NavHintCache Class Reference

LRU cache for faster "paging" through daughter hits for a branch server. More...

#include <NavHint.h>

Inheritance diagram for NavHintCache:

Collaboration diagram for NavHintCache:

Public Types
typedef NavHintKey	KeyT
	navigation cache key type More...
typedef NavHint	ValT
	navigation cache value type More...
typedef ddcLRUCache< KeyT, ValT >	CacheT
	typedef for underlying LRU cache object More...

Public Member Functions
	NavHintCache (size_t capacity=1024)
	~NavHintCache ()
	default destructor (empty) More...
void	reserve (size_t capacity_)
	wraps lock(); m_Cache.reserve(capacity_); unlock() More...
size_t	size () const
	wraps lock(); m_Cache.size(); unlock() More...
void	clear ()
	wraps lock(); m_Cache.clear(); unlock() More...
bool	lower_bound (ValT &val, const KeyT &key, bool doPromote=true)
ValT	lower_bound (const KeyT &key, bool doPromote=true)
void	insert (const KeyT &key, const ValT &val)
ValT	lower_bound (const string &QueryStr, size_t HitNo)
	wrapper for lower_bound(KeyT(QueryStr, HitNo)) More...
void	insert (const string &QueryStr, size_t HitNo, const string &SortKey, const size_t Offset, const vector< string > &DtrHints)
	wrapper for insert(KeyT(QueryStr, HitNo), ValT(SortKey,Offset,DtrHints)) More...
string	toJson () const
	debug: stringification More...
Public Member Functions inherited from ddcLockable
	ddcLockable ()
virtual	~ddcLockable ()
int	lock () const
int	unlock () const

Public Attributes
CacheT	m_Cache
	underlying LRU cache More...
Public Attributes inherited from ddcLockable
pthread_mutex_t	m_Mutex

Detailed Description

LRU cache for faster "paging" through daughter hits for a branch server.

Member Typedef Documentation

KeyT

typedef NavHintKey NavHintCache::KeyT

navigation cache key type

ValT

typedef NavHint NavHintCache::ValT

navigation cache value type

CacheT

typedef ddcLRUCache<KeyT,ValT> NavHintCache::CacheT

typedef for underlying LRU cache object

Constructor & Destructor Documentation

NavHintCache()

NavHintCache::NavHintCache ( size_t  capacity = 1024 )

inline

default constructor

• initializes m_Cache to use m_Mutex inherited from ddcLockable

~NavHintCache()

NavHintCache::~NavHintCache ( )

inline

default destructor (empty)

Member Function Documentation

reserve()

void NavHintCache::reserve ( size_t  capacity_ )

inline

wraps lock(); m_Cache.reserve(capacity_); unlock()

References ddcLRUCache< Key, Val >::reserve().

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size()

size_t NavHintCache::size ( void  ) const

inline

wraps lock(); m_Cache.size(); unlock()

References ddcLRUCache< Key, Val >::size().

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clear()

void NavHintCache::clear ( void  )

inline

wraps lock(); m_Cache.clear(); unlock()

References ddcLRUCache< Key, Val >::clear().

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lower_bound() [1/3]

bool NavHintCache::lower_bound	(	ValT &	val,
		const KeyT &	key,
		bool	doPromote = true
	)

get lower bound for key key = (QueryStr,HitNo)

Returns

true iff a match was found in cache, false otherwise

• copies lower-bound cached hint for key if QueryStr matches, otherwise clears hint
• if a valid match is found, it is promoted to MRU position iff doPromote is true
• wraps operation in lock() + unlock()

Parameters

val	(output) hint to be extracted (data copied from cache if found, otherwise an empty hint)
key	(input) key to search for
doPromote	(input) whether to implicitly promote match to MRU position

References NavHint::clear(), ddcLogTrace, escapeCString(), Format(), NavHintKey::m_QueryStr, NAVCACHE_TRACE, and NavHintKey::toString().

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lower_bound() [2/3]

ValT NavHintCache::lower_bound ( const KeyT &  key, bool  doPromote = true  )

inline

get lower bound for key key = (QueryStr,HitNo)

Returns

copy of lower-bound cached hint for key if QueryStr matches, otherwise an empty hint for nSubs

insert() [1/2]

void NavHintCache::insert ( const KeyT &  key, const ValT &  val  )

inline

insert new entry for key = (QueryStr,HitNo)

• promotes new entry to MRU position
• implicitly wraps operation in lock() + unlock()

References ddcLogTrace, escapeCString(), Format(), ddcLRUCache< Key, Val >::insert(), NAVCACHE_TRACE, NavHintKey::toString(), and NavHint::toString().

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lower_bound() [3/3]

ValT NavHintCache::lower_bound ( const string &  QueryStr, size_t  HitNo  )

inline

wrapper for lower_bound(KeyT(QueryStr, HitNo))

insert() [2/2]

void NavHintCache::insert ( const string &  QueryStr, size_t  HitNo, const string &  SortKey, const size_t  Offset, const vector< string > &  DtrHints  )

inline

wrapper for insert(KeyT(QueryStr, HitNo), ValT(SortKey,Offset,DtrHints))

References NavHintKey::toJson().

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toJson()

string NavHintCache::toJson

(

)

const

debug: stringification

References Format(), listPos(), and NAVCACHE_VERBOSE_JSON.

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Member Data Documentation

m_Cache

CacheT NavHintCache::m_Cache

underlying LRU cache

Referenced by listPos().

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

• NavHint.h
• NavHint.cpp