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linked-list.c
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% L IIIII N N K K EEEEE DDDD L IIIII SSSSS TTTTT %
% L I NN N K K E D D L I SS T %
% L I N N N KKK EEE D D = L I SSS T %
% L I N NN K K E D D L I SS T %
% LLLLL IIIII N N K K EEEEE DDDD LLLLL IIIII SSSSS T %
% %
% %
% MagickCore Linked-list Methods %
% %
% Software Design %
% Cristy %
% December 2002 %
% %
% %
% Copyright @ 1999 ImageMagick Studio LLC, a non-profit organization %
% dedicated to making software imaging solutions freely available. %
% %
% You may not use this file except in compliance with the License. You may %
% obtain a copy of the License at %
% %
% https://imagemagick.org/script/license.php %
% %
% Unless required by applicable law or agreed to in writing, software %
% distributed under the License is distributed on an "AS IS" BASIS, %
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
% See the License for the specific language governing permissions and %
% limitations under the License. %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% This module implements the standard handy hash and linked-list methods for
% storing and retrieving large numbers of data elements. It is loosely based
% on the Java implementation of these algorithms.
%
*/
␌
/*
Include declarations.
*/
#include "MagickCore/studio.h"
#include "MagickCore/exception.h"
#include "MagickCore/exception-private.h"
#include "MagickCore/linked-list.h"
#include "MagickCore/linked-list-private.h"
#include "MagickCore/locale_.h"
#include "MagickCore/memory_.h"
#include "MagickCore/memory-private.h"
#include "MagickCore/semaphore.h"
#include "MagickCore/signature-private.h"
#include "MagickCore/string_.h"
␌
/*
Typedef declarations.
*/
struct _LinkedListInfo
{
size_t
capacity,
elements;
ElementInfo
*head,
*tail,
*next;
SemaphoreInfo
*semaphore;
size_t
signature;
};
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% A p p e n d V a l u e T o L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% AppendValueToLinkedList() appends a value to the end of the linked-list.
%
% The format of the AppendValueToLinkedList method is:
%
% MagickBooleanType AppendValueToLinkedList(LinkedListInfo *list_info,
% const void *value)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
% o value: the value.
%
*/
MagickExport MagickBooleanType AppendValueToLinkedList(
LinkedListInfo *list_info,const void *value)
{
ElementInfo
*next;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if (list_info->elements == list_info->capacity)
return(MagickFalse);
next=(ElementInfo *) AcquireMagickMemory(sizeof(*next));
if (next == (ElementInfo *) NULL)
return(MagickFalse);
next->value=(void *) value;
next->next=(ElementInfo *) NULL;
LockSemaphoreInfo(list_info->semaphore);
if (list_info->next == (ElementInfo *) NULL)
list_info->next=next;
if (list_info->elements == 0)
list_info->head=next;
else
list_info->tail->next=next;
list_info->tail=next;
list_info->elements++;
UnlockSemaphoreInfo(list_info->semaphore);
return(MagickTrue);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% C l e a r L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ClearLinkedList() clears all the elements from the linked-list.
%
% The format of the ClearLinkedList method is:
%
% void ClearLinkedList(LinkedListInfo *list_info,
% void *(*relinquish_value)(void *))
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
% o relinquish_value: the value deallocation method; typically
% RelinquishMagickMemory().
%
*/
MagickExport void ClearLinkedList(LinkedListInfo *list_info,
void *(*relinquish_value)(void *))
{
ElementInfo
*element;
ElementInfo
*next;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
LockSemaphoreInfo(list_info->semaphore);
next=list_info->head;
while (next != (ElementInfo *) NULL)
{
if (relinquish_value != (void *(*)(void *)) NULL)
next->value=relinquish_value(next->value);
element=next;
next=next->next;
element=(ElementInfo *) RelinquishMagickMemory(element);
}
list_info->head=(ElementInfo *) NULL;
list_info->tail=(ElementInfo *) NULL;
list_info->next=(ElementInfo *) NULL;
list_info->elements=0;
UnlockSemaphoreInfo(list_info->semaphore);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% D e s t r o y L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DestroyLinkedList() frees the linked-list and all associated resources.
%
% The format of the DestroyLinkedList method is:
%
% LinkedListInfo *DestroyLinkedList(LinkedListInfo *list_info,
% void *(*relinquish_value)(void *))
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
% o relinquish_value: the value deallocation method; typically
% RelinquishMagickMemory().
%
*/
MagickExport LinkedListInfo *DestroyLinkedList(LinkedListInfo *list_info,
void *(*relinquish_value)(void *))
{
ElementInfo
*entry;
ElementInfo
*next;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
LockSemaphoreInfo(list_info->semaphore);
for (next=list_info->head; next != (ElementInfo *) NULL; )
{
if (relinquish_value != (void *(*)(void *)) NULL)
next->value=relinquish_value(next->value);
entry=next;
next=next->next;
entry=(ElementInfo *) RelinquishMagickMemory(entry);
}
list_info->signature=(~MagickCoreSignature);
UnlockSemaphoreInfo(list_info->semaphore);
RelinquishSemaphoreInfo(&list_info->semaphore);
list_info=(LinkedListInfo *) RelinquishMagickMemory(list_info);
return(list_info);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t H e a d E l e m e n t I n L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetHeadElementInLinkedList() gets the head element in the linked-list.
%
% The format of the GetHeadElementInLinkedList method is:
%
% ElementInfo *GetHeadElementInLinkedList(LinkedListInfo *list_info)
%
% A description of each parameter follows:
%
% o list_info: the linked_list info.
%
*/
MagickPrivate ElementInfo *GetHeadElementInLinkedList(
LinkedListInfo *list_info)
{
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
return(list_info->head);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t L a s t V a l u e I n L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetLastValueInLinkedList() gets the last value in the linked-list.
%
% The format of the GetLastValueInLinkedList method is:
%
% void *GetLastValueInLinkedList(LinkedListInfo *list_info)
%
% A description of each parameter follows:
%
% o list_info: the linked_list info.
%
*/
MagickExport void *GetLastValueInLinkedList(LinkedListInfo *list_info)
{
void
*value;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if (list_info->elements == 0)
return((void *) NULL);
LockSemaphoreInfo(list_info->semaphore);
value=list_info->tail->value;
UnlockSemaphoreInfo(list_info->semaphore);
return(value);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t N e x t V a l u e I n L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetNextValueInLinkedList() gets the next value in the linked-list.
%
% The format of the GetNextValueInLinkedList method is:
%
% void *GetNextValueInLinkedList(LinkedListInfo *list_info)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
*/
MagickExport void *GetNextValueInLinkedList(LinkedListInfo *list_info)
{
void
*value;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
LockSemaphoreInfo(list_info->semaphore);
if (list_info->next == (ElementInfo *) NULL)
{
UnlockSemaphoreInfo(list_info->semaphore);
return((void *) NULL);
}
value=list_info->next->value;
list_info->next=list_info->next->next;
UnlockSemaphoreInfo(list_info->semaphore);
return(value);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t N u m b e r O f E l e m e n t s I n L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetNumberOfElementsInLinkedList() returns the number of entries in the
% linked-list.
%
% The format of the GetNumberOfElementsInLinkedList method is:
%
% size_t GetNumberOfElementsInLinkedList(
% const LinkedListInfo *list_info)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
*/
MagickExport size_t GetNumberOfElementsInLinkedList(
const LinkedListInfo *list_info)
{
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
return(list_info->elements);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t V a l u e F r o m L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetValueFromLinkedList() gets a value from the linked-list at the specified
% location.
%
% The format of the GetValueFromLinkedList method is:
%
% void *GetValueFromLinkedList(LinkedListInfo *list_info,
% const size_t index)
%
% A description of each parameter follows:
%
% o list_info: the linked_list info.
%
% o index: the list index.
%
*/
MagickExport void *GetValueFromLinkedList(LinkedListInfo *list_info,
const size_t index)
{
ElementInfo
*next;
ssize_t
i;
void
*value;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if (index >= list_info->elements)
return((void *) NULL);
LockSemaphoreInfo(list_info->semaphore);
if (index == 0)
{
value=list_info->head->value;
UnlockSemaphoreInfo(list_info->semaphore);
return(value);
}
if (index == (list_info->elements-1))
{
value=list_info->tail->value;
UnlockSemaphoreInfo(list_info->semaphore);
return(value);
}
next=list_info->head;
for (i=0; i < (ssize_t) index; i++)
next=next->next;
value=next->value;
UnlockSemaphoreInfo(list_info->semaphore);
return(value);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% I n s e r t V a l u e I n L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% InsertValueInLinkedList() inserts an element in the linked-list at the
% specified location.
%
% The format of the InsertValueInLinkedList method is:
%
% MagickBooleanType InsertValueInLinkedList(ListInfo *list_info,
% const size_t index,const void *value)
%
% A description of each parameter follows:
%
% o list_info: the hashmap info.
%
% o index: the index.
%
% o value: the value.
%
*/
MagickExport MagickBooleanType InsertValueInLinkedList(
LinkedListInfo *list_info,const size_t index,const void *value)
{
ElementInfo
*next;
ssize_t
i;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if (value == (const void *) NULL)
return(MagickFalse);
if ((index > list_info->elements) ||
(list_info->elements == list_info->capacity))
return(MagickFalse);
next=(ElementInfo *) AcquireMagickMemory(sizeof(*next));
if (next == (ElementInfo *) NULL)
return(MagickFalse);
next->value=(void *) value;
next->next=(ElementInfo *) NULL;
LockSemaphoreInfo(list_info->semaphore);
if (list_info->elements == 0)
{
if (list_info->next == (ElementInfo *) NULL)
list_info->next=next;
list_info->head=next;
list_info->tail=next;
}
else
{
if (index == 0)
{
if (list_info->next == list_info->head)
list_info->next=next;
next->next=list_info->head;
list_info->head=next;
}
else
if (index == list_info->elements)
{
if (list_info->next == (ElementInfo *) NULL)
list_info->next=next;
list_info->tail->next=next;
list_info->tail=next;
}
else
{
ElementInfo
*element;
element=list_info->head;
next->next=element->next;
for (i=1; i < (ssize_t) index; i++)
{
element=element->next;
next->next=element->next;
}
next=next->next;
element->next=next;
if (list_info->next == next->next)
list_info->next=next;
}
}
list_info->elements++;
UnlockSemaphoreInfo(list_info->semaphore);
return(MagickTrue);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% I n s e r t V a l u e I n S o r t e d L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% InsertValueInSortedLinkedList() inserts a value in the sorted linked-list.
%
% The format of the InsertValueInSortedLinkedList method is:
%
% MagickBooleanType InsertValueInSortedLinkedList(ListInfo *list_info,
% int (*compare)(const void *,const void *),void **replace,
% const void *value)
%
% A description of each parameter follows:
%
% o list_info: the hashmap info.
%
% o index: the index.
%
% o compare: the compare method.
%
% o replace: return previous element here.
%
% o value: the value.
%
*/
MagickExport MagickBooleanType InsertValueInSortedLinkedList(
LinkedListInfo *list_info,int (*compare)(const void *,const void *),
void **replace,const void *value)
{
ElementInfo
*element;
ElementInfo
*next;
ssize_t
i;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if ((compare == (int (*)(const void *,const void *)) NULL) ||
(value == (const void *) NULL))
return(MagickFalse);
if (list_info->elements == list_info->capacity)
return(MagickFalse);
next=(ElementInfo *) AcquireMagickMemory(sizeof(*next));
if (next == (ElementInfo *) NULL)
return(MagickFalse);
next->value=(void *) value;
element=(ElementInfo *) NULL;
LockSemaphoreInfo(list_info->semaphore);
next->next=list_info->head;
while (next->next != (ElementInfo *) NULL)
{
i=(ssize_t) compare(value,next->next->value);
if ((i < 0) || ((replace != (void **) NULL) && (i == 0)))
{
if (i == 0)
{
*replace=next->next->value;
next->next=next->next->next;
if (element != (ElementInfo *) NULL)
element->next=(ElementInfo *) RelinquishMagickMemory(
element->next);
list_info->elements--;
}
if (element != (ElementInfo *) NULL)
element->next=next;
else
list_info->head=next;
break;
}
element=next->next;
next->next=next->next->next;
}
if (next->next == (ElementInfo *) NULL)
{
if (element != (ElementInfo *) NULL)
element->next=next;
else
list_info->head=next;
list_info->tail=next;
}
list_info->elements++;
UnlockSemaphoreInfo(list_info->semaphore);
return(MagickTrue);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% I s L i n k e d L i s t E m p t y %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% IsLinkedListEmpty() returns MagickTrue if the linked-list is empty.
%
% The format of the IsLinkedListEmpty method is:
%
% MagickBooleanType IsLinkedListEmpty(LinkedListInfo *list_info)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
*/
MagickExport MagickBooleanType IsLinkedListEmpty(
const LinkedListInfo *list_info)
{
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
return(list_info->elements == 0 ? MagickTrue : MagickFalse);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% L i n k e d L i s t T o A r r a y %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% LinkedListToArray() converts the linked-list to an array.
%
% The format of the LinkedListToArray method is:
%
% MagickBooleanType LinkedListToArray(LinkedListInfo *list_info,
% void **array)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
% o array: the array.
%
*/
MagickExport MagickBooleanType LinkedListToArray(LinkedListInfo *list_info,
void **array)
{
ElementInfo
*next;
ssize_t
i;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if (array == (void **) NULL)
return(MagickFalse);
LockSemaphoreInfo(list_info->semaphore);
next=list_info->head;
for (i=0; next != (ElementInfo *) NULL; i++)
{
array[i]=next->value;
next=next->next;
}
UnlockSemaphoreInfo(list_info->semaphore);
return(MagickTrue);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% N e w L i n k e d L i s t I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% NewLinkedList() returns a pointer to a LinkedListInfo structure
% initialized to default values.
%
% The format of the NewLinkedList method is:
%
% LinkedListInfo *NewLinkedList(const size_t capacity)
%
% A description of each parameter follows:
%
% o capacity: the maximum number of elements in the list.
%
*/
MagickExport LinkedListInfo *NewLinkedList(const size_t capacity)
{
LinkedListInfo
*list_info;
list_info=(LinkedListInfo *) AcquireCriticalMemory(sizeof(*list_info));
(void) memset(list_info,0,sizeof(*list_info));
list_info->capacity=capacity == 0 ? (size_t) (~0) : capacity;
list_info->elements=0;
list_info->head=(ElementInfo *) NULL;
list_info->tail=(ElementInfo *) NULL;
list_info->next=(ElementInfo *) NULL;
list_info->semaphore=AcquireSemaphoreInfo();
list_info->signature=MagickCoreSignature;
return(list_info);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% R e m o v e E l e m e n t B y V a l u e F r o m L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% RemoveElementByValueFromLinkedList() removes an element from the linked-list
% by value.
%
% The format of the RemoveElementByValueFromLinkedList method is:
%
% void *RemoveElementByValueFromLinkedList(LinkedListInfo *list_info,
% const void *value)
%
% A description of each parameter follows:
%
% o list_info: the list info.
%
% o value: the value.
%
*/
MagickExport void *RemoveElementByValueFromLinkedList(LinkedListInfo *list_info,
const void *value)
{
ElementInfo
*next;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if ((list_info->elements == 0) || (value == (const void *) NULL))
return((void *) NULL);
LockSemaphoreInfo(list_info->semaphore);
if (value == list_info->head->value)
{
if (list_info->next == list_info->head)
list_info->next=list_info->head->next;
next=list_info->head;
list_info->head=list_info->head->next;
next=(ElementInfo *) RelinquishMagickMemory(next);
}
else
{
ElementInfo
*element;
next=list_info->head;
while ((next->next != (ElementInfo *) NULL) &&
(next->next->value != value))
next=next->next;
if (next->next == (ElementInfo *) NULL)
{
UnlockSemaphoreInfo(list_info->semaphore);
return((void *) NULL);
}
element=next->next;
next->next=element->next;
if (element == list_info->tail)
list_info->tail=next;
if (list_info->next == element)
list_info->next=element->next;
element=(ElementInfo *) RelinquishMagickMemory(element);
}
list_info->elements--;
UnlockSemaphoreInfo(list_info->semaphore);
return((void *) value);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% R e m o v e E l e m e n t F r o m L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% RemoveElementFromLinkedList() removes an element from the linked-list at the
% specified location.
%
% The format of the RemoveElementFromLinkedList method is:
%
% void *RemoveElementFromLinkedList(LinkedListInfo *list_info,
% const size_t index)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
% o index: the index.
%
*/
MagickExport void *RemoveElementFromLinkedList(LinkedListInfo *list_info,
const size_t index)
{
ElementInfo
*next;
ssize_t
i;
void
*value;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if (index >= list_info->elements)
return((void *) NULL);
LockSemaphoreInfo(list_info->semaphore);
if (index == 0)
{
if (list_info->next == list_info->head)
list_info->next=list_info->head->next;
value=list_info->head->value;
next=list_info->head;
list_info->head=list_info->head->next;
next=(ElementInfo *) RelinquishMagickMemory(next);
}
else
{
ElementInfo
*element;
next=list_info->head;
for (i=1; i < (ssize_t) index; i++)
next=next->next;
element=next->next;
next->next=element->next;
if (element == list_info->tail)
list_info->tail=next;
if (list_info->next == element)
list_info->next=element->next;
value=element->value;
element=(ElementInfo *) RelinquishMagickMemory(element);
}
list_info->elements--;
UnlockSemaphoreInfo(list_info->semaphore);
return(value);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% R e m o v e L a s t E l e m e n t F r o m L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% RemoveLastElementFromLinkedList() removes the last element from the
% linked-list.
%
% The format of the RemoveLastElementFromLinkedList method is:
%
% void *RemoveLastElementFromLinkedList(LinkedListInfo *list_info)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
*/
MagickExport void *RemoveLastElementFromLinkedList(LinkedListInfo *list_info)
{
void
*value;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
if (list_info->elements == 0)
return((void *) NULL);
LockSemaphoreInfo(list_info->semaphore);
if (list_info->next == list_info->tail)
list_info->next=(ElementInfo *) NULL;
if (list_info->elements == 1UL)
{
value=list_info->head->value;
list_info->head=(ElementInfo *) NULL;
list_info->tail=(ElementInfo *) RelinquishMagickMemory(list_info->tail);
}
else
{
ElementInfo
*next;
value=list_info->tail->value;
next=list_info->head;
while (next->next != list_info->tail)
next=next->next;
list_info->tail=(ElementInfo *) RelinquishMagickMemory(list_info->tail);
list_info->tail=next;
next->next=(ElementInfo *) NULL;
}
list_info->elements--;
UnlockSemaphoreInfo(list_info->semaphore);
return(value);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% R e s e t L i n k e d L i s t I t e r a t o r %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ResetLinkedListIterator() resets the lined-list iterator. Use it in
% conjunction with GetNextValueInLinkedList() to iterate over all the values
% in the linked-list.
%
% The format of the ResetLinkedListIterator method is:
%
% ResetLinkedListIterator(LinkedListInfo *list_info)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
*/
MagickExport void ResetLinkedListIterator(LinkedListInfo *list_info)
{
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
LockSemaphoreInfo(list_info->semaphore);
list_info->next=list_info->head;
UnlockSemaphoreInfo(list_info->semaphore);
}
␌
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% S e t H e a d E l e m e n t I n L i n k e d L i s t %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% SetHeadElementInLinkedList() sets the head element of the linked-list.
%
% The format of the SetHeadElementInLinkedList method is:
%
% SetHeadElementInLinkedList(LinkedListInfo *list_info,
% ElementInfo *element)
%
% A description of each parameter follows:
%
% o list_info: the linked-list info.
%
% o element: the element to set as the head.
%
*/
MagickPrivate void SetHeadElementInLinkedList(LinkedListInfo *list_info,
ElementInfo *element)
{
ElementInfo
*prev;
assert(list_info != (LinkedListInfo *) NULL);
assert(list_info->signature == MagickCoreSignature);
assert(element != (ElementInfo *) NULL);
if (element == list_info->head)
return;
prev=list_info->head;
while (prev != (ElementInfo *) NULL)
{
if (prev->next == element)
{
prev->next=element->next;
element->next=list_info->head;
if (list_info->head == list_info->next)
list_info->next=element;
list_info->head=element;
break;
}
prev=prev->next;
}
}
SemaphoreInfo
Definition semaphore.c:61
_ElementInfo
Definition draw.c:133
_LinkedListInfo
Definition linked-list.c:61