column family names
*
* @throws RocksDBException
*/
public static List<byte[]> listColumnFamilies(Options options, String path)
throws RocksDBException {
return RocksDB.listColumnFamilies(options.nativeHandle_, path);
}
private void storeOptionsInstance(Options options) {
options_ = options;
}
@Override protected void disposeInternal() {
assert(isInitialized());
disposeInternal(nativeHandle_);
}
/**
* Close the RocksDB instance.
* This function is equivalent to dispose().
*/
public void close() {
dispose();
}
/**
* Set the database entry for "key" to "value".
*
* @param key the specified key to be inserted.
* @param value the value associated with the specified key.
*
* @see RocksDBException
*/
public void put(byte[] key, byte[] value) throws RocksDBException {
put(nativeHandle_, key, key.length, value, value.length);
}
/**
* Set the database entry for "key" to "value" in the specified
* column family.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param key the specified key to be inserted.
* @param value the value associated with the specified key.
*
* throws IllegalArgumentException if column family is not present
*
* @see RocksDBException
*/
public void put(ColumnFamilyHandle columnFamilyHandle, byte[] key,
byte[] value) throws RocksDBException {
put(nativeHandle_, key, key.length, value, value.length,
columnFamilyHandle.nativeHandle_);
}
/**
* Set the database entry for "key" to "value".
*
* @param key the specified key to be inserted.
* @param value the value associated with the specified key.
*
* @see RocksDBException
*/
public void put(WriteOptions writeOpts, byte[] key, byte[] value)
throws RocksDBException {
put(nativeHandle_, writeOpts.nativeHandle_,
key, key.length, value, value.length);
}
/**
* Set the database entry for "key" to "value" for the specified
* column family.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param key the specified key to be inserted.
* @param value the value associated with the specified key.
*
* throws IllegalArgumentException if column family is not present
*
* @see RocksDBException
* @see IllegalArgumentException
*/
public void put(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpts,
byte[] key, byte[] value) throws RocksDBException {
put(nativeHandle_, writeOpts.nativeHandle_, key, key.length, value, value.length,
columnFamilyHandle.nativeHandle_);
}
/**
* If the key definitely does not exist in the database, then this method
* returns false, else true.
*
* This check is potentially lighter-weight than invoking DB::Get(). One way
* to make this lighter weight is to avoid doing any IOs.
*
* @param columnFamilyHandle {@link ColumnFamilyHandle} instance
* @param key byte array of a key to search for
* @param value StringBuffer instance which is a out parameter if a value is
* found in block-cache.
* @return boolean value indicating if key does not exist or might exist.
*/
public boolean keyMayExist(ColumnFamilyHandle columnFamilyHandle,
byte[] key, StringBuffer value){
return keyMayExist(key, key.length, columnFamilyHandle.nativeHandle_,
value);
}
/**
* If the key definitely does not exist in the database, then this method
* returns false, else true.
*
* This check is potentially lighter-weight than invoking DB::Get(). One way
* to make this lighter weight is to avoid doing any IOs.
*
* @param readOptions {@link ReadOptions} instance
* @param columnFamilyHandle {@link ColumnFamilyHandle} instance
* @param key byte array of a key to search for
* @param value StringBuffer instance which is a out parameter if a value is
* found in block-cache.
* @return boolean value indicating if key does not exist or might exist.
*/
public boolean keyMayExist(ReadOptions readOptions,
ColumnFamilyHandle columnFamilyHandle, byte[] key, StringBuffer value){
return keyMayExist(readOptions.nativeHandle_,
key, key.length, columnFamilyHandle.nativeHandle_,
value);
}
/**
* Apply the specified updates to the database.
*
* @param writeOpts WriteOptions instance
* @param updates WriteBatch instance
*
* @see RocksDBException
*/
public void write(WriteOptions writeOpts, WriteBatch updates)
throws RocksDBException {
write(writeOpts.nativeHandle_, updates.nativeHandle_);
}
/**
* Add merge operand for key/value pair.
*
* @param key the specified key to be merged.
* @param value the value to be nerged with the current value for
* the specified key.
*/
public void merge(byte[] key, byte[] value) throws RocksDBException {
merge(nativeHandle_, key, key.length, value, value.length);
}
/**
* Add merge operand for key/value pair in a ColumnFamily.
*
* @param columnFamilyHandle {@link ColumnFamilyHandle} instance
* @param key the specified key to be merged.
* @param value the value to be nerged with the current value for
* the specified key.
*/
public void merge(ColumnFamilyHandle columnFamilyHandle, byte[] key,
byte[] value) throws RocksDBException {
merge(nativeHandle_, key, key.length, value, value.length,
columnFamilyHandle.nativeHandle_);
}
/**
* Add merge operand for key/value pair.
*
* @param writeOpts {@link WriteOptions} for this write.
* @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(WriteOptions writeOpts, byte[] key, byte[] value)
throws RocksDBException {
merge(nativeHandle_, writeOpts.nativeHandle_,
key, key.length, value, value.length);
}
/**
* Add merge operand for key/value pair.
*
* @param columnFamilyHandle {@link ColumnFamilyHandle} instance
* @param writeOpts {@link WriteOptions} for this write.
* @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,
WriteOptions writeOpts, byte[] key, byte[] value)
throws RocksDBException {
merge(nativeHandle_, writeOpts.nativeHandle_,
key, key.length, value, value.length,
columnFamilyHandle.nativeHandle_);
}
/**
* Get the value associated with the specified key within column family*
* @param key the key to retrieve the value.
* @param value the out-value to receive the retrieved value.
* @return The size of the actual value that matches the specified
* {@code key} in byte. If the return value is greater than the
* length of {@code value}, then it indicates that the size of the
* input buffer {@code value} is insufficient and partial result will
* be returned. RocksDB.NOT_FOUND will be returned if the value not
* found.
*
* @see RocksDBException
*/
public int get(byte[] key, byte[] value) throws RocksDBException {
return get(nativeHandle_, key, key.length, value, value.length);
}
/**
* Get the value associated with the specified key within column family.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param key the key to retrieve the value.
* @param value the out-value to receive the retrieved value.
* @return The size of the actual value that matches the specified
* {@code key} in byte. If the return value is greater than the
* length of {@code value}, then it indicates that the size of the
* input buffer {@code value} is insufficient and partial result will
* be returned. RocksDB.NOT_FOUND will be returned if the value not
* found.
*
* @throws RocksDBException
*/
public int get(ColumnFamilyHandle columnFamilyHandle, byte[] key, byte[] value)
throws RocksDBException, IllegalArgumentException {
return get(nativeHandle_, key, key.length, value, value.length,
columnFamilyHandle.nativeHandle_);
}
/**
* Get the value associated with the specified key.
*
* @param key the key to retrieve the value.
* @param value the out-value to receive the retrieved value.
* @return The size of the actual value that matches the specified
* {@code key} in byte. If the return value is greater than the
* length of {@code value}, then it indicates that the size of the
* input buffer {@code value} is insufficient and partial result will
* be returned. RocksDB.NOT_FOUND will be returned if the value not
* found.
*
* @throws RocksDBException
*/
public int get(ReadOptions opt, byte[] key, byte[] value)
throws RocksDBException {
return get(nativeHandle_, opt.nativeHandle_,
key, key.length, value, value.length);
}
/**
* Get the value associated with the specified key within column family.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param key the key to retrieve the value.
* @param value the out-value to receive the retrieved value.
* @return The size of the actual value that matches the specified
* {@code key} in byte. If the return value is greater than the
* length of {@code value}, then it indicates that the size of the
* input buffer {@code value} is insufficient and partial result will
* be returned. RocksDB.NOT_FOUND will be returned if the value not
* found.
*
* @throws RocksDBException
*/
public int get(ColumnFamilyHandle columnFamilyHandle, ReadOptions opt, byte[] key,
byte[] value) throws RocksDBException {
return get(nativeHandle_, opt.nativeHandle_, key, key.length, value,
value.length, columnFamilyHandle.nativeHandle_);
}
/**
* The simplified version of get which returns a new byte array storing
* the value associated with the specified input key if any. null will be
* returned if the specified key is not found.
*
* @param key the key retrieve the value.
* @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
*/
public byte[] get(byte[] key) throws RocksDBException {
return get(nativeHandle_, key, key.length);
}
/**
* The simplified version of get which returns a new byte array storing
* the value associated with the specified input key if any. null will be
* returned if the specified key is not found.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param key the key retrieve the value.
* @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
*/
public byte[] get(ColumnFamilyHandle columnFamilyHandle, byte[] key)
throws RocksDBException {
return get(nativeHandle_, key, key.length, columnFamilyHandle.nativeHandle_);
}
/**
* The simplified version of get which returns a new byte array storing
* the value associated with the specified input key if any. null will be
* returned if the specified key is not found.
*
* @param key the key retrieve the value.
* @param opt Read options.
* @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
*/
public byte[] get(ReadOptions opt, byte[] key) throws RocksDBException {
return get(nativeHandle_, opt.nativeHandle_, key, key.length);
}
/**
* The simplified version of get which returns a new byte array storing
* the value associated with the specified input key if any. null will be
* returned if the specified key is not found.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param key the key retrieve the value.
* @param opt Read options.
* @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
*/
public byte[] get(ColumnFamilyHandle columnFamilyHandle, ReadOptions opt,
byte[] key) throws RocksDBException {
return get(nativeHandle_, opt.nativeHandle_, key, key.length,
columnFamilyHandle.nativeHandle_);
}
/**
* Returns a map of keys for which values were found in DB.
*
* @param keys List of keys for which values need to be retrieved.
* @return Map where key of map is the key passed by user and value for map
* entry is the corresponding value in DB.
*
* @throws RocksDBException
*/
public Map<byte[], byte[]> multiGet(List<byte[]> keys)
throws RocksDBException {
assert(keys.size() != 0);
List<byte[]> values = multiGet(
nativeHandle_, keys, keys.size());
Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
for(int i = 0; i < values.size(); i++) {
if(values.get(i) == null) {
continue;
}
keyValueMap.put(keys.get(i), values.get(i));
}
return keyValueMap;
}
/**
* Returns a map of keys for which values were found in DB.
* <p>
* Note: Every key needs to have a related column family name in
* {@code columnFamilyHandleList}.
* </p>
*
* @param columnFamilyHandleList {@link java.util.List} containing
* {@link org.rocksdb.ColumnFamilyHandle} instances.
* @param keys List of keys for which values need to be retrieved.
* @return Map where key of map is the key passed by user and value for map
* entry is the corresponding value in DB.
*
* @throws RocksDBException
* @throws IllegalArgumentException
*/
public Map<byte[], byte[]> multiGet(List<ColumnFamilyHandle> columnFamilyHandleList,
List<byte[]> keys) throws RocksDBException, IllegalArgumentException {
assert(keys.size() != 0);
// Check if key size equals cfList size. If not a exception must be
// thrown. If not a Segmentation fault happens.
if (keys.size()!=columnFamilyHandleList.size()) {
throw new IllegalArgumentException(
"For each key there must be a ColumnFamilyHandle.");
}
List<byte[]> values = multiGet(nativeHandle_, keys, keys.size(),
columnFamilyHandleList);
Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
for(int i = 0; i < values.size(); i++) {
if (values.get(i) == null) {
continue;
}
keyValueMap.put(keys.get(i), values.get(i));
}
return keyValueMap;
}
/**
* Returns a map of keys for which values were found in DB.
*
* @param opt Read options.
* @param keys of keys for which values need to be retrieved.
* @return Map where key of map is the key passed by user and value for map
* entry is the corresponding value in DB.
*
* @throws RocksDBException
*/
public Map<byte[], byte[]> multiGet(ReadOptions opt, List<byte[]> keys)
throws RocksDBException {
assert(keys.size() != 0);
List<byte[]> values = multiGet(
nativeHandle_, opt.nativeHandle_, keys, keys.size());
Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
for(int i = 0; i < values.size(); i++) {
if(values.get(i) == null) {
continue;
}
keyValueMap.put(keys.get(i), values.get(i));
}
return keyValueMap;
}
/**
* Returns a map of keys for which values were found in DB.
* <p>
* Note: Every key needs to have a related column family name in
* {@code columnFamilyHandleList}.
* </p>
*
* @param opt Read options.
* @param columnFamilyHandleList {@link java.util.List} containing
* {@link org.rocksdb.ColumnFamilyHandle} instances.
* @param keys of keys for which values need to be retrieved.
* @return Map where key of map is the key passed by user and value for map
* entry is the corresponding value in DB.
*
* @throws RocksDBException
* @throws java.lang.IllegalArgumentException
*/
public Map<byte[], byte[]> multiGet(ReadOptions opt,
List<ColumnFamilyHandle> columnFamilyHandleList, List<byte[]> keys)
throws RocksDBException {
assert(keys.size() != 0);
// Check if key size equals cfList size. If not a exception must be
// thrown. If not a Segmentation fault happens.
if (keys.size()!=columnFamilyHandleList.size()){
throw new IllegalArgumentException(
"For each key there must be a ColumnFamilyHandle.");
}
List<byte[]> values = multiGet(nativeHandle_, opt.nativeHandle_,
keys, keys.size(), columnFamilyHandleList);
Map<byte[], byte[]> keyValueMap = new HashMap<byte[], byte[]>();
for(int i = 0; i < values.size(); i++) {
if(values.get(i) == null) {
continue;
}
keyValueMap.put(keys.get(i), values.get(i));
}
return keyValueMap;
}
/**
* Remove the database entry (if any) for "key". Returns OK on
* success, and a non-OK status on error. It is not an error if "key"
* did not exist in the database.
*
* @param key Key to delete within database
*
* @throws RocksDBException
*/
public void remove(byte[] key) throws RocksDBException {
remove(nativeHandle_, key, key.length);
}
/**
* Remove the database entry (if any) for "key". Returns OK on
* success, and a non-OK status on error. It is not an error if "key"
* did not exist in the database.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param key Key to delete within database
*
* @throws RocksDBException
*/
public void remove(ColumnFamilyHandle columnFamilyHandle, byte[] key)
throws RocksDBException {
remove(nativeHandle_, key, key.length, columnFamilyHandle.nativeHandle_);
}
/**
* Remove the database entry (if any) for "key". Returns OK on
* success, and a non-OK status on error. It is not an error if "key"
* did not exist in the database.
*
* @param writeOpt WriteOptions to be used with delete operation
* @param key Key to delete within database
*
* @throws RocksDBException
*/
public void remove(WriteOptions writeOpt, byte[] key)
throws RocksDBException {
remove(nativeHandle_, writeOpt.nativeHandle_, key, key.length);
}
/**
* Remove the database entry (if any) for "key". Returns OK on
* success, and a non-OK status on error. It is not an error if "key"
* did not exist in the database.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param writeOpt WriteOptions to be used with delete operation
* @param key Key to delete within database
*
* @throws RocksDBException
*/
public void remove(ColumnFamilyHandle columnFamilyHandle, WriteOptions writeOpt,
byte[] key) throws RocksDBException {
remove(nativeHandle_, writeOpt.nativeHandle_, key, key.length,
columnFamilyHandle.nativeHandle_);
}
/**
* DB implements can export properties about their state
* via this method on a per column family level.
*
* <p>If {@code property} is a valid property understood by this DB
* implementation, fills {@code value} with its current value and
* returns true. Otherwise returns false.</p>
*
* <p>Valid property names include:
* <ul>
* <li>"rocksdb.num-files-at-level<N>" - return the number of files at level <N>,
* where <N> is an ASCII representation of a level number (e.g. "0").</li>
* <li>"rocksdb.stats" - returns a multi-line string that describes statistics
* about the internal operation of the DB.</li>
* <li>"rocksdb.sstables" - returns a multi-line string that describes all
* of the sstables that make up the db contents.</li>
*</ul></p>
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @param property to be fetched. See above for examples
* @return property value
*
* @throws RocksDBException
*/
public String getProperty(ColumnFamilyHandle columnFamilyHandle, String property)
throws RocksDBException {
return getProperty0(nativeHandle_, columnFamilyHandle.nativeHandle_, property,
property.length());
}
/**
* DB implementations can export properties about their state
* via this method. If "property" is a valid property understood by this
* DB implementation, fills "*value" with its current value and returns
* true. Otherwise returns false.
*
* <p>Valid property names include:
* <ul>
* <li>"rocksdb.num-files-at-level<N>" - return the number of files at level <N>,
* where <N> is an ASCII representation of a level number (e.g. "0").</li>
* <li>"rocksdb.stats" - returns a multi-line string that describes statistics
* about the internal operation of the DB.</li>
* <li>"rocksdb.sstables" - returns a multi-line string that describes all
* of the sstables that make up the db contents.</li>
*</ul></p>
*
* @param property to be fetched. See above for examples
* @return property value
*
* @throws RocksDBException
*/
public String getProperty(String property) throws RocksDBException {
return getProperty0(nativeHandle_, property, property.length());
}
/**
* Return a heap-allocated iterator over the contents of the database.
* The result of newIterator() is initially invalid (caller must
* call one of the Seek methods on the iterator before using it).
*
* Caller should close the iterator when it is no longer needed.
* The returned iterator should be closed before this db is closed.
*
* @return instance of iterator object.
*/
public RocksIterator newIterator() {
return new RocksIterator(this, iterator0(nativeHandle_));
}
/**
* <p>Return a handle to the current DB state. Iterators created with
* this handle will all observe a stable snapshot of the current DB
* state. The caller must call ReleaseSnapshot(result) when the
* snapshot is no longer needed.</p>
*
* <p>nullptr will be returned if the DB fails to take a snapshot or does
* not support snapshot.</p>
*
* @return Snapshot
*/
public Snapshot getSnapshot() {
long snapshotHandle = getSnapshot(nativeHandle_);
if (snapshotHandle != 0) {
return new Snapshot(snapshotHandle);
}
return null;
}
/**
* Release a previously acquired snapshot. The caller must not
* use "snapshot" after this call.
*
* @param snapshot {@link Snapshot} instance
*/
public void releaseSnapshot(final Snapshot snapshot) {
if (snapshot != null) {
releaseSnapshot(nativeHandle_, snapshot.nativeHandle_);
}
}
/**
* Return a heap-allocated iterator over the contents of the database.
* The result of newIterator() is initially invalid (caller must
* call one of the Seek methods on the iterator before using it).
*
* Caller should close the iterator when it is no longer needed.
* The returned iterator should be closed before this db is closed.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
* @return instance of iterator object.
*/
public RocksIterator newIterator(ColumnFamilyHandle columnFamilyHandle) {
return new RocksIterator(this, iterator0(nativeHandle_,
columnFamilyHandle.nativeHandle_));
}
/**
* Returns iterators from a consistent database state across multiple
* column families. Iterators are heap allocated and need to be deleted
* before the db is deleted
*
* @param columnFamilyHandleList {@link java.util.List} containing
* {@link org.rocksdb.ColumnFamilyHandle} instances.
* @return {@link java.util.List} containing {@link org.rocksdb.RocksIterator}
* instances
*
* @throws RocksDBException
*/
public List<RocksIterator> newIterators(
List<ColumnFamilyHandle> columnFamilyHandleList) throws RocksDBException {
List<RocksIterator> iterators =
new ArrayList<RocksIterator>(columnFamilyHandleList.size());
long[] iteratorRefs = iterators(nativeHandle_, columnFamilyHandleList);
for (int i=0; i<columnFamilyHandleList.size(); i++){
iterators.add(new RocksIterator(this, iteratorRefs[i]));
}
return iterators;
}
/**
* Creates a new column family with the name columnFamilyName and
* allocates a ColumnFamilyHandle within an internal structure.
* The ColumnFamilyHandle is automatically disposed with DB disposal.
*
* @param columnFamilyName Name of column family to be created.
* @return {@link org.rocksdb.ColumnFamilyHandle} instance
* @see RocksDBException
*/
public ColumnFamilyHandle createColumnFamily(String columnFamilyName)
throws RocksDBException {
return new ColumnFamilyHandle(this, createColumnFamily(nativeHandle_,
options_.nativeHandle_, columnFamilyName));
}
/**
* Drops the column family identified by columnFamilyName. Internal
* handles to this column family will be disposed. If the column family
* is not known removal will fail.
*
* @param columnFamilyHandle {@link org.rocksdb.ColumnFamilyHandle}
* instance
*
* @throws RocksDBException
*/
public void dropColumnFamily(ColumnFamilyHandle columnFamilyHandle)
throws RocksDBException, IllegalArgumentException {
// throws RocksDBException if something goes wrong
dropColumnFamily(nativeHandle_, columnFamilyHandle.nativeHandle_);
}
/**
* Private constructor.
*/
protected RocksDB() {
super();
}
// native methods
protected native void open(
long optionsHandle, String path) throws RocksDBException;
protected native List<Long> open(long optionsHandle, String path,
List<String> columnFamilyNames, int columnFamilyNamesLength)
throws RocksDBException;
protected native static List<byte[]> listColumnFamilies(
long optionsHandle, String path) throws RocksDBException;
protected native void openROnly(
long optionsHandle, String path) throws RocksDBException;
protected native List<Long> openROnly(
long optionsHandle, String path, List<String> columnFamilyNames,
int columnFamilyNamesLength) throws RocksDBException;
protected native void put(
long handle, byte[] key, int keyLen,
byte[] value, int valueLen) throws RocksDBException;
protected native void put(
long handle, byte[] key, int keyLen,
byte[] value, int valueLen, long cfHandle) throws RocksDBException;
protected native void put(
long handle, long writeOptHandle,
byte[] key, int keyLen,
byte[] value, int valueLen) throws RocksDBException;
protected native void put(
long handle, long writeOptHandle,
byte[] key, int keyLen,
byte[] value, int valueLen, long cfHandle) throws RocksDBException;
protected native void write(
long writeOptHandle, long batchHandle) throws RocksDBException;
protected native boolean keyMayExist(byte[] key, int keyLen,
long cfHandle, StringBuffer stringBuffer);
protected native boolean keyMayExist(long optionsHandle, byte[] key, int keyLen,
long cfHandle, StringBuffer stringBuffer);
protected native void merge(
long handle, byte[] key, int keyLen,
byte[] value, int valueLen) throws RocksDBException;
protected native void merge(
long handle, byte[] key, int keyLen,
byte[] value, int valueLen, long cfHandle) throws RocksDBException;
protected native void merge(
long handle, long writeOptHandle,
byte[] key, int keyLen,
byte[] value, int valueLen) throws RocksDBException;
protected native void merge(
long handle, long writeOptHandle,
byte[] key, int keyLen,
byte[] value, int valueLen, long cfHandle) throws RocksDBException;
protected native int get(
long handle, byte[] key, int keyLen,
byte[] value, int valueLen) throws RocksDBException;
protected native int get(
long handle, byte[] key, int keyLen,
byte[] value, int valueLen, long cfHandle) throws RocksDBException;
protected native int get(
long handle, long readOptHandle, byte[] key, int keyLen,
byte[] value, int valueLen) throws RocksDBException;
protected native int get(
long handle, long readOptHandle, byte[] key, int keyLen,
byte[] value, int valueLen, long cfHandle) throws RocksDBException;
protected native List<byte[]> multiGet(
long dbHandle, List<byte[]> keys, int keysCount);
protected native List<byte[]> multiGet(
long dbHandle, List<byte[]> keys, int keysCount, List<ColumnFamilyHandle>
cfHandles);
protected native List<byte[]> multiGet(
long dbHandle, long rOptHandle, List<byte[]> keys, int keysCount);
protected native List<byte[]> multiGet(
long dbHandle, long rOptHandle, List<byte[]> keys, int keysCount,
List<ColumnFamilyHandle> cfHandles);
protected native byte[] get(
long handle, byte[] key, int keyLen) throws RocksDBException;
protected native byte[] get(
long handle, byte[] key, int keyLen, long cfHandle) throws RocksDBException;
protected native byte[] get(
long handle, long readOptHandle,
byte[] key, int keyLen) throws RocksDBException;
protected native byte[] get(
long handle, long readOptHandle,
byte[] key, int keyLen, long cfHandle) throws RocksDBException;
protected native void remove(
long handle, byte[] key, int keyLen) throws RocksDBException;
protected native void remove(
long handle, byte[] key, int keyLen, long cfHandle) throws RocksDBException;
protected native void remove(
long handle, long writeOptHandle,
byte[] key, int keyLen) throws RocksDBException;
protected native void remove(
long handle, long writeOptHandle,
byte[] key, int keyLen, long cfHandle) throws RocksDBException;
protected native String getProperty0(long nativeHandle,
String property, int propertyLength) throws RocksDBException;
protected native String getProperty0(long nativeHandle, long cfHandle,
String property, int propertyLength) throws RocksDBException;
protected native long iterator0(long handle);
protected native long iterator0(long handle, long cfHandle);
protected native long[] iterators(long handle,
List<ColumnFamilyHandle> columnFamilyNames) throws RocksDBException;
protected native long getSnapshot(long nativeHandle);
protected native void releaseSnapshot(
long nativeHandle, long snapshotHandle);
private native void disposeInternal(long handle);
private native long createColumnFamily(long handle, long opt_handle,
String name) throws RocksDBException;
private native void dropColumnFamily(long handle, long cfHandle) throws RocksDBException;
protected Options options_;
}