#include <extent_manager.h>

Inheritance diagram for mongo::ExtentManager:

Detailed Description

one per database
responsible for managing <db>.# files
NOT responsible for .ns file
gives out extents
responsible for figuring out how to get a new extent
can use any method it wants to do so
this structure is NOT stored on disk
files will not be removed from the EM
extent size and loc are immutable
this class is thread safe, once constructed and init()-ialized

Classes
class	CacheHint

class	Factory

Public Types
enum	HintType { Sequential, Random }

Public Member Functions
	ExtentManager ()

virtual	~ExtentManager ()

virtual void	close (OperationContext *opCtx)=0

virtual Status	init (OperationContext *opCtx)=0
	opens all current files More...

virtual int	numFiles () const =0

virtual long long	fileSize () const =0

virtual DiskLoc	allocateExtent (OperationContext *opCtx, bool capped, int size, bool enforceQuota)=0

virtual void	freeExtents (OperationContext *opCtx, DiskLoc firstExt, DiskLoc lastExt)=0
	firstExt has to be == lastExt or a chain More...

virtual void	freeExtent (OperationContext *opCtx, DiskLoc extent)=0
	frees a single extent ignores all fields in the Extent except: magic, myLoc, length More...

virtual void	freeListStats (OperationContext opCtx, int numExtents, int64_t *totalFreeSizeBytes) const =0
	Retrieve statistics on the the free list managed by this ExtentManger. More...

virtual MmapV1RecordHeader *	recordForV1 (const DiskLoc &loc) const =0

virtual std::unique_ptr< RecordFetcher >	recordNeedsFetch (const DiskLoc &loc) const =0
	The extent manager tracks accesses to DiskLocs. More...

virtual Extent *	extentForV1 (const DiskLoc &loc) const =0

virtual DiskLoc	extentLocForV1 (const DiskLoc &loc) const =0

virtual Extent *	getExtent (const DiskLoc &loc, bool doSanityCheck=true) const =0

virtual int	maxSize () const =0

virtual int	minSize () const

virtual int	followupSize (int recordLen, int lastExtentLen) const

virtual int	initialSize (int recordLen) const
	get a suggested size for the first extent in a namespace More...

virtual int	quantizeExtentSize (int size) const
	quantizes extent size to >= min + page boundary More...

virtual CacheHint *	cacheHint (const DiskLoc &extentLoc, const HintType &hint)=0
	Tell the system that for this extent, it will have this kind of disk access. More...

virtual DataFileVersion	getFileFormat (OperationContext *opCtx) const =0

virtual void	setFileFormat (OperationContext *opCtx, DataFileVersion newVersion)=0

virtual const DataFile *	getOpenFile (int n) const =0

Private Member Functions
	MONGO_DISALLOW_COPYING (ExtentManager)

Member Enumeration Documentation

◆ HintType

enum mongo::ExtentManager::HintType

Enumerator
Sequential
Random

Constructor & Destructor Documentation

◆ ExtentManager()

mongo::ExtentManager::ExtentManager ( )

inline

◆ ~ExtentManager()

virtual mongo::ExtentManager::~ExtentManager ( )

inlinevirtual

Member Function Documentation

◆ allocateExtent()

virtual DiskLoc mongo::ExtentManager::allocateExtent	(	OperationContext *	opCtx,
		bool	capped,
		int	size,
		bool	enforceQuota
	)

pure virtual

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ cacheHint()

virtual CacheHint* mongo::ExtentManager::cacheHint	(	const DiskLoc &	extentLoc,
		const HintType &	hint
	)

pure virtual

Tell the system that for this extent, it will have this kind of disk access.

Caller takes owernship of CacheHint

Implemented in mongo::MmapV1ExtentManager, and mongo::DummyExtentManager.

◆ close()

virtual void mongo::ExtentManager::close ( OperationContext * opCtx )

pure virtual

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ extentForV1()

virtual Extent* mongo::ExtentManager::extentForV1 ( const DiskLoc & loc ) const

pure virtual

Parameters

loc	- has to be for a specific MmapV1RecordHeader (not an Extent) Note(erh) see comment on recordFor

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ extentLocForV1()

virtual DiskLoc mongo::ExtentManager::extentLocForV1 ( const DiskLoc & loc ) const

pure virtual

Parameters

loc	- has to be for a specific MmapV1RecordHeader (not an Extent) Note(erh) see comment on recordFor

Implemented in mongo::MmapV1ExtentManager, and mongo::DummyExtentManager.

◆ fileSize()

virtual long long mongo::ExtentManager::fileSize ( ) const

pure virtual

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ followupSize()

int mongo::ExtentManager::followupSize	(	int	recordLen,
		int	lastExtentLen
	)		const

virtual

Parameters

recordLen	length of record we need
lastExt	size of last extent which is a factor in next extent size

◆ freeExtent()

virtual void mongo::ExtentManager::freeExtent	(	OperationContext *	opCtx,
		DiskLoc	extent
	)

pure virtual

frees a single extent ignores all fields in the Extent except: magic, myLoc, length

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ freeExtents()

virtual void mongo::ExtentManager::freeExtents	(	OperationContext *	opCtx,
		DiskLoc	firstExt,
		DiskLoc	lastExt
	)

pure virtual

firstExt has to be == lastExt or a chain

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ freeListStats()

virtual void mongo::ExtentManager::freeListStats	(	OperationContext *	opCtx,
		int *	numExtents,
		int64_t *	totalFreeSizeBytes
	)		const

pure virtual

Retrieve statistics on the the free list managed by this ExtentManger.

Parameters

numExtents	- non-null pointer to an int that will receive the number of extents
totalFreeSizeBytes	- non-null pointer to an int64_t receiving the total free space in the free list.

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ getExtent()

virtual Extent* mongo::ExtentManager::getExtent	(	const DiskLoc &	loc,
		bool	doSanityCheck = `true`
	)		const

pure virtual

Parameters

loc	- has to be for a specific Extent

Implemented in mongo::MmapV1ExtentManager, and mongo::DummyExtentManager.

◆ getFileFormat()

virtual DataFileVersion mongo::ExtentManager::getFileFormat ( OperationContext * opCtx ) const

pure virtual

Implemented in mongo::MmapV1ExtentManager, and mongo::DummyExtentManager.

◆ getOpenFile()

virtual const DataFile* mongo::ExtentManager::getOpenFile ( int n ) const

pure virtual

Implemented in mongo::MmapV1ExtentManager, and mongo::DummyExtentManager.

◆ init()

virtual Status mongo::ExtentManager::init ( OperationContext * opCtx )

pure virtual

opens all current files

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ initialSize()

int mongo::ExtentManager::initialSize ( int recordLen ) const

virtual

get a suggested size for the first extent in a namespace

Parameters

recordLen length of record we need to insert

◆ maxSize()

virtual int mongo::ExtentManager::maxSize ( ) const

pure virtual

Returns: maximum size of an Extent

Implemented in mongo::MmapV1ExtentManager, and mongo::DummyExtentManager.

◆ minSize()

virtual int mongo::ExtentManager::minSize ( ) const

inlinevirtual

Returns: minimum size of an Extent

◆ MONGO_DISALLOW_COPYING()

mongo::ExtentManager::MONGO_DISALLOW_COPYING ( ExtentManager )

private

◆ numFiles()

virtual int mongo::ExtentManager::numFiles ( ) const

pure virtual

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ quantizeExtentSize()

int mongo::ExtentManager::quantizeExtentSize ( int size ) const

virtual

quantizes extent size to >= min + page boundary

◆ recordForV1()

virtual MmapV1RecordHeader* mongo::ExtentManager::recordForV1 ( const DiskLoc & loc ) const

pure virtual

Parameters

loc	- has to be for a specific MmapV1RecordHeader Note(erh): this sadly cannot be removed. A MmapV1RecordHeader DiskLoc has an offset from a file, while a RecordStore really wants an offset from an extent. This intrinsically links an original record store to the original extent manager.

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ recordNeedsFetch()

virtual std::unique_ptr<RecordFetcher> mongo::ExtentManager::recordNeedsFetch ( const DiskLoc & loc ) const

pure virtual

The extent manager tracks accesses to DiskLocs.

This returns non-NULL if the DiskLoc has been recently accessed, and therefore has likely been paged into physical memory. Returns nullptr if the DiskLoc is Null.

Implemented in mongo::DummyExtentManager, and mongo::MmapV1ExtentManager.

◆ setFileFormat()

virtual void mongo::ExtentManager::setFileFormat	(	OperationContext *	opCtx,
		DataFileVersion	newVersion
	)

pure virtual

Implemented in mongo::MmapV1ExtentManager, and mongo::DummyExtentManager.

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

/home/louis/git/mongodbsource.github.io/src/src/mongo/db/storage/mmap_v1/extent_manager.h
/home/louis/git/mongodbsource.github.io/src/src/mongo/db/storage/mmap_v1/extent_manager.cpp

Detailed Description

Classes

Public Types

Public Member Functions

Private Member Functions

Member Enumeration Documentation

◆ HintType

Constructor & Destructor Documentation

◆ ExtentManager()

◆ ~ExtentManager()

Member Function Documentation

◆ allocateExtent()

◆ cacheHint()

◆ close()

◆ extentForV1()

◆ extentLocForV1()

◆ fileSize()

◆ followupSize()

◆ freeExtent()

◆ freeExtents()

◆ freeListStats()

◆ getExtent()

◆ getFileFormat()

◆ getOpenFile()

◆ init()

◆ initialSize()

◆ maxSize()

◆ minSize()

◆ MONGO_DISALLOW_COPYING()

◆ numFiles()

◆ quantizeExtentSize()

◆ recordForV1()

◆ recordNeedsFetch()

◆ setFileFormat()