OpenDDS::DCPS::WriterDataSampleList Class Reference

#include <WriterDataSampleList.h>

Collaboration diagram for OpenDDS::DCPS::WriterDataSampleList:

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List of all members.

Public Member Functions
	WriterDataSampleList ()
	Default constructor clears the list.
	~WriterDataSampleList ()
void	reset ()
	Reset to initial state.
ssize_t	size () const
DataSampleElement *	head () const
DataSampleElement *	tail () const
void	enqueue_tail (const DataSampleElement *element)
bool	dequeue_head (DataSampleElement *&stale)
bool	dequeue (const DataSampleElement *stale)
Protected Attributes
DataSampleElement *	head_
	The first element of the list.
DataSampleElement *	tail_
	The last element of the list.
ssize_t	size_
	Number of elements in the list.

---

Detailed Description

A list of DataSampleElement pointers to be queued by the order the samples are written to the DataWriter (within PRESENTATION.access_scope==TOPIC). Cache the number of elements in the list so that list traversal is not required to find this information. Manages DataSampleElement's previous_writer_sample/next_writer_sample pointers

Definition at line 28 of file WriterDataSampleList.h.

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Constructor & Destructor Documentation

ACE_INLINE OpenDDS::DCPS::WriterDataSampleList::WriterDataSampleList

(

)

Default constructor clears the list.

Definition at line 17 of file WriterDataSampleList.inl.

  : head_(0),
    tail_(0),
    size_(0)
{
}

OpenDDS::DCPS::WriterDataSampleList::~WriterDataSampleList

(

)

[inline]

Definition at line 34 of file WriterDataSampleList.h.

{}

---

Member Function Documentation

bool OpenDDS::DCPS::WriterDataSampleList::dequeue

(

const DataSampleElement *

stale

)

Definition at line 22 of file WriterDataSampleList.cpp.

References dequeue_head(), head(), head_, item(), OpenDDS::DCPS::DataSampleElement::next_writer_sample_, OpenDDS::DCPS::DataSampleElement::previous_writer_sample_, size_, and tail_.

Referenced by OpenDDS::DCPS::WriteDataContainer::release_buffer().

{
  if (head_ == 0) {
    return false;
  }

  if (stale == head_) {
    DataSampleElement* head = head_;
    return dequeue_head(head);
  }

  // Search from head_->next_writer_sample_.
  bool found = false;

  for (DataSampleElement* item = head_->next_writer_sample_ ;
       item != 0 ;
       item = item->next_writer_sample_) {
    if (item == stale) {
      found = true;
      break;
    }
  }

  if (found) {
    // Adjust list size.
    -- size_ ;

    //
    // Remove from the previous element.
    //
    if (stale->previous_writer_sample_ != 0) {
      // Remove from inside of the list.
      stale->previous_writer_sample_->next_writer_sample_ = stale->next_writer_sample_ ;

    } else {
      // Remove from the head of the list.
      head_ = stale->next_writer_sample_ ;

      if (head_ != 0) {
        head_->previous_writer_sample_ = 0;
      }
    }

    //
    // Remove from the next element.
    //
    if (stale->next_writer_sample_ != 0) {
      // Remove the inside of the list.
      stale->next_writer_sample_->previous_writer_sample_ = stale->previous_writer_sample_ ;

    } else {
      // Remove from the tail of the list.
      tail_ = stale->previous_writer_sample_ ;
    }

    stale->next_writer_sample_ = 0;
    stale->previous_writer_sample_ = 0;
  }

  return found;
}

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ACE_INLINE bool OpenDDS::DCPS::WriterDataSampleList::dequeue_head

(

DataSampleElement *&

stale

)

Definition at line 80 of file WriterDataSampleList.inl.

References head_, OpenDDS::DCPS::DataSampleElement::next_writer_sample_, OpenDDS::DCPS::DataSampleElement::previous_writer_sample_, size_, and tail_.

Referenced by dequeue().

{
  //
  // Remove the oldest sample from the list.
  //
  stale = head_;

  if (head_ == 0) {
    return false;

  } else {
    --size_ ;
    head_ = head_->next_writer_sample_;

    if (head_ == 0) {
      tail_ = 0;

    } else {
      head_->previous_writer_sample_ = 0;
    }

    stale->next_writer_sample_ = 0;
    stale->previous_writer_sample_ = 0;
    return true;
  }
}

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ACE_INLINE void OpenDDS::DCPS::WriterDataSampleList::enqueue_tail

(

const DataSampleElement *

element

)

Definition at line 54 of file WriterDataSampleList.inl.

References head_, OpenDDS::DCPS::DataSampleElement::next_writer_sample_, OpenDDS::DCPS::DataSampleElement::previous_writer_sample_, size_, and tail_.

Referenced by OpenDDS::DCPS::WriteDataContainer::obtain_buffer().

{
  // const_cast here so that higher layers don't need to pass around so many
  // non-const pointers to DataSampleElement.  Ideally the design would be
  // changed to accommodate const-correctness throughout.
  DataSampleElement* mSample = const_cast<DataSampleElement*>(sample);

  //sample->previous_writer_sample_ = 0;
  //sample->next_writer_sample_ = 0;

  ++size_ ;

  if (head_ == 0) {
    // First sample in the list.
    head_ = tail_ = mSample ;

  } else {
    // Add to existing list.
    tail_->next_writer_sample_ = mSample ;
    mSample->previous_writer_sample_ = tail_;
    tail_ = mSample;
  }
}

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ACE_INLINE DataSampleElement * OpenDDS::DCPS::WriterDataSampleList::head

(

void

)

const

Definition at line 40 of file WriterDataSampleList.inl.

References head_.

Referenced by dequeue().

{
  return head_;
}

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ACE_INLINE void OpenDDS::DCPS::WriterDataSampleList::reset

(

void

)

Reset to initial state.

Definition at line 25 of file WriterDataSampleList.inl.

References head_, size_, and tail_.

{
  head_ = tail_ = 0;
  size_ = 0;
}

ACE_INLINE ssize_t OpenDDS::DCPS::WriterDataSampleList::size

(

void

)

const

Definition at line 33 of file WriterDataSampleList.inl.

References size_.

{
  return size_;
}

ACE_INLINE DataSampleElement * OpenDDS::DCPS::WriterDataSampleList::tail

(

void

)

const

Definition at line 47 of file WriterDataSampleList.inl.

References tail_.

{
  return tail_;
}

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Member Data Documentation

DataSampleElement* OpenDDS::DCPS::WriterDataSampleList::head_ [protected]

The first element of the list.

Definition at line 52 of file WriterDataSampleList.h.

Referenced by dequeue(), dequeue_head(), enqueue_tail(), head(), and reset().

ssize_t OpenDDS::DCPS::WriterDataSampleList::size_ [protected]

Number of elements in the list.

Definition at line 58 of file WriterDataSampleList.h.

Referenced by dequeue(), dequeue_head(), enqueue_tail(), reset(), and size().

DataSampleElement* OpenDDS::DCPS::WriterDataSampleList::tail_ [protected]

The last element of the list.

Definition at line 55 of file WriterDataSampleList.h.

Referenced by dequeue(), dequeue_head(), enqueue_tail(), reset(), and tail().

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The documentation for this class was generated from the following files:

• WriterDataSampleList.h
• WriterDataSampleList.cpp
• WriterDataSampleList.inl