Queues various operations on files, such as writes and fsyncs, to be executed later. More...

Inheritance diagram for LogCabin::Storage::SegmentedLog::Sync:

Classes
struct	Op
Public Member Functions
	Sync (uint64_t lastIndex, std::chrono::nanoseconds diskWriteDurationThreshold)
	~Sync ()
void	updateStats (Core::RollingStat &nanos) const
	Add how long the filesystem ops took to 'nanos'.
void	optimize ()
	Called at the start of wait to avoid some redundant disk flushes.
void	wait ()
	Wait for the log entries to be durable.
Public Attributes
const std::chrono::nanoseconds	diskWriteDurationThreshold
	If a wait() exceeds this time, log a warning.
std::deque< Op >	ops
	List of operations to perform during wait().
TimePoint	waitStart
	Time at start of wait() call.
TimePoint	waitEnd
	Time at end of wait() call.

Detailed Description

Queues various operations on files, such as writes and fsyncs, to be executed later.

Definition at line 263 of file SegmentedLog.h.

Constructor & Destructor Documentation

LogCabin::Storage::SegmentedLog::Sync::Sync	(	uint64_t	lastIndex,
		std::chrono::nanoseconds	diskWriteDurationThreshold
	)		`[explicit]`

Definition at line 178 of file SegmentedLog.cc.

LogCabin::Storage::SegmentedLog::Sync::~Sync ( ) [virtual]

Reimplemented from LogCabin::Storage::Log::Sync.

Definition at line 188 of file SegmentedLog.cc.

Member Function Documentation

void LogCabin::Storage::SegmentedLog::Sync::updateStats ( Core::RollingStat & nanos ) const

Add how long the filesystem ops took to 'nanos'.

This is invoked from syncCompleteVirtual so that it is thread-safe with respect to the 'nanos' variable. We can't do it in 'wait' directly since that can execute concurrently with someone reading 'nanos'.

Definition at line 305 of file SegmentedLog.cc.

void LogCabin::Storage::SegmentedLog::Sync::optimize ( )

Called at the start of wait to avoid some redundant disk flushes.

Definition at line 193 of file SegmentedLog.cc.

void LogCabin::Storage::SegmentedLog::Sync::wait ( ) [virtual]

Wait for the log entries to be durable.

This is safe to call while the Log is being accessed and modified from a separate thread. PANICs on errors.

Reimplemented from LogCabin::Storage::Log::Sync.

Definition at line 215 of file SegmentedLog.cc.