mirror of https://github.com/acidanthera/audk.git
447 lines
13 KiB
C
447 lines
13 KiB
C
/** @file
|
|
Linked List Library Functions.
|
|
|
|
Copyright (c) 2006, Intel Corporation<BR>
|
|
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
|
|
|
|
**/
|
|
|
|
BOOLEAN
|
|
EFIAPI
|
|
IsNodeInList (
|
|
IN CONST LIST_ENTRY *List,
|
|
IN CONST LIST_ENTRY *Node
|
|
)
|
|
{
|
|
UINTN Count;
|
|
CONST LIST_ENTRY *Ptr;
|
|
BOOLEAN Found;
|
|
|
|
//
|
|
// Test the validity of List and Node
|
|
//
|
|
ASSERT (List != NULL);
|
|
ASSERT (List->ForwardLink != NULL);
|
|
ASSERT (List->BackLink != NULL);
|
|
ASSERT (Node != NULL);
|
|
|
|
Count = PcdGet32 (PcdMaximumLinkedListLength);
|
|
if (Count != 0) {
|
|
Count++;
|
|
}
|
|
|
|
Ptr = List;
|
|
do {
|
|
Ptr = Ptr->ForwardLink;
|
|
Count--;
|
|
} while ((Ptr != List) && (Ptr != Node) && (Count > 0));
|
|
Found = (BOOLEAN)(Ptr == Node);
|
|
|
|
if (PcdGet32 (PcdMaximumLinkedListLength) > 0) {
|
|
while ((Count > 0) && (Ptr != List)) {
|
|
Ptr = Ptr->ForwardLink;
|
|
Count--;
|
|
}
|
|
ASSERT (Count > 0);
|
|
}
|
|
|
|
return Found;
|
|
}
|
|
|
|
/**
|
|
Initializes the head node of a doubly linked list, and returns the pointer to
|
|
the head node of the doubly linked list.
|
|
|
|
Initializes the forward and backward links of a new linked list. After
|
|
initializing a linked list with this function, the other linked list
|
|
functions may be used to add and remove nodes from the linked list. It is up
|
|
to the caller of this function to allocate the memory for ListHead.
|
|
|
|
If ListHead is NULL, then ASSERT().
|
|
|
|
@param ListHead A pointer to the head node of a new doubly linked list.
|
|
|
|
@return ListHead
|
|
|
|
**/
|
|
LIST_ENTRY *
|
|
EFIAPI
|
|
InitializeListHead (
|
|
IN OUT LIST_ENTRY *List
|
|
)
|
|
|
|
{
|
|
ASSERT (List != NULL);
|
|
|
|
List->ForwardLink = List;
|
|
List->BackLink = List;
|
|
return List;
|
|
}
|
|
|
|
/**
|
|
Adds a node to the beginning of a doubly linked list, and returns the pointer
|
|
to the head node of the doubly linked list.
|
|
|
|
Adds the node Entry at the beginning of the doubly linked list denoted by
|
|
ListHead, and returns ListHead.
|
|
|
|
If ListHead is NULL, then ASSERT().
|
|
If Entry is NULL, then ASSERT().
|
|
If ListHead was not initialized with InitializeListHead(), then ASSERT().
|
|
If PcdMaximumLinkedListLenth is not zero, and prior to insertion the number
|
|
of nodes in ListHead, including the ListHead node, is greater than or
|
|
equal to PcdMaximumLinkedListLength, then ASSERT().
|
|
|
|
@param ListHead A pointer to the head node of a doubly linked list.
|
|
@param Entry A pointer to a node that is to be inserted at the beginning
|
|
of a doubly linked list.
|
|
|
|
@return ListHead
|
|
|
|
**/
|
|
LIST_ENTRY *
|
|
EFIAPI
|
|
InsertHeadList (
|
|
IN OUT LIST_ENTRY *List,
|
|
IN OUT LIST_ENTRY *Entry
|
|
)
|
|
{
|
|
//
|
|
// ASSERT List not too long and Entry is not one of the nodes of List
|
|
//
|
|
ASSERT (!IsNodeInList (List, Entry));
|
|
|
|
Entry->ForwardLink = List->ForwardLink;
|
|
Entry->BackLink = List;
|
|
Entry->ForwardLink->BackLink = Entry;
|
|
List->ForwardLink = Entry;
|
|
return List;
|
|
}
|
|
|
|
/**
|
|
Adds a node to the end of a doubly linked list, and returns the pointer to
|
|
the head node of the doubly linked list.
|
|
|
|
Adds the node Entry to the end of the doubly linked list denoted by ListHead,
|
|
and returns ListHead.
|
|
|
|
If ListHead is NULL, then ASSERT().
|
|
If Entry is NULL, then ASSERT().
|
|
If ListHead was not initialized with InitializeListHead(), then ASSERT().
|
|
If PcdMaximumLinkedListLenth is not zero, and prior to insertion the number
|
|
of nodes in ListHead, including the ListHead node, is greater than or
|
|
equal to PcdMaximumLinkedListLength, then ASSERT().
|
|
|
|
@param ListHead A pointer to the head node of a doubly linked list.
|
|
@param Entry A pointer to a node that is to be added at the end of the
|
|
doubly linked list.
|
|
|
|
@return ListHead
|
|
|
|
**/
|
|
LIST_ENTRY *
|
|
EFIAPI
|
|
InsertTailList (
|
|
IN OUT LIST_ENTRY *List,
|
|
IN OUT LIST_ENTRY *Entry
|
|
)
|
|
{
|
|
//
|
|
// ASSERT List not too long and Entry is not one of the nodes of List
|
|
//
|
|
ASSERT (!IsNodeInList (List, Entry));
|
|
|
|
Entry->ForwardLink = List;
|
|
Entry->BackLink = List->BackLink;
|
|
Entry->BackLink->ForwardLink = Entry;
|
|
List->BackLink = Entry;
|
|
return List;
|
|
}
|
|
|
|
/**
|
|
Retrieves the first node of a doubly linked list.
|
|
|
|
Returns the first node of a doubly linked list. List must have been
|
|
initialized with InitializeListHead(). If List is empty, then NULL is
|
|
returned.
|
|
|
|
If List is NULL, then ASSERT().
|
|
If List was not initialized with InitializeListHead(), then ASSERT().
|
|
If PcdMaximumLinkedListLenth is not zero, and the number of nodes
|
|
in List, including the List node, is greater than or equal to
|
|
PcdMaximumLinkedListLength, then ASSERT().
|
|
|
|
@param List A pointer to the head node of a doubly linked list.
|
|
|
|
@return The first node of a doubly linked list.
|
|
@retval NULL The list is empty.
|
|
|
|
**/
|
|
LIST_ENTRY *
|
|
EFIAPI
|
|
GetFirstNode (
|
|
IN CONST LIST_ENTRY *List
|
|
)
|
|
{
|
|
//
|
|
// ASSERT List not too long
|
|
//
|
|
ASSERT (IsNodeInList (List, List));
|
|
|
|
return List->ForwardLink;
|
|
}
|
|
|
|
/**
|
|
Retrieves the next node of a doubly linked list.
|
|
|
|
Returns the node of a doubly linked list that follows Node. List must have
|
|
been initialized with InitializeListHead(). If List is empty, then List is
|
|
returned.
|
|
|
|
If List is NULL, then ASSERT().
|
|
If Node is NULL, then ASSERT().
|
|
If List was not initialized with InitializeListHead(), then ASSERT().
|
|
If PcdMaximumLinkedListLenth is not zero, and List contains more than
|
|
PcdMaximumLinkedListLenth nodes, then ASSERT().
|
|
If Node is not a node in List, then ASSERT().
|
|
|
|
@param List A pointer to the head node of a doubly linked list.
|
|
@param Node A pointer to a node in the doubly linked list.
|
|
|
|
@return Pointer to the next node if one exists. Otherwise a null value which
|
|
is actually List is returned.
|
|
|
|
**/
|
|
LIST_ENTRY *
|
|
EFIAPI
|
|
GetNextNode (
|
|
IN CONST LIST_ENTRY *List,
|
|
IN CONST LIST_ENTRY *Node
|
|
)
|
|
{
|
|
//
|
|
// ASSERT List not too long and Node is one of the nodes of List
|
|
//
|
|
ASSERT (IsNodeInList (List, Node));
|
|
|
|
return Node->ForwardLink;
|
|
}
|
|
|
|
/**
|
|
Checks to see if a doubly linked list is empty or not.
|
|
|
|
Checks to see if the doubly linked list is empty. If the linked list contains
|
|
zero nodes, this function returns TRUE. Otherwise, it returns FALSE.
|
|
|
|
If ListHead is NULL, then ASSERT().
|
|
If ListHead was not initialized with InitializeListHead(), then ASSERT().
|
|
If PcdMaximumLinkedListLenth is not zero, and the number of nodes
|
|
in List, including the List node, is greater than or equal to
|
|
PcdMaximumLinkedListLength, then ASSERT().
|
|
|
|
@param ListHead A pointer to the head node of a doubly linked list.
|
|
|
|
@retval TRUE The linked list is empty.
|
|
@retval FALSE The linked list is not empty.
|
|
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
IsListEmpty (
|
|
IN CONST LIST_ENTRY *List
|
|
)
|
|
{
|
|
//
|
|
// ASSERT List not too long
|
|
//
|
|
ASSERT (IsNodeInList (List, List));
|
|
|
|
return (BOOLEAN)(List->ForwardLink == List);
|
|
}
|
|
|
|
/**
|
|
Determines if a node in a doubly linked list is null.
|
|
|
|
Returns FALSE if Node is one of the nodes in the doubly linked list specified
|
|
by List. Otherwise, TRUE is returned. List must have been initialized with
|
|
InitializeListHead().
|
|
|
|
If List is NULL, then ASSERT().
|
|
If Node is NULL, then ASSERT().
|
|
If List was not initialized with InitializeListHead(), then ASSERT().
|
|
If PcdMaximumLinkedListLenth is not zero, and the number of nodes
|
|
in List, including the List node, is greater than or equal to
|
|
PcdMaximumLinkedListLength, then ASSERT().
|
|
If Node is not a node in List and Node is not equal to List, then ASSERT().
|
|
|
|
@param List A pointer to the head node of a doubly linked list.
|
|
@param Node A pointer to a node in the doubly linked list.
|
|
|
|
@retval TRUE Node is one of the nodes in the doubly linked list.
|
|
@retval FALSE Node is not one of the nodes in the doubly linked list.
|
|
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
IsNull (
|
|
IN CONST LIST_ENTRY *List,
|
|
IN CONST LIST_ENTRY *Node
|
|
)
|
|
{
|
|
//
|
|
// ASSERT List not too long and Node is one of the nodes of List
|
|
//
|
|
ASSERT (IsNodeInList (List, Node));
|
|
|
|
return (BOOLEAN)(Node == List);
|
|
}
|
|
|
|
/**
|
|
Determines if a node the last node in a doubly linked list.
|
|
|
|
Returns TRUE if Node is the last node in the doubly linked list specified by
|
|
List. Otherwise, FALSE is returned. List must have been initialized with
|
|
InitializeListHead().
|
|
|
|
If List is NULL, then ASSERT().
|
|
If Node is NULL, then ASSERT().
|
|
If List was not initialized with InitializeListHead(), then ASSERT().
|
|
If PcdMaximumLinkedListLenth is not zero, and the number of nodes
|
|
in List, including the List node, is greater than or equal to
|
|
PcdMaximumLinkedListLength, then ASSERT().
|
|
If Node is not a node in List, then ASSERT().
|
|
|
|
@param List A pointer to the head node of a doubly linked list.
|
|
@param Node A pointer to a node in the doubly linked list.
|
|
|
|
@retval TRUE Node is the last node in the linked list.
|
|
@retval FALSE Node is not the last node in the linked list.
|
|
|
|
**/
|
|
BOOLEAN
|
|
EFIAPI
|
|
IsNodeAtEnd (
|
|
IN CONST LIST_ENTRY *List,
|
|
IN CONST LIST_ENTRY *Node
|
|
)
|
|
{
|
|
//
|
|
// ASSERT List not too long and Node is one of the nodes of List
|
|
//
|
|
ASSERT (IsNodeInList (List, Node));
|
|
|
|
return (BOOLEAN)(!IsNull (List, Node) && List->BackLink == Node);
|
|
}
|
|
|
|
/**
|
|
Swaps the location of two nodes in a doubly linked list, and returns the
|
|
first node after the swap.
|
|
|
|
If FirstEntry is identical to SecondEntry, then SecondEntry is returned.
|
|
Otherwise, the location of the FirstEntry node is swapped with the location
|
|
of the SecondEntry node in a doubly linked list. SecondEntry must be in the
|
|
same double linked list as FirstEntry and that double linked list must have
|
|
been initialized with InitializeListHead(). SecondEntry is returned after the
|
|
nodes are swapped.
|
|
|
|
If FirstEntry is NULL, then ASSERT().
|
|
If SecondEntry is NULL, then ASSERT().
|
|
If SecondEntry and FirstEntry are not in the same linked list, then ASSERT().
|
|
If PcdMaximumLinkedListLength is not zero, and the number of nodes in the
|
|
linked list containing the FirstEntry and SecondEntry nodes, including
|
|
the FirstEntry and SecondEntry nodes, is greater than or equal to
|
|
PcdMaximumLinkedListLength, then ASSERT().
|
|
|
|
@param FirstEntry A pointer to a node in a linked list.
|
|
@param SecondEntry A pointer to another node in the same linked list.
|
|
|
|
**/
|
|
LIST_ENTRY *
|
|
EFIAPI
|
|
SwapListEntries (
|
|
IN OUT LIST_ENTRY *FirstEntry,
|
|
IN OUT LIST_ENTRY *SecondEntry
|
|
)
|
|
{
|
|
LIST_ENTRY *Ptr;
|
|
|
|
if (FirstEntry == SecondEntry) {
|
|
return SecondEntry;
|
|
}
|
|
|
|
//
|
|
// ASSERT Entry1 and Entry2 are in the same linked list
|
|
//
|
|
ASSERT (IsNodeInList (FirstEntry, SecondEntry));
|
|
|
|
//
|
|
// Ptr is the node pointed to by FirstEntry->ForwardLink
|
|
//
|
|
Ptr = RemoveEntryList (FirstEntry);
|
|
|
|
//
|
|
// If FirstEntry immediately follows SecondEntry, FirstEntry willl be placed
|
|
// immediately in front of SecondEntry
|
|
//
|
|
if (Ptr->BackLink == SecondEntry) {
|
|
return InsertTailList (SecondEntry, FirstEntry);
|
|
}
|
|
|
|
//
|
|
// Ptr == SecondEntry means SecondEntry immediately follows FirstEntry,
|
|
// then there are no further steps necessary
|
|
//
|
|
if (Ptr == InsertHeadList (SecondEntry, FirstEntry)) {
|
|
return Ptr;
|
|
}
|
|
|
|
//
|
|
// Move SecondEntry to the front of Ptr
|
|
//
|
|
RemoveEntryList (SecondEntry);
|
|
InsertTailList (Ptr, SecondEntry);
|
|
return SecondEntry;
|
|
}
|
|
|
|
/**
|
|
Removes a node from a doubly linked list, and returns the node that follows
|
|
the removed node.
|
|
|
|
Removes the node Entry from a doubly linked list. It is up to the caller of
|
|
this function to release the memory used by this node if that is required. On
|
|
exit, the node following Entry in the doubly linked list is returned. If
|
|
Entry is the only node in the linked list, then the head node of the linked
|
|
list is returned.
|
|
|
|
If Entry is NULL, then ASSERT().
|
|
If Entry is the head node of an empty list, then ASSERT().
|
|
If PcdMaximumLinkedListLength is not zero, and the number of nodes in the
|
|
linked list containing Entry, including the Entry node, is greater than
|
|
or equal to PcdMaximumLinkedListLength, then ASSERT().
|
|
|
|
@param Entry A pointer to a node in a linked list
|
|
|
|
@return Entry
|
|
|
|
**/
|
|
LIST_ENTRY *
|
|
EFIAPI
|
|
RemoveEntryList (
|
|
IN CONST LIST_ENTRY *Entry
|
|
)
|
|
{
|
|
ASSERT (!IsListEmpty (Entry));
|
|
|
|
Entry->ForwardLink->BackLink = Entry->BackLink;
|
|
Entry->BackLink->ForwardLink = Entry->ForwardLink;
|
|
return Entry->ForwardLink;
|
|
}
|