The PageArena allocator is simple and fast, avoiding individual mallocs/frees. More...

#include <PageArena.h>

Inheritance diagram for Hypertable::PageArena< CharT, PageAllocatorT >:

Collaboration diagram for Hypertable::PageArena< CharT, PageAllocatorT >:

Classes
struct	LtPageRemain
	predicate which sorts by size More...

struct	Page
	A structure to manage a single memory page which is used to allocate smaller memory chunks. More...

struct	TinyBuffer
	A small buffer (128 bytes) to satisfy very small memory allocations without allocating a page from the heap. More...

Public Member Functions
	PageArena (size_t page_size=DEFAULT_PAGE_SIZE, const PageAllocatorT &alloc=PageAllocatorT())
	Constructor; creates a new PageArena. More...

	~PageArena ()
	Destructor releases the whole memory and invalidates all allocated objects. More...

size_t	page_size ()
	Returns the page size. More...

void	set_page_size (size_t sz)
	Sets the page size. More...

CharT *	alloc (size_t sz)
	Allocate sz bytes. More...

CharT *	realloc (void *p, size_t oldsz, size_t newsz)
	Realloc for newsz bytes. More...

CharT *	dup (const CharT *s)
	Duplicate a null terminated string; memory is allocated from the pool. More...

CharT *	dup (const std::string &s)
	Duplicate a std::string; memory is allocated from the pool. More...

CharT *	dup (const void *s, size_t len)
	Duplicate a buffer of size len; memory is allocated from the pool. More...

void	free ()
	Free the whole arena. More...

void	swap (Self &other)
	Efficiently swaps the state with another allocator. More...

std::ostream &	dump_stat (std::ostream &out) const
	Write allocator statistics to output stream. More...

size_t	used () const
	Statistic accessors - returns used bytes. More...

size_t	pages () const
	Statistic accessors - returns number of allocated pages. More...

size_t	total () const
	Statistic accessors - returns total allocated size. More...

Private Types
enum	{ DEFAULT_PAGE_SIZE = 8192 }
	The default page size is 8 kb. More...

typedef PageArena< CharT, PageAllocatorT >	Self

typedef std::set< Page *, LtPageRemain >	GappyPages
	a list of pages with gaps, sorted by gap size More...

Private Member Functions
Page *	alloc_page (size_t sz, bool prepend=true)
	Allocates a page of size sz. More...

void	ensure_cur_page ()

bool	is_normal_overflow (size_t sz)

CharT *	alloc_big (size_t sz)

Private Attributes
Page *	m_cur_page

size_t	m_used

size_t	m_page_limit
	total number of bytes allocated by users More...

size_t	m_page_size
	capacity in bytes of an empty page More...

size_t	m_pages
	page size in number of bytes More...

size_t	m_total
	number of pages allocated More...

PageAllocatorT	m_page_allocator
	total number of bytes occupied by pages More...

GappyPages	m_gappy_pages

size_t	m_gappy_limit

struct Hypertable::PageArena::TinyBuffer	m_tinybuf

Detailed Description

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>
class Hypertable::PageArena< CharT, PageAllocatorT >

The PageArena allocator is simple and fast, avoiding individual mallocs/frees.

Good for usage patterns that just load, use and free the entire container repeatedly.

Definition at line 69 of file PageArena.h.

Member Typedef Documentation

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

typedef std::set<Page*, LtPageRemain> Hypertable::PageArena< CharT, PageAllocatorT >::GappyPages

private

a list of pages with gaps, sorted by gap size

Definition at line 120 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

typedef PageArena<CharT, PageAllocatorT> Hypertable::PageArena< CharT, PageAllocatorT >::Self

private

Definition at line 76 of file PageArena.h.

Constructor & Destructor Documentation

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

Hypertable::PageArena< CharT, PageAllocatorT >::PageArena	(	size_t	page_size = `DEFAULT_PAGE_SIZE`,
		const PageAllocatorT &	alloc = `PageAllocatorT()`
	)

inline

Constructor; creates a new PageArena.

Parameters

page_size	Size (in bytes) of the allocated pages
alloc	The allocator for the pages

Definition at line 189 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

Hypertable::PageArena< CharT, PageAllocatorT >::~PageArena ( )

inline

Destructor releases the whole memory and invalidates all allocated objects.

Definition at line 200 of file PageArena.h.

Member Function Documentation

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

CharT* Hypertable::PageArena< CharT, PageAllocatorT >::alloc ( size_t sz )

inline

Allocate sz bytes.

Definition at line 216 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

CharT* Hypertable::PageArena< CharT, PageAllocatorT >::alloc_big ( size_t sz )

inlineprivate

Definition at line 177 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

Page* Hypertable::PageArena< CharT, PageAllocatorT >::alloc_page	(	size_t	sz,
		bool	prepend = `true`
	)

inlineprivate

Allocates a page of size sz.

Definition at line 145 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

std::ostream& Hypertable::PageArena< CharT, PageAllocatorT >::dump_stat ( std::ostream & out ) const

inline

Write allocator statistics to output stream.

Parameters

out	Output stream

Returns: Output stream

Definition at line 344 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

CharT* Hypertable::PageArena< CharT, PageAllocatorT >::dup ( const CharT * s )

inline

Duplicate a null terminated string; memory is allocated from the pool.

Parameters

s	The original string which is duplicated

Returns: The new string, or NULL if the original string also pointed to NULL

Definition at line 274 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

CharT* Hypertable::PageArena< CharT, PageAllocatorT >::dup ( const std::string & s )

inline

Duplicate a std::string; memory is allocated from the pool.

Parameters

s	The original string which is duplicated

Returns: The new string

Definition at line 289 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

CharT* Hypertable::PageArena< CharT, PageAllocatorT >::dup	(	const void *	s,
		size_t	len
	)

inline

Duplicate a buffer of size len; memory is allocated from the pool.

Parameters

s	Pointer to the buffer
len	Size of the buffer

Returns: A duplicate of the buffer, or NULL if s also pointed to NULL

Definition at line 299 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

void Hypertable::PageArena< CharT, PageAllocatorT >::ensure_cur_page ( )

inlineprivate

Definition at line 166 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

void Hypertable::PageArena< CharT, PageAllocatorT >::free ( )

inline

Free the whole arena.

This releases the total memory allocated by the arena and invalidates all pointers that were previously allocated. This is implicitely called in the destructor.

Definition at line 312 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

bool Hypertable::PageArena< CharT, PageAllocatorT >::is_normal_overflow ( size_t sz )

inlineprivate

Definition at line 173 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::page_size ( )

inline

Returns the page size.

Definition at line 205 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::pages ( ) const

inline

Statistic accessors - returns number of allocated pages.

Definition at line 354 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

CharT* Hypertable::PageArena< CharT, PageAllocatorT >::realloc	(	void *	p,
		size_t	oldsz,
		size_t	newsz
	)

inline

Realloc for newsz bytes.

Definition at line 255 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

void Hypertable::PageArena< CharT, PageAllocatorT >::set_page_size ( size_t sz )

inline

Sets the page size.

Definition at line 210 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

void Hypertable::PageArena< CharT, PageAllocatorT >::swap ( Self & other )

inline

Efficiently swaps the state with another allocator.

Definition at line 329 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::total ( ) const

inline

Statistic accessors - returns total allocated size.

Definition at line 357 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::used ( ) const

inline

Statistic accessors - returns used bytes.

Definition at line 351 of file PageArena.h.

Member Data Documentation

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

Page* Hypertable::PageArena< CharT, PageAllocatorT >::m_cur_page

private

Definition at line 104 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::m_gappy_limit

private

Definition at line 123 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

GappyPages Hypertable::PageArena< CharT, PageAllocatorT >::m_gappy_pages

private

Definition at line 121 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

PageAllocatorT Hypertable::PageArena< CharT, PageAllocatorT >::m_page_allocator

private

total number of bytes occupied by pages

Definition at line 110 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::m_page_limit

private

total number of bytes allocated by users

Definition at line 106 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::m_page_size

private

capacity in bytes of an empty page

Definition at line 107 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::m_pages

private

page size in number of bytes

Definition at line 108 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

struct Hypertable::PageArena::TinyBuffer Hypertable::PageArena< CharT, PageAllocatorT >::m_tinybuf

private

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::m_total

private

number of pages allocated

Definition at line 109 of file PageArena.h.

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>

size_t Hypertable::PageArena< CharT, PageAllocatorT >::m_used

private

Definition at line 105 of file PageArena.h.

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

/home/doug/src/hypertable/src/cc/Common/PageArena.h

Classes

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Detailed Description

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator> class Hypertable::PageArena< CharT, PageAllocatorT >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<typename CharT = char, class PageAllocatorT = DefaultPageAllocator>
class Hypertable::PageArena< CharT, PageAllocatorT >