txn.h

About: hamsterdb is a database engine written in ANSI C. It supports a B+Tree index structure, uses

/**
 * Copyright (C) 2005-2007 Christoph Rupp ([e-mail]).
 * All rights reserved. See file LICENSE for licence and copyright
 * information.
 *
 * transactions
 *
 */

#ifndef HAM_TXN_H__
#define HAM_TXN_H__

#ifdef __cplusplus
extern "C" {
#endif 

#include <ham/hamsterdb.h>

struct ham_page_t;

/**
 * a dummy transaction structure
 */
typedef struct 
{
    /**
     * owner of this transaction 
     */
    ham_db_t *_db;

    /**
     * a list of pages which are referenced by this transaction
     */
    struct ham_page_t *_pagelist;

} ham_txn_t;

/**
 * get the database pointer
 */
#define txn_get_db(txn)                         (txn)->_db

/**
 * set the database pointer
 */
#define txn_set_db(txn, db)                     (txn)->_db=db

/**
 * get the page list
 */
#define txn_get_pagelist(txn)                   (txn)->_pagelist

/**
 * set the page list
 */
#define txn_set_pagelist(txn, pl)                (txn)->_pagelist=pl

/**
 * add a page to the transaction's pagelist
 */
extern ham_status_t
txn_add_page(ham_txn_t *txn, struct ham_page_t *page);

/**
 * remove a page from the transaction's pagelist
 */
extern ham_status_t
txn_remove_page(ham_txn_t *txn, struct ham_page_t *page);

/**
 * get a page from the transaction's pagelist; returns 0 if the page
 * is not in the list
 */
extern struct ham_page_t *
txn_get_page(ham_txn_t *txn, ham_offset_t address);

/**
 * mark a page in the transaction as 'deleted'
 * it will be deleted when the transaction is committed
 */
extern ham_status_t
txn_free_page(ham_txn_t *txn, struct ham_page_t *page);

/**
 * start a transaction
 *
 * @remark flags are defined below
 */
extern ham_status_t
ham_txn_begin(ham_txn_t *txn, ham_db_t *db);

/**
 * commit a transaction
 */
extern ham_status_t
ham_txn_commit(ham_txn_t *txn, ham_u32_t flags);

#define TXN_FORCE_WRITE         1

/**
 * abort a transaction
 */
extern ham_status_t
ham_txn_abort(ham_txn_t *txn);


#ifdef __cplusplus
} // extern "C"
#endif 

#endif /* HAM_TXN_H__ */