#ifndef _SCOUTFS_BTREE_H_
#define _SCOUTFS_BTREE_H_

#include <linux/uio.h>

struct scoutfs_alloc;
struct scoutfs_block_writer;
struct scoutfs_block;

struct scoutfs_btree_item_ref {
	struct super_block *sb;
	struct scoutfs_block *bl;
	struct scoutfs_key *key;
	void *val;
	unsigned val_len;
};

#define SCOUTFS_BTREE_ITEM_REF(name) \
	struct scoutfs_btree_item_ref name = {NULL,}

/* caller gives an item to the callback */
typedef int (*scoutfs_btree_item_cb)(struct super_block *sb,
				     struct scoutfs_key *key, u64 seq, u8 flags,
				     void *val, int val_len, void *arg);

/* simple singly-linked list of items */
struct scoutfs_btree_item_list {
	struct scoutfs_btree_item_list *next;
	struct scoutfs_key key;
	u64 seq;
	u8 flags;
	int val_len;
	u8 val[0];
};

int scoutfs_btree_lookup(struct super_block *sb,
			 struct scoutfs_btree_root *root,
			 struct scoutfs_key *key,
			 struct scoutfs_btree_item_ref *iref);
int scoutfs_btree_insert(struct super_block *sb,
			 struct scoutfs_alloc *alloc,
			 struct scoutfs_block_writer *wri,
			 struct scoutfs_btree_root *root,
			 struct scoutfs_key *key,
			 void *val, unsigned val_len);
int scoutfs_btree_update(struct super_block *sb,
			 struct scoutfs_alloc *alloc,
			 struct scoutfs_block_writer *wri,
			 struct scoutfs_btree_root *root,
			 struct scoutfs_key *key,
			 void *val, unsigned val_len);
int scoutfs_btree_force(struct super_block *sb,
			struct scoutfs_alloc *alloc,
			struct scoutfs_block_writer *wri,
			struct scoutfs_btree_root *root,
			struct scoutfs_key *key,
			void *val, unsigned val_len);
int scoutfs_btree_delete(struct super_block *sb,
			 struct scoutfs_alloc *alloc,
			 struct scoutfs_block_writer *wri,
			 struct scoutfs_btree_root *root,
			 struct scoutfs_key *key);
int scoutfs_btree_next(struct super_block *sb, struct scoutfs_btree_root *root,
		       struct scoutfs_key *key,
		       struct scoutfs_btree_item_ref *iref);
int scoutfs_btree_prev(struct super_block *sb, struct scoutfs_btree_root *root,
		       struct scoutfs_key *key,
		       struct scoutfs_btree_item_ref *iref);
int scoutfs_btree_dirty(struct super_block *sb,
			struct scoutfs_alloc *alloc,
			struct scoutfs_block_writer *wri,
			struct scoutfs_btree_root *root,
			struct scoutfs_key *key);

int scoutfs_btree_read_items(struct super_block *sb,
			     struct scoutfs_btree_root *root,
			     struct scoutfs_key *key,
			     struct scoutfs_key *start,
			     struct scoutfs_key *end,
			     scoutfs_btree_item_cb cb, void *arg);
int scoutfs_btree_insert_list(struct super_block *sb,
			      struct scoutfs_alloc *alloc,
			      struct scoutfs_block_writer *wri,
			      struct scoutfs_btree_root *root,
			      struct scoutfs_btree_item_list *lst);

int scoutfs_btree_parent_range(struct super_block *sb,
			       struct scoutfs_btree_root *root,
			       struct scoutfs_key *key,
			       struct scoutfs_key *start,
			       struct scoutfs_key *end);
int scoutfs_btree_get_parent(struct super_block *sb,
			     struct scoutfs_btree_root *root,
			     struct scoutfs_key *key,
			     struct scoutfs_btree_root *par_root);
int scoutfs_btree_set_parent(struct super_block *sb,
			     struct scoutfs_alloc *alloc,
			     struct scoutfs_block_writer *wri,
			     struct scoutfs_btree_root *root,
			     struct scoutfs_key *key,
			     struct scoutfs_btree_root *par_root);
int scoutfs_btree_rebalance(struct super_block *sb,
			    struct scoutfs_alloc *alloc,
			    struct scoutfs_block_writer *wri,
			    struct scoutfs_btree_root *root,
			    struct scoutfs_key *key);

/* merge input is a list of roots */
struct scoutfs_btree_root_head {
	struct list_head head;
	struct scoutfs_btree_root root;
};

int scoutfs_btree_merge(struct super_block *sb,
			struct scoutfs_alloc *alloc,
			struct scoutfs_block_writer *wri,
			struct scoutfs_key *start,
			struct scoutfs_key *end,
			struct scoutfs_key *next_ret,
			struct scoutfs_btree_root *root,
			struct list_head *input_list,
			bool subtree, int dirty_limit, int alloc_low, int merge_window);

int scoutfs_btree_free_blocks(struct super_block *sb,
			      struct scoutfs_alloc *alloc,
			      struct scoutfs_block_writer *wri,
			      struct scoutfs_key *key,
			      struct scoutfs_btree_root *root, int free_budget);

void scoutfs_btree_put_iref(struct scoutfs_btree_item_ref *iref);

#endif