An implementation of StoreImpl for publication. More...

#include <HybridPublishStore.hpp>

Inheritance diagram for AMPS::HybridPublishStore:

Public Member Functions
	HybridPublishStore (const char *fileName_, size_t maxMemoryCapacity_, bool errorOnPublishGap_=false)
	Create a HybridPublishStore that will use fileName_ as its file storage and stores at most maxMemoryCapacity_ messages in memory before offloading some messages to the file. More...

	HybridPublishStore (const std::string &fileName_, size_t maxMemoryCapacity_, bool errorOnPublishGap_=false)
	Create a HybridPublishStore that will use fileName_ as its file storage and stores at most maxMemoryCapacity_ messages in memory before offloading some messages to the file. More...

void	setLowWatermark (size_t lowWatermark_)
	Set how many messags remain in memory after messages get offlined. More...

size_t	getLowWatermark ()
	Get how many messags remain in memory after messages get offlined. More...

void	discardUpTo (amps_uint64_t index_)
	Discard all messages in the store up to and including index_. More...

void	replay (StoreReplayer &replayer_)
	Used internally by Client to replay messages in the store to AMPS after a successful connection. More...

size_t	unpersistedCount () const
	The number of messages in the Store that have not been discarded. More...

virtual void	flush (long timeout_)
	Method to wait for the Store to discard everything that has been stored up to the point in time when flush is called. More...

bool	replaySingle (StoreReplayer &replayer_, amps_uint64_t index_)
	Called by Client to get a single message replayed by the store onto the StoreReplayer. More...

amps_uint64_t	store (const Message &message_)
	Used internally by Client to put messages into the Store. More...

void	setResizeHandler (PublishStoreResizeHandler handler_, void *data_)
	Set a handler to be called if the Store needs to resize in order to keep storing messages. More...

amps_uint64_t	getLowestUnpersisted () const
	Get the oldest unpersisted message sequence in the store. More...

amps_uint64_t	getLastPersisted (void)
	Get the last persisted sequence number. More...

Public Member Functions inherited from AMPS::StoreImpl
	StoreImpl (bool errorOnPublishGap_=false)
	Default constructor. More...

Additional Inherited Members
Static Public Member Functions inherited from AMPS::StoreImpl
static size_t	getUnsetPosition ()
	Method to return the value used to represent not found or unset.

static amps_uint64_t	getUnsetSequence ()
	Method to return the value used to represent no such sequence.

Detailed Description

An implementation of StoreImpl for publication.

This store uses memory up to a specified capacity, then starts using a file if it will exceed the set maximum memory capacity. This store does not provide guaranteed durable publication if the application is restarted. However, this store does help to limit the amount of memory consumed by a publisher when the publisher cannot connect to AMPS.

Constructor & Destructor Documentation

AMPS::HybridPublishStore::HybridPublishStore	(	const char *	fileName_,
		size_t	maxMemoryCapacity_,
		bool	errorOnPublishGap_ = `false`
	)

inline

Create a HybridPublishStore that will use fileName_ as its file storage and stores at most maxMemoryCapacity_ messages in memory before offloading some messages to the file.

Parameters

fileName_	The name to use for the file-based storage.
maxMemoryCapacity_	The maximum number of messages to store in in memory before starting to use a file.
errorOnPublishGap_	If true, PublishStoreGapException can be thrown by the store if the client logs onto a server that appears to be missing messages no longer held in the store.

AMPS::HybridPublishStore::HybridPublishStore	(	const std::string &	fileName_,
		size_t	maxMemoryCapacity_,
		bool	errorOnPublishGap_ = `false`
	)

inline

Create a HybridPublishStore that will use fileName_ as its file storage and stores at most maxMemoryCapacity_ messages in memory before offloading some messages to the file.

Parameters

fileName_	The name to use for the file-based storage.
maxMemoryCapacity_	The maximum number of messages to store in in memory before starting to use a file.
errorOnPublishGap_	If true, PublishStoreGapException can be thrown by the store if the client logs onto a server that appears to be missing messages no longer held in the store.

Member Function Documentation

void AMPS::HybridPublishStore::discardUpTo ( amps_uint64_t index_ )

inlinevirtual

Discard all messages in the store up to and including index_.

Parameters

index_ The maximum index to remove from storage.

Implements AMPS::StoreImpl.

virtual void AMPS::HybridPublishStore::flush ( long timeout_ )

inlinevirtual

Method to wait for the Store to discard everything that has been stored up to the point in time when flush is called.

It will get the current max and wait up to timeout for that message to be discarded

Parameters

timeout_ The number of milliseconds to wait.

Exceptions

DisconnectedException	The Client is no longer connected to a server.
ConnectionException	An error occurred while sending the message.
TimedOutException	The publish command was not acked in the allowed time.

Implements AMPS::StoreImpl.

amps_uint64_t AMPS::HybridPublishStore::getLastPersisted ( void )

inlinevirtual

Get the last persisted sequence number.

Returns: The sequence of the last persisted message.

Implements AMPS::StoreImpl.

amps_uint64_t AMPS::HybridPublishStore::getLowestUnpersisted ( ) const

inlinevirtual

Get the oldest unpersisted message sequence in the store.

Returns: The sequence of the oldest message.

Implements AMPS::StoreImpl.

size_t AMPS::HybridPublishStore::getLowWatermark ( )

inline

Get how many messags remain in memory after messages get offlined.

When memory storage reaches its cap, it will write its oldest messages to its file until it is holding only lowWatermark_ messages.

Returns: The number of messages that remain in memory after offlining completes.

void AMPS::HybridPublishStore::replay ( StoreReplayer & replayer_ )

inlinevirtual

Used internally by Client to replay messages in the store to AMPS after a successful connection.

Parameters

replayer_ The StoreReplayer that replays the messages.

Implements AMPS::StoreImpl.

bool AMPS::HybridPublishStore::replaySingle	(	StoreReplayer &	replayer_,
		amps_uint64_t	index_
	)

inlinevirtual

Called by Client to get a single message replayed by the store onto the StoreReplayer.

Parameters

replayer_	The StoreReplayer to be used to replay the messages.
index_	The index of the message to replay.

Returns: Returns true for success, false for failure such as an invalid index.

Implements AMPS::StoreImpl.

void AMPS::HybridPublishStore::setLowWatermark ( size_t lowWatermark_ )

inline

Set how many messags remain in memory after messages get offlined.

When memory storage reaches its cap, it will write its oldest messages to its file until it is holding only lowWatermark_ messages.

Parameters

lowWatermark_ The number of messages that remain in memory after offlining completes.

void AMPS::HybridPublishStore::setResizeHandler	(	PublishStoreResizeHandler	handler_,
		void *	userData_
	)

inlinevirtual

Set a handler to be called if the Store needs to resize in order to keep storing messages.

Resize could be caused by not being connected to the server, publishing messages faster than the network or AMPS can keep up, not properly discarding messages when receiving persisted acks, or AMPS being unable to complete persistence such as when its connection to a sync replication destination is unavailable.

Parameters

handler_	The handler to be called when a resize event is required.
userData_	The data to pass to the handler each time it is called.

Reimplemented from AMPS::StoreImpl.

amps_uint64_t AMPS::HybridPublishStore::store ( const Message & message_ )

inlinevirtual

Used internally by Client to put messages into the Store.

Parameters

message_ The Message to be stored.

Implements AMPS::StoreImpl.

size_t AMPS::HybridPublishStore::unpersistedCount ( ) const

inlinevirtual

The number of messages in the Store that have not been discarded.

Returns: The number of messages still in the Store.

Implements AMPS::StoreImpl.

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

include/amps/HybridPublishStore.hpp

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation