[linux-2.6-block.git] / fs / squashfs / page_actor.h

#ifndef PAGE_ACTOR_H
#define PAGE_ACTOR_H
/*
 * Copyright (c) 2013
 * Phillip Lougher <phillip@squashfs.org.uk>
 *
 * This work is licensed under the terms of the GNU GPL, version 2. See
 * the COPYING file in the top-level directory.
 */

struct squashfs_page_actor {
	void	**page;
	int	pages;
	int	length;
	int	next_page;
};

static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page,
	int pages, int length)
{
	struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);

	if (actor == NULL)
		return NULL;

	actor->length = length ? : pages * PAGE_CACHE_SIZE;
	actor->page = page;
	actor->pages = pages;
	actor->next_page = 0;
	return actor;
}

static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
	actor->next_page = 1;
	return actor->page[0];
}

static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
{
	return actor->next_page == actor->pages ? NULL :
		actor->page[actor->next_page++];
}

static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
{
	/* empty */
}
#endif
Commit	Line	Data
846b730e PL	1	#ifndef PAGE_ACTOR_H
	2	#define PAGE_ACTOR_H
	3	/*
	4	* Copyright (c) 2013
	5	* Phillip Lougher <phillip@squashfs.org.uk>
	6	*
	7	* This work is licensed under the terms of the GNU GPL, version 2. See
	8	* the COPYING file in the top-level directory.
	9	*/
	10
	11	struct squashfs_page_actor {
	12	void **page;
	13	int pages;
	14	int length;
	15	int next_page;
	16	};
	17
	18	static inline struct squashfs_page_actor squashfs_page_actor_init(void *page,
	19	int pages, int length)
	20	{
	21	struct squashfs_page_actor actor = kmalloc(sizeof(actor), GFP_KERNEL);
	22
	23	if (actor == NULL)
	24	return NULL;
	25
	26	actor->length = length ? : pages * PAGE_CACHE_SIZE;
	27	actor->page = page;
	28	actor->pages = pages;
	29	actor->next_page = 0;
	30	return actor;
	31	}
	32
	33	static inline void squashfs_first_page(struct squashfs_page_actor actor)
	34	{
	35	actor->next_page = 1;
	36	return actor->page[0];
	37	}
	38
	39	static inline void squashfs_next_page(struct squashfs_page_actor actor)
	40	{
	41	return actor->next_page == actor->pages ? NULL :
	42	actor->page[actor->next_page++];
	43	}
	44
	45	static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
	46	{
	47	/* empty */
	48	}
	49	#endif