class TransactionManager A class for managing transactions. More... Definition #include <transaction.hh> List of all Methods

Annotated List Files Globals Hierarchy Index

Public Types

• typedef ref_ptr<TransactionOperation> Operation

Public Methods

•  TransactionManager (EventLoop& e, uint32_t timeout_ms = 0, uint32_t max_pending = 10)
• virtual  ~TransactionManager ()
• bool  start (uint32_t& new_tid)
• bool  commit (uint32_t tid)
• bool  abort (uint32_t tid)
• virtual bool  add (uint32_t tid, const Operation& op)
• bool  retrieve_size (uint32_t tid, uint32_t& count) const
• inline uint32_t  timeout_ms () const
• inline uint32_t  max_pending () const
• inline uint32_t  pending () const

Protected Types

• struct Transaction

Protected Methods

• virtual void  pre_commit (uint32_t tid)
• virtual void  post_commit (uint32_t tid)
• virtual void  operation_result (bool success, const TransactionOperation& op)
• bool  flush (uint32_t tid)

Detailed Description

The TransactionManager creates, manages, and dispatches transactions. A Transaction is comprised of a sequence of TransactionOperation s. Each transaction is uniquely identified by a transaction id.

Constuctor with a given event loop, timeout, and max pending commits.

Parameters:

e	the EventLoop instance.
timeout_ms	the inter-operation addition timeout. If zero, timeouts are not used, otherwise a timeout will occur and the transaction aborted if the transaction is not updated for timeout_ms.
max_pending	the maximum number of uncommitted transactions pending commit.

[virtual]

Destructor

Start transaction

Parameters:

new_tid

variable to assigned new transaction id.

Returns: true on success, false if maximum number of pending transactions is reached.

Commit transaction

Parameters:

tid	the transaction ID.

Returns: true on success, false on error.

Abort transaction

Parameters:

tid	the transaction ID.

Returns: true on success, false on error.

[virtual]

Add operation to transaction.

Parameters:

tid	the transaction ID.
operation	to be added.

Returns: true on success, false if tid is invalid.

[const]

Retrieve number of operations in pending transaction.

Parameters:

tid	the transaction ID.
count	variable to be assigned number of operations in transaction.

Returns: true if tid is valid, false otherwise.

[const]

Get the inter-operation additional timeout.

If the inter-operation addition timeout is zero, timeouts are not used, otherwise a timeout will occur and the transaction aborted if the transaction is not updated for timeout_ms.

Returns: the inter-operation additional timeout.

[const]

Get the maximum number of uncommited pending transactions.

Returns: the maximum number of uncommitted transactions pending commit.

[const]

Get the current number of uncommited pending transactions.

Returns: the current number of uncommitted transactions pending commit.

[protected virtual]

Overrideable function that can be called before the first operation in a commit is dispatched.

Default implementation is a no-op.

[protected virtual]

Overrideable function that can be called after commit occurs

Default implementation is a no-op.

[protected virtual]

Overrideable function that is called immediately after an individual operation is dispatched.

Default implementation is a no-op.

Parameters:

success	whether the operation succeed.
op	the operation.

[protected]

Flush operations in transaction list. May be use by operation_result methods to safely prevent further operations being dispatched when errors are detected. flush() always succeeds if transaction exists.

Parameters:

tid	transaction id of transaction to be flushed.

Returns: true if transaction exists, false otherwise.

[protected]

Transaction class, just a list of operations to be dispatched.

It is defined here so classes derived from TransactionManager can operate, eg sort operations in list, before committing transaction.