diff options
Diffstat (limited to 'utils')
| -rw-r--r-- | utils/Makefile.am | 9 | ||||
| -rw-r--r-- | utils/list.h | 244 | ||||
| -rw-r--r-- | utils/lru.c | 112 | ||||
| -rw-r--r-- | utils/lru.h | 31 |
4 files changed, 393 insertions, 3 deletions
diff --git a/utils/Makefile.am b/utils/Makefile.am index 40442c3..0da7857 100644 --- a/utils/Makefile.am +++ b/utils/Makefile.am @@ -1,10 +1,13 @@ noinst_LTLIBRARIES = libgb.la -libgb_la_SOURCES = common.c utils.c +libgb_la_SOURCES = common.c utils.c lru.c -noinst_HEADERS = common.h utils.h +noinst_HEADERS = common.h utils.h lru.h list.h -libgb_la_CFLAGS = -DDATADIR=\"$(localstatedir)\" -I$(top_builddir)/rpc/rpcl +libgb_la_CFLAGS = $(GFAPI_CFLAGS) -DDATADIR=\"$(localstatedir)\" \ + -I$(top_builddir)/rpc/rpcl + +libgb_la_LIBADD = $(GFAPI_LIBS) libgb_ladir = $(includedir)/gluster-block/utils diff --git a/utils/list.h b/utils/list.h new file mode 100644 index 0000000..98b5b25 --- /dev/null +++ b/utils/list.h @@ -0,0 +1,244 @@ +#ifndef __LIST_H +#define __LIST_H + +/* This file is from Linux Kernel (include/linux/list.h) + * and modified by simply removing hardware prefetching of list items. + * Here by copyright, credits attributed to wherever they belong. + * Kulesh Shanmugasundaram (kulesh [squiggly] isis.poly.edu) + */ + +/* + * Simple doubly linked list implementation. + * + * Some of the internal functions ("__xxx") are useful when + * manipulating whole lists rather than single entries, as + * sometimes we already know the next/prev entries and we can + * generate better code by using them directly rather than + * using the generic single-entry routines. + */ + +struct list_head { + struct list_head *next, *prev; +}; + +#define LIST_HEAD_INIT(name) { &(name), &(name) } + +#define LIST_HEAD(name) \ + struct list_head name = LIST_HEAD_INIT(name) + +#define INIT_LIST_HEAD(ptr) do { \ + (ptr)->next = (ptr); (ptr)->prev = (ptr); \ +} while (0) + +/* + * Insert a new entry between two known consecutive entries. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static inline void __list_add(struct list_head *new, + struct list_head *prev, + struct list_head *next) +{ + next->prev = new; + new->next = next; + new->prev = prev; + prev->next = new; +} + +/** + * list_add - add a new entry + * @new: new entry to be added + * @head: list head to add it after + * + * Insert a new entry after the specified head. + * This is good for implementing stacks. + */ +static inline void list_add(struct list_head *new, struct list_head *head) +{ + __list_add(new, head, head->next); +} + +/** + * list_add_tail - add a new entry + * @new: new entry to be added + * @head: list head to add it before + * + * Insert a new entry before the specified head. + * This is useful for implementing queues. + */ +static inline void list_add_tail(struct list_head *new, struct list_head *head) +{ + __list_add(new, head->prev, head); +} + +/* + * Delete a list entry by making the prev/next entries + * point to each other. + * + * This is only for internal list manipulation where we know + * the prev/next entries already! + */ +static inline void __list_del(struct list_head *prev, struct list_head *next) +{ + next->prev = prev; + prev->next = next; +} + +/** + * list_del - deletes entry from list. + * @entry: the element to delete from the list. + * Note: list_empty on entry does not return true after this, the entry is in an undefined state. + */ +static inline void list_del(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + entry->next = (void *) 0; + entry->prev = (void *) 0; +} + +/** + * list_del_init - deletes entry from list and reinitialize it. + * @entry: the element to delete from the list. + */ +static inline void list_del_init(struct list_head *entry) +{ + __list_del(entry->prev, entry->next); + INIT_LIST_HEAD(entry); +} + +/** + * list_move - delete from one list and add as another's head + * @list: the entry to move + * @head: the head that will precede our entry + */ +static inline void list_move(struct list_head *list, struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add(list, head); +} + +/** + * list_move_tail - delete from one list and add as another's tail + * @list: the entry to move + * @head: the head that will follow our entry + */ +static inline void list_move_tail(struct list_head *list, + struct list_head *head) +{ + __list_del(list->prev, list->next); + list_add_tail(list, head); +} + +/** + * list_empty - tests whether a list is empty + * @head: the list to test. + */ +static inline int list_empty(struct list_head *head) +{ + return head->next == head; +} + +static inline void __list_splice(struct list_head *list, + struct list_head *head) +{ + struct list_head *first = list->next; + struct list_head *last = list->prev; + struct list_head *at = head->next; + + first->prev = head; + head->next = first; + + last->next = at; + at->prev = last; +} + +/** + * list_splice - join two lists + * @list: the new list to add. + * @head: the place to add it in the first list. + */ +static inline void list_splice(struct list_head *list, struct list_head *head) +{ + if (!list_empty(list)) + __list_splice(list, head); +} + +/** + * list_splice_init - join two lists and reinitialise the emptied list. + * @list: the new list to add. + * @head: the place to add it in the first list. + * + * The list at @list is reinitialised + */ +static inline void list_splice_init(struct list_head *list, + struct list_head *head) +{ + if (!list_empty(list)) { + __list_splice(list, head); + INIT_LIST_HEAD(list); + } +} + +/** + * list_entry - get the struct for this entry + * @ptr: the &struct list_head pointer. + * @type: the type of the struct this is embedded in. + * @member: the name of the list_struct within the struct. + */ +#define list_entry(ptr, type, member) \ + ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member))) + +/** + * list_for_each - iterate over a list + * @pos: the &struct list_head to use as a loop counter. + * @head: the head for your list. + */ +#define list_for_each(pos, head) \ + for (pos = (head)->next; pos != (head); \ + pos = pos->next) +/** + * list_for_each_prev - iterate over a list backwards + * @pos: the &struct list_head to use as a loop counter. + * @head: the head for your list. + */ +#define list_for_each_prev(pos, head) \ + for (pos = (head)->prev; pos != (head); \ + pos = pos->prev) + +/** + * list_for_each_safe - iterate over a list safe against removal of list entry + * @pos: the &struct list_head to use as a loop counter. + * @n: another &struct list_head to use as temporary storage + * @head: the head for your list. + */ +#define list_for_each_safe(pos, n, head) \ + for (pos = (head)->next, n = pos->next; pos != (head); \ + pos = n, n = pos->next) + +/** + * list_for_each_entry - iterate over list of given type + * @pos: the type * to use as a loop counter. + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry(pos, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = list_entry(pos->member.next, typeof(*pos), member)) + +/** + * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry + * @pos: the type * to use as a loop counter. + * @n: another type * to use as temporary storage + * @head: the head for your list. + * @member: the name of the list_struct within the struct. + */ +#define list_for_each_entry_safe(pos, n, head, member) \ + for (pos = list_entry((head)->next, typeof(*pos), member), \ + n = list_entry(pos->member.next, typeof(*pos), member); \ + &pos->member != (head); \ + pos = n, n = list_entry(n->member.next, typeof(*n), member)) + + +#endif diff --git a/utils/lru.c b/utils/lru.c new file mode 100644 index 0000000..f1e884b --- /dev/null +++ b/utils/lru.c @@ -0,0 +1,112 @@ +/* + Copyright (c) 2017 Red Hat, Inc. <http://www.redhat.com> + This file is part of gluster-block. + + This file is licensed to you under your choice of the GNU Lesser + General Public License, version 3 or any later version (LGPLv3 or + later), or the GNU General Public License, version 2 (GPLv2), in all + cases as published by the Free Software Foundation. +*/ + +# include "lru.h" + +# define LRU_CAPACITY 5 + + +static struct list_head Cache; +static int lruCount; + +typedef struct Entry { + char volume[256]; + glfs_t *glfs; + + struct list_head list; +} Entry; + + +static void +releaseColdEntry(void) +{ + Entry *tmp; + struct list_head *pos, *q = &Cache; + + + list_for_each_prev(pos, q) { + tmp = list_entry(pos, Entry, list); + list_del(pos); + + glfs_fini(tmp->glfs); + GB_FREE(tmp); + lruCount--; + + break; + } +} + + +int +appendNewEntry(const char *volname, glfs_t *fs) +{ + Entry *tmp; + + + if (lruCount == LRU_CAPACITY) { + releaseColdEntry(); + } + + if (GB_ALLOC(tmp) < 0) { + return -1; + } + strcpy(tmp->volume, volname); + tmp->glfs = fs; + + list_add(&(tmp->list), &Cache); + + lruCount++; + + return 0; +} + + +static void +boostEntryWarmness(const char *volname) +{ + Entry *tmp; + struct list_head *pos, *q; + + + list_for_each_safe(pos, q, &Cache){ + tmp = list_entry(pos, Entry, list); + if (!strcmp(tmp->volume, volname)) { + list_del(pos); + list_add(&(tmp->list), &Cache); + break; + } + } +} + + +glfs_t * +queryCache(const char *volname) +{ + Entry *tmp; + struct list_head *pos, *q, *r = &Cache; + + + list_for_each_safe(pos, q, r){ + tmp = list_entry(pos, Entry, list); + if (!strcmp(tmp->volume, volname)) { + boostEntryWarmness(volname); + return tmp->glfs; + } + } + + return NULL; +} + + +void +initCache(void) +{ + INIT_LIST_HEAD(&Cache); +} diff --git a/utils/lru.h b/utils/lru.h new file mode 100644 index 0000000..e9af217 --- /dev/null +++ b/utils/lru.h @@ -0,0 +1,31 @@ +/* + Copyright (c) 2017 Red Hat, Inc. <http://www.redhat.com> + This file is part of gluster-block. + + This file is licensed to you under your choice of the GNU Lesser + General Public License, version 3 or any later version (LGPLv3 or + later), or the GNU General Public License, version 2 (GPLv2), in all + cases as published by the Free Software Foundation. +*/ + + +# ifndef _LRU_H +# define _LRU_H 1 + +# include <api/glfs.h> + +# include "common.h" +# include "list.h" + + +void +initCache(void); + +glfs_t * +queryCache(const char *volname); + +int +appendNewEntry(const char *volname, glfs_t *glfs); + + +# endif /* _LRU_H */ |