/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef PAGE_ACTOR_H
#define PAGE_ACTOR_H
/*
 * Copyright (c) 2013
 * Phillip Lougher <phillip@squashfs.org.uk>
 */

struct squashfs_page_actor {
        union {
                void            **buffer;
                struct page     **page;
        };
        void    *pageaddr;
        void    *tmp_buffer;
        void    *(*squashfs_first_page)(struct squashfs_page_actor *);
        void    *(*squashfs_next_page)(struct squashfs_page_actor *);
        void    (*squashfs_finish_page)(struct squashfs_page_actor *);
        struct page *last_page;
        int     pages;
        int     length;
        int     next_page;
        int     alloc_buffer;
        int     returned_pages;
        pgoff_t next_index;
};

extern struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
                                int pages, int length);
extern struct squashfs_page_actor *squashfs_page_actor_init_special(
                                struct squashfs_sb_info *msblk,
                                struct page **page, int pages, int length,
                                loff_t start_index);
static inline struct page *squashfs_page_actor_free(struct squashfs_page_actor *actor)
{
        struct page *last_page = actor->next_page == actor->pages ? actor->last_page : ERR_PTR(-EIO);

        kfree(actor->tmp_buffer);
        kfree(actor);

        return last_page;
}
static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
        return actor->squashfs_first_page(actor);
}
static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
{
        return actor->squashfs_next_page(actor);
}
static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
{
        actor->squashfs_finish_page(actor);
}
static inline void squashfs_actor_nobuff(struct squashfs_page_actor *actor)
{
        actor->alloc_buffer = 0;
}
#endif