#include <StorageDrive.h>

Inherits AZ::IO::StreamStackEntry.

Public Member Functions
	StorageDrive (u32 maxFileHandles)

void	SetNext (AZStd::shared_ptr< StreamStackEntry > next) override

void	PrepareRequest (FileRequest *request) override

void	QueueRequest (FileRequest *request) override

bool	ExecuteRequests () override

void	UpdateStatus (Status &status) const override
	Gets a combined status update from all the nodes in the stack.

void	UpdateCompletionEstimates (AZStd::chrono::steady_clock::time_point now, AZStd::vector< FileRequest * > &internalPending, StreamerContext::PreparedQueue::iterator pendingBegin, StreamerContext::PreparedQueue::iterator pendingEnd) override

void	CollectStatistics (AZStd::vector< Statistic > &statistics) const override

Public Member Functions inherited from AZ::IO::StreamStackEntry
	StreamStackEntry (AZStd::string &&name)

virtual const AZStd::string &	GetName () const
	Returns the name that uniquely identifies this entry.

virtual void	SetNext (AZStd::shared_ptr< StreamStackEntry > next)

virtual AZStd::shared_ptr< StreamStackEntry >	GetNext () const

virtual void	SetContext (StreamerContext &context)

virtual void	PrepareRequest (FileRequest *request)

virtual void	QueueRequest (FileRequest *request)

virtual bool	ExecuteRequests ()

virtual void	UpdateStatus (Status &status) const
	Gets a combined status update from all the nodes in the stack.

virtual void	UpdateCompletionEstimates (AZStd::chrono::steady_clock::time_point now, AZStd::vector< FileRequest * > &internalPending, StreamerContext::PreparedQueue::iterator pendingBegin, StreamerContext::PreparedQueue::iterator pendingEnd)

virtual void	CollectStatistics (AZStd::vector< Statistic > &statistics) const

Protected Member Functions
size_t	FindFileInCache (const RequestPath &filePath) const

void	ReadFile (FileRequest *request)

void	CancelRequest (FileRequest *cancelRequest, FileRequestPtr &target)

void	FileExistsRequest (FileRequest *request)

void	FileMetaDataRetrievalRequest (FileRequest *request)

void	FlushCache (const RequestPath &filePath)

void	FlushEntireCache ()

void	EstimateCompletionTimeForRequest (FileRequest request, AZStd::chrono::steady_clock::time_point &startTime, const RequestPath &activeFile, u64 &activeOffset) const

void	Report (const Requests::ReportData &data) const

Protected Attributes
TimedAverageWindow< s_statisticsWindowSize >	m_fileOpenCloseTimeAverage

TimedAverageWindow< s_statisticsWindowSize >	m_getFileExistsTimeAverage

TimedAverageWindow< s_statisticsWindowSize >	m_getFileMetaDataTimeAverage

TimedAverageWindow< s_statisticsWindowSize >	m_readTimeAverage

AverageWindow< u64, float, s_statisticsWindowSize >	m_readSizeAverage

AZStd::deque< FileRequest * >	m_pendingRequests
	File requests that are queued for processing.

AZStd::vector< AZStd::chrono::steady_clock::time_point >	m_fileLastUsed
	The last time a file handle was used to access a file. The handle is stored in m_fileHandles.

AZStd::vector< RequestPath >	m_filePaths
	The file path to the file handle. The handle is stored in m_fileHandles.

AZStd::vector< AZStd::unique_ptr< SystemFile > >	m_fileHandles
	A list of file handles that's being cached in case they're needed again in the future.

u64	m_activeOffset = 0
	The offset into the file that's cached by the active cache slot.

size_t	m_activeCacheSlot = s_fileNotFound
	The index into m_fileHandles for the file that's currently being read.

Protected Attributes inherited from AZ::IO::StreamStackEntry
AZStd::string	m_name
	The name that uniquely identifies this entry.

AZStd::shared_ptr< StreamStackEntry >	m_next
	The next entry in the stack.

StreamerContext *	m_context
	Context information for the entire streaming stack.

Static Protected Attributes
static const AZStd::chrono::microseconds	s_averageSeekTime

static constexpr s32	s_maxRequests = 1

Detailed Description

Platform agnostic version of a storage drive, such as hdd, ssd, dvd, etc. This stream stack entry is responsible for accessing a storage drive to retrieve file information and data. This entry is designed as a catch-all for any reads that weren't handled by platform specific implementations or the virtual file system. It should by the last entry in the stack as it will not forward calls to the next entry.

Member Function Documentation

◆ CollectStatistics()

void AZ::IO::StorageDrive::CollectStatistics ( AZStd::vector< Statistic > & statistics ) const

overridevirtual

Collect various statistics on this stack entry. These are for profiling and debugging purposes only.

Reimplemented from AZ::IO::StreamStackEntry.

◆ ExecuteRequests()

bool AZ::IO::StorageDrive::ExecuteRequests ( )

overridevirtual

Executes one or more queued requests. This is needed for synchronously executing requests, but asynchronous requests can already be running from the PrepareRequest call in which case this call is ignored.

Returns: True if a request was processed, otherwise false.

Reimplemented from AZ::IO::StreamStackEntry.

◆ PrepareRequest()

void AZ::IO::StorageDrive::PrepareRequest ( FileRequest * request )

overridevirtual

Prepare an external request for processing. This can include resolving file paths, create more specific internal requests, etc. The returned will be queued for further processing by QueueRequest and ExecuteRequest.

Reimplemented from AZ::IO::StreamStackEntry.

◆ QueueRequest()

void AZ::IO::StorageDrive::QueueRequest ( FileRequest * request )

overridevirtual

Queues a request to be executed at a later point when ExecuteRequests is called. This can include splitting up the request in more fine-grained steps.

Reimplemented from AZ::IO::StreamStackEntry.

◆ SetNext()

void AZ::IO::StorageDrive::SetNext ( AZStd::shared_ptr< StreamStackEntry > next )

overridevirtual

Set the next entry in the stack or reset it by using a nullptr. If the next entry has already been set, this will overwrite it.

Reimplemented from AZ::IO::StreamStackEntry.

◆ UpdateCompletionEstimates()

void AZ::IO::StorageDrive::UpdateCompletionEstimates	(	AZStd::chrono::steady_clock::time_point	now,
		AZStd::vector< FileRequest * > &	internalPending,
		StreamerContext::PreparedQueue::iterator	pendingBegin,
		StreamerContext::PreparedQueue::iterator	pendingEnd
	)

overridevirtual

Updates the estimate of the time the requests will complete. This generally works by bubbling up the estimation and each stack entry adding it's additional overhead if any. When chaining this call, first call the next entry in the stack before adding the current entry's estimate.

Parameters

now	The current time. This is captured once to avoid repeatedly querying the system clock.
internalPending	The requests that are pending in the stream stack. These are always estimated as coming after the queued requests. Because this call will go from the top of the stack to the bottom, but estimation is calculated from the bottom to the top, this list should be processed in reverse order.
pendingBegin	Iterator pointing to the start of the requests that are waiting for a processing slot in the stack.
pendingEnd	Iterator pointing to the end of the requests that are waiting for a processing slot in the stack.

Reimplemented from AZ::IO::StreamStackEntry.

◆ UpdateStatus()

void AZ::IO::StorageDrive::UpdateStatus ( Status & status ) const

overridevirtual

Gets a combined status update from all the nodes in the stack.

Reimplemented from AZ::IO::StreamStackEntry.

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

Code/Framework/AzCore/AzCore/IO/Streamer/StorageDrive.h

Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Member Function Documentation

◆ CollectStatistics()

◆ ExecuteRequests()

◆ PrepareRequest()

◆ QueueRequest()

◆ SetNext()

◆ UpdateCompletionEstimates()

◆ UpdateStatus()