eformat::PagedMemory< TMAXPAGES > Class Template Reference

#include <PagedMemory.h>

Classes
class	const_iterator
struct	node_t

Public Types
typedef struct eformat::PagedMemory::node_t	node_t

Public Member Functions
	PagedMemory (const struct iovec *pages, size_t count)
const struct iovec *	pages (void) const
size_t	count (void) const
size_t	size (void) const
const_iterator	begin (void) const
const_iterator	end (void) const

Static Public Attributes
static const unsigned int	MAXPAGES = TMAXPAGES

Detailed Description

template<unsigned int TMAXPAGES = 128>
class eformat::PagedMemory< TMAXPAGES >

A list of nodes. To gain speed, the PagedMemory uses an internal page index. The default maximum size of this index is 128. The user can instanciate bigger PagedMemory objects by increasing the default template parameter size to a more suitable value.

@warn Attention: PagedMemory's with different index sizes cannot interact directly.

Definition at line 39 of file PagedMemory.h.

Member Typedef Documentation

node_t

template<unsigned int TMAXPAGES = 128>

typedef struct eformat::PagedMemory::node_t eformat::PagedMemory< TMAXPAGES >::node_t

Define a private type that is used to index the access to this type of eformat::Memory. The performance of this iterator is dependent on the distance from the current offset and on the page sizes. Try to use the iterator for small scale reach and readjust if necessary.

Constructor & Destructor Documentation

PagedMemory()

template<unsigned int TMAXPAGES>

eformat::PagedMemory< TMAXPAGES >::PagedMemory	(	const struct iovec *	pages,
		size_t	count
	)

Simpler constructor: starts from an existing set of base addresses and sizes. Please note that for reasons of simplicity, the data in all memory blocks have to be 32-bit aligned. Otherwise, the implementation should be DC::Buffer, where this has all been thought about.

Also note that this class is intended for reading data and optimized for such. If you just want to manipulate fragments you are better doing it your self or using the writing part of the library.

Parameters

pages	The memory area I would like to read data from
count	The number of pages pointed by the variable pages. This has to be smaller than TMAXPAGES.

Definition at line 274 of file PagedMemory.h.

  : m_iovec(pages),
    m_count(count),
    m_size(0)
{
  if (m_count > MAXPAGES) {
    //Problem, I cannot index this amount of data
    throw EFORMAT_TOO_BIG_COUNT(count, MAXPAGES);
  }
  for (size_t i=0; i<count; ++i) {
    m_node[i].page = &pages[i];
    if (pages[i].iov_len % 4 != 0) {
      //Problem, one of the data blocks is *not* 32-bit aligned
      throw EFORMAT_NOT_ALIGNED(pages[i].iov_base, pages[i].iov_len);
    }
    m_node[i].start = m_size;
    m_size += pages[i].iov_len >> 2;
    m_node[i].end = m_size;
    if (i > 0) m_node[i].previous = &m_node[i-1];
    else m_node[i].previous = 0;
    if (i < (count-1) ) m_node[i].next = &m_node[i+1];
    else m_node[i].next = 0;
  }
}

Member Function Documentation

begin()

template<unsigned int TMAXPAGES = 128>

const_iterator eformat::PagedMemory< TMAXPAGES >::begin ( void  ) const

inline

Returns a const iterator to the begin of this list

Parameters

it	An updateable iterator you should provide.

Definition at line 249 of file PagedMemory.h.

    { return const_iterator(m_node, 0); }

Referenced by main().

count()

template<unsigned int TMAXPAGES = 128>

size_t eformat::PagedMemory< TMAXPAGES >::count ( void  ) const

inline

Returns the number of blocks in this IO vector

Definition at line 71 of file PagedMemory.h.

{ return m_count; }

Referenced by eformat::PagedMemory< TMAXPAGES >::PagedMemory().

end()

template<unsigned int TMAXPAGES = 128>

const_iterator eformat::PagedMemory< TMAXPAGES >::end ( void  ) const

inline

Returns a const iterator to the end of this list

Parameters

it	An updateable iterator you should provide.

Definition at line 257 of file PagedMemory.h.

    { return const_iterator(&m_node[m_count], m_size); }

pages()

template<unsigned int TMAXPAGES = 128>

const struct iovec * eformat::PagedMemory< TMAXPAGES >::pages ( void  ) const

inline

Returns the base address of the input IO vector

Definition at line 66 of file PagedMemory.h.

{ return m_iovec; }

Referenced by eformat::PagedMemory< TMAXPAGES >::PagedMemory().

size()

template<unsigned int TMAXPAGES = 128>

size_t eformat::PagedMemory< TMAXPAGES >::size ( void  ) const

inline

Returns the size in bytes words for this PagedMemory.

Definition at line 76 of file PagedMemory.h.

{ return m_size; }

Member Data Documentation

MAXPAGES

template<unsigned int TMAXPAGES>

const unsigned int eformat::PagedMemory< TMAXPAGES >::MAXPAGES = TMAXPAGES

static

Definition at line 43 of file PagedMemory.h.

Referenced by eformat::PagedMemory< TMAXPAGES >::PagedMemory().

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

• PagedMemory.h