Json::BatchAllocator< AllocatedType, objectPerAllocation > Class Template Reference

#include <json_batchallocator.h>

Classes
struct	BatchInfo

Public Types
typedef AllocatedType	Type

Public Member Functions
AllocatedType *	allocate ()
	BatchAllocator (unsigned int objectsPerPage=255)
void	release (AllocatedType *object)
	~BatchAllocator ()

Private Member Functions
	BatchAllocator (const BatchAllocator &)
void	operator= (const BatchAllocator &)

Static Private Member Functions
static BatchInfo *	allocateBatch (unsigned int objectsPerPage)

Private Attributes
BatchInfo *	batches_
BatchInfo *	currentBatch_
AllocatedType *	freeHead_
	Head of a single linked list within the allocated space of freeed object. More...
unsigned int	objectsPerPage_

Detailed Description

template<typename AllocatedType, const unsigned int objectPerAllocation>
class Json::BatchAllocator< AllocatedType, objectPerAllocation >

Definition at line 25 of file json_batchallocator.h.

Member Typedef Documentation

template<typename AllocatedType , const unsigned int objectPerAllocation>

typedef AllocatedType Json::BatchAllocator< AllocatedType, objectPerAllocation >::Type

Definition at line 28 of file json_batchallocator.h.

Constructor & Destructor Documentation

template<typename AllocatedType , const unsigned int objectPerAllocation>

Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchAllocator ( unsigned int  objectsPerPage = 255 )

inline

Definition at line 30 of file json_batchallocator.h.

References Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocateBatch(), Json::BatchAllocator< AllocatedType, objectPerAllocation >::batches_, and Json::BatchAllocator< AllocatedType, objectPerAllocation >::currentBatch_.

      : freeHead_( 0 )
      , objectsPerPage_( objectsPerPage )
   {
//      printf( "Size: %d => %s\n", sizeof(AllocatedType), typeid(AllocatedType).name() );
      assert( sizeof(AllocatedType) * objectPerAllocation >= sizeof(AllocatedType *) ); // We must be able to store a slist in the object free space.
      assert( objectsPerPage >= 16 );
      batches_ = allocateBatch( 0 );   // allocated a dummy page
      currentBatch_ = batches_;
   }

template<typename AllocatedType , const unsigned int objectPerAllocation>

Json::BatchAllocator< AllocatedType, objectPerAllocation >::~BatchAllocator ( )

inline

Definition at line 41 of file json_batchallocator.h.

References python.rootplot.core::batch, and Json::BatchAllocator< AllocatedType, objectPerAllocation >::batches_.

   {
      for ( BatchInfo *batch = batches_; batch;  )
      {
         BatchInfo *nextBatch = batch->next_;
         free( batch );
         batch = nextBatch;
      }
   }

template<typename AllocatedType , const unsigned int objectPerAllocation>

Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchAllocator ( const BatchAllocator< AllocatedType, objectPerAllocation > &  )

private

Member Function Documentation

template<typename AllocatedType , const unsigned int objectPerAllocation>

AllocatedType* Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocate ( )

inline

allocate space for an array of objectPerAllocation object.

Warning

it is the responsability of the caller to call objects constructors.

Definition at line 53 of file json_batchallocator.h.

References Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocateBatch(), Json::BatchAllocator< AllocatedType, objectPerAllocation >::batches_, Json::BatchAllocator< AllocatedType, objectPerAllocation >::currentBatch_, Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchInfo::end_, Json::BatchAllocator< AllocatedType, objectPerAllocation >::freeHead_, Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchInfo::next_, dbtoconf::object, Json::BatchAllocator< AllocatedType, objectPerAllocation >::objectsPerPage_, and Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchInfo::used_.

   {
      if ( freeHead_ ) // returns node from free list.
      {
         AllocatedType *object = freeHead_;
         freeHead_ = *(AllocatedType **)object;
         return object;
      }
      if ( currentBatch_->used_ == currentBatch_->end_ )
      {
         currentBatch_ = currentBatch_->next_;
         while ( currentBatch_  &&  currentBatch_->used_ == currentBatch_->end_ )
            currentBatch_ = currentBatch_->next_;

         if ( !currentBatch_  ) // no free batch found, allocate a new one
         { 
            currentBatch_ = allocateBatch( objectsPerPage_ );
            currentBatch_->next_ = batches_; // insert at the head of the list
            batches_ = currentBatch_;
         }
      }
      AllocatedType *allocated = currentBatch_->used_;
      currentBatch_->used_ += objectPerAllocation;
      return allocated;
   }

template<typename AllocatedType , const unsigned int objectPerAllocation>

static BatchInfo* Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocateBatch ( unsigned int  objectsPerPage )

inlinestaticprivate

Definition at line 101 of file json_batchallocator.h.

References python.rootplot.core::batch, Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchInfo::next_, and Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchInfo::used_.

Referenced by Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocate(), and Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchAllocator().

   {
      const unsigned int mallocSize = sizeof(BatchInfo) - sizeof(AllocatedType)* objectPerAllocation
                                + sizeof(AllocatedType) * objectPerAllocation * objectsPerPage;
      BatchInfo *batch = static_cast<BatchInfo*>( malloc( mallocSize ) );
      batch->next_ = 0;
      batch->used_ = batch->buffer_;
      batch->end_ = batch->buffer_ + objectsPerPage;
      return batch;
   }

template<typename AllocatedType , const unsigned int objectPerAllocation>

void Json::BatchAllocator< AllocatedType, objectPerAllocation >::operator= ( const BatchAllocator< AllocatedType, objectPerAllocation > &  )

private

template<typename AllocatedType , const unsigned int objectPerAllocation>

void Json::BatchAllocator< AllocatedType, objectPerAllocation >::release ( AllocatedType *  object )

inline

Release the object.

Warning

it is the responsability of the caller to actually destruct the object.

Definition at line 81 of file json_batchallocator.h.

References Json::BatchAllocator< AllocatedType, objectPerAllocation >::freeHead_, and dbtoconf::object.

Referenced by cuy.ValElement::__init__().

   {
      assert( object != 0 );
      *(AllocatedType **)object = freeHead_;
      freeHead_ = object;
   }

Member Data Documentation

template<typename AllocatedType , const unsigned int objectPerAllocation>

BatchInfo* Json::BatchAllocator< AllocatedType, objectPerAllocation >::batches_

private

Definition at line 112 of file json_batchallocator.h.

Referenced by Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocate(), Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchAllocator(), and Json::BatchAllocator< AllocatedType, objectPerAllocation >::~BatchAllocator().

template<typename AllocatedType , const unsigned int objectPerAllocation>

BatchInfo* Json::BatchAllocator< AllocatedType, objectPerAllocation >::currentBatch_

private

Definition at line 113 of file json_batchallocator.h.

Referenced by Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocate(), and Json::BatchAllocator< AllocatedType, objectPerAllocation >::BatchAllocator().

template<typename AllocatedType , const unsigned int objectPerAllocation>

AllocatedType* Json::BatchAllocator< AllocatedType, objectPerAllocation >::freeHead_

private

Head of a single linked list within the allocated space of freeed object.

Definition at line 115 of file json_batchallocator.h.

Referenced by Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocate(), and Json::BatchAllocator< AllocatedType, objectPerAllocation >::release().

template<typename AllocatedType , const unsigned int objectPerAllocation>

unsigned int Json::BatchAllocator< AllocatedType, objectPerAllocation >::objectsPerPage_

private

Definition at line 116 of file json_batchallocator.h.

Referenced by Json::BatchAllocator< AllocatedType, objectPerAllocation >::allocate().