Skip list. More...

#include <SkipList.h>

Inheritance diagram for utl::SkipList:

[legend]

Public Member Functions
	SkipList (bool owner, bool multiSet=false, Ordering *ordering=nullptr, uint_t maxLevel=19)
	Constructor. More...

virtual void	steal (Object &rhs)
	"Steal" the internal representation from another instance. More...

virtual size_t	innerAllocatedSize () const
	Get the "inner" allocated size. More...

Searching
virtual Object *	find (const Object &key) const
	Find an object matching a given key. More...

iterator	findIt (const Object &key) const

iterator	findIt (const Object &key)

void	findIt (const Object &key, BidIt &it) const

virtual void	findIt (const Object &key, BidIt &it)
	Find an object matching a given key. More...

void	findFirstIt (const Object &key, BidIt &it, bool insert=false) const

virtual void	findFirstIt (const Object &key, BidIt &it, bool insert=false)
	Find the first object matching the given key. More...

iterator	findFirstIt (const Object &key, bool insert=false) const
	Find the first object matching the given key. More...

iterator	findFirstIt (const Object &key, bool insert=false)
	Find the first object matching the given key. More...

void	findLastIt (const Object &key, BidIt &it) const

virtual void	findLastIt (const Object &key, BidIt &it)
	Find the last object matching the given key. More...

iterator	findLastIt (const Object &key) const
	Find the last object matching the given key. More...

iterator	findLastIt (const Object &key)
	Find the last object matching the given key. More...

Adding Objects
bool	add (const Object &object)

virtual bool	add (const Object *object)
	Add an object to the collection. More...

void	add (const Collection &collection)

void	insert (const Object &object, const BidIt &it)

virtual void	insert (const Object *object, const BidIt &it)
	Insert an object before the pointed-to location. More...

Removing Objects
virtual void	clear ()
	Clear the collection by removing all objects. More...

bool	remove (const Object *key)

virtual bool	remove (const Object &key)
	Remove the object matching the given key. More...

virtual void	removeIt (BidIt &it)
	Remove the object the given iterator points to. More...

Iterators
iterator	begin () const

iterator	begin ()

virtual BidIt *	beginNew () const
	Return a const iterator pointing to the beginning of the collection. More...

virtual BidIt *	beginNew ()
	Return an iterator pointing to the beginning of the collection. More...

iterator	end () const

iterator	end ()

virtual BidIt *	endNew () const
	Return a const iterator pointing to the end of the collection. More...

virtual BidIt *	endNew ()
	Return an iterator pointing to the end of the collection. More...

Public Member Functions inherited from utl::SortedCollection
void	clobber (const SortedCollection *rhs)
	Where self and rhs intersect, make self's object equal to the rhs version (i.e. More...

virtual int	compare (const Object &rhs) const
	Compare with another SortedCollection by comparing contained objects. More...

virtual Object *	addOrFind (const Object *object)
	Add the given object, or find a matching object already contained. More...

virtual bool	addOrUpdate (const Object *object)
	Add or update the given object. More...

void	insert (const Object &object, const BidIt &it)
	Insert an object before the pointed-to location. More...

void	reverse ()
	Reverse the order of the contained objects. More...

void	setOrdering (const Ordering &ordering, uint_t algorithm=sort_quickSort)
	Set the ordering, and optionally sort the collection to reflect the new ordering. More...

virtual void	setOrdering (Ordering *ordering, uint_t algorithm=sort_quickSort)
	Set the ordering, and optionally sort the collection to reflect the new ordering. More...

void	findEqualRange (const Object &key, BidIt &begin, BidIt &end) const
	Find the range elements [begin,end) that match a given key. More...

virtual void	findEqualRange (const Object &key, BidIt &begin, BidIt &end)
	Find the range of elements [begin,end) that match a given key. More...

void	findFirstIt (const Object &key, BidIt &it, bool insert=false) const
	Find the first object matching the given key. More...

void	findLastIt (const Object &key, BidIt &it) const
	Find the last object matching the given key. More...

Object *	findLinear (const Object &key) const
	Linear search for an object matching the given key. More...

Object *	findLinearSorted (const Object &key) const
	Linear search for an object matching the given key. More...

bool	remove (const Object *key)

void	remove (const SortedCollection *rhs)
	Remove objects that have a match in rhs. More...

virtual void	removeIt (BidIt &begin, const BidIt &end)
	Remove part of the collection. More...

SortedCollection &	operator-= (const SortedCollection &rhs)
	Remove objects that have a match in rhs. More...

Collection *	difference (const SortedCollection rhs, Collection out=nullptr) const
	Determine the difference between self and rhs. More...

void	intersect (const SortedCollection *rhs)
	Set self to the intersection of self and rhs. More...

Collection *	intersection (const SortedCollection rhs, Collection out=nullptr, bool multiSet=false) const
	Determine the intersection of self and rhs. More...

size_t	intersectCard (const SortedCollection *rhs) const
	Determine the cardinality of the intersection of self and rhs. More...

bool	intersects (const SortedCollection *rhs) const
	Determine whether the intersection of self and rhs is non-empty. More...

bool	isSubSet (const SortedCollection *rhs) const
	Determine whether self is a subset of rhs. More...

bool	isSuperSet (const SortedCollection *rhs) const
	Determine whether self is a superset of rhs. More...

Collection *	merge (const SortedCollection rhs, Collection out=nullptr) const
	Merge with rhs to form a single sorted sequence. More...

Collection *	symmetricDifference (const SortedCollection rhs, Collection out=nullptr) const
	Determine the symmetric difference of self and rhs. More...

void	symmetricDifference (const SortedCollection rhs, Collection lhsOut, Collection *rhsOut) const
	Determine the symmetric difference of self and rhs. More...

Collection *	unique (Collection *out=nullptr)
	Remove duplicate objects. More...

SortedCollection &	operator &= (const SortedCollection *rhs)
	Intersect with rhs. More...

bool	operator<= (const SortedCollection *rhs)
	Determine whether self is a subset of rhs. More...

bool	operator>= (const SortedCollection *rhs)
	Determine whether self is a superset of rhs. More...

bool	testSorted () const
	Determine whether the collection is sorted (often useful for testing). More...

void	multiKeyQuickSort (bool key=true, bool reverse=false)
	Multi-key quick-sort the collection. More...

void	sort ()
	Sort the collection using the quicksort algorithm. More...

virtual void	sort (uint_t algorithm)
	Sort the collection using the given algorithm. More...

Public Member Functions inherited from utl::Collection
void	assertOwner ()
	Assert ownership of contained objects. More...

virtual void	copy (const Object &rhs)
	Copy another instance. More...

virtual void	vclone (const Object &rhs)
	Make an exact copy of another instance. More...

virtual void	dump (Stream &os, uint_t level=uint_t_max) const
	Dump a human-readable representation of self to the given output stream. More...

virtual void	serialize (Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize to or from a stream. More...

void	serialize (const RunTimeClass *rtc, Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize to/from the given stream. More...

virtual bool	update (const Object *object)
	Update the given object. More...

bool	isOwner () const
	Get the owner flag. More...

void	setOwner (bool owner)
	Set the owner flag. More...

const Ordering *	ordering () const
	Get the ordering. More...

Ordering *	ordering ()
	Get the ordering. More...

void	setOrdering (const Ordering &ordering, uint_t algorithm=sort_quickSort)
	Set the ordering, and optionally sort the collection to reflect the new ordering. More...

bool	empty () const
	Determine whether the collection is empty. More...

bool	isMultiSet () const
	Get the multiSet flag. More...

void	setMultiSet (bool multiSet)
	Set the multiSet flag. More...

bool	isMarked () const
	Get marked flag. More...

void	setMarked (bool marked=true)
	Set marked flag. More...

size_t	items () const
	Get the number of contained objects. More...

size_t	size () const
	Get the number of contained objects. More...

bool	add (const Object &object)
	Add an object to the collection. More...

void	add (const Collection &collection)
	Add another collection's objects. More...

virtual BidIt *	addIt (const Object *object)
	Add an object to the collection. More...

Object *	addOrFind (const Object &object)
	Add the given object, or find a matching object already contained. More...

bool	addOrUpdate (const Object &object)
	Add or update the given object. More...

Collection &	copyItems (const Collection src, const Predicate pred=nullptr, bool predVal=true)
	Copy objects from another collection. More...

Collection &	copyItems (const ListNode src, const Predicate pred=nullptr, bool predVal=true)
	Copy objects from a double-linked list. More...

Collection &	copyItems (const SlistNode src, const Predicate pred=nullptr, bool predVal=true)
	Copy objects from a single-linked list. More...

Collection &	stealItems (Collection *src)
	"Steal" items from another collection. More...

Collection &	operator+= (const Object &rhs)
	Add an object to the collection. More...

Collection &	operator+= (const Object *rhs)
	Add an object to the collection. More...

Collection &	operator+= (const Collection &rhs)
	Add another collection's objects. More...

Collection &	operator-= (const Object &rhs)
	Remove an object from the collection. More...

void	dump (Stream &os, uint_t level, bool key, bool printClassName, uint_t indent, const char *separator) const
	Dump contained objects to a stream. More...

virtual String	toString () const
	Obtain a string representation by invoking Object::toString() on all contained objects.

String	toString (bool key) const
	Obtain a string representation by invoking Object::toString() on all contained objects (or their keys). More...

String	toString (const char *sep, bool key=false) const
	Obtain a string represenation by invoking Object::toString() on all contained objects (or their keys). More...

String	toString (const String &sep, bool key=false) const
	Obtain a string represenation of the collection by invoking Object::toString() on all contained objects (or their keys). More...

iterator	begin () const
	Return a const iterator pointing to the first object in the collection. More...

iterator	begin ()
	Return an iterator pointing to the first object in the collection. More...

virtual BidIt *	createIt () const
	Create a const iterator. More...

virtual BidIt *	createIt ()
	Create an iterator. More...

iterator	end () const
	Return a const iterator pointing to the end of the collection. More...

iterator	end ()
	Return an iterator pointing to the end of the collection. More...

bool	contains (const Object *key) const
	Determine whether the collection contains an object matching the given key. More...

bool	contains (const Object &key) const
	Determine whether the collection contains an object matching the given key. More...

size_t	count (const Predicate *pred=nullptr, bool predVal=true) const
	Count contained objects. More...

Object *	find (const Object *key) const
	Find an object matching a given key. More...

void	findIt (const Object &key, BidIt &it) const
	Find an object matching a given key. More...

Object *	first () const
	Return the first object (nullptr if empty). More...

bool	has (const Object *key) const
	See contains(). More...

bool	has (const Object &key) const
	See contains(). More...

Object *	last () const
	Get the last object (nullptr if empty). More...

bool	remove (const Object *key)
	Remove the object matching the given key. More...

Object *	take (BidIt &it)
	Remove the object the given iterator points to, but do not delete the object even if the collection owns its objects. More...

Object *	operator[] (const Object *object)
	add-or-find access operator (returns Object*). More...

Object &	operator() (const Object *object)
	add-or-find access operator (returns Object&). More...

Public Member Functions inherited from utl::Object
void	clear ()
	Revert to initial state. More...

void	dumpWithClassName (Stream &os, uint_t indent=4, uint_t level=uint_t_max) const
	Front-end for dump() that prints the object's class name. More...

virtual const Object &	getKey () const
	Get the key for this object. More...

bool	hasKey () const
	Determine whether or not the object has a key. More...

virtual const Object &	getProxiedObject () const
	Get the proxied object (= self if none). More...

virtual Object &	getProxiedObject ()
	Get the proxied object (= self if none). More...

virtual size_t	hash (size_t size) const
	Get the hash code for the object. More...

bool	_isA (const RunTimeClass *runTimeClass) const
	Determine whether self's class is a descendent of the given class. More...

	operator String () const
	Conversion to String. More...

size_t	allocatedSize () const
	Get the total allocated size of this object. More...

virtual void	addOwnedIt (const class FwdIt *it) const
	Notify self that it owns the given iterator. More...

virtual void	removeOwnedIt (const class FwdIt *it) const
	Notify self that the given owned iterator has been destroyed. More...

bool	operator< (const Object &rhs) const
	Less-than operator. More...

bool	operator<= (const Object &rhs) const
	Less-than-or-equal-to operator. More...

bool	operator> (const Object &rhs) const
	Greater-than operator. More...

bool	operator>= (const Object &rhs) const
	Greater-than-or-equal-to operator. More...

bool	operator== (const Object &rhs) const
	Equal-to operator. More...

bool	operator!= (const Object &rhs) const
	Unequal-to operator. More...

void	serializeIn (Stream &is, uint_t mode=ser_default)
	Serialize from an input stream. More...

void	serializeOut (Stream &os, uint_t mode=ser_default) const
	Serialize to an output stream. More...

void	serializeOutBoxed (Stream &os, uint_t mode=ser_default) const
	Serialize a boxed object to an output stream. More...

Additional Inherited Members
Static Public Member Functions inherited from utl::Object
static Object *	serializeInNullable (Stream &is, uint_t mode=ser_default)
	Serialize a nullptr-able object from an input stream. More...

static void	serializeOutNullable (const Object *object, Stream &os, uint_t mode=ser_default)
	Serialize a nullptr-able object to an output stream. More...

static void	serializeNullable (Object *&object, Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize a nullptr-able object to or from a stream. More...

static Object *	serializeInBoxed (Stream &is, uint_t mode=ser_default)
	Serialize a boxed object from an input stream. More...

static void	serializeBoxed (Object *&object, Stream &stream, uint_t io, uint_t mode=ser_default)
	Serialize a boxed object to or from a stream. More...

Protected Member Functions inherited from utl::FlagsMI
	FlagsMI ()
	Constructor. More...

virtual	~FlagsMI ()
	Destructor. More...

void	copyFlags (const FlagsMI &rhs)
	Copy the given flags. More...

void	copyFlags (const FlagsMI &rhs, uint_t lsb, uint_t msb)
	Copy (some of) the given flags. More...

void	copyFlags (uint64_t flags, uint_t lsb, uint_t msb)
	Copy (some of) the given flags. More...

bool	getFlag (uint_t flagNum) const
	Get a user-defined flag. More...

void	setFlag (uint_t flagNum, bool val)
	Set a user-defined flag. More...

uint64_t	getFlagsNumber (uint64_t mask, uint64_t shift=0)
	Get a multi-bit value in the flags data (which is stored as one 64-bit integer). More...

void	setFlagsNumber (uint64_t mask, uint64_t shift, uint64_t num)
	Set a multi-bit value in the flags data (which is stored as one 64-bit integer). More...

uint64_t	getFlags () const
	Get the flags. More...

void	setFlags (uint64_t flags)
	Set the flags. More...

Detailed Description

Skip list.

A skip list is simpler to implement and understand than a balanced binary tree. In theory, the performance characteristics of a skip list are similar to those of a balanced binary tree. In my own performance tests, I found that for adding & removing objects, this implementation is slower than RBtree by a constant (but significant) factor. On the other hand, the iteration performance of SkipList is markedly superior to that of RBtree (since there is no need to do inorder traversal of a tree structure). I encourage you to look at the code to see how it can be optimized. I'll happily accept any patches that help the performance.

For practical use, I would recommend RBtree over SkipList. I leave SkipList in the library for educational purposes.

If you decide to use SkipList or experiment with it, I recommend you set maxLevel (in the constructor) based on your expectation of how many objects the data structure will contain. The default value of maxLevel is 19 which is appropriate for storing around 2^20 objects (just over one million). If you expected to store up to about sixty thousand objects, you'd use a maxLevel of 15 (2^16 = 65,536). If you aren't sure how many objects the structure will contain, you're probably better off to err on the side of a larger value for maxLevel.

Author: Adam McKee

Definition at line 51 of file SkipList.h.

Constructor & Destructor Documentation

◆ SkipList()

utl::SkipList::SkipList	(	bool	owner,
		bool	multiSet = `false`,
		Ordering *	ordering = `nullptr`,
		uint_t	maxLevel = `19`
	)

inline

Constructor.

Parameters

owner	owner flag
multiSet	(optional : false) multiSet flag
ordering	(optional) ordering
maxLevel	(optional : 19) number of levels minus one

Definition at line 67 of file SkipList.h.

References ASSERTD, const_cast_this, utl::deInit(), utl::find_first, IFDEBUG, utl::init(), and utl::FwdIt::setConst().

Member Function Documentation

◆ steal()

virtual void utl::SkipList::steal ( Object & rhs )

virtual

"Steal" the internal representation from another instance.

The default implementation just calls vclone(), so you have to override this if you want a "move" capability.

Reimplemented from utl::Collection.

◆ innerAllocatedSize()

virtual size_t utl::SkipList::innerAllocatedSize ( ) const

virtual

Get the "inner" allocated size.

Reimplemented from utl::Collection.

◆ find()

virtual Object* utl::SkipList::find ( const Object & key ) const

virtual

Find an object matching a given key.

Returns: found object (nullptr if none)

Parameters

key	search key

Reimplemented from utl::Collection.

◆ findIt()

virtual void utl::SkipList::findIt	(	const Object &	key,
		BidIt &	it
	)

virtual

Find an object matching a given key.

Parameters

key	search key
it	result iterator (= end() if no object found)

Reimplemented from utl::Collection.

◆ findFirstIt() [1/3]

virtual void utl::SkipList::findFirstIt	(	const Object &	key,
		BidIt &	it,
		bool	insert = `false`
	)

virtual

Find the first object matching the given key.

Parameters

key	search key
it	result iterator (= end if no object found)
insert	(optional : false) find insertion point?

Reimplemented from utl::SortedCollection.

Reimplemented in utl::TSkipList< T >.

◆ findFirstIt() [2/3]

iterator utl::SkipList::findFirstIt	(	const Object &	key,
		bool	insert = `false`
	)		const

Find the first object matching the given key.

Returns: const iterator for found object (= end if none found)

Parameters

key	search key
insert	(optional : false) find insertion point?

◆ findFirstIt() [3/3]

iterator utl::SkipList::findFirstIt	(	const Object &	key,
		bool	insert = `false`
	)

Find the first object matching the given key.

Returns: iterator for found object (= end if none found)

Parameters

key	search key
insert	(optional : false) find insertion point?

◆ findLastIt() [1/3]

virtual void utl::SkipList::findLastIt	(	const Object &	key,
		BidIt &	it
	)

virtual

Find the last object matching the given key.

Parameters

key	search key
it	result iterator (= end if no object found)

Reimplemented from utl::SortedCollection.

Reimplemented in utl::TSkipList< T >.

◆ findLastIt() [2/3]

iterator utl::SkipList::findLastIt ( const Object & key ) const

Find the last object matching the given key.

Returns: const iterator for found object (= end if none found)

Parameters

key	search key

◆ findLastIt() [3/3]

iterator utl::SkipList::findLastIt ( const Object & key )

Find the last object matching the given key.

Returns: iterator for found object (= end if none found)

Parameters

key	search key

◆ add()

virtual bool utl::SkipList::add ( const Object * object )

virtual

Add an object to the collection.

Returns: true if successful, false otherwise

Parameters

object object to add

Implements utl::Collection.

◆ insert()

virtual void utl::SkipList::insert	(	const Object *	object,
		const BidIt &	it
	)

virtual

Insert an object before the pointed-to location.

Parameters

object	object being inserted
it	reference location

Reimplemented from utl::SortedCollection.

◆ clear()

virtual void utl::SkipList::clear ( )

virtual

Clear the collection by removing all objects.

Implements utl::Collection.

◆ remove()

virtual bool utl::SkipList::remove ( const Object & key )

virtual

Remove the object matching the given key.

Returns: true if object found and removed, false otherwise

Parameters

key	search key

Reimplemented from utl::SortedCollection.

Reimplemented in utl::TSkipList< T >.

◆ removeIt()

virtual void utl::SkipList::removeIt ( BidIt & it )

virtual

Remove the object the given iterator points to.

Parameters

it iterator

Reimplemented from utl::SortedCollection.

◆ beginNew() [1/2]

BidIt * utl::SkipList::beginNew ( ) const

inlinevirtual

Return a const iterator pointing to the beginning of the collection.

Implements utl::Collection.

Definition at line 163 of file SkipListIt.h.

References IFDEBUG, and utl::FwdIt::setConst().

◆ beginNew() [2/2]

BidIt * utl::SkipList::beginNew ( )

inlinevirtual

Return an iterator pointing to the beginning of the collection.

Implements utl::Collection.

Definition at line 173 of file SkipListIt.h.

References IFDEBUG, and utl::FwdIt::setConst().

◆ endNew() [1/2]

BidIt * utl::SkipList::endNew ( ) const

inlinevirtual

Return a const iterator pointing to the end of the collection.

Implements utl::Collection.

Definition at line 199 of file SkipListIt.h.

References IFDEBUG, and utl::FwdIt::setConst().

◆ endNew() [2/2]

BidIt * utl::SkipList::endNew ( )

inlinevirtual

Return an iterator pointing to the end of the collection.

Implements utl::Collection.

Definition at line 209 of file SkipListIt.h.

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

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SkipList()

Member Function Documentation

◆ steal()

◆ innerAllocatedSize()

◆ find()

◆ findIt()

◆ findFirstIt() [1/3]

◆ findFirstIt() [2/3]

◆ findFirstIt() [3/3]

◆ findLastIt() [1/3]

◆ findLastIt() [2/3]

◆ findLastIt() [3/3]

◆ add()

◆ insert()

◆ clear()

◆ remove()

◆ removeIt()

◆ beginNew() [1/2]

◆ beginNew() [2/2]

◆ endNew() [1/2]

◆ endNew() [2/2]