mongo::dur::Journal Class Reference

the writeahead journal for durability More...

#include <dur_journalimpl.h>

Detailed Description

the writeahead journal for durability

Classes
struct	JFile

Public Member Functions
	Journal ()
void	init (ClockSource *cs, int64_t serverStartMs)
	call during startup by journalMakeDir() More...
void	rotate ()
	check if time to rotate files. More...
void	journal (const JSectHeader &h, const AlignedBuilder &b)
	append to the journal file More...
boost::filesystem::path	getFilePathFor (int filenumber) const
void	cleanup (bool log)
unsigned long long	curFileId () const
void	assureLogFileOpen ()
void	open ()
	open a journal file to journal operations to. More...

Public Attributes
std::string	dir

Private Member Functions
void	_rotate (unsigned long long lsnOfCurrentJournalEntry)
	check if time to rotate files. More...
void	_open ()
void	closeCurrentJournalFile ()
void	removeUnneededJournalFiles ()
	remove older journal files. More...
void	updateLSNFile (unsigned long long lsnOfCurrentJournalEntry)
	remember "last sequence number" to speed recoveries concurrency: called by durThread only. More...

Private Attributes
unsigned long long	_written = 0
unsigned	_nextFileNumber = 0
SimpleMutex	_curLogFileMutex
LogFile *	_curLogFile
unsigned long long	_curFileId
std::list< JFile >	_oldJournalFiles
AtomicUInt64	_lastSeqNumberWrittenToSharedView
AtomicUInt64	_preFlushTime
AtomicUInt64	_lastFlushTime
AtomicWord< bool >	_writeToLSNNeeded
ClockSource *	_clock
int64_t	_serverStartMs

Friends
void	setLastSeqNumberWrittenToSharedView (uint64_t seqNumber)
	Informs the journaling system that all writes on or before the passed in sequence number have been written to the data files' shared mmap view. More...
void	notifyPreDataFileFlush ()
	Call these before (pre) and after (post) the datafiles are flushed to disk by the DataFileSync thread. More...
void	notifyPostDataFileFlush ()

Constructor & Destructor Documentation

Journal()

mongo::dur::Journal::Journal

(

)

Member Function Documentation

_open()

void mongo::dur::Journal::_open ( )

private

_rotate()

void mongo::dur::Journal::_rotate ( unsigned long long  lsnOfCurrentJournalEntry )

private

check if time to rotate files.

assure a file is open. internally called with every commit

assureLogFileOpen()

void mongo::dur::Journal::assureLogFileOpen ( )

inline

cleanup()

void mongo::dur::Journal::cleanup

(

bool

log

)

closeCurrentJournalFile()

void mongo::dur::Journal::closeCurrentJournalFile ( )

private

curFileId()

unsigned long long mongo::dur::Journal::curFileId ( ) const

inline

getFilePathFor()

boost::filesystem::path mongo::dur::Journal::getFilePathFor

(

int

filenumber

)

const

init()

void mongo::dur::Journal::init	(	ClockSource *	cs,
		int64_t	serverStartMs
	)

call during startup by journalMakeDir()

journal()

void mongo::dur::Journal::journal	(	const JSectHeader &	h,
		const AlignedBuilder &	b
	)

append to the journal file

open()

void mongo::dur::Journal::open

(

)

open a journal file to journal operations to.

removeUnneededJournalFiles()

void mongo::dur::Journal::removeUnneededJournalFiles ( )

private

remove older journal files.

be in _curLogFileMutex but not dbMutex when calling

rotate()

void mongo::dur::Journal::rotate

(

)

check if time to rotate files.

assure a file is open. done separately from the journal() call as we can do this part outside of lock. thread: durThread()

updateLSNFile()

void mongo::dur::Journal::updateLSNFile ( unsigned long long  lsnOfCurrentJournalEntry )

private

remember "last sequence number" to speed recoveries concurrency: called by durThread only.

Friends And Related Function Documentation

notifyPostDataFileFlush

void notifyPostDataFileFlush ( )

friend

notifyPreDataFileFlush

void notifyPreDataFileFlush ( )

friend

Call these before (pre) and after (post) the datafiles are flushed to disk by the DataFileSync thread.

These should not be called for any other flushes.

setLastSeqNumberWrittenToSharedView

void setLastSeqNumberWrittenToSharedView ( uint64_t  seqNumber )

friend

Informs the journaling system that all writes on or before the passed in sequence number have been written to the data files' shared mmap view.

Member Data Documentation

_clock

ClockSource* mongo::dur::Journal::_clock

private

_curFileId

unsigned long long mongo::dur::Journal::_curFileId

private

_curLogFile

LogFile* mongo::dur::Journal::_curLogFile

private

_curLogFileMutex

SimpleMutex mongo::dur::Journal::_curLogFileMutex

private

_lastFlushTime

AtomicUInt64 mongo::dur::Journal::_lastFlushTime

private

_lastSeqNumberWrittenToSharedView

AtomicUInt64 mongo::dur::Journal::_lastSeqNumberWrittenToSharedView

private

_nextFileNumber

unsigned mongo::dur::Journal::_nextFileNumber = 0

private

_oldJournalFiles

std::list<JFile> mongo::dur::Journal::_oldJournalFiles

private

_preFlushTime

AtomicUInt64 mongo::dur::Journal::_preFlushTime

private

_serverStartMs

int64_t mongo::dur::Journal::_serverStartMs

private

_writeToLSNNeeded

AtomicWord<bool> mongo::dur::Journal::_writeToLSNNeeded

private

_written

unsigned long long mongo::dur::Journal::_written = 0

private

dir

std::string mongo::dur::Journal::dir

---

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

• /home/louis/git/mongodbsource.github.io/src/src/mongo/db/storage/mmap_v1/dur_journalimpl.h
• /home/louis/git/mongodbsource.github.io/src/src/mongo/db/storage/mmap_v1/dur_journal.cpp