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// 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;
/**
* This class provides a custom logger functionality
* in Java which wraps {@code RocksDB} logging facilities.
*
*
* Using this class RocksDB can log with common
* Java logging APIs like Log4j or Slf4j without keeping
* database logs in the filesystem.
*
* Performance
* There are certain performance penalties using a Java
* {@code Logger} implementation within production code.
*
*
*
* A log level can be set using {@link org.rocksdb.Options} or
* {@link Logger#setInfoLogLevel(InfoLogLevel)}. The set log level
* influences the underlying native code. Each log message is
* checked against the set log level and if the log level is more
* verbose as the set log level, native allocations will be made
* and data structures are allocated.
*
*
* Every log message which will be emitted by native code will
* trigger expensive native to Java transitions. So the preferred
* setting for production use is either
* {@link org.rocksdb.InfoLogLevel#ERROR_LEVEL} or
* {@link org.rocksdb.InfoLogLevel#FATAL_LEVEL}.
*
*/
public abstract class Logger extends RocksCallbackObject {
private final static long WITH_OPTIONS = 0;
private final static long WITH_DBOPTIONS = 1;
/**
* AbstractLogger constructor.
*
* Important: the log level set within
* the {@link org.rocksdb.Options} instance will be used as
* maximum log level of RocksDB.
*
* @param options {@link org.rocksdb.Options} instance.
*/
public Logger(final Options options) {
super(options.nativeHandle_, WITH_OPTIONS);
}
/**
* AbstractLogger constructor.
*
* Important: the log level set within
* the {@link org.rocksdb.DBOptions} instance will be used
* as maximum log level of RocksDB.
*
* @param dboptions {@link org.rocksdb.DBOptions} instance.
*/
public Logger(final DBOptions dboptions) {
super(dboptions.nativeHandle_, WITH_DBOPTIONS);
}
@Override
protected long initializeNative(long... nativeParameterHandles) {
if(nativeParameterHandles[1] == WITH_OPTIONS) {
return createNewLoggerOptions(nativeParameterHandles[0]);
} else if(nativeParameterHandles[1] == WITH_DBOPTIONS) {
return createNewLoggerDbOptions(nativeParameterHandles[0]);
} else {
throw new IllegalArgumentException();
}
}
/**
* Set {@link org.rocksdb.InfoLogLevel} to AbstractLogger.
*
* @param infoLogLevel {@link org.rocksdb.InfoLogLevel} instance.
*/
public void setInfoLogLevel(final InfoLogLevel infoLogLevel) {
setInfoLogLevel(nativeHandle_, infoLogLevel.getValue());
}
/**
* Return the loggers log level.
*
* @return {@link org.rocksdb.InfoLogLevel} instance.
*/
public InfoLogLevel infoLogLevel() {
return InfoLogLevel.getInfoLogLevel(
infoLogLevel(nativeHandle_));
}
protected abstract void log(InfoLogLevel infoLogLevel,
String logMsg);
protected native long createNewLoggerOptions(
long options);
protected native long createNewLoggerDbOptions(
long dbOptions);
protected native void setInfoLogLevel(long handle,
byte infoLogLevel);
protected native byte infoLogLevel(long handle);
/**
* We override {@link RocksCallbackObject#disposeInternal()}
* as disposing of a rocksdb::LoggerJniCallback requires
* a slightly different approach as it is a std::shared_ptr
*/
@Override
protected void disposeInternal() {
disposeInternal(nativeHandle_);
}
private native void disposeInternal(final long handle);
}