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[Loki-lib-cvs] SF.net SVN: loki-lib:[1054] trunk/include/loki/CachedFactory.h
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From: <ric...@us...> - 2009-11-14 07:12:53
|
Revision: 1054
http://loki-lib.svn.sourceforge.net/loki-lib/?rev=1054&view=rev
Author: rich_sposato
Date: 2009-11-14 07:12:39 +0000 (Sat, 14 Nov 2009)
Log Message:
-----------
Added include statement. Removed const declaration.
Modified Paths:
--------------
trunk/include/loki/CachedFactory.h
Modified: trunk/include/loki/CachedFactory.h
===================================================================
--- trunk/include/loki/CachedFactory.h 2009-11-10 19:27:20 UTC (rev 1053)
+++ trunk/include/loki/CachedFactory.h 2009-11-14 07:12:39 UTC (rev 1054)
@@ -4,16 +4,16 @@
//
// Code covered by the MIT License
//
-// Permission to use, copy, modify, distribute and sell this software for any
-// purpose is hereby granted without fee, provided that the above copyright
-// notice appear in all copies and that both that copyright notice and this
+// Permission to use, copy, modify, distribute and sell this software for any
+// purpose is hereby granted without fee, provided that the above copyright
+// notice appear in all copies and that both that copyright notice and this
// permission notice appear in supporting documentation.
//
// The authors make no representations about the suitability of this software
// for any purpose. It is provided "as is" without express or implied warranty.
//
// This code DOES NOT accompany the book:
-// Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design
+// Alexandrescu, Andrei. "Modern C++ Design: Generic Programming and Design
// Patterns Applied". Copyright (c) 2001. Addison-Wesley.
//
////////////////////////////////////////////////////////////////////////////////
@@ -22,6 +22,7 @@
// $Id$
+#include <time.h> ///< For clock_t definition.
#include <functional>
#include <algorithm>
#include <iostream>
@@ -47,7 +48,7 @@
* \ingroup FactoriesGroup
* \brief CachedFactory provides an extension of a Factory with caching
* support.
- *
+ *
* Once used objects are returned to the CachedFactory that manages its
* destruction.
* If your code uses lots of "long to construct/destruct objects" using the
@@ -64,11 +65,11 @@
* \class SimplePointer
* \ingroup EncapsulationPolicyCachedFactoryGroup
* \brief No encaspulation : returns the pointer
- *
+ *
* This implementation does not make any encapsulation.
* It simply returns the object's pointer.
*/
- template<class AbstractProduct>
+ template<class AbstractProduct>
class SimplePointer
{
protected:
@@ -77,7 +78,7 @@
{
return pProduct;
}
-
+
AbstractProduct* release(ProductReturn &pProduct)
{
AbstractProduct* pPointer(pProduct);
@@ -91,7 +92,7 @@
* \defgroup CreationPolicyCachedFactoryGroup Creation policies
* \ingroup CachedFactoryGroup
* \brief Defines a way to limit the creation operation.
- *
+ *
* For instance one may want to be alerted (Exception) when
* - Cache has created a more than X object within the last x seconds
* - Cache creation rate has increased dramatically
@@ -102,7 +103,7 @@
* \class NeverCreate
* \ingroup CreationPolicyCachedFactoryGroup
* \brief Never allows creation. Testing purposes only.
- *
+ *
* Using this policy will throw an exception.
*/
class NeverCreate
@@ -112,22 +113,22 @@
{
const char* what() const throw() { return "NeverFetch Policy : No Fetching allowed"; }
};
-
+
bool canCreate()
{
throw Exception();
}
-
+
void onCreate(){}
void onDestroy(){}
const char* name(){return "never";}
};
-
+
/**
* \class AlwaysCreate
* \ingroup CreationPolicyCachedFactoryGroup
* \brief Always allows creation.
- *
+ *
* Doesn't limit the creation in any way
*/
class AlwaysCreate
@@ -148,7 +149,7 @@
* \class RateLimitedCreation
* \ingroup CreationPolicyCachedFactoryGroup
* \brief Limit in rate.
- *
+ *
* This implementation will prevent from Creating more than maxCreation objects
* within byTime ms by throwing an exception.
* Could be usefull to detect prevent loads (http connection for instance).
@@ -167,7 +168,7 @@
unsigned maxCreation;
clock_t timeValidity;
clock_t lastUpdate;
-
+
void cleanVector()
{
using namespace std;
@@ -193,7 +194,7 @@
}
lastUpdate = currentTime;
}
-#ifdef DO_EXTRA_LOKI_TESTS
+#ifdef DO_EXTRA_LOKI_TESTS
void displayVector()
{
std::cout << "Vector : ";
@@ -204,12 +205,12 @@
protected:
RateLimitedCreation() : maxCreation(10), timeValidity(CLOCKS_PER_SEC), lastUpdate(clock())
{}
-
+
struct Exception : public std::exception
{
const char* what() const throw() { return "RateLimitedCreation Policy : Exceeded the authorized creation rate"; }
};
-
+
bool canCreate()
{
cleanVector();
@@ -223,7 +224,7 @@
{
m_vTimes.push_back(clock());
}
-
+
void onDestroy()
{
}
@@ -239,12 +240,12 @@
D( std::cout << "Setting no more than "<< maxCreation <<" creation within " << this->timeValidity <<" ms"<< std::endl; )
}
};
-
+
/**
* \class AmountLimitedCreation
* \ingroup CreationPolicyCachedFactoryGroup
* \brief Limit by number of objects
- *
+ *
* This implementation will prevent from Creating more than maxCreation objects
* within byTime ms by calling eviction policy.
* Use the setRate method to set the rate parameters.
@@ -255,11 +256,11 @@
private:
unsigned maxCreation;
unsigned created;
-
+
protected:
AmountLimitedCreation() : maxCreation(10), created(0)
{}
-
+
bool canCreate()
{
return !(created>=maxCreation);
@@ -269,7 +270,7 @@
{
++created;
}
-
+
void onDestroy()
{
--created;
@@ -284,7 +285,7 @@
D( std::cout << "Setting no more than " << maxCreation <<" creation" << std::endl; )
}
};
-
+
/**
* \defgroup EvictionPolicyCachedFactoryGroup Eviction policies
* \ingroup CachedFactoryGroup
@@ -316,7 +317,7 @@
typedef typename SwappedHitMap::iterator SwappedHitMapItr;
protected:
HitMap m_mHitCount;
-
+
// This function sorts the map according to the score
// and returns the lower bound of the sorted container
DT& getLowerBound(){
@@ -330,15 +331,15 @@
return (*copyMap.begin()).second;
}
};
-
+
/**
* \class EvictLRU
* \ingroup EvictionPolicyCachedFactoryGroup
* \brief Evicts least accessed objects first.
- *
+ *
* Implementation of the Least recent used algorithm as
* described in http://en.wikipedia.org/wiki/Page_replacement_algorithms .
- *
+ *
* WARNING : If an object is heavily fetched
* (more than ULONG_MAX = UINT_MAX = 4294967295U)
* it could unfortunately be removed from the cache.
@@ -353,20 +354,20 @@
private:
typedef EvictionHelper< ST , DT > EH;
protected:
-
+
virtual ~EvictLRU(){}
-
+
// OnStore initialize the counter for the new key
// If the key already exists, the counter is reseted
void onCreate(const DT& key)
{
EH::m_mHitCount[key] = 0;
}
-
+
void onFetch(const DT&)
{
}
-
+
// onRelease increments the hit counter associated with the object
void onRelease(const DT& key)
{
@@ -377,7 +378,7 @@
{
EH::m_mHitCount.erase(key);
}
-
+
// this function is implemented in Cache and redirected
// to the Storage Policy
virtual void remove(DT const key)=0;
@@ -389,15 +390,15 @@
}
const char* name(){return "LRU";}
};
-
+
/**
* \class EvictAging
* \ingroup EvictionPolicyCachedFactoryGroup
* \brief LRU aware of the time span of use
- *
+ *
* Implementation of the Aging algorithm as
* described in http://en.wikipedia.org/wiki/Page_replacement_algorithms .
- *
+ *
* This method is much more costly than evict LRU so
* if you need extreme performance consider switching to EvictLRU
*/
@@ -414,7 +415,7 @@
typedef EvictionHelper< ST, DT > EH;
typedef typename EH::HitMap HitMap;
typedef typename EH::HitMapItr HitMapItr;
-
+
// update the counter
template<class T> struct updateCounter : public std::unary_function<T, void>
{
@@ -432,15 +433,15 @@
protected:
EvictAging(){}
virtual ~EvictAging(){}
-
+
// OnStore initialize the counter for the new key
// If the key already exists, the counter is reseted
void onCreate(const DT& key){
EH::m_mHitCount[key] = 0;
}
-
+
void onFetch(const DT&){}
-
+
// onRelease increments the hit counter associated with the object
// Updating every counters by iterating over the map
// If the key is the key of the fetched object :
@@ -451,7 +452,7 @@
{
std::for_each(EH::m_mHitCount.begin(), EH::m_mHitCount.end(), updateCounter< typename HitMap::value_type >(key));
}
-
+
void onDestroy(const DT& key)
{
EH::m_mHitCount.erase(key);
@@ -468,12 +469,12 @@
}
const char* name(){return "LRU with aging";}
};
-
+
/**
* \class EvictRandom
* \ingroup EvictionPolicyCachedFactoryGroup
* \brief Evicts a random object
- *
+ *
* Implementation of the Random algorithm as
* described in http://en.wikipedia.org/wiki/Page_replacement_algorithms .
*/
@@ -490,24 +491,24 @@
typedef typename std::vector< DT >::iterator iterator;
protected:
-
+
virtual ~EvictRandom(){}
-
+
void onCreate(const DT&){
}
-
+
void onFetch(const DT& ){
}
void onRelease(const DT& key){
m_vKeys.push_back(key);
}
-
+
void onDestroy(const DT& key){
using namespace std;
m_vKeys.erase(remove_if(m_vKeys.begin(), m_vKeys.end(), bind2nd(equal_to< DT >(), key)), m_vKeys.end());
}
-
+
// Implemented in Cache and redirected to the Storage Policy
virtual void remove(DT const key)=0;
@@ -526,7 +527,7 @@
* \defgroup StatisticPolicyCachedFactoryGroup Statistic policies
* \ingroup CachedFactoryGroup
* \brief Gathers information about the cache.
- *
+ *
* For debugging purpose this policy proposes to gather informations
* about the cache. This could be useful to determine whether the cache is
* mandatory or if the policies are well suited to the application.
@@ -536,7 +537,7 @@
* \ingroup StatisticPolicyCachedFactoryGroup
* \brief Do nothing
*
- * Should be used in release code for better performances
+ * Should be used in release code for better performances
*/
class NoStatisticPolicy
{
@@ -548,7 +549,7 @@
void onDestroy(){}
const char* name(){return "no";}
};
-
+
/**
* \class SimpleStatisticPolicy
* \ingroup StatisticPolicyCachedFactoryGroup
@@ -572,7 +573,7 @@
SimpleStatisticPolicy() : allocated(0), created(0), hit(0), out(0), fetched(0)
{
}
-
+
void onDebug()
{
using namespace std;
@@ -592,7 +593,7 @@
}
cout << endl;
}
-
+
void onFetch()
{
++fetched;
@@ -623,8 +624,8 @@
unsigned getAllocated(){return allocated;}
unsigned getOut(){return out;}
unsigned getDestroyed(){return created-allocated;}
- };
-
+ };
+
///////////////////////////////////////////////////////////////////////////
// Cache Factory definition
///////////////////////////////////////////////////////////////////////////
@@ -633,16 +634,16 @@
public:
const char* what() const throw() { return "Internal Cache Error"; }
};
-
+
/**
* \class CachedFactory
* \ingroup CachedFactoryGroup
* \brief Factory with caching support
- *
+ *
* This class acts as a Factory (it creates objects)
* but also keeps the already created objects to prevent
* long constructions time.
- *
+ *
* Note this implementation do not retain ownership.
*/
template
@@ -657,7 +658,7 @@
template<typename, class> class FactoryErrorPolicy = DefaultFactoryError,
class ObjVector = std::vector<AbstractProduct*>
>
- class CachedFactory :
+ class CachedFactory :
protected EncapsulationPolicy<AbstractProduct>,
public CreationPolicy, public StatisticPolicy, EvictionPolicy< AbstractProduct * , unsigned >
{
@@ -669,7 +670,7 @@
typedef CreationPolicy CP;
typedef StatisticPolicy SP;
typedef EvictionPolicy< AbstractProduct* , unsigned > EP;
-
+
typedef typename Impl::Parm1 Parm1;
typedef typename Impl::Parm2 Parm2;
typedef typename Impl::Parm3 Parm3;
@@ -685,14 +686,14 @@
typedef typename Impl::Parm13 Parm13;
typedef typename Impl::Parm14 Parm14;
typedef typename Impl::Parm15 Parm15;
-
+
public:
typedef typename NP::ProductReturn ProductReturn;
private:
typedef Key< Impl, IdentifierType > MyKey;
typedef std::map< MyKey, ObjVector > KeyToObjVectorMap;
typedef std::map< AbstractProduct*, MyKey > FetchedObjToKeyMap;
-
+
MyFactory factory;
KeyToObjVectorMap fromKeyToObjVector;
FetchedObjToKeyMap providedObjects;
@@ -702,7 +703,7 @@
return fromKeyToObjVector[key];
}
- AbstractProduct* const getPointerToObjectInContainer(ObjVector &entry)
+ AbstractProduct* getPointerToObjectInContainer(ObjVector &entry)
{
if(entry.empty()) // No object available
{ // the object will be created in the calling function.
@@ -718,7 +719,7 @@
return pObject;
}
}
-
+
bool shouldCreateObject(AbstractProduct * const pProduct){
if(pProduct!=NULL) // object already exists
return false;
@@ -726,40 +727,40 @@
EP::evict(); // calling Eviction Policy to clean up
return true;
}
-
+
void ReleaseObjectFromContainer(ObjVector &entry, AbstractProduct * const object)
{
entry.push_back(object);
}
-
+
void onFetch(AbstractProduct * const pProduct)
{
SP::onFetch();
EP::onFetch(pProduct);
++outObjects;
}
-
+
void onRelease(AbstractProduct * const pProduct)
{
SP::onRelease();
EP::onRelease(pProduct);
--outObjects;
}
-
+
void onCreate(AbstractProduct * const pProduct)
{
CP::onCreate();
SP::onCreate();
EP::onCreate(pProduct);
}
-
+
void onDestroy(AbstractProduct * const pProduct)
{
CP::onDestroy();
SP::onDestroy();
EP::onDestroy(pProduct);
}
-
+
// delete the object
template<class T> struct deleteObject : public std::unary_function<T, void>
{
@@ -779,7 +780,7 @@
template<class T> struct deleteMapKeys : public std::unary_function<T, void>
{
void operator()(T x){ delete x.first; }
- };
+ };
protected:
virtual void remove(AbstractProduct * const pProduct)
@@ -834,23 +835,23 @@
);
}
}
-
+
///////////////////////////////////
// Acts as the proxy pattern and //
// forwards factory methods //
///////////////////////////////////
-
+
bool Register(const IdentifierType& id, ProductCreator creator)
{
return factory.Register(id, creator);
}
-
+
template <class PtrObj, typename CreaFn>
bool Register(const IdentifierType& id, const PtrObj& p, CreaFn fn)
{
return factory.Register(id, p, fn);
}
-
+
bool Unregister(const IdentifierType& id)
{
return factory.Unregister(id);
@@ -875,7 +876,7 @@
providedObjects[pProduct] = key;
return NP::encapsulate(pProduct);
}
-
+
ProductReturn CreateObject(const IdentifierType& id,
Parm1 p1)
{
@@ -1020,7 +1021,7 @@
providedObjects[pProduct] = key;
return NP::encapsulate(pProduct);
}
-
+
ProductReturn CreateObject(const IdentifierType& id,
Parm1 p1, Parm2 p2, Parm3 p3, Parm4 p4, Parm5 p5,
Parm6 p6, Parm7 p7, Parm8 p8, Parm9 p9,Parm10 p10)
@@ -1147,7 +1148,7 @@
ReleaseObjectFromContainer(getContainerFromKey((*itr).second), pProduct);
providedObjects.erase(itr);
}
-
+
/// display the cache configuration
void displayCacheType()
{
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