net_instaweb::PropertyCache Class Reference

Adds property-semantics to a raw cache API. More...

#include "property_cache.h"

Classes
class	Cohort

Public Types
typedef std::vector< const Cohort * >	CohortVector

Public Member Functions
	PropertyCache (PropertyStore *property_store, Timer *timer, Statistics *stats, ThreadSystem *threads)
void	Read (PropertyPage *property_page) const
void	ReadWithCohorts (const CohortVector &cohort_list, PropertyPage *property_page) const
const CohortVector &	GetAllCohorts () const
	Returns all the cohorts from cache.
bool	IsStable (const PropertyValue *property) const
	Determines whether a value that was read is reasonably stable.
bool	IsExpired (const PropertyValue *property_value, int64 ttl_ms) const
void	set_mutations_per_1000_writes_threshold (int x)
const Cohort *	AddCohort (const StringPiece &cohort_name)
const Cohort *	GetCohort (const StringPiece &cohort_name) const
void	set_enabled (bool x)
bool	enabled () const
	Indicates if the property cache is enabled.
Timer *	timer () const
	Returns timer pointer.
ThreadSystem *	thread_system () const
PropertyStore *	property_store ()

Static Public Member Functions
static void	InitCohortStats (const GoogleString &cohort, Statistics *statistics)
	Initialize stats for the specified cohort.
static GoogleString	GetStatsPrefix (const GoogleString &cohort_name)
	Creates stats prefix for the given cohort.

Detailed Description

Adds property-semantics to a raw cache API.

Constructor & Destructor Documentation

net_instaweb::PropertyCache::PropertyCache	(	PropertyStore *	property_store,
		Timer *	timer,
		Statistics *	stats,
		ThreadSystem *	threads
	)

Does not take ownership of the property_store, timer, stats, or threads objects.

Member Function Documentation

const Cohort* net_instaweb::PropertyCache::AddCohort

(

const StringPiece &

cohort_name

)

Establishes a new Cohort for this property cache. Note that you must call InitCohortStats prior to calling AddCohort.

const Cohort* net_instaweb::PropertyCache::GetCohort

(

const StringPiece &

cohort_name

)

const

Returns the specified Cohort* or NULL if not found. Cohorts must be established at startup time, via AddCohort before any pages are processed via Read & Write.

bool net_instaweb::PropertyCache::IsExpired	(	const PropertyValue *	property_value,
		int64	ttl_ms
	)		const

Determines whether a value is expired relative to the specified TTL.

It is an error (DCHECK) to call this method when !property->has_value().

Note; we could also store the TTL in the cache-value itself. That would be useful if we derived the TTL from the data or other transients. But our envisioned usage has the TTL coming from a configuration that is available at read-time, so for now we just use that.

void net_instaweb::PropertyCache::Read

(

PropertyPage *

property_page

)

const

Reads all the PropertyValues in all the known Cohorts from cache, calling PropertyPage::Done when done. It is essential that the Cohorts are established prior to calling this function.

void net_instaweb::PropertyCache::ReadWithCohorts	(	const CohortVector &	cohort_list,
		PropertyPage *	property_page
	)		const

Reads all the PropertyValues in the specified Cohorts from cache, calling PropertyPage::Done when done.

void net_instaweb::PropertyCache::set_enabled ( bool  x )

inline

Allows turning off all reads/writes with a switch. Writes to a disabled cache are ignored. Reads cause Done(false) to be called immediately.

---

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

• pagespeed/opt/http/property_cache.h