#
#--
# Copyright (c) 2006-2008, Nicolas Modryzk and John Mettraux, OpenWFE.org
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without 
# modification, are permitted provided that the following conditions are met:
# 
# . Redistributions of source code must retain the above copyright notice, this
#   list of conditions and the following disclaimer.  
# 
# . Redistributions in binary form must reproduce the above copyright notice, 
#   this list of conditions and the following disclaimer in the documentation 
#   and/or other materials provided with the distribution.
# 
# . Neither the name of the "OpenWFE" nor the names of its contributors may be
#   used to endorse or promote products derived from this software without
#   specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
# POSSIBILITY OF SUCH DAMAGE.
#++
#

#
# "made in Japan"
#
# Nicolas Modrzyk at openwfe.org
# John Mettraux at openwfe.org
#

require 'openwfe/engine/engine'
require 'openwfe/expool/yamlexpstorage'


module OpenWFE

    #
    # An engine persisted to a tree of yaml files.
    #
    # Remember that once you have added the participants to a persisted
    # engine, you should call its reload method, to reschedule expressions
    # like 'sleep', 'cron', ... But if you do it before registering the
    # participants you'll end up with broken processes.
    #
    class FilePersistedEngine < Engine

        protected

            #
            # Overrides the method already found in Engine with a persisted 
            # expression storage
            #
            def build_expression_storage ()

                init_service S_EXPRESSION_STORAGE, YamlFileExpressionStorage
            end

            #
            # Uses a file persisted error journal.
            #
            def build_error_journal ()

                init_service S_ERROR_JOURNAL, YamlErrorJournal
            end
    end

    #
    # An engine with a cache in front of its file persisted expression storage.
    #
    # Remember that once you have added the participants to a persisted
    # engine, you should call its reload method, to reschedule expressions
    # like 'sleep', 'cron', ... But if you do it before registering the
    # participants you'll end up with broken processes.
    #
    class CachedFilePersistedEngine < FilePersistedEngine

        protected

            def build_expression_storage ()

                @application_context[:expression_cache_size] ||= 1000

                init_service(
                    S_EXPRESSION_STORAGE, 
                    CacheExpressionStorage)

                #init_service(
                #    S_EXPRESSION_STORAGE + ".1",
                #    YamlFileExpressionStorage)
                init_service(
                    S_EXPRESSION_STORAGE + ".1",
                    ThreadedYamlFileExpressionStorage)
            end
    end
end