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Diffstat (limited to 'EDK/Foundation/Library/EdkIIGlueLib/Library/BaseLib/LinkedList.c')
-rw-r--r-- | EDK/Foundation/Library/EdkIIGlueLib/Library/BaseLib/LinkedList.c | 473 |
1 files changed, 473 insertions, 0 deletions
diff --git a/EDK/Foundation/Library/EdkIIGlueLib/Library/BaseLib/LinkedList.c b/EDK/Foundation/Library/EdkIIGlueLib/Library/BaseLib/LinkedList.c new file mode 100644 index 0000000..cb84470 --- /dev/null +++ b/EDK/Foundation/Library/EdkIIGlueLib/Library/BaseLib/LinkedList.c @@ -0,0 +1,473 @@ +/*++ + +Copyright (c) 2004 - 2006, 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 "BaseLibInternal.h" +#include "Pcd\EdkIIGluePcdBaseLib.h" + + +/** + Worker function that locates the Node in the List + + By searching the List, finds the location of the Node in List. At the same time, + verifies the validity of this list. + + If List is NULL, then ASSERT(). + If List->ForwardLink is NULL, then ASSERT(). + If List->backLink is NULL, then ASSERT(). + If Node is NULL, 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 List A pointer to a node in a linked list. + @param Node A pointer to one nod. + + @retval TRUE Node is in List + @retval FALSE Node isn't in List, or List is invalid + +**/ +BOOLEAN +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); + + 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 +GlueInitializeListHead ( + 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 +GlueInsertHeadList ( + 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 +GlueInsertTailList ( + 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 +GlueGetFirstNode ( + 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 +GlueGetNextNode ( + 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 +GlueIsListEmpty ( + 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 +GlueIsNull ( + 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 +GlueIsNodeAtEnd ( + 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 +GlueSwapListEntries ( + 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 +GlueRemoveEntryList ( + IN CONST LIST_ENTRY *Entry + ) +{ + ASSERT (!IsListEmpty (Entry)); + + Entry->ForwardLink->BackLink = Entry->BackLink; + Entry->BackLink->ForwardLink = Entry->ForwardLink; + return Entry->ForwardLink; +} |