diff options
Diffstat (limited to 'src/backend/lib/dllist.c')
| -rw-r--r-- | src/backend/lib/dllist.c | 214 |
1 files changed, 0 insertions, 214 deletions
diff --git a/src/backend/lib/dllist.c b/src/backend/lib/dllist.c deleted file mode 100644 index 52af56a0795..00000000000 --- a/src/backend/lib/dllist.c +++ /dev/null @@ -1,214 +0,0 @@ -/*------------------------------------------------------------------------- - * - * dllist.c - * this is a simple doubly linked list implementation - * the elements of the lists are void* - * - * Portions Copyright (c) 1996-2012, PostgreSQL Global Development Group - * Portions Copyright (c) 1994, Regents of the University of California - * - * - * IDENTIFICATION - * src/backend/lib/dllist.c - * - *------------------------------------------------------------------------- - */ -#include "postgres.h" - -#include "lib/dllist.h" - - -Dllist * -DLNewList(void) -{ - Dllist *l; - - l = (Dllist *) palloc(sizeof(Dllist)); - - l->dll_head = NULL; - l->dll_tail = NULL; - - return l; -} - -void -DLInitList(Dllist *list) -{ - list->dll_head = NULL; - list->dll_tail = NULL; -} - -/* - * free up a list and all the nodes in it --- but *not* whatever the nodes - * might point to! - */ -void -DLFreeList(Dllist *list) -{ - Dlelem *curr; - - while ((curr = DLRemHead(list)) != NULL) - pfree(curr); - - pfree(list); -} - -Dlelem * -DLNewElem(void *val) -{ - Dlelem *e; - - e = (Dlelem *) palloc(sizeof(Dlelem)); - - e->dle_next = NULL; - e->dle_prev = NULL; - e->dle_val = val; - e->dle_list = NULL; - return e; -} - -void -DLInitElem(Dlelem *e, void *val) -{ - e->dle_next = NULL; - e->dle_prev = NULL; - e->dle_val = val; - e->dle_list = NULL; -} - -void -DLFreeElem(Dlelem *e) -{ - pfree(e); -} - -void -DLRemove(Dlelem *e) -{ - Dllist *l = e->dle_list; - - if (e->dle_prev) - e->dle_prev->dle_next = e->dle_next; - else - { - /* must be the head element */ - Assert(e == l->dll_head); - l->dll_head = e->dle_next; - } - if (e->dle_next) - e->dle_next->dle_prev = e->dle_prev; - else - { - /* must be the tail element */ - Assert(e == l->dll_tail); - l->dll_tail = e->dle_prev; - } - - e->dle_next = NULL; - e->dle_prev = NULL; - e->dle_list = NULL; -} - -void -DLAddHead(Dllist *l, Dlelem *e) -{ - e->dle_list = l; - - if (l->dll_head) - l->dll_head->dle_prev = e; - e->dle_next = l->dll_head; - e->dle_prev = NULL; - l->dll_head = e; - - if (l->dll_tail == NULL) /* if this is first element added */ - l->dll_tail = e; -} - -void -DLAddTail(Dllist *l, Dlelem *e) -{ - e->dle_list = l; - - if (l->dll_tail) - l->dll_tail->dle_next = e; - e->dle_prev = l->dll_tail; - e->dle_next = NULL; - l->dll_tail = e; - - if (l->dll_head == NULL) /* if this is first element added */ - l->dll_head = e; -} - -Dlelem * -DLRemHead(Dllist *l) -{ - /* remove and return the head */ - Dlelem *result = l->dll_head; - - if (result == NULL) - return result; - - if (result->dle_next) - result->dle_next->dle_prev = NULL; - - l->dll_head = result->dle_next; - - if (result == l->dll_tail) /* if the head is also the tail */ - l->dll_tail = NULL; - - result->dle_next = NULL; - result->dle_list = NULL; - - return result; -} - -Dlelem * -DLRemTail(Dllist *l) -{ - /* remove and return the tail */ - Dlelem *result = l->dll_tail; - - if (result == NULL) - return result; - - if (result->dle_prev) - result->dle_prev->dle_next = NULL; - - l->dll_tail = result->dle_prev; - - if (result == l->dll_head) /* if the tail is also the head */ - l->dll_head = NULL; - - result->dle_prev = NULL; - result->dle_list = NULL; - - return result; -} - -/* Same as DLRemove followed by DLAddHead, but faster */ -void -DLMoveToFront(Dlelem *e) -{ - Dllist *l = e->dle_list; - - if (l->dll_head == e) - return; /* Fast path if already at front */ - - Assert(e->dle_prev != NULL); /* since it's not the head */ - e->dle_prev->dle_next = e->dle_next; - - if (e->dle_next) - e->dle_next->dle_prev = e->dle_prev; - else - { - /* must be the tail element */ - Assert(e == l->dll_tail); - l->dll_tail = e->dle_prev; - } - - l->dll_head->dle_prev = e; - e->dle_next = l->dll_head; - e->dle_prev = NULL; - l->dll_head = e; - /* We need not check dll_tail, since there must have been > 1 entry */ -} |