Page Speed Optimization Libraries
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Pages
Public Member Functions | Static Public Member Functions | Friends | List of all members
net_instaweb::DelayCache Class Reference

See file comment. More...

#include "delay_cache.h"

Inheritance diagram for net_instaweb::DelayCache:

Public Member Functions

 DelayCache (CacheInterface *cache, ThreadSystem *thread_system)
 Note: takes ownership of nothing.
virtual void Get (const GoogleString &key, Callback *callback)
 Reimplementations of CacheInterface methods.
virtual void Put (const GoogleString &key, const SharedString &value)
virtual void Delete (const GoogleString &key)
virtual void MultiGet (MultiGetRequest *request)
void DelayKey (const GoogleString &key)
void ReleaseKey (const GoogleString &key)
void ReleaseKeyInSequence (const GoogleString &key, QueuedWorkerPool::Sequence *sequence)
virtual GoogleString Name () const
virtual bool IsBlocking () const
virtual bool IsHealthy () const
virtual void ShutDown ()
- Public Member Functions inherited from net_instaweb::CacheInterface
void PutSwappingString (const GoogleString &key, GoogleString *value)
virtual CacheInterfaceBackend ()
virtual bool MustEncodeKeyInValueOnPut () const
virtual void PutWithKeyInValue (const GoogleString &key, const SharedString &key_and_value)

Static Public Member Functions

static GoogleString FormatName (StringPiece name)
- Static Public Member Functions inherited from net_instaweb::CacheInterface
static const char * KeyStateName (KeyState state)


class DelayCallback

Additional Inherited Members

- Public Types inherited from net_instaweb::CacheInterface
enum  KeyState {
  kAvailable = 0, kNotFound = 1, kOverload = 2, kNetworkError = 3,
  kTimeout = 4
typedef std::vector< KeyCallbackMultiGetRequest
- Protected Member Functions inherited from net_instaweb::CacheInterface
void ValidateAndReportResult (const GoogleString &key, KeyState state, Callback *callback)
 Invokes callback->ValidateCandidate() and callback->Done() as appropriate.
void ReportMultiGetNotFound (MultiGetRequest *request)

Detailed Description

See file comment.

Member Function Documentation

void net_instaweb::DelayCache::DelayKey ( const GoogleString key)

Instructs the cache to delay delivery of callbacks for specific cache-key. It is a fatal error – reported at class destruction, to request delay of a key that is never looked up and released.

virtual bool net_instaweb::DelayCache::IsBlocking ( ) const

Returns true if this cache is guaranteed to call its callbacks before returning from Get and MultiGet.

Implements net_instaweb::CacheInterface.

virtual bool net_instaweb::DelayCache::IsHealthy ( ) const

IsHealthy() is a rough estimation of whether cache is available for any operations. If it's false, caller may reasonably expect that making calls right now is useless as they will fail or have high latency. If it's true, operations should succeed, but some still may fail occasionally. The primary goal is to avoid sending commands to 'unhealthy' caches, e.g. if cache is under heavy load, we do not want to send even more requests.

Memory and file-based caches can simply return 'true'. It should be safe to call this frequently – the implementation shouldn't do much more that check a bool flag under mutex.

Implements net_instaweb::CacheInterface.

virtual void net_instaweb::DelayCache::MultiGet ( MultiGetRequest *  request)

Gets multiple keys, calling multiple callbacks. Default implementation simply loops over all the keys and calls Get.

MultiGetRequest, declared above, is a vector of structs of keys and callbacks.

Ownership of the request is transferred to this function.

Reimplemented from net_instaweb::CacheInterface.

virtual GoogleString net_instaweb::DelayCache::Name ( ) const

The name of this CacheInterface – used for logging and debugging.

It is strongly recommended that you provide a static GoogleString FormatName(...) method for use in formatting the Name() return, and in testing, e.g. in third_party/pagespeed/system/

Implements net_instaweb::CacheInterface.

virtual void net_instaweb::DelayCache::Put ( const GoogleString key,
const SharedString value 

Puts a value into the cache. The value that is passed in is not modified, but the SharedString is passed by non-const pointer because its reference count is bumped.

Implements net_instaweb::CacheInterface.

void net_instaweb::DelayCache::ReleaseKey ( const GoogleString key)

Release the delay on the callback delivered for a specific key. It is ane error to attempt to release a key that was never delayed.

void net_instaweb::DelayCache::ReleaseKeyInSequence ( const GoogleString key,
QueuedWorkerPool::Sequence sequence 

See ReleaseKey. If sequence is non-NULL, the callback is delivered on the sequence, otherwise it is delivered directly from ReleaseKey.

virtual void net_instaweb::DelayCache::ShutDown ( )

Stops all cache activity. Further Put/Delete calls will be dropped, and MultiGet/Get will call the callback with kNotFound immediately. Note there is no Enable(); once the cache is stopped it is stopped forever. This function is intended for use during process shutdown.

Implements net_instaweb::CacheInterface.

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