com.neocoretechs.rocksack.session

Class TransactionSession

java.lang.Object

com.neocoretechs.rocksack.session.Session

com.neocoretechs.rocksack.session.TransactionSession

Direct Known Subclasses:

OptimisticTransactionSession, TransactionSessionAlias

public class TransactionSession
extends Session

Extends the Session class to include transaction semantics. In RocksDb a TransactionDB instance contains the transaction classes and methods to provide atomicity. Transactions are linked to a TransactionDb, or OptimisticTransactionDb, both subclasses of RocksDB. Each transaction may be named, and the name must be unique. To enforce uniqueness considering these constraints, the name formed will be a concatenation of Transaction Id, which is a UUID, the class name, which is also a column family or the default column family, and the Alias, or none, which is the default database path.

From the TransactionManager we link the transaction Id's to an instance of this and associated transaction.

Author:

Jonathan Groff Copyright (C) NeoCoreTechs 2023,2024

Constructor Summary

Constructors

Constructor and Description
TransactionSession(org.rocksdb.OptimisticTransactionDB kvStore, org.rocksdb.Options options, java.util.ArrayList<org.rocksdb.ColumnFamilyDescriptor> columnFamilyDescriptor, java.util.List<org.rocksdb.ColumnFamilyHandle> columnFamilyHandles)

Method Summary

Modifier and Type	Method and Description
org.rocksdb.Transaction	BeginTransaction() Initiate a transaction.
org.rocksdb.Transaction	BeginTransaction(long timeout)
java.util.List<org.rocksdb.Transaction>	getAllPreparedTransactions() Get all prepared transactions
java.util.Map<java.lang.Long,org.rocksdb.TransactionDB.KeyLockInfo>	getLockStatusData() Get the map of lock status from TransactionDb
org.rocksdb.Transaction	getTransaction(TransactionId transactionId, java.lang.String clazz, boolean create) Get the Transaction object formed from id and class.
boolean	isTransactionLinked(TransactionId xid, TransactionalMap tm, java.util.concurrent.ConcurrentHashMap<java.lang.String,com.neocoretechs.rocksack.session.TransactionManager.SessionAndTransaction> tLink) Check the mangled name identifier of transaction id, classname, and optionally the alias, to identify this entry in the mapping of mangled name to SessionAndTransaction instances from the passed map.
boolean	linkSessionAndTransaction(TransactionId xid, TransactionalMap tm, java.util.concurrent.ConcurrentHashMap<java.lang.String,com.neocoretechs.rocksack.session.TransactionManager.SessionAndTransaction> tLink) Generate a mangled name identifier of transaction id, classname, and optionally the alias, to identify this entry in the mapping of mangled name to SessionAndTransaction instances.
java.lang.String	toString()

Methods inherited from class com.neocoretechs.rocksack.session.Session

Close, Close

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

TransactionSession

public TransactionSession(org.rocksdb.OptimisticTransactionDB kvStore,
                          org.rocksdb.Options options,
                          java.util.ArrayList<org.rocksdb.ColumnFamilyDescriptor> columnFamilyDescriptor,
                          java.util.List<org.rocksdb.ColumnFamilyHandle> columnFamilyHandles)

Method Detail

BeginTransaction

public org.rocksdb.Transaction BeginTransaction()

Initiate a transaction.

Returns:

The RocksDB transaction instance.

BeginTransaction

public org.rocksdb.Transaction BeginTransaction(long timeout)

getTransaction

public org.rocksdb.Transaction getTransaction(TransactionId transactionId,
                                              java.lang.String clazz,
                                              boolean create)

Get the Transaction object formed from id and class. If the transaction id is in use for another class in this, the default db, use the existing transaction.

Parameters:

transactionId -

clazz -

create - true to create if not existing

Returns:

The RocksDb Transaction object or null if not found and create was false

linkSessionAndTransaction

public boolean linkSessionAndTransaction(TransactionId xid,
                                         TransactionalMap tm,
                                         java.util.concurrent.ConcurrentHashMap<java.lang.String,com.neocoretechs.rocksack.session.TransactionManager.SessionAndTransaction> tLink)
                                  throws java.io.IOException

Generate a mangled name identifier of transaction id, classname, and optionally the alias, to identify this entry in the mapping of mangled name to SessionAndTransaction instances. Create a new SessionAndTransaction instance, populate it with session from TransactionalMap and a new transaction, then insert them into the passed map.

Parameters:

xid - the TransactionId

tm - the TransactionalMap we want to use for classname and sesssion

tLink - The map entry from TransactionManager idToNameToSessionAndTransaction from key xid

Returns:

true if passed map contains mangled name

Throws:

java.io.IOException

isTransactionLinked

public boolean isTransactionLinked(TransactionId xid,
                                   TransactionalMap tm,
                                   java.util.concurrent.ConcurrentHashMap<java.lang.String,com.neocoretechs.rocksack.session.TransactionManager.SessionAndTransaction> tLink)
                            throws java.io.IOException

Check the mangled name identifier of transaction id, classname, and optionally the alias, to identify this entry in the mapping of mangled name to SessionAndTransaction instances from the passed map.

Parameters:

xid - the TransactionId

tm - the TransactionalMap we want to use for classname and sesssion

tLink - The map entry from TransactionManager idToNameToSessionAndTransaction from key xid

Returns:

true if passed map contains mangled name

Throws:

java.io.IOException

getLockStatusData

public java.util.Map<java.lang.Long,org.rocksdb.TransactionDB.KeyLockInfo> getLockStatusData()

Get the map of lock status from TransactionDb

Returns:

getAllPreparedTransactions

public java.util.List<org.rocksdb.Transaction> getAllPreparedTransactions()

Get all prepared transactions

Returns:

toString

public java.lang.String toString()

Overrides:

toString in class Session