Qx::FreeIndexTracker Class Reference

The FreeIndexTracker class tracks which slots from a given range of indices are in use and which are available. More...

#include <qx/core/qx-freeindextracker.h>

Public Member Functions
	FreeIndexTracker (quint64 min=0, quint64 max=1, QSet< quint64 > reserved=QSet< quint64 >())
std::optional< quint64 >	firstFree () const
std::optional< quint64 >	firstReserved () const
quint64	free () const
bool	isBooked () const
bool	isReserved (quint64 index) const
std::optional< quint64 >	lastFree () const
std::optional< quint64 >	lastReserved () const
quint64	maximum () const
quint64	minimum () const
std::optional< quint64 >	nearestFree (quint64 index) const
std::optional< quint64 >	nextFree (quint64 index) const
std::optional< quint64 >	previousFree (quint64 index) const
quint64	range () const
bool	release (quint64 index)
bool	reserve (quint64 index)
quint64	reserved () const
std::optional< quint64 >	reserveFirstFree ()
std::optional< quint64 >	reserveLastFree ()
std::optional< quint64 >	reserveNearestFree (quint64 index)
std::optional< quint64 >	reserveNextFree (quint64 index)
std::optional< quint64 >	reservePreviousFree (quint64 index)

Detailed Description

The range of an index tracker can be expanded or contracted, and indices within that range can be reserved or released. An example use-case for this class might be tracking which spaces in a parking lot are free.

Constructor & Destructor Documentation

FreeIndexTracker()

Qx::FreeIndexTracker::FreeIndexTracker	(	quint64	min = 0,
		quint64	max = 1,
		QSet< quint64 >	reserved = QSet<quint64>() )

Creates an index tracker for the range min to max, with the indices from reserved already reserved.

If any of the values within reserved fall outside the range of min:max, the range of the tracker will automatically be resized to cover them.

Warning

min must be less than max.

Member Function Documentation

firstFree()

std::optional< quint64 > Qx::FreeIndexTracker::firstFree

(

)

const

Returns the lowest available index, or std::nullopt if all are reserved.

firstReserved()

std::optional< quint64 > Qx::FreeIndexTracker::firstReserved

(

)

const

Returns the lowest index that is currently reserved, or std::nullopt if all are free.

free()

quint64 Qx::FreeIndexTracker::free

(

)

const

Returns the number of unoccupied indices.

isBooked()

bool Qx::FreeIndexTracker::isBooked

(

)

const

Returns true if all indices are reserved; otherwise, returns false.

isReserved()

bool Qx::FreeIndexTracker::isReserved

(

quint64

index

)

const

Returns true if index is occupied; otherwise returns false.

lastFree()

std::optional< quint64 > Qx::FreeIndexTracker::lastFree

(

)

const

Returns the highest available index, or std::nullopt if all are reserved.

lastReserved()

std::optional< quint64 > Qx::FreeIndexTracker::lastReserved

(

)

const

Returns the highest index that is currently reserved, or std::nullopt if all are free.

maximum()

quint64 Qx::FreeIndexTracker::maximum

(

)

const

Returns the upper bound of the index tracker.

minimum()

quint64 Qx::FreeIndexTracker::minimum

(

)

const

Returns the lower bound of the index tracker.

nearestFree()

std::optional< quint64 > Qx::FreeIndexTracker::nearestFree

(

quint64

index

)

const

Returns the nearest free index to index, or std::nullopt if all are reserved.

nextFree()

std::optional< quint64 > Qx::FreeIndexTracker::nextFree

(

quint64

index

)

const

Returns the nearest free index that is at or after index, or std::nullopt if all are reserved.

previousFree()

std::optional< quint64 > Qx::FreeIndexTracker::previousFree

(

quint64

index

)

const

Returns the nearest free index that is at or before index, or std::nullopt if all are reserved.

range()

quint64 Qx::FreeIndexTracker::range

(

)

const

Returns the range of indices that the tracker covers.

This function is equivalent to (maximum() - minimum()) + 1.

release()

bool Qx::FreeIndexTracker::release

(

quint64

index

)

Attempts to mark index as unoccupied and returns true if successful, or false if the index was already free.

reserve()

bool Qx::FreeIndexTracker::reserve

(

quint64

index

)

Attempts to mark index as occupied and returns true if successful, or false if the index was already reserved.

reserved()

quint64 Qx::FreeIndexTracker::reserved

(

)

const

Returns the number of occupied indices.

reserveFirstFree()

std::optional< quint64 > Qx::FreeIndexTracker::reserveFirstFree

(

)

Attempts to mark the lowest available index as occupied and return it if successful, or std::nullopt if there are no free indices.

reserveLastFree()

std::optional< quint64 > Qx::FreeIndexTracker::reserveLastFree

(

)

Attempts to mark the highest available index as occupied and return it if successful, or std::nullopt if there are no free indices.

reserveNearestFree()

std::optional< quint64 > Qx::FreeIndexTracker::reserveNearestFree

(

quint64

index

)

Attempts to mark the nearest free index to index as occupied and returns it if successful, or std::nullopt if there are no free indices.

reserveNextFree()

std::optional< quint64 > Qx::FreeIndexTracker::reserveNextFree

(

quint64

index

)

Attempts to mark the nearest free index that is at or after index as occupied and returns it if successful, or std::nullopt if there are no free indices.

reservePreviousFree()

std::optional< quint64 > Qx::FreeIndexTracker::reservePreviousFree

(

quint64

index

)

Attempts to mark the nearest free index that is at or before index as occupied and returns it if successful, or std::nullopt if there are no free indices.

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

• qx-freeindextracker.h
• qx-freeindextracker.cpp