/*
  Copyright (c) 2008-2012 Red Hat, Inc. <http://www.redhat.com>
  This file is part of GlusterFS.

  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 __READ_AHEAD_H
#define __READ_AHEAD_H

#include <glusterfs/glusterfs.h>
#include <glusterfs/logging.h>
#include <glusterfs/dict.h>
#include <glusterfs/xlator.h>
#include <glusterfs/common-utils.h>
#include "read-ahead-mem-types.h"

struct ra_conf;
struct ra_local;
struct ra_page;
struct ra_file;
struct ra_waitq;

struct ra_waitq {
    struct ra_waitq *next;
    void *data;
};

struct ra_fill {
    struct ra_fill *next;
    struct ra_fill *prev;
    off_t offset;
    size_t size;
    struct iovec *vector;
    int32_t count;
    struct iobref *iobref;
};

struct ra_local {
    mode_t mode;
    struct ra_fill fill;
    off_t offset;
    size_t size;
    int32_t op_ret;
    int32_t op_errno;
    off_t pending_offset;
    size_t pending_size;
    fd_t *fd;
    int32_t wait_count;
    pthread_mutex_t local_lock;
};

struct ra_page {
    struct ra_page *next;
    struct ra_page *prev;
    struct ra_file *file;
    char dirty;    /* Internal request, not from user. */
    char poisoned; /* Pending read invalidated by write. */
    char ready;
    struct iovec *vector;
    int32_t count;
    off_t offset;
    size_t size;
    struct ra_waitq *waitq;
    struct iobref *iobref;
    char stale;
};

struct ra_file {
    struct ra_file *next;
    struct ra_file *prev;
    struct ra_conf *conf;
    fd_t *fd;
    int disabled;
    size_t expected;
    struct ra_page pages;
    off_t offset;
    size_t size;
    int32_t refcount;
    pthread_mutex_t file_lock;
    struct iatt stbuf;
    uint64_t page_size;
    uint32_t page_count;
};

struct ra_conf {
    uint64_t page_size;
    uint32_t page_count;
    void *cache_block;
    struct ra_file files;
    gf_boolean_t force_atime_update;
    pthread_mutex_t conf_lock;
};

typedef struct ra_conf ra_conf_t;
typedef struct ra_local ra_local_t;
typedef struct ra_page ra_page_t;
typedef struct ra_file ra_file_t;
typedef struct ra_waitq ra_waitq_t;
typedef struct ra_fill ra_fill_t;

ra_page_t *
ra_page_get(ra_file_t *file, off_t offset);

ra_page_t *
ra_page_create(ra_file_t *file, off_t offset);

void
ra_page_fault(ra_file_t *file, call_frame_t *frame, off_t offset);
void
ra_wait_on_page(ra_page_t *page, call_frame_t *frame);

ra_waitq_t *
ra_page_wakeup(ra_page_t *page);

void
ra_page_flush(ra_page_t *page);

ra_waitq_t *
ra_page_error(ra_page_t *page, int32_t op_ret, int32_t op_errno);
void
ra_page_purge(ra_page_t *page);

void
ra_frame_return(call_frame_t *frame);

void
ra_frame_fill(ra_page_t *page, call_frame_t *frame);

void
ra_file_destroy(ra_file_t *file);

static inline void
ra_file_lock(ra_file_t *file)
{
    pthread_mutex_lock(&file->file_lock);
}

static inline void
ra_file_unlock(ra_file_t *file)
{
    pthread_mutex_unlock(&file->file_lock);
}

static inline void
ra_conf_lock(ra_conf_t *conf)
{
    pthread_mutex_lock(&conf->conf_lock);
}

static inline void
ra_conf_unlock(ra_conf_t *conf)
{
    pthread_mutex_unlock(&conf->conf_lock);
}
static inline void
ra_local_lock(ra_local_t *local)
{
    pthread_mutex_lock(&local->local_lock);
}

static inline void
ra_local_unlock(ra_local_t *local)
{
    pthread_mutex_unlock(&local->local_lock);
}

#endif /* __READ_AHEAD_H */