/* -*- mode: C; c-basic-offset: 4 -*- */
#ifndef BRT_H
#define BRT_H
#ident "Copyright (c) 2007, 2008 Tokutek Inc.  All rights reserved."

// This must be first to make the 64-bit file mode work right in Linux
#define _FILE_OFFSET_BITS 64
#include "brttypes.h"
#include "ybt.h"
#include <db.h>
#include "cachetable.h"
#include "log.h"
#include "brt-search.h"

// A callback function is invoked with the key, and the data.
// The pointers (to the bytevecs) must not be modified.  The data must be copied out before the callback function returns.
// Note: In the thread-safe version, the brt node remains locked while the callback function runs.  So return soon, and don't call the BRT code from the callback function.
// If the callback function returns a nonzero value (an error code), then that error code is returned from the get function itself.
// The cursor object will have been updated (so that if result==0 the current value is the value being passed)
//  (If r!=0 then the cursor won't have been updated.)
// If r!=0, it's up to the callback function to return that value of r.
//A 'key' bytevec of NULL means that element is not found (effectively infinity or
//-infinity depending on direction)
typedef int(*BRT_GET_CALLBACK_FUNCTION)(ITEMLEN, bytevec, ITEMLEN, bytevec, void*);
//Same as BRT_GET_CALLBACK_FUNCTION but returns both the answer to the query and
//the element on the other side of the border (as in heaviside function).
typedef int(*BRT_GET_STRADDLE_CALLBACK_FUNCTION)(ITEMLEN, bytevec, ITEMLEN, bytevec, ITEMLEN, bytevec, ITEMLEN, bytevec, void*);

int toku_open_brt (const char *fname, int is_create, BRT *, int nodesize, CACHETABLE, TOKUTXN, int(*)(DB*,const DBT*,const DBT*), DB*);

struct descriptor {
    u_int32_t version;
    DBT       dbt;
};
u_int32_t toku_serialize_descriptor_size(struct descriptor *desc);
int toku_brt_create(BRT *);
int toku_brt_set_flags(BRT, unsigned int flags);
int toku_brt_set_descriptor (BRT t, u_int32_t version, const DBT* descriptor, toku_dbt_upgradef dbt_userformat_upgrade);
int toku_brt_get_flags(BRT, unsigned int *flags);
int toku_brt_set_nodesize(BRT, unsigned int nodesize);
int toku_brt_get_nodesize(BRT, unsigned int *nodesize);
int toku_brt_set_bt_compare(BRT, int (*bt_compare)(DB *, const DBT*, const DBT*));
int toku_brt_set_dup_compare(BRT, int (*dup_compare)(DB *, const DBT*, const DBT*));
int brt_set_cachetable(BRT, CACHETABLE);
int toku_brt_open(BRT, const char *fname, const char *fname_in_env, int is_create, int only_create, CACHETABLE ct, TOKUTXN txn, DB *db);

int toku_brt_remove_subdb(BRT brt, const char *dbname, u_int32_t flags);

int toku_brt_insert (BRT, DBT *, DBT *, TOKUTXN);
int toku_brt_lookup (BRT brt, DBT *k, DBT *v, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v);
int toku_brt_delete (BRT brt, DBT *k, TOKUTXN);
int toku_brt_delete_both (BRT brt, DBT *k, DBT *v, TOKUTXN); // Delete a pair only if both k and v are equal according to the comparison function.
int toku_brt_db_delay_closed (BRT brt, DB* db, int (*close_db)(DB*, u_int32_t), u_int32_t close_flags);
int toku_close_brt (BRT, TOKULOGGER, char **error_string);

int toku_dump_brt (FILE *,BRT brt);

void brt_fsync (BRT); /* fsync, but don't clear the caches. */
void brt_flush (BRT); /* fsync and clear the caches. */

int toku_brt_get_cursor_count (BRT brt);
// get the number of cursors in the tree
// returns: the number of cursors.
// asserts: the number of cursors >= 0.

int toku_brt_flush (BRT brt);
// effect: the tree's cachefile is flushed
// returns: 0 if success

int toku_brt_truncate (BRT brt);
// effect: remove everything from the tree
// returns: 0 if success

// create and initialize a cache table
// cachesize is the upper limit on the size of the size of the values in the table
// pass 0 if you want the default
int toku_brt_create_cachetable(CACHETABLE *t, long cachesize, LSN initial_lsn, TOKULOGGER);

extern int toku_brt_debug_mode;
int toku_verify_brt (BRT brt);

//int show_brt_blocknumbers(BRT);

typedef struct brt_cursor *BRT_CURSOR;
int toku_brt_cursor (BRT, BRT_CURSOR*);

// get is deprecated in favor of the individual functions below
int toku_brt_cursor_get (BRT_CURSOR cursor, DBT *key, DBT *val, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, int get_flags, TOKUTXN txn);

int toku_brt_cursor_first(BRT_CURSOR cursor, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_last(BRT_CURSOR cursor, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_next(BRT_CURSOR cursor, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_next_nodup(BRT_CURSOR cursor, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_next_dup(BRT_CURSOR cursor, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_prev(BRT_CURSOR cursor, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_prev_nodup(BRT_CURSOR cursor, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_prev_dup(BRT_CURSOR cursor, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_current(BRT_CURSOR cursor, int op, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_set(BRT_CURSOR cursor, DBT *key, DBT *val, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_set_range(BRT_CURSOR cursor, DBT *key, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);
int toku_brt_cursor_get_both_range(BRT_CURSOR cursor, DBT *key, DBT *val, BRT_GET_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger);


typedef struct {
    YDB_HEAVISIDE_FUNCTION h;
    void *extra_h;
    int r_h;
    int direction;
} *HEAVI_WRAPPER, HEAVI_WRAPPER_S;
int toku_brt_cursor_heaviside(BRT_CURSOR cursor, BRT_GET_STRADDLE_CALLBACK_FUNCTION getf, void *getf_v, TOKULOGGER logger, HEAVI_WRAPPER wrapper);
int toku_brt_cursor_delete(BRT_CURSOR cursor, int flags, TOKUTXN);
int toku_brt_cursor_close (BRT_CURSOR curs);
BOOL toku_brt_cursor_uninitialized(BRT_CURSOR c);

void toku_brt_cursor_peek(BRT_CURSOR cursor, const DBT **pkey, const DBT **pval);

typedef struct brtenv *BRTENV;
int brtenv_checkpoint (BRTENV env);

extern int toku_brt_do_push_cmd; // control whether push occurs eagerly.

// TODO: Get rid of this
int toku_brt_dbt_set(DBT* key, DBT* key_source);

int toku_brt_get_fd(BRT, int *);

int toku_brt_height_of_root(BRT, int *height); // for an open brt, return the current height.

enum brt_header_flags {
    TOKU_DB_DUP = 1,
    TOKU_DB_DUPSORT = 2,
};

int toku_brt_keyrange (BRT brt, DBT *key, u_int64_t *less,  u_int64_t *equal,  u_int64_t *greater);
int toku_brt_stat64 (BRT, TOKUTXN,
		     u_int64_t *nkeys, /* estimate how many unique keys (even when flattened this may be an estimate)     */
		     u_int64_t *ndata, /* estimate the number of pairs (exact when flattened and committed)               */
		     u_int64_t *dsize, /* estimate the sum of the sizes of the pairs (exact when flattened and committed) */
		     u_int64_t *fsize  /* the size of the underlying file                                                 */
		     );

void toku_brt_init(void (*ydb_lock_callback)(void), void (*ydb_unlock_callback)(void));
void toku_brt_destroy(void);
void toku_pwrite_lock_init(void);
void toku_pwrite_lock_destroy(void);

void toku_maybe_truncate_cachefile (CACHEFILE cf, u_int64_t size_used);
// Effect: truncate file if overallocated by at least 32MiB

int maybe_preallocate_in_file (int fd, u_int64_t size);
// Effect: If file size is less than SIZE, make it bigger by either doubling it or growing by 16MB whichever is less.

int toku_brt_note_table_lock (BRT brt, TOKUTXN txn);
// Effect: Record the fact that the BRT has a table lock (and thus no other txn will modify it until this txn completes.  As a result, we can limit the amount of information in the rollback data structure.

#endif