Class: OpenWFE::CacheExpressionStorage

Inherits:
Object
  • Object
show all
Includes:
ExpressionStorageBase, OwfeServiceLocator, ServiceMixin
Defined in:
lib/openwfe/expool/expstorage.rb

Overview

This cache uses a LruHash (Least Recently Used) to store expressions. If an expression is not cached, the ‘real storage’ is consulted. The real storage is supposed to be the service named “expressionStorage.1”

Constant Summary collapse

MIN_SIZE =

under 20 stored expressions, the unit tests for the CachedFilePersistedEngine do fail because the persistent storage behind the cache hasn’t the time to flush its work queue. a min size limit has been set to 77.

77
DEFAULT_SIZE = 
5000

Instance Attribute Summary

Attributes included from ServiceMixin

#service_name

Attributes included from Contextual

#application_context

Instance Method Summary collapse

Methods included from ExpressionStorageBase

#class_accepted?, #does_match?, #observe_expool, #to_s

Methods included from OwfeServiceLocator

#get_engine, #get_error_journal, #get_expool, #get_expression_map, #get_expression_pool, #get_expression_storage, #get_expression_storages, #get_journal, #get_participant_map, #get_scheduler, #get_wfid_generator

Methods included from ServiceMixin

#service_init, #stop

Methods included from Contextual

#get_work_directory, #init_service, #lookup

Methods included from Logging

#ldebug, #ldebug_callstack, #lerror, #lfatal, #linfo, #llog, #lunknown, #lwarn

Constructor Details

#initialize(service_name, application_context) ⇒ CacheExpressionStorage

Returns a new instance of CacheExpressionStorage.



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# File 'lib/openwfe/expool/expstorage.rb', line 192

def initialize (service_name, application_context)

    super()

    service_init(service_name, application_context)

    size = @application_context[:expression_cache_size] || DEFAULT_SIZE
    size = MIN_SIZE unless size > MIN_SIZE

    linfo { "new() size is #{size}" }

    @cache = LruHash.new(size)

    @real_storage = nil

    observe_expool
end

Instance Method Details

#[](fei) ⇒ Object 



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# File 'lib/openwfe/expool/expstorage.rb', line 210

def [] (fei)

    #ldebug { "[] size is #{@cache.size}" }
    #ldebug { "[] (sz #{@cache.size}) for #{fei.to_debug_s}" }

    fe = @cache[fei.hash]
    return fe if fe

    #ldebug { "[] (reload) for #{fei.to_debug_s}" }

    fe = get_real_storage[fei]

    unless fe
        #ldebug { "[] (reload) miss for #{fei.to_debug_s}" }
        return nil 
    end

    @cache[fei.hash] = fe

    fe
end

#[]=(fei, fe) ⇒ Object 



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# File 'lib/openwfe/expool/expstorage.rb', line 232

def []= (fei, fe)

    ldebug { "[]= caching #{fei}" }

    @cache[fei.hash] = fe
end

#clear ⇒ Object Also known as: purge 



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# File 'lib/openwfe/expool/expstorage.rb', line 251

def clear

    @cache.clear
end

#delete(fei) ⇒ Object 



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# File 'lib/openwfe/expool/expstorage.rb', line 239

def delete (fei)

    @cache.delete fei.hash
end

#fetch_root(wfid) ⇒ Object

Attempts at fetching the root expression of a given process instance.



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# File 'lib/openwfe/expool/expstorage.rb', line 271

def fetch_root (wfid)

    #
    # at first, look in the cache

    @cache.each do |hashed_fei, fexp|

        return fexp \
            if fexp.fei.wfid == wfid and fexp.is_a?(DefineExpression)
    end

    get_real_storage.fetch_root wfid
end

#find_expressions(options = {}) ⇒ Object

This implementations of find_expressions() immediately passes the call to the underlying real storage.



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# File 'lib/openwfe/expool/expstorage.rb', line 262

def find_expressions (options={})

    get_real_storage.find_expressions options
end

#length ⇒ Object Also known as: size 



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# File 'lib/openwfe/expool/expstorage.rb', line 244

def length

    @cache.length
end