org.rocksdb

Class Env

java.lang.Object

org.rocksdb.AbstractNativeReference

org.rocksdb.AbstractImmutableNativeReference

org.rocksdb.RocksObject

org.rocksdb.Env

All Implemented Interfaces:

AutoCloseable

Direct Known Subclasses:

HdfsEnv, RocksEnv, RocksMemEnv, TimedEnv

public abstract class Env
extends RocksObject

Base class for all Env implementations in RocksDB.

Field Summary

Fields inherited from class org.rocksdb.RocksObject

nativeHandle_

Fields inherited from class org.rocksdb.AbstractImmutableNativeReference

owningHandle_

Method Summary

Modifier and Type	Method and Description
int	getBackgroundThreads(Priority priority) Gets the number of background worker threads of the pool for this environment.
static Env	getDefault() Returns the default environment suitable for the current operating system.
List<ThreadStatus>	getThreadList() Returns the status of all threads that belong to the current Env.
int	getThreadPoolQueueLen(Priority priority) Returns the length of the queue associated with the specified thread pool.
Env	incBackgroundThreadsIfNeeded(int number, Priority priority) Enlarge number of background worker threads of a specific thread pool for this environment if it is smaller than specified.
Env	lowerThreadPoolCPUPriority(Priority priority) Lower CPU priority for threads from the specified pool.
Env	lowerThreadPoolIOPriority(Priority priority) Lower IO priority for threads from the specified pool.
Env	setBackgroundThreads(int number) Sets the number of background worker threads of the flush pool for this environment.
Env	setBackgroundThreads(int number, Priority priority) Sets the number of background worker threads of the specified thread pool for this environment.

Methods inherited from class org.rocksdb.RocksObject

disposeInternal, disposeInternal, getNativeHandle

Methods inherited from class org.rocksdb.AbstractImmutableNativeReference

close, disOwnNativeHandle, isOwningHandle

Methods inherited from class org.rocksdb.AbstractNativeReference

dispose, finalize

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getDefault

public static Env getDefault()

Returns the default environment suitable for the current operating system.

The result of getDefault() is a singleton whose ownership belongs to rocksdb c++. As a result, the returned RocksEnv will not have the ownership of its c++ resource, and calling its dispose()/close() will be no-op.

Returns:

the default RocksEnv instance.

setBackgroundThreads

public Env setBackgroundThreads(int number)

Sets the number of background worker threads of the flush pool for this environment.

Default number: 1

Parameters:

number - the number of threads

Returns:

current RocksEnv instance.

getBackgroundThreads

public int getBackgroundThreads(Priority priority)

Gets the number of background worker threads of the pool for this environment.

Parameters:

priority - the priority id of a specified thread pool.

Returns:

the number of threads.

setBackgroundThreads

public Env setBackgroundThreads(int number,
                                Priority priority)

Sets the number of background worker threads of the specified thread pool for this environment.

Parameters:

number - the number of threads

priority - the priority id of a specified thread pool.

Default number: 1

Returns:

current RocksEnv instance.

getThreadPoolQueueLen

public int getThreadPoolQueueLen(Priority priority)

Returns the length of the queue associated with the specified thread pool.

Parameters:

priority - the priority id of a specified thread pool.

Returns:

the thread pool queue length.

incBackgroundThreadsIfNeeded

public Env incBackgroundThreadsIfNeeded(int number,
                                        Priority priority)

Enlarge number of background worker threads of a specific thread pool for this environment if it is smaller than specified. 'LOW' is the default pool.

Parameters:

number - the number of threads.

priority - the priority id of a specified thread pool.

Returns:

current RocksEnv instance.

lowerThreadPoolIOPriority

public Env lowerThreadPoolIOPriority(Priority priority)

Lower IO priority for threads from the specified pool.

Parameters:

priority - the priority id of a specified thread pool.

Returns:

current RocksEnv instance.

lowerThreadPoolCPUPriority

public Env lowerThreadPoolCPUPriority(Priority priority)

Lower CPU priority for threads from the specified pool.

Parameters:

priority - the priority id of a specified thread pool.

Returns:

current RocksEnv instance.

getThreadList

public List<ThreadStatus> getThreadList()
                                 throws RocksDBException

Returns the status of all threads that belong to the current Env.

Returns:

the status of all threads belong to this env.

Throws:

RocksDBException - if the thread list cannot be acquired.