/*
   Copyright (c) 2014 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 __META_H__
#define __META_H__

#include <glusterfs/strfd.h>

#define DEFAULT_META_DIR_NAME ".meta"

#define META_ROOT_GFID "ba926388-bb9c-4eec-ad60-79dba4cc083a"

#define IS_META_ROOT_GFID(g) (strcmp(uuid_utoa(g), META_ROOT_GFID) == 0)

typedef int (*meta_hook_t)(call_frame_t *frame, xlator_t *this, loc_t *loc,
                           dict_t *xdata);

typedef struct {
    dict_t *xdata;
} meta_local_t;

typedef struct {
    char *meta_dir_name;
} meta_priv_t;

struct meta_dirent {
    const char *name;
    ia_type_t type;
    meta_hook_t hook;
};

#define DOT_DOTDOT                                                             \
    {.name = ".", .type = IA_IFDIR}, { .name = "..", .type = IA_IFDIR }

struct meta_ops {
    struct meta_dirent *fixed_dirents;
    int (*dir_fill)(xlator_t *this, inode_t *dir, struct meta_dirent **entries);
    int (*file_fill)(xlator_t *this, inode_t *file, strfd_t *strfd);
    int (*iatt_fill)(xlator_t *this, inode_t *inode, struct iatt *iatt);
    int (*link_fill)(xlator_t *this, inode_t *inode, strfd_t *strfd);
    int (*file_write)(xlator_t *this, fd_t *fd, struct iovec *iov, int count);
    struct xlator_fops fops;
    struct xlator_cbks cbks;
};

typedef struct {
    char *data;
    struct meta_dirent *dirents;
    size_t size;
} meta_fd_t;

#define COUNT(arr) (sizeof(arr) / sizeof(arr[0]))

#define META_HOOK(loc)                                                         \
    (__is_root_gfid(loc->pargfid) &&                                           \
     !strcmp(loc->name, META_PRIV(THIS)->meta_dir_name))

#define META_PRIV(t) ((meta_priv_t *)(t->private))

#define META_STACK_UNWIND(fop, frame, params...)                               \
    do {                                                                       \
        meta_local_t *__local = NULL;                                          \
        xlator_t *__this = NULL;                                               \
        if (frame) {                                                           \
            __local = frame->local;                                            \
            __this = frame->this;                                              \
            frame->local = NULL;                                               \
        }                                                                      \
        STACK_UNWIND_STRICT(fop, frame, params);                               \
        if (__local) {                                                         \
            meta_local_cleanup(__local, __this);                               \
        }                                                                      \
    } while (0)

#define META_FOP(i, fop, fr, t, params...)                                     \
    {                                                                          \
        struct xlator_fops *_fops = NULL;                                      \
                                                                               \
        _fops = meta_fops_get(i, t);                                           \
                                                                               \
        _fops->fop(fr, t, params);                                             \
    }                                                                          \
    while (0)

void
meta_iatt_fill(struct iatt *iatt, inode_t *inode, ia_type_t type);

int
meta_inode_discover(call_frame_t *frame, xlator_t *this, loc_t *loc,
                    dict_t *xdata);

int
meta_ops_set(inode_t *inode, xlator_t *this, struct meta_ops *ops);

struct xlator_fops *
meta_fops_get(inode_t *inode, xlator_t *this);
struct xlator_cbks *
meta_cbks_get(inode_t *inode, xlator_t *this);
struct meta_ops *
meta_ops_get(inode_t *inode, xlator_t *this);

int
meta_ctx_set(inode_t *inode, xlator_t *this, void *ctx);

void *
meta_ctx_get(inode_t *inode, xlator_t *this);

void
meta_local_cleanup(meta_local_t *local, xlator_t *this);

struct xlator_fops *
meta_defaults_init(struct xlator_fops *fops);

meta_fd_t *
meta_fd_get(fd_t *fd, xlator_t *this);

int
meta_fd_release(fd_t *fd, xlator_t *this);

dict_t *
meta_direct_io_mode(dict_t *xdata, call_frame_t *frame);

meta_local_t *
meta_local(call_frame_t *frame);

int
meta_file_fill(xlator_t *this, fd_t *fd);

int
meta_dir_fill(xlator_t *this, fd_t *fd);

int
fixed_dirents_len(struct meta_dirent *dirents);
#endif /* __META_H__ */