org.rocksdb

类 TransactionDBOptions

java.lang.Object

org.rocksdb.AbstractNativeReference

org.rocksdb.AbstractImmutableNativeReference

org.rocksdb.RocksObject

org.rocksdb.TransactionDBOptions

所有已实现的接口:

java.lang.AutoCloseable

public class TransactionDBOptions
extends RocksObject

字段概要

从类继承的字段 org.rocksdb.RocksObject

nativeHandle_

从类继承的字段 org.rocksdb.AbstractImmutableNativeReference

owningHandle_

构造器概要

构造器

构造器和说明
TransactionDBOptions()

方法概要

限定符和类型	方法和说明
protected void	disposeInternal(long handle)
long	getDefaultLockTimeout() The wait timeout in milliseconds when writing a key OUTSIDE of a transaction (ie by calling RocksDB.put(byte[], byte[]), RocksDB.merge(byte[], byte[]), RocksDB.delete(byte[]) or RocksDB.write(org.rocksdb.WriteOptions, org.rocksdb.WriteBatch) directly).
long	getMaxNumLocks() Specifies the maximum number of keys that can be locked at the same time per column family.
long	getNumStripes() The number of sub-tables per lock table (per column family)
long	getTransactionLockTimeout() The default wait timeout in milliseconds when a transaction attempts to lock a key if not specified by TransactionOptions.setLockTimeout(long) If 0, no waiting is done if a lock cannot instantly be acquired.
TxnDBWritePolicy	getWritePolicy() The policy for when to write the data into the DB.
TransactionDBOptions	setDefaultLockTimeout(long defaultLockTimeout) If positive, specifies the wait timeout in milliseconds when writing a key OUTSIDE of a transaction (ie by calling RocksDB.put(byte[], byte[]), RocksDB.merge(byte[], byte[]), RocksDB.delete(byte[]) or RocksDB.write(org.rocksdb.WriteOptions, org.rocksdb.WriteBatch) directly).
TransactionDBOptions	setMaxNumLocks(long maxNumLocks) Specifies the maximum number of keys that can be locked at the same time per column family.
TransactionDBOptions	setNumStripes(long numStripes) Increasing this value will increase the concurrency by dividing the lock table (per column family) into more sub-tables, each with their own separate mutex.
TransactionDBOptions	setTransactionLockTimeout(long transactionLockTimeout) If positive, specifies the default wait timeout in milliseconds when a transaction attempts to lock a key if not specified by TransactionOptions.setLockTimeout(long) If 0, no waiting is done if a lock cannot instantly be acquired.
TransactionDBOptions	setWritePolicy(TxnDBWritePolicy writePolicy) The policy for when to write the data into the DB.

从类继承的方法 org.rocksdb.RocksObject

disposeInternal, getNativeHandle

从类继承的方法 org.rocksdb.AbstractImmutableNativeReference

close, disOwnNativeHandle, isOwningHandle

从类继承的方法 java.lang.Object

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

构造器详细资料

TransactionDBOptions

public TransactionDBOptions()

方法详细资料

getMaxNumLocks

public long getMaxNumLocks()

Specifies the maximum number of keys that can be locked at the same time per column family.

If the number of locked keys is greater than #getMaxNumLocks(), transaction writes (or GetForUpdate) will return an error.

返回:

The maximum number of keys that can be locked

setMaxNumLocks

public TransactionDBOptions setMaxNumLocks(long maxNumLocks)

Specifies the maximum number of keys that can be locked at the same time per column family.

If the number of locked keys is greater than getMaxNumLocks(), transaction writes (or GetForUpdate) will return an error.

参数:

maxNumLocks - The maximum number of keys that can be locked; If this value is not positive, no limit will be enforced.

返回:

this TransactionDBOptions instance

getNumStripes

public long getNumStripes()

The number of sub-tables per lock table (per column family)

返回:

The number of sub-tables

setNumStripes

public TransactionDBOptions setNumStripes(long numStripes)

Increasing this value will increase the concurrency by dividing the lock table (per column family) into more sub-tables, each with their own separate mutex.

Default: 16

参数:

numStripes - The number of sub-tables

返回:

this TransactionDBOptions instance

getTransactionLockTimeout

public long getTransactionLockTimeout()

The default wait timeout in milliseconds when a transaction attempts to lock a key if not specified by TransactionOptions.setLockTimeout(long) If 0, no waiting is done if a lock cannot instantly be acquired. If negative, there is no timeout.

返回:

the default wait timeout in milliseconds

setTransactionLockTimeout

public TransactionDBOptions setTransactionLockTimeout(long transactionLockTimeout)

If positive, specifies the default wait timeout in milliseconds when a transaction attempts to lock a key if not specified by TransactionOptions.setLockTimeout(long) If 0, no waiting is done if a lock cannot instantly be acquired. If negative, there is no timeout. Not using a timeout is not recommended as it can lead to deadlocks. Currently, there is no deadlock-detection to recover from a deadlock.

Default: 1000

参数:

transactionLockTimeout - the default wait timeout in milliseconds

返回:

this TransactionDBOptions instance

getDefaultLockTimeout

public long getDefaultLockTimeout()

The wait timeout in milliseconds when writing a key OUTSIDE of a transaction (ie by calling RocksDB.put(byte[], byte[]), RocksDB.merge(byte[], byte[]), RocksDB.delete(byte[]) or RocksDB.write(org.rocksdb.WriteOptions, org.rocksdb.WriteBatch) directly).

If 0, no waiting is done if a lock cannot instantly be acquired. If negative, there is no timeout and will block indefinitely when acquiring a lock.

返回:

the timeout in milliseconds when writing a key OUTSIDE of a transaction

setDefaultLockTimeout

public TransactionDBOptions setDefaultLockTimeout(long defaultLockTimeout)

If positive, specifies the wait timeout in milliseconds when writing a key OUTSIDE of a transaction (ie by calling RocksDB.put(byte[], byte[]), RocksDB.merge(byte[], byte[]), RocksDB.delete(byte[]) or RocksDB.write(org.rocksdb.WriteOptions, org.rocksdb.WriteBatch) directly).

If 0, no waiting is done if a lock cannot instantly be acquired. If negative, there is no timeout and will block indefinitely when acquiring a lock.

Not using a timeout can lead to deadlocks. Currently, there is no deadlock-detection to recover from a deadlock. While DB writes cannot deadlock with other DB writes, they can deadlock with a transaction. A negative timeout should only be used if all transactions have a small expiration set.

Default: 1000

参数:

defaultLockTimeout - the timeout in milliseconds when writing a key OUTSIDE of a transaction

返回:

this TransactionDBOptions instance

getWritePolicy

public TxnDBWritePolicy getWritePolicy()

The policy for when to write the data into the DB. The default policy is to write only the committed data TxnDBWritePolicy.WRITE_COMMITTED. The data could be written before the commit phase. The DB then needs to provide the mechanisms to tell apart committed from uncommitted data.

返回:

The write policy.

setWritePolicy

public TransactionDBOptions setWritePolicy(TxnDBWritePolicy writePolicy)

The policy for when to write the data into the DB. The default policy is to write only the committed data TxnDBWritePolicy.WRITE_COMMITTED. The data could be written before the commit phase. The DB then needs to provide the mechanisms to tell apart committed from uncommitted data.

参数:

writePolicy - The write policy.

返回:

this TransactionDBOptions instance

disposeInternal

protected final void disposeInternal(long handle)

指定者:

disposeInternal 在类中 RocksObject