DispatchHandler class for managing async RangeServer requests. More...

#include <DispatchHandlerOperation.h>

Inheritance diagram for Hypertable::DispatchHandlerOperation:

Collaboration diagram for Hypertable::DispatchHandlerOperation:

Classes
struct	LtEventPtr
	Strict Weak Ordering for comparing events by source address. More...

class	Result
	Holds request result information. More...

Public Member Functions
	DispatchHandlerOperation (ContextPtr &context)
	Constructor. More...

void	start (StringSet &locations)
	Starts asynchronous request. More...

virtual void	start (const String &location)=0
	Method overridden in derived class for issuing requests. More...

virtual void	result_callback (const EventPtr &event)
	Post-request hook method. More...

virtual void	handle (EventPtr &event)
	Process response event. More...

bool	wait_for_completion ()
	Waits for requests to complete. More...

void	process_events ()
	Processes m_events set. More...

void	get_results (std::set< Result > &results)
	Returns the Result set. More...

Public Member Functions inherited from Hypertable::DispatchHandler
virtual	~DispatchHandler ()
	Destructor. More...

Protected Attributes
ContextPtr	m_context
	Master context More...

RangeServer::Client	m_rsclient
	Range server client object More...

Private Attributes
std::mutex	m_mutex
	Mutex for serializing concurrent access More...

std::condition_variable	m_cond
	Condition variable used to wait for completion. More...

std::set< EventPtr, LtEventPtr >	m_events
	Set of events generated by range server responses. More...

int	m_outstanding {}
	Outstanding request count that have not completed. More...

int	m_error_count {}
	Error count More...

StringSet	m_locations
	Set of servers participating in operation. More...

std::set< Result >	m_results
	Set of result objects. More...

Detailed Description

DispatchHandler class for managing async RangeServer requests.

This class is a DispatchHandler class that is used for managing asynchronous requests to a set of range servers.

Definition at line 57 of file DispatchHandlerOperation.h.

Constructor & Destructor Documentation

DispatchHandlerOperation::DispatchHandlerOperation ( ContextPtr & context )

Constructor.

Parameters

context Master context

Definition at line 41 of file DispatchHandlerOperation.cc.

Member Function Documentation

void DispatchHandlerOperation::get_results ( std::set< Result > & results )

Returns the Result set.

This method copies m_results to the results parameter.

Parameters

results Reference to Result set to be populated.

Definition at line 132 of file DispatchHandlerOperation.cc.

void DispatchHandlerOperation::handle ( EventPtr & event )

virtual

Process response event.

This method inserts event int m_events set, decrements m_outstanding, and then signals m_cond if m_outstanding has dropped to zero

Parameters

event Response event

Implements Hypertable::DispatchHandler.

Definition at line 78 of file DispatchHandlerOperation.cc.

void DispatchHandlerOperation::process_events ( )

Processes m_events set.

For each event in m_events, this method creates a Result object, sets the error code and error message extracted from the event payload, and adds the result object to the m_results set. This method also makes a call to result_callback() for each event.

Definition at line 94 of file DispatchHandlerOperation.cc.

virtual void Hypertable::DispatchHandlerOperation::result_callback ( const EventPtr & event )

inlinevirtual

Post-request hook method.

This method can be overridden by derived classes to do post-processing on each request result.

Parameters

event Response event

Reimplemented in Hypertable::DispatchHandlerOperationSystemStatus, and Hypertable::DispatchHandlerOperationGetStatistics.

Definition at line 107 of file DispatchHandlerOperation.h.

void DispatchHandlerOperation::start ( StringSet & locations )

Starts asynchronous request.

This method first initializes m_error_count to 0, m_locations to locations, and m_outstanding to locations.size(), and then kicks of a request for each location with a call to start().

Parameters

locations Set of locations for which to issue requests

Definition at line 46 of file DispatchHandlerOperation.cc.

virtual void Hypertable::DispatchHandlerOperation::start ( const String & location )

pure virtual

Method overridden in derived class for issuing requests.

Parameters

location Proxy name of server to issue request.

Implemented in Hypertable::DispatchHandlerOperationSystemStatus, Hypertable::DispatchHandlerOperationSetState, Hypertable::DispatchHandlerOperationCompact, Hypertable::DispatchHandlerOperationToggleTableMaintenance, Hypertable::DispatchHandlerOperationGetStatistics, Hypertable::DispatchHandlerOperationAlterTable, and Hypertable::DispatchHandlerOperationDropTable.

bool DispatchHandlerOperation::wait_for_completion ( )

Waits for requests to complete.

This method waits on m_cond until m_outstanding drops to zero and then calls process_events().