ut0lst.h
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- /**********************************************************************
- List utilities
- (c) 1995 Innobase Oy
- Created 9/10/1995 Heikki Tuuri
- ***********************************************************************/
- #ifndef ut0lst_h
- #define ut0lst_h
- #include "univ.i"
- /* This module implements the two-way linear list which should be used
- if a list is used in the database. Note that a single struct may belong
- to two or more lists, provided that the list are given different names.
- An example of the usage of the lists can be found in fil0fil.c. */
- /***********************************************************************
- This macro expands to the unnamed type definition of a struct which acts
- as the two-way list base node. The base node contains pointers
- to both ends of the list and a count of nodes in the list (excluding
- the base node from the count). TYPE should be the list node type name. */
- #define UT_LIST_BASE_NODE_T(TYPE)
- struct {
- ulint count; /* count of nodes in list */
- TYPE * start; /* pointer to list start, NULL if empty */
- TYPE * end; /* pointer to list end, NULL if empty */
- }
- /***********************************************************************
- This macro expands to the unnamed type definition of a struct which
- should be embedded in the nodes of the list, the node type must be a struct.
- This struct contains the pointers to next and previous nodes in the list.
- The name of the field in the node struct should be the name given
- to the list. TYPE should be the list node type name. Example of usage:
- typedef struct LRU_node_struct LRU_node_t;
- struct LRU_node_struct {
- UT_LIST_NODE_T(LRU_node_t) LRU_list;
- ...
- }
- The example implements an LRU list of name LRU_list. Its nodes are of type
- LRU_node_t.
- */
- #define UT_LIST_NODE_T(TYPE)
- struct {
- TYPE * prev; /* pointer to the previous node,
- NULL if start of list */
- TYPE * next; /* pointer to next node, NULL if end of list */
- }
- /***********************************************************************
- Initializes the base node of a two-way list. */
- #define UT_LIST_INIT(BASE)
- {
- (BASE).count = 0;
- (BASE).start = NULL;
- (BASE).end = NULL;
- }
- /***********************************************************************
- Adds the node as the first element in a two-way linked list.
- BASE has to be the base node (not a pointer to it). N has to be
- the pointer to the node to be added to the list. NAME is the list name. */
- #define UT_LIST_ADD_FIRST(NAME, BASE, N)
- {
- ut_ad(N);
- ((BASE).count)++;
- ((N)->NAME).next = (BASE).start;
- ((N)->NAME).prev = NULL;
- if ((BASE).start != NULL) {
- (((BASE).start)->NAME).prev = (N);
- }
- (BASE).start = (N);
- if ((BASE).end == NULL) {
- (BASE).end = (N);
- }
- }
- /***********************************************************************
- Adds the node as the last element in a two-way linked list.
- BASE has to be the base node (not a pointer to it). N has to be
- the pointer to the node to be added to the list. NAME is the list name. */
- #define UT_LIST_ADD_LAST(NAME, BASE, N)
- {
- ut_ad(N);
- ((BASE).count)++;
- ((N)->NAME).prev = (BASE).end;
- ((N)->NAME).next = NULL;
- if ((BASE).end != NULL) {
- (((BASE).end)->NAME).next = (N);
- }
- (BASE).end = (N);
- if ((BASE).start == NULL) {
- (BASE).start = (N);
- }
- }
- /***********************************************************************
- Inserts a NODE2 after NODE1 in a list.
- BASE has to be the base node (not a pointer to it). NAME is the list
- name, NODE1 and NODE2 are pointers to nodes. */
- #define UT_LIST_INSERT_AFTER(NAME, BASE, NODE1, NODE2)
- {
- ut_ad(NODE1);
- ut_ad(NODE2);
- ((BASE).count)++;
- ((NODE2)->NAME).prev = (NODE1);
- ((NODE2)->NAME).next = ((NODE1)->NAME).next;
- if (((NODE1)->NAME).next != NULL) {
- ((((NODE1)->NAME).next)->NAME).prev = (NODE2);
- }
- ((NODE1)->NAME).next = (NODE2);
- if ((BASE).end == (NODE1)) {
- (BASE).end = (NODE2);
- }
- }
- /***********************************************************************
- Removes a node from a two-way linked list. BASE has to be the base node
- (not a pointer to it). N has to be the pointer to the node to be removed
- from the list. NAME is the list name. */
- #define UT_LIST_REMOVE(NAME, BASE, N)
- {
- ut_ad(N);
- ut_a((BASE).count > 0);
- ((BASE).count)--;
- if (((N)->NAME).next != NULL) {
- ((((N)->NAME).next)->NAME).prev = ((N)->NAME).prev;
- } else {
- (BASE).end = ((N)->NAME).prev;
- }
- if (((N)->NAME).prev != NULL) {
- ((((N)->NAME).prev)->NAME).next = ((N)->NAME).next;
- } else {
- (BASE).start = ((N)->NAME).next;
- }
- }
- /************************************************************************
- Gets the next node in a two-way list. NAME is the name of the list
- and N is pointer to a node. */
- #define UT_LIST_GET_NEXT(NAME, N)
- (((N)->NAME).next)
- /************************************************************************
- Gets the previous node in a two-way list. NAME is the name of the list
- and N is pointer to a node. */
- #define UT_LIST_GET_PREV(NAME, N)
- (((N)->NAME).prev)
- /************************************************************************
- Alternative macro to get the number of nodes in a two-way list, i.e.,
- its length. BASE is the base node (not a pointer to it). */
- #define UT_LIST_GET_LEN(BASE)
- (BASE).count
- /************************************************************************
- Gets the first node in a two-way list, or returns NULL,
- if the list is empty. BASE is the base node (not a pointer to it). */
- #define UT_LIST_GET_FIRST(BASE)
- (BASE).start
- /************************************************************************
- Gets the last node in a two-way list, or returns NULL,
- if the list is empty. BASE is the base node (not a pointer to it). */
- #define UT_LIST_GET_LAST(BASE)
- (BASE).end
- /************************************************************************
- Checks the consistency of a two-way list. NAME is the name of the list,
- TYPE is the node type, and BASE is the base node (not a pointer to it). */
- #define UT_LIST_VALIDATE(NAME, TYPE, BASE)
- {
- ulint ut_list_i_313;
- TYPE * ut_list_node_313;
- ut_list_node_313 = (BASE).start;
- for (ut_list_i_313 = 0; ut_list_i_313 < (BASE).count;
- ut_list_i_313++) {
- ut_a(ut_list_node_313);
- ut_list_node_313 = (ut_list_node_313->NAME).next;
- }
- ut_a(ut_list_node_313 == NULL);
- ut_list_node_313 = (BASE).end;
- for (ut_list_i_313 = 0; ut_list_i_313 < (BASE).count;
- ut_list_i_313++) {
- ut_a(ut_list_node_313);
- ut_list_node_313 = (ut_list_node_313->NAME).prev;
- }
- ut_a(ut_list_node_313 == NULL);
- }
-
- #endif