Manages the cell cache of an access group. More...

#include <CellCacheManager.h>

Public Member Functions
	CellCacheManager ()
	Constructor. More...

virtual	~CellCacheManager ()
	Destructor. More...

void	install_new_active_cache (CellCachePtr new_cache)
	Installs a new active cache. More...

void	install_new_immutable_cache (CellCachePtr new_cache)
	Installs a new immutable cache. More...

void	merge_caches (SchemaPtr &schema)
	Merges immutable cache into active cache. More...

void	add (const Key &key, const ByteString value)
	Inserts a key/value pair to the active cache. More...

void	add_counter (const Key &key, const ByteString value)
	Inserts a key/value pair for a counter column into the active cache. More...

void	add (CellListScannerPtr &scanner)
	Inserts key/value pairs from a scanner into the active cache. More...

void	add_immutable_scanner (MergeScannerAccessGroup mscanner, ScanContext scan_ctx)
	Creates a scanner on the immutable cache and adds it to a merge scanner. More...

void	add_scanners (MergeScannerAccessGroup scanner, ScanContext scan_ctx)
	Creates scanners on the active and immutable caches and adds them to a merge scanner. More...

void	split_row_estimate_data (CellList::SplitRowDataMapT &split_row_data)
	Populates map of split row data. More...

CellListScannerPtr	create_immutable_scanner (ScanContext *scan_ctx)
	Creates and returns a scanner on the immutable cache. More...

void	lock ()
	Locks the active cache. More...

void	unlock ()
	Unlocks the active cache. More...

CellCachePtr &	active_cache ()
	Returns a pointer to the active cache. More...

CellCachePtr &	immutable_cache ()
	Returns a pointer to the immutable cache. More...

void	drop_immutable_cache ()
	Drops the immutable cache. More...

size_t	immutable_items ()
	Returns the number of cells in the immutable cache. More...

bool	empty ()
	Checks if active and immutable caches are empty. More...

bool	immutable_cache_empty ()
	Checks if immutable cache is not installed or is empty. More...

int64_t	memory_used ()
	Returns the amount of memory used by the active and immutable caches. More...

int64_t	logical_size ()
	Returns the logical amount of memory used by the active and immutable caches. More...

void	get_cache_statistics (CellCache::Statistics &stats)
	Gets cache statistics. More...

int32_t	delete_count ()
	Returns the number of deletes present in the caches. More...

void	freeze ()
	Freezes the active cache. More...

void	populate_key_set (KeySet &keys)
	Populates a set with all keys in the cell caches. More...

Private Attributes
CellCachePtr	m_active_cache
	Active cache. More...

CellCachePtr	m_immutable_cache
	Immutable cache. More...

Detailed Description

Manages the cell cache of an access group.

When an access group undergoes a compaction, the cell cache needs to be frozen (i.e. made immutable) before it is written out to a cell store file. This class manages this process by maintaining two caches, an active cache that receives inserts, and an immutable cache, created when the active cache is frozen in preparation for a compaction. It provides member functions for freezing the active cache to the immutable cache, dropping the immutable cache when it is no longer needed, and merging the two caches back together if a compaction was aborted.

Definition at line 54 of file CellCacheManager.h.

Constructor & Destructor Documentation

Hypertable::CellCacheManager::CellCacheManager ( )

inline

Constructor.

Initializes m_active_cache with a newly allocated CellCache

Definition at line 60 of file CellCacheManager.h.

virtual Hypertable::CellCacheManager::~CellCacheManager ( )

inlinevirtual

Destructor.

Definition at line 63 of file CellCacheManager.h.

Member Function Documentation

CellCachePtr& Hypertable::CellCacheManager::active_cache ( )

inline

Returns a pointer to the active cache.

Returns: Pointer to the active cache.

Definition at line 153 of file CellCacheManager.h.

void Hypertable::CellCacheManager::add	(	const Key &	key,
		const ByteString	value
	)

inline

Inserts a key/value pair to the active cache.

Adds key and value directly into m_active_cache.

Note: lock() must be called before calling this function.

Parameters

key	key to be inserted
value	value to inserted

Definition at line 88 of file CellCacheManager.h.

void CellCacheManager::add ( CellListScannerPtr & scanner )

Inserts key/value pairs from a scanner into the active cache.

This method retrieves all key/value pairs from scanner and inserts them into the active cache.

Parameters

scanner Scanner from which to fetch key/value pairs

Definition at line 75 of file CellCacheManager.cc.

void Hypertable::CellCacheManager::add_counter	(	const Key &	key,
		const ByteString	value
	)

inline

Inserts a key/value pair for a counter column into the active cache.

Adds key and value directly into m_active_cache.

Note: lock() must be called before calling this function.

Parameters

key	key to be inserted
value	value to inserted

Definition at line 98 of file CellCacheManager.h.

void CellCacheManager::add_immutable_scanner	(	MergeScannerAccessGroup *	mscanner,
		ScanContext *	scan_ctx
	)

Creates a scanner on the immutable cache and adds it to a merge scanner.

If an immutable cache is installed, a scanner is created on it and added to mscanner.

Parameters

mscanner	Merge scanner to which immutable cache scanner should be added
scan_ctx	Scan context for initializing immutable cache scanner

Definition at line 84 of file CellCacheManager.cc.

void CellCacheManager::add_scanners	(	MergeScannerAccessGroup *	scanner,
		ScanContext *	scan_ctx
	)

Creates scanners on the active and immutable caches and adds them to a merge scanner.

If the active cache is not empty, a scanner is created on it and added to scanner. If an immutable cache is installed, a scanner is created on it and added to scanner as well.

Parameters

scanner	Merge scanner to which immutable cache scanner should be added
scan_context	Scan context for initializing scanners

Definition at line 90 of file CellCacheManager.cc.

CellListScannerPtr Hypertable::CellCacheManager::create_immutable_scanner ( ScanContext * scan_ctx )

inline

Creates and returns a scanner on the immutable cache.

If m_immutable_cache is not empty, then a scanner is created on it and returned, otherwise, 0 is returned.

Parameters

scan_ctx Scan context for initializing immutable cache scanner

Returns: Newly created scanner on the immutable cache, or 0 if an immutable cache is not installed.

Definition at line 140 of file CellCacheManager.h.

int32_t CellCacheManager::delete_count ( )

Returns the number of deletes present in the caches.

This function returns the sum of the delete counts from the active and immutable caches.

Returns: Number of deletes present in the caches.

Definition at line 122 of file CellCacheManager.cc.

void Hypertable::CellCacheManager::drop_immutable_cache ( )

inline

Drops the immutable cache.

Definition at line 164 of file CellCacheManager.h.

bool Hypertable::CellCacheManager::empty ( )

inline

Checks if active and immutable caches are empty.

Returns: true if active cache is empty and immutable cache is not installed or is empty, false otherwise.

Definition at line 175 of file CellCacheManager.h.

void CellCacheManager::freeze ( )

Freezes the active cache.

This function sets the immutable cache to the active cache and points the active cache to a newly allocated (empty) cache.

Definition at line 127 of file CellCacheManager.cc.

void CellCacheManager::get_cache_statistics ( CellCache::Statistics & stats )

Gets cache statistics.

This function computes the sum of the cache statistics from the active and immutable caches.

Parameters

stats Reference to cell cache statistics structure

Definition at line 116 of file CellCacheManager.cc.

CellCachePtr& Hypertable::CellCacheManager::immutable_cache ( )

inline

Returns a pointer to the immutable cache.

Returns a pointer to the immutable cache if it is installed, otherewise nullptr.

Returns: Pointer to the immutable cache.

Definition at line 159 of file CellCacheManager.h.

bool Hypertable::CellCacheManager::immutable_cache_empty ( )

inline

Checks if immutable cache is not installed or is empty.

Returns: true if immutable cache is not installed or is empty, false otherwise.

Definition at line 182 of file CellCacheManager.h.

size_t Hypertable::CellCacheManager::immutable_items ( )

inline

Returns the number of cells in the immutable cache.

Returns: Number of cells in the immutable cache.

Definition at line 168 of file CellCacheManager.h.

void Hypertable::CellCacheManager::install_new_active_cache ( CellCachePtr new_cache )

inline

Installs a new active cache.

This function replaces m_active_cache with new_cache.

Parameters

new_cache New active cache

Definition at line 68 of file CellCacheManager.h.

void Hypertable::CellCacheManager::install_new_immutable_cache ( CellCachePtr new_cache )

inline

Installs a new immutable cache.

This function replaces m_immutable_cache with new_cache.

Parameters

new_cache New immutable cache

Definition at line 75 of file CellCacheManager.h.

void Hypertable::CellCacheManager::lock ( )

inline

Locks the active cache.

Definition at line 146 of file CellCacheManager.h.

int64_t CellCacheManager::logical_size ( )

Returns the logical amount of memory used by the active and immutable caches.

This member function calls CellCache::logical_size() on the active and immutable caches and returns their sum.

Returns: Amount of logical memory used by the active and immutable caches

Definition at line 111 of file CellCacheManager.cc.

int64_t CellCacheManager::memory_used ( )

Returns the amount of memory used by the active and immutable caches.

This member function calls CellCache::memory_used() on the active and immutable caches and returns their sum.

Returns: Amount of memory used by the active and immutable caches.

Definition at line 106 of file CellCacheManager.cc.

void CellCacheManager::merge_caches ( SchemaPtr & schema )

Merges immutable cache into active cache.

Definition at line 39 of file CellCacheManager.cc.

void CellCacheManager::populate_key_set ( KeySet & keys )

Populates a set with all keys in the cell caches.

This function inserts all keys from the active cache and the immutable cache into keys.

Parameters

keys Key set

Definition at line 132 of file CellCacheManager.cc.

void CellCacheManager::split_row_estimate_data ( CellList::SplitRowDataMapT & split_row_data )

Populates map of split row data.

This method calls CellCache::split_row_estimate_data() on both the active and immutable caches to add data to split_row_data.

Parameters

split_row_data Map of split row data.

Definition at line 99 of file CellCacheManager.cc.

void Hypertable::CellCacheManager::unlock ( )

inline

Unlocks the active cache.

Definition at line 149 of file CellCacheManager.h.

Member Data Documentation

CellCachePtr Hypertable::CellCacheManager::m_active_cache

private

Active cache.

Definition at line 224 of file CellCacheManager.h.

CellCachePtr Hypertable::CellCacheManager::m_immutable_cache

private

Immutable cache.

Definition at line 227 of file CellCacheManager.h.

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

/home/doug/src/hypertable/src/cc/Hypertable/RangeServer/CellCacheManager.h
/home/doug/src/hypertable/src/cc/Hypertable/RangeServer/CellCacheManager.cc

Public Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation