btcursor.h

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/*
 * (c) Copyright 2011-2013, Hewlett-Packard Development Company, LP
 */

#ifndef __BTCURSOR_H
#define __BTCURSOR_H

#include "w_defines.h"
#include "w_key.h"
#include "buffer_pool.hpp"

class btree_page_h;

class bt_cursor_t : private smlevel_0 {
public:
    bt_cursor_t(StoreID store, bool forward);

    bt_cursor_t(
            StoreID store,
            const w_keystr_t& lower, bool lower_inclusive,
            const w_keystr_t& upper, bool upper_inclusive,
            bool forward);

    bt_cursor_t(
            StoreID store,
            const w_keystr_t& bound, bool inclusive,
            bool forward);

    ~bt_cursor_t() {
        close();
    }

    rc_t next();

    bool is_valid() const {
        return _first_time || !_eof;
    }

    bool is_forward() const {
        return _forward;
    }

    void close();

    const w_keystr_t& key() {
        return _key;
    }

    bool eof() {
        return _eof;
    }

    int elen() const {
        return _elen;
    }

    char* elem() {
        return _eof ? 0 : _elbuf;
    }

private:
    void _init(
            StoreID store,
            const w_keystr_t& lower, bool lower_inclusive,
            const w_keystr_t& upper, bool upper_inclusive,
            bool forward);

    rc_t _locate_first();

    rc_t _check_page_update(btree_page_h& p);

    rc_t _find_next(btree_page_h& p, bool& eof);

    void _release_current_page();

    void _set_current_page(btree_page_h& page);

    w_rc_t _refix_current_key(btree_page_h& p);

    rc_t _advance_one_slot(btree_page_h& p, bool& eof);

    rc_t _make_rec(const btree_page_h& page);

    StoreID _store;

    w_keystr_t _lower;

    w_keystr_t _upper;

    bool _lower_inclusive;

    bool _upper_inclusive;

    bool _forward;

    bool _needs_lock;

    bool _ex_lock;

    bool _dont_move_next;

    bool _first_time;

    bool _eof;

    PageID _pid;

    pin_for_refix_holder _pid_bfidx;

    slotid_t _slot;

    lsn_t _lsn;

    w_keystr_t _key;

    w_keystr_t _tmp_next_key_buf;

    smsize_t _elen;

    char _elbuf[SM_PAGESIZE];
};

#endif // __BTCURSOR_H