From 6035e7d6d1ed462176402615da37d4f987588c16 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 24 Jan 2011 21:53:27 +0100 Subject: [PATCH] Remove flist_sort(), it's no longer used Signed-off-by: Jens Axboe --- flist_sort.h | 9 --- lib/flist_sort.c | 140 ----------------------------------------------- 2 files changed, 149 deletions(-) delete mode 100644 flist_sort.h delete mode 100644 lib/flist_sort.c diff --git a/flist_sort.h b/flist_sort.h deleted file mode 100644 index 686b7a5a..00000000 --- a/flist_sort.h +++ /dev/null @@ -1,9 +0,0 @@ -#ifndef FIO_FLIST_SORT_H -#define FIO_FLIST_SORT_H - -struct flist_head; - -void flist_sort(void *priv, struct flist_head *head, - int (*cmp)(void *priv, struct flist_head *a, - struct flist_head *b)); -#endif diff --git a/lib/flist_sort.c b/lib/flist_sort.c deleted file mode 100644 index 9a2da841..00000000 --- a/lib/flist_sort.c +++ /dev/null @@ -1,140 +0,0 @@ -#include -#include - -#include "../flist.h" -#include "../flist_sort.h" - -#ifndef ARRAY_SIZE -#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0])) -#endif - -#define MAX_LIST_LENGTH_BITS 65 - -/* - * Returns a list organized in an intermediate format suited - * to chaining of merge() calls: null-terminated, no reserved or - * sentinel head node, "prev" links not maintained. - */ -static struct flist_head *merge(void *priv, - int (*cmp)(void *priv, struct flist_head *a, - struct flist_head *b), - struct flist_head *a, struct flist_head *b) -{ - struct flist_head head, *tail = &head; - - while (a && b) { - /* if equal, take 'a' -- important for sort stability */ - if ((*cmp)(priv, a, b) <= 0) { - tail->next = a; - a = a->next; - } else { - tail->next = b; - b = b->next; - } - tail = tail->next; - } - tail->next = a?:b; - return head.next; -} - -/* - * Combine final list merge with restoration of standard doubly-linked - * list structure. This approach duplicates code from merge(), but - * runs faster than the tidier alternatives of either a separate final - * prev-link restoration pass, or maintaining the prev links - * throughout. - */ -static void merge_and_restore_back_links(void *priv, - int (*cmp)(void *priv, struct flist_head *a, - struct flist_head *b), - struct flist_head *head, - struct flist_head *a, struct flist_head *b) -{ - struct flist_head *tail = head; - - while (a && b) { - /* if equal, take 'a' -- important for sort stability */ - if ((*cmp)(priv, a, b) <= 0) { - tail->next = a; - a->prev = tail; - a = a->next; - } else { - tail->next = b; - b->prev = tail; - b = b->next; - } - tail = tail->next; - } - tail->next = a ? : b; - - do { - /* - * In worst cases this loop may run many iterations. - * Continue callbacks to the client even though no - * element comparison is needed, so the client's cmp() - * routine can invoke cond_resched() periodically. - */ - cmp(priv, tail, tail); - - tail->next->prev = tail; - tail = tail->next; - } while (tail->next); - - tail->next = head; - head->prev = tail; -} - -/** - * flist_sort - sort a list - * @priv: private data, opaque to flist_sort(), passed to @cmp - * @head: the list to sort - * @cmp: the elements comparison function - * - * This function implements "merge sort", which has O(nlog(n)) - * complexity. - * - * The comparison function @cmp must return a negative value if @a - * should sort before @b, and a positive value if @a should sort after - * @b. If @a and @b are equivalent, and their original relative - * ordering is to be preserved, @cmp must return 0. - */ -void flist_sort(void *priv, struct flist_head *head, - int (*cmp)(void *priv, struct flist_head *a, - struct flist_head *b)) -{ - struct flist_head *part[MAX_LIST_LENGTH_BITS+1]; /* sorted partial lists - -- last slot is a sentinel */ - int lev; /* index into part[] */ - int max_lev = 0; - struct flist_head *list; - - if (flist_empty(head)) - return; - - memset(part, 0, sizeof(part)); - - head->prev->next = NULL; - list = head->next; - - while (list) { - struct flist_head *cur = list; - list = list->next; - cur->next = NULL; - - for (lev = 0; part[lev]; lev++) { - cur = merge(priv, cmp, part[lev], cur); - part[lev] = NULL; - } - if (lev > max_lev) { - assert(lev < ARRAY_SIZE(part) - 1); - max_lev = lev; - } - part[lev] = cur; - } - - for (lev = 0; lev < max_lev; lev++) - if (part[lev]) - list = merge(priv, cmp, part[lev], list); - - merge_and_restore_back_links(priv, cmp, head, part[max_lev], list); -} -- 2.25.1