audk/EdkCompatibilityPkg/Foundation/Library/EfiCommonLib/linkedlist.c

357 lines
8.0 KiB
C

/*++
Copyright (c) 2004, Intel Corporation
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
Module Name:
LinkedList.c
Abstract:
Linked List Library Functions
--*/
#include "Tiano.h"
#include "EfiDriverLib.h"
VOID
InitializeListHead (
EFI_LIST_ENTRY *List
)
/*++
Routine Description:
Initialize the head of the List. The caller must allocate the memory
for the EFI_LIST. This function must be called before the other linked
list macros can be used.
Arguments:
List - Pointer to list head to initialize
Returns:
None.
--*/
{
List->ForwardLink = List;
List->BackLink = List;
}
BOOLEAN
IsListEmpty (
EFI_LIST_ENTRY *List
)
/*++
Routine Description:
Return TRUE is the list contains zero nodes. Otherzise return FALSE.
The list must have been initialized with InitializeListHead () before using
this function.
Arguments:
List - Pointer to list head to test
Returns:
Return TRUE is the list contains zero nodes. Otherzise return FALSE.
--*/
{
return (BOOLEAN)(List->ForwardLink == List);
}
VOID
RemoveEntryList (
EFI_LIST_ENTRY *Entry
)
/*++
Routine Description:
Remove Node from the doubly linked list. It is the caller's responsibility
to free any memory used by the entry if needed. The list must have been
initialized with InitializeListHead () before using this function.
Arguments:
Entry - Element to remove from the list.
Returns:
None
--*/
{
EFI_LIST_ENTRY *_ForwardLink;
EFI_LIST_ENTRY *_BackLink;
_ForwardLink = Entry->ForwardLink;
_BackLink = Entry->BackLink;
_BackLink->ForwardLink = _ForwardLink;
_ForwardLink->BackLink = _BackLink;
DEBUG_CODE (
Entry->ForwardLink = (EFI_LIST_ENTRY *) EFI_BAD_POINTER;
Entry->BackLink = (EFI_LIST_ENTRY *) EFI_BAD_POINTER;
)
}
VOID
InsertTailList (
EFI_LIST_ENTRY *ListHead,
EFI_LIST_ENTRY *Entry
)
/*++
Routine Description:
Insert a Node into the end of a doubly linked list. The list must have
been initialized with InitializeListHead () before using this function.
Arguments:
ListHead - Head of doubly linked list
Entry - Element to insert at the end of the list.
Returns:
None
--*/
{
EFI_LIST_ENTRY *_ListHead;
EFI_LIST_ENTRY *_BackLink;
_ListHead = ListHead;
_BackLink = _ListHead->BackLink;
Entry->ForwardLink = _ListHead;
Entry->BackLink = _BackLink;
_BackLink->ForwardLink = Entry;
_ListHead->BackLink = Entry;
}
VOID
InsertHeadList (
EFI_LIST_ENTRY *ListHead,
EFI_LIST_ENTRY *Entry
)
/*++
Routine Description:
Insert a Node into the start of a doubly linked list. The list must have
been initialized with InitializeListHead () before using this function.
Arguments:
ListHead - Head of doubly linked list
Entry - Element to insert to beginning of list
Returns:
None
--*/
{
EFI_LIST_ENTRY *_ListHead;
EFI_LIST_ENTRY *_ForwardLink;
_ListHead = ListHead;
_ForwardLink = _ListHead->ForwardLink;
Entry->ForwardLink = _ForwardLink;
Entry->BackLink = _ListHead;
_ForwardLink->BackLink = Entry;
_ListHead->ForwardLink = Entry;
}
VOID
SwapListEntries (
EFI_LIST_ENTRY *Entry1,
EFI_LIST_ENTRY *Entry2
)
/*++
Routine Description:
Swap the location of the two elements of a doubly linked list. Node2
is placed in front of Node1. The list must have been initialized with
InitializeListHead () before using this function.
Arguments:
Entry1 - Element in the doubly linked list in front of Node2.
Entry2 - Element in the doubly linked list behind Node1.
Returns:
None
--*/
{
EFI_LIST_ENTRY *Entry1ForwardLink;
EFI_LIST_ENTRY *Entry1BackLink;
EFI_LIST_ENTRY *Entry2ForwardLink;
EFI_LIST_ENTRY *Entry2BackLink;
Entry2ForwardLink = Entry2->ForwardLink;
Entry2BackLink = Entry2->BackLink;
Entry1ForwardLink = Entry1->ForwardLink;
Entry1BackLink = Entry1->BackLink;
Entry2BackLink->ForwardLink = Entry2ForwardLink;
Entry2ForwardLink->BackLink = Entry2BackLink;
Entry2->ForwardLink = Entry1;
Entry2->BackLink = Entry1BackLink;
Entry1BackLink->ForwardLink = Entry2;
Entry1->BackLink = Entry2;
}
EFI_LIST_ENTRY *
GetFirstNode (
EFI_LIST_ENTRY *List
)
/*++
Routine Description:
Return the first node pointed to by the list head. The list must
have been initialized with InitializeListHead () before using this
function and must contain data.
Arguments:
List - The head of the doubly linked list.
Returns:
Pointer to the first node, if the list contains nodes. The list will
return a null value--that is, the value of List--when the list is empty.
See the description of IsNull for more information.
--*/
{
return List->ForwardLink;
}
EFI_LIST_ENTRY *
GetNextNode (
EFI_LIST_ENTRY *List,
EFI_LIST_ENTRY *Node
)
/*++
Routine Description:
Returns the node following Node in the list. The list must
have been initialized with InitializeListHead () before using this
function and must contain data.
Arguments:
List - The head of the list. MUST NOT be the literal value NULL.
Node - The node in the list. This value MUST NOT be the literal value NULL.
See the description of IsNull for more information.
Returns:
Pointer to the next node, if one exists. Otherwise, returns a null value,
which is actually a pointer to List.
See the description of IsNull for more information.
--*/
{
if (Node == List) {
return List;
}
return Node->ForwardLink;
}
BOOLEAN
IsNull (
EFI_LIST_ENTRY *List,
EFI_LIST_ENTRY *Node
)
/*++
Routine Description:
Determines whether the given node is null. Note that Node is null
when its value is equal to the value of List. It is an error for
Node to be the literal value NULL [(VOID*)0x0].
Arguments:
List - The head of the list. MUST NOT be the literal value NULL.
Node - The node to test. MUST NOT be the literal value NULL. See
the description above.
Returns:
Returns true if the node is null.
--*/
{
return (BOOLEAN)(Node == List);
}
BOOLEAN
IsNodeAtEnd (
EFI_LIST_ENTRY *List,
EFI_LIST_ENTRY *Node
)
/*++
Routine Description:
Determines whether the given node is at the end of the list. Used
to walk the list. The list must have been initialized with
InitializeListHead () before using this function and must contain
data.
Arguments:
List - The head of the list. MUST NOT be the literal value NULL.
Node - The node to test. MUST NOT be the literal value NULL.
See the description of IsNull for more information.
Returns:
Returns true if the list is the tail.
--*/
{
if (IsNull (List, Node)) {
return FALSE;
}
return (BOOLEAN)(List->BackLink == Node);
}