NAME
    Perinci::Tx::Manager - Transaction manager

VERSION
    version 0.28

SYNOPSIS
     # used by Perinci::Access::InProcess

DESCRIPTION
    This class implements transaction and undo manager (TM), as specified by
    Rinci::function::Transaction and Riap::Transaction. It is meant to be
    instantiated by Perinci::Access::InProcess, but will also be passed to
    transactional functions to save undo/redo data.

    It uses SQLite database to store transaction list and undo/redo data as
    well as transaction data directory to provide trash_dir/tmp_dir for
    functions that require it.

ATTRIBUTES
  _tx_id
    This is just a convenience so that methods that require tx_id will get
    the default value from here if tx_id not specified in arguments.

METHODS
  new(%args) => OBJ
    Create new object. Arguments:

    *   pa => OBJ

        Perinci::Access::InProcess object. This is required by
        Perinci::Tx::Manager to load/get functions when it wants to perform
        undo/redo/recovery. Perinci::Access::InProcess conveniently
        require() the Perl modules and wraps the functions.

    *   data_dir => STR (default "~/.perinci/.tx")

    *   max_txs => INT (default 1000)

        Limit maximum number of transactions maintained by the TM, including
        all rolled back and committed transactions, since they are still
        recorded in the database. The default is 1000.

        Not yet implemented.

        After this limit is reached, cleanup will be performed to delete
        rolled back transactions, and after that committed transactions.

    *   max_open_txs => INT (default 100)

        Limit maximum number of open (in progress, aborted, prepared)
        transactions. This exclude resolved transactions (rolled back and
        committed). The default is no limit.

        Not yet implemented.

        After this limit is reached, starting a new transaction will fail.

    *   max_committed_txs => INT (default 100)

        Limit maximum number of committed transactions that is recorded by
        the database. This is equal to the number of undo steps that are
        remembered.

        After this limit is reached, cleanup will automatically be performed
        so that the oldest committed transactions are purged.

        Not yet implemented.

    *   max_open_age => INT

        Limit the maximum age of open transactions (in seconds). If this
        limit is reached, in progress transactions will automatically be
        purged because it times out.

        Not yet implemented.

    *   max_committed_age => INT

        Limit the maximum age of committed transactions (in seconds). If
        this limit is reached, the old transactions will start to be purged.

        Not yet implemented.

  $tx->begin(%args) => RESP
    Start a new transaction.

    Arguments: tx_id (str, required, unless already supplied via _tx_id()),
    twopc (bool, optional, currently must be false since distributed
    transaction is not yet supported), summary (optional).

    TM will create an entry for this transaction in its database.

  $tx->record_call(%args) => RESP
    Record a function call. This method needs to be called before function
    does any step.

    Arguments: tx_id, f (optional, function name, will be retrieved from
    caller(1) if not specified, assuming the call is from the function
    itself), args (required, function arguments).

    TM will create an entry for this call in its database.

    Return call ID in enveloped response.

  $tx->record_undo_step(%args) => RESP
    Record an undo step. This method needs to be called before performing a
    step.

    Arguments: tx_id, call_id, data (an array).

  $tx->record_redo_step(%args) => RESP
    Record a redo step. This method needs to be called before performing an
    undo step.

    Arguments: tx_id, call_id, data (an array).

  $tx->get_trash_dir => RESP
  $tx->get_tmp_dir => RESP
  $tx->commit(%args) => RESP
    Arguments: tx_id

  $tx->rollback(%args) => RESP
    Arguments: tx_id, sp (optional, savepoint name to rollback to a specific
    savepoint only).

    Currently rolling back to a savepoint is not implemented.

  $tx->prepare(%args) => RESP
    Currently will return 501 (not implemented). This TM does not support
    distributed transaction.

    Arguments: tx_id

  $tx->savepoint(%args) => RESP
    Arguments: tx_id, sp (savepoint name).

    Currently not implemented.

  $tx->release_savepoint(%args) => RESP
    Arguments: tx_id, sp (savepoint name).

    Currently not implemented.

  $tx->undo(%args) => RESP
    Arguments: tx_id

  $tx->redo(%args) => RESP
    Arguments: tx_id

  $tx->list(%args) => RESP
    List transactions. Return an array of results sorted by creation date
    (in ascending order).

    Arguments: detail (bool, default 0, whether to return transaction
    records instead of just a list of transaction ID's).

  $tx->discard(%args) => RESP
    Discard (forget) a committed transaction. The transaction will no longer
    be undoable.

    Arguments: tx_id

  $tx->discard_all(%args) => RESP
    Discard (forget) all committed transactions.

SEE ALSO
    Riap::Transaction

    Perinci::Access::InProcess

    Rinci::function::Undo

    Rinci::function::Transaction

AUTHOR
    Steven Haryanto <stevenharyanto@gmail.com>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2012 by Steven Haryanto.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.