Manages reading and writing metadata to and from sbIMediaItem objects and media files. More...

#include <sbFileMetadataService.h>

Inheritance diagram for sbFileMetadataService:

Collaboration diagram for sbFileMetadataService:

Public Member Functions
NS_DECL_ISUPPORTS NS_DECL_SBIFILEMETADATASERVICE NS_DECL_SBPIFILEMETADATASERVICE NS_DECL_NSIOBSERVER	sbFileMetadataService ()

virtual	~sbFileMetadataService ()

nsresult	Init ()

nsresult	GetQueuedJobItem (PRBool aMainThreadOnly, sbMetadataJobItem **aJobItem)

nsresult	PutProcessedJobItem (sbMetadataJobItem *aJobItem)

nsresult	GetJobItemIsBlocked (sbMetadataJobItem aJobItem, PRBool aJobItemIsBlocked)

Public Member Functions inherited from sbIFileMetadataService
sbIJobProgress	read (in nsIArray aMediaItemArray)
	Start a processing job to read metadata from the files associated with the given media items. More...

sbIJobProgress	write (in nsIArray aMediaItemArray, in nsIStringEnumerator aRequiredProperties)
	Start a processing job to write metadata from the given media items back to their associated files. More...

void	restartProcessors (in unsigned short aProcessorsToRestart)
	Restart the processors. More...

Public Member Functions inherited from sbPIFileMetadataService
void	AddBlacklistURL (in ACString aURL)

Protected Member Functions
nsresult	ProxiedRestartProcessors (PRUint16 aProcessorsToRestart)
	Proxied version of RestartProcessors present on the sbIFileMetadataService interface. More...

nsresult	ProxiedStartJob (nsIArray aMediaItemsArray, nsIStringEnumerator aRequiredProperties, sbMetadataJob::JobType aJobType, sbIJobProgress **_retval)

nsresult	StartJob (nsIArray aMediaItemsArray, nsIStringEnumerator aRequiredProperties, sbMetadataJob::JobType aJobType, sbIJobProgress **_retval)

nsresult	Shutdown ()

nsresult	EnsureWritePermitted ()

nsresult	UpdateDataRemotes (PRInt64 aJobCount)

Protected Attributes
nsCOMPtr< sbIDataRemote >	mDataCurrentMetadataJobs

nsRefPtr < sbMainThreadMetadataProcessor >	mMainThreadProcessor

nsRefPtr < sbBackgroundThreadMetadataProcessor >	mBackgroundThreadProcessor

PRBool	mInitialized

PRBool	mRunning

nsCOMPtr< nsITimer >	mNotificationTimer

PRLock *	mJobLock

nsTArray< nsRefPtr < sbMetadataJob > >	mJobArray

PRUint32	mNextJobIndex

nsRefPtr< sbMetadataCrashTracker >	mCrashTracker

nsCOMPtr< sbIMediacoreManager >	mMediacoreManager

Additional Inherited Members
Public Attributes inherited from sbIFileMetadataService
const unsigned short	MAIN_THREAD_PROCESSOR = 1
	Main Thread Processor Flag for restartProcessors. More...

const unsigned short	BACKGROUND_THREAD_PROCESSOR = 2
	Background Thread Processor Flag for restartProcessors. More...

Detailed Description

Manages reading and writing metadata to and from sbIMediaItem objects and media files.

Supports the creation of threaded read/write jobs for local media (URIs beginning with file://), and timer driven read jobs for remote media.

Simplified Architecture:

sbFileMetadataService creates and owns all active sbMetadataJobs, which are representations of user read/write requests.
sbMetadataJob keeps sbMetadataJobItems in a waiting list, and is responsible for managing sbIJobProgress requests.
sbFileMetadataService owns two job processors, sbBackgroundThreadMetadataProcessor and sbMainThreadMetadataProcessor, which pull sbMetadataJobItems from waiting jobs, run the associated sbIMetadataJobHandlers, and then give the items back.
When sbMetadataJobItems are returned to a sbMetadataJob, they are handled by reading the found properties (if needed) and tracking progress.
sbFileMetadataService contains a timer that drives sbIJobProgress notification.

[ Processor ] [ Service ] | |-Create-----—>[ Job ]-Create—>[ Handler ]

<---------—Start–
–GetQueuedItem-—>	-GetQueuedItem-—>

The complexity results from the fact that much of the work can only be done on the main thread (due to limitations of sbIMetadataHandlers and Mozilla APIs).

In theory we could do everything on the main thread, but since some handlers do blocking IO this is very undesirable. Instead we run some safe sbIMetadataHandlers on a background thread, and use timers to do all other work on the main thread.

Additional Notes:

All interactions other than GetQueuedJobItem and PutProcessedJobItem must be performed on the main thread.

See Also: sbIJobProgress, sbIFileMetadataService

Definition at line 127 of file sbFileMetadataService.h.

Constructor & Destructor Documentation

NS_DECL_ISUPPORTS NS_DECL_SBIFILEMETADATASERVICE NS_DECL_SBPIFILEMETADATASERVICE NS_DECL_NSIOBSERVER sbFileMetadataService::sbFileMetadataService ( )

sbFileMetadataService::~sbFileMetadataService ( )

virtual

Definition at line 97 of file sbFileMetadataService.cpp.

Member Function Documentation

nsresult sbFileMetadataService::EnsureWritePermitted ( )

protected

Return NS_OK if write jobs are permitted, or NS_ERROR_NOT_AVAILABLE if not.

May prompt the user to permit write jobs.

Definition at line 690 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::GetJobItemIsBlocked	(	sbMetadataJobItem *	aJobItem,
		PRBool *	aJobItemIsBlocked
	)

If completion of the job item specified by aJobItem is blocked (e.g., writing to a playing file), return true in aJobItemIsBlocked; otherwise, return false.

Parameters

aJobItem	Job item to check.
aJobItemIsBlocked	If true, job item is blocked.

Definition at line 524 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::GetQueuedJobItem	(	PRBool	aMainThreadOnly,
		sbMetadataJobItem **	aJobItem
	)

Take a waiting job item for processing from the next active job.

Rotates through available jobs so that they are processed in parallel.

May be called off of the main thread.

Parameters

aMainThreadOnly	If true, will return a job item that needs to be run on the main thread due to implementation details.
aJobItem	The job item to be processed

Returns: NS_ERROR_NOT_AVAILABLE if there are no more items

Definition at line 421 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::Init ( )

Called automatically on first GetService()

Definition at line 107 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::ProxiedRestartProcessors ( PRUint16 aProcessorsToRestart )

protected

Proxied version of RestartProcessors present on the sbIFileMetadataService interface.

Definition at line 238 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::ProxiedStartJob	(	nsIArray *	aMediaItemsArray,
		nsIStringEnumerator *	aRequiredProperties,
		sbMetadataJob::JobType	aJobType,
		sbIJobProgress **	_retval
	)

protected

Calls StartJob on the main thread, proxying if necessary.

Parameters

aMediaItemsArray	Array of sbIMediaItems
aRequiredProperties	String Enumerator of the properties to be written, null for read.
aJobType	Operation to perform (TYPE_READ or TYPE_WRITE)

Returns: An sbIJobProgress interface used to track the work.

Definition at line 283 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::PutProcessedJobItem ( sbMetadataJobItem * aJobItem )

Give back a job item after processing has been attempted.

May be called off of the main thread.

Parameters

aJobItem The job item that has been processed

Definition at line 498 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::Shutdown ( )

protected

Called automatically on library manager shutdown

Definition at line 145 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::StartJob	(	nsIArray *	aMediaItemsArray,
		nsIStringEnumerator *	aRequiredProperties,
		sbMetadataJob::JobType	aJobType,
		sbIJobProgress **	_retval
	)

protected

Create and begin a new job to process the given media items

Notes:

*** MAIN THREAD ONLY ***
All media items must be from the same library

Parameters

aMediaItemsArray	Array of sbIMediaItems
aRequiredProperties	String Enumerator of the properties to be written, null for read.
aJobType	Operation to perform (TYPE_READ or TYPE_WRITE)

Returns: An sbIJobProgress interface used to track the work.

Definition at line 320 of file sbFileMetadataService.cpp.

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nsresult sbFileMetadataService::UpdateDataRemotes ( PRInt64 aJobCount )

protected

Update the legacy dataremote flags based on the job count. Note that job count is passed as a param because UpdateDataRemotes is to be called while mJobArray is locked.

Definition at line 755 of file sbFileMetadataService.cpp.

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Member Data Documentation

nsRefPtr<sbBackgroundThreadMetadataProcessor> sbFileMetadataService::mBackgroundThreadProcessor

protected

Definition at line 249 of file sbFileMetadataService.h.

nsRefPtr<sbMetadataCrashTracker> sbFileMetadataService::mCrashTracker

protected

Definition at line 269 of file sbFileMetadataService.h.

nsCOMPtr<sbIDataRemote> sbFileMetadataService::mDataCurrentMetadataJobs

protected

Definition at line 244 of file sbFileMetadataService.h.

PRBool sbFileMetadataService::mInitialized

protected

Definition at line 251 of file sbFileMetadataService.h.

nsTArray<nsRefPtr<sbMetadataJob> > sbFileMetadataService::mJobArray

protected

Definition at line 261 of file sbFileMetadataService.h.

PRLock* sbFileMetadataService::mJobLock

protected

Definition at line 258 of file sbFileMetadataService.h.

nsRefPtr<sbMainThreadMetadataProcessor> sbFileMetadataService::mMainThreadProcessor

protected

Definition at line 247 of file sbFileMetadataService.h.

nsCOMPtr<sbIMediacoreManager> sbFileMetadataService::mMediacoreManager

protected

Definition at line 272 of file sbFileMetadataService.h.

PRUint32 sbFileMetadataService::mNextJobIndex

protected

Definition at line 265 of file sbFileMetadataService.h.

nsCOMPtr<nsITimer> sbFileMetadataService::mNotificationTimer

protected

Definition at line 255 of file sbFileMetadataService.h.

PRBool sbFileMetadataService::mRunning

protected

Definition at line 252 of file sbFileMetadataService.h.

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

/home/martin/dev/nightingale-hacking/components/mediacore/metadata/manager/src/sbFileMetadataService.h
/home/martin/dev/nightingale-hacking/components/mediacore/metadata/manager/src/sbFileMetadataService.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation