A utility class designed to help decide whether to store cache data (for example FFT outputs) in memory or on disk in the TempDirectory. More...

#include <StorageAdviser.h>

Public Types
enum	Criteria { NoCriteria = 0, SpeedCritical = 1, PrecisionCritical = 2, LongRetentionLikely = 4, FrequentLookupLikely = 8 }

enum	Recommendation { NoRecommendation = 0, UseMemory = 1, PreferMemory = 2, PreferDisc = 4, UseDisc = 8, ConserveSpace = 16, UseAsMuchAsYouLike = 32 }

enum	AllocationArea { MemoryAllocation, DiscAllocation }

Static Public Member Functions
static Recommendation	recommend (Criteria criteria, size_t minimumSize, size_t maximumSize)
	Recommend where to store some data, given certain storage and recall criteria. More...

static void	notifyPlannedAllocation (AllocationArea area, size_t size)
	Specify that we are planning to use a given amount of storage (in kilobytes), but haven't allocated it yet. More...

static void	notifyDoneAllocation (AllocationArea area, size_t size)
	Specify that we have now allocated, or abandoned the allocation of, the given amount (in kilobytes) of a storage area that was previously notified using notifyPlannedAllocation. More...

static void	setFixedRecommendation (Recommendation recommendation)
	Force all subsequent recommendations to use the (perhaps partial) specification given here. More...

Private Types
enum	StorageStatus { Unknown, Insufficient, Marginal, Sufficient }

Static Private Member Functions
static QString	criteriaToString (int)

static QString	recommendationToString (int)

static QString	storageStatusToString (StorageStatus)

Static Private Attributes
static size_t	m_discPlanned = 0

static size_t	m_memoryPlanned = 0

static Recommendation	m_baseRecommendation = StorageAdviser::NoRecommendation

Detailed Description

A utility class designed to help decide whether to store cache data (for example FFT outputs) in memory or on disk in the TempDirectory.

This is basically a compendium of simple rules of thumb.

Definition at line 30 of file StorageAdviser.h.

Member Enumeration Documentation

enum StorageAdviser::Criteria

Enumerator
NoCriteria
SpeedCritical
PrecisionCritical
LongRetentionLikely
FrequentLookupLikely

Definition at line 34 of file StorageAdviser.h.

enum StorageAdviser::Recommendation

Enumerator
NoRecommendation
UseMemory
PreferMemory
PreferDisc
UseDisc
ConserveSpace
UseAsMuchAsYouLike

Definition at line 43 of file StorageAdviser.h.

enum StorageAdviser::AllocationArea

Enumerator
MemoryAllocation
DiscAllocation

Definition at line 67 of file StorageAdviser.h.

enum StorageAdviser::StorageStatus

private

Enumerator
Unknown
Insufficient
Marginal
Sufficient

Definition at line 97 of file StorageAdviser.h.

Member Function Documentation

StorageAdviser::Recommendation StorageAdviser::recommend	(	Criteria	criteria,
		size_t	minimumSize,
		size_t	maximumSize
	)

static

Recommend where to store some data, given certain storage and recall criteria.

The minimum size is the approximate amount of data in kilobytes that will be stored if the recommendation is to ConserveSpace; the maximum size is approximately the amount that will be used if UseAsMuchAsYouLike is returned.

May throw InsufficientDiscSpace exception if there appears to be nowhere the minimum amount of data can be stored.

!! We have a potentially serious problem here if multiple

Definition at line 67 of file StorageAdviser.cpp.

References ConserveSpace, criteriaToString(), FrequentLookupLikely, GetDiscSpaceMBAvailable(), TempDirectory::getInstance(), TempDirectory::getPath(), GetRealMemoryMBAvailable(), Insufficient, LongRetentionLikely, m_baseRecommendation, m_discPlanned, m_memoryPlanned, Marginal, NoRecommendation, PrecisionCritical, PreferDisc, PreferMemory, recommendationToString(), SpeedCritical, storageStatusToString(), Sufficient, SVDEBUG, Unknown, UseAsMuchAsYouLike, UseDisc, and UseMemory.

Referenced by AudioFileReaderFactory::createReader().

void StorageAdviser::notifyPlannedAllocation	(	AllocationArea	area,
		size_t	size
	)

static

Specify that we are planning to use a given amount of storage (in kilobytes), but haven't allocated it yet.

Definition at line 248 of file StorageAdviser.cpp.

References DiscAllocation, m_discPlanned, m_memoryPlanned, MemoryAllocation, and SVDEBUG.

Referenced by CodedAudioFileReader::finishDecodeCache().

void StorageAdviser::notifyDoneAllocation	(	AllocationArea	area,
		size_t	size
	)

static

Specify that we have now allocated, or abandoned the allocation of, the given amount (in kilobytes) of a storage area that was previously notified using notifyPlannedAllocation.

Definition at line 257 of file StorageAdviser.cpp.

References DiscAllocation, m_discPlanned, m_memoryPlanned, MemoryAllocation, and SVDEBUG.

Referenced by CodedAudioFileReader::~CodedAudioFileReader().

void StorageAdviser::setFixedRecommendation ( Recommendation recommendation )

static

Force all subsequent recommendations to use the (perhaps partial) specification given here.

If NoRecommendation given here, this will reset to the default free behaviour.

Definition at line 271 of file StorageAdviser.cpp.

References m_baseRecommendation.

QString StorageAdviser::criteriaToString ( int criteria )

staticprivate

Definition at line 26 of file StorageAdviser.cpp.