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net_instaweb::ThreadsafeCache Class Reference

#include "threadsafe_cache.h"

Inheritance diagram for net_instaweb::ThreadsafeCache:
net_instaweb::CacheInterface

List of all members.

Public Member Functions

 ThreadsafeCache (CacheInterface *cache, AbstractMutex *mutex)
 Does not takes ownership of cache. Takes ownership of mutex.
virtual void Get (const GoogleString &key, Callback *callback)
virtual void Put (const GoogleString &key, SharedString *value)
virtual void Delete (const GoogleString &key)
virtual CacheInterfaceBackend ()
virtual bool IsBlocking () const
virtual bool IsHealthy () const
virtual void ShutDown ()
virtual GoogleString Name () const

Static Public Member Functions

static GoogleString FormatName (StringPiece cache)

Detailed Description

Composes a cache with a Mutex to form a threadsafe cache. Note that cache callbacks will be run in a thread that is dependent on the cache implementation. This wrapper class just guarantees the thread safety of the cache itself, not the callbacks.


Member Function Documentation

If this cache is merely a wrapper around a backend that actually does all the work, returns that backend cache object. Otherwise just returns 'this'. Used for testing.

Reimplemented from net_instaweb::CacheInterface.

virtual void net_instaweb::ThreadsafeCache::Get ( const GoogleString &  key,
Callback callback 
) [virtual]

Initiates a cache fetch, calling callback->ValidateCandidate() and then callback->Done(state) when done.

Note: implementations should normally invoke the callback via ValidateAndReportResult, which will combine ValidateCandidate() and Done() together properly.

Implements net_instaweb::CacheInterface.

virtual bool net_instaweb::ThreadsafeCache::IsBlocking ( ) const [inline, virtual]

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::ThreadsafeCache::IsHealthy ( ) const [virtual]

Returns true if the cache is in a healthy state. Memory and file-based caches can simply return 'true'. But for server-based caches, it is handy to be able to query to see whether it is in a good state. It should be safe to call this frequently -- the implementation shouldn't do much more than check a bool flag under mutex.

Implements net_instaweb::CacheInterface.

virtual GoogleString net_instaweb::ThreadsafeCache::Name ( ) const [inline, virtual]

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 net/instaweb/system/system_caches_test.cc.

Implements net_instaweb::CacheInterface.

virtual void net_instaweb::ThreadsafeCache::Put ( const GoogleString &  key,
SharedString value 
) [virtual]

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.

virtual void net_instaweb::ThreadsafeCache::ShutDown ( ) [virtual]

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:
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