db_am.h   [plain text]

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996,2008 Oracle.  All rights reserved.
 *
 * $Id: db_am.h,v 12.44 2008/05/07 12:27:33 bschmeck Exp $
 */
#ifndef _DB_AM_H_
#define	_DB_AM_H_

#if defined(__cplusplus)
extern "C" {
#endif

struct __db_foreign_info; \
                        typedef struct __db_foreign_info DB_FOREIGN_INFO;

/*
 * Keep track of information for foreign keys.  Used to maintain a linked list
 * of 'primary' DBs which reference this 'foreign' DB.
 */
struct __db_foreign_info {
	DB *dbp;
	u_int32_t flags;
	int (*callback) __P((DB *, const DBT *, DBT *, const DBT *, int *));

	/*
	 * List entries for foreign key.
	 *
	 * !!!
	 * Explicit representations of structures from queue.h.
	 * LIST_ENTRY(__db) s_links;
	 */
	struct {
		struct __db_foreign_info *le_next;
		struct __db_foreign_info **le_prev;
	} f_links;
};

/*
 * IS_ENV_AUTO_COMMIT --
 *	Auto-commit test for enviroment operations: DbEnv::{open,remove,rename}
 */
#define	IS_ENV_AUTO_COMMIT(env, txn, flags)				\
	(LF_ISSET(DB_AUTO_COMMIT) || ((txn) == NULL &&			\
	    F_ISSET((env)->dbenv, DB_ENV_AUTO_COMMIT) &&		\
	    !LF_ISSET(DB_NO_AUTO_COMMIT)))

/*
 * IS_DB_AUTO_COMMIT --
 *	Auto-commit test for database operations.
 */
#define	IS_DB_AUTO_COMMIT(dbp, txn)					\
	    ((txn) == NULL && F_ISSET((dbp), DB_AM_TXN))

/*
 * STRIP_AUTO_COMMIT --
 *	Releases after 4.3 no longer requires DB operations to specify the
 *	AUTO_COMMIT flag, but the API continues to allow it to be specified.
 */
#define	STRIP_AUTO_COMMIT(f)	FLD_CLR((f), DB_AUTO_COMMIT)

/* DB recovery operation codes. */
#define	DB_ADD_DUP	1
#define	DB_REM_DUP	2
#define	DB_ADD_BIG	3
#define	DB_REM_BIG	4
#define	DB_ADD_PAGE_COMPAT	5	/* Compatibility for 4.2 db_relink */
#define	DB_REM_PAGE_COMPAT	6	/* Compatibility for 4.2 db_relink */

/*
 * Standard initialization and shutdown macros for all recovery functions.
 */
#define	REC_INTRO(func, ip, do_cursor) do {				\
	argp = NULL;							\
	dbc = NULL;							\
	file_dbp = NULL;						\
	COMPQUIET(mpf, NULL);	/* Not all recovery routines use mpf. */\
	if ((ret = func(env, &file_dbp,					\
	    (info != NULL) ? ((DB_TXNHEAD *)info)->td : NULL,		\
	    dbtp->data, &argp)) != 0) {					\
		if (ret	== DB_DELETED) {				\
			ret = 0;					\
			goto done;					\
		}							\
		goto out;						\
	}								\
	if (do_cursor) {						\
		if ((ret =						\
		    __db_cursor(file_dbp, ip, NULL, &dbc, 0)) != 0)	\
			goto out;					\
		F_SET(dbc, DBC_RECOVER);				\
	}								\
	mpf = file_dbp->mpf;						\
} while (0)

#define	REC_CLOSE {							\
	int __t_ret;							\
	if (argp != NULL)						\
		__os_free(env, argp);					\
	if (dbc != NULL &&						\
	    (__t_ret = __dbc_close(dbc)) != 0 && ret == 0)		\
		ret = __t_ret;						\
	}								\
	return (ret)

/*
 * No-op versions of the same macros.
 */
#define	REC_NOOP_INTRO(func) do {					\
	argp = NULL;							\
	if ((ret = func(env, dbtp->data, &argp)) != 0)		\
		return (ret);						\
} while (0)
#define	REC_NOOP_CLOSE							\
	if (argp != NULL)						\
		__os_free(env, argp);					\
	return (ret)

/*
 * Macro for reading pages during recovery.  In most cases we
 * want to avoid an error if the page is not found during rollback.
 */
#define	REC_FGET(mpf, ip, pgno, pagep, cont)				\
	if ((ret = __memp_fget(mpf,					\
	     &(pgno), ip, NULL, 0, pagep)) != 0) { 			\
		if (ret != DB_PAGE_NOTFOUND) {				\
			ret = __db_pgerr(file_dbp, pgno, ret);		\
			goto out;					\
		} else							\
			goto cont;					\
	}
#define	REC_DIRTY(mpf, ip, priority, pagep)				\
	if ((ret = __memp_dirty(mpf,					\
	    pagep, ip, NULL, priority, DB_MPOOL_EDIT)) != 0) {		\
		ret = __db_pgerr(file_dbp, PGNO(*(pagep)), ret);	\
		goto out;						\
	}

/*
 * Standard debugging macro for all recovery functions.
 */
#ifdef DEBUG_RECOVER
#define	REC_PRINT(func)							\
	(void)func(env, dbtp, lsnp, op, info);
#else
#define	REC_PRINT(func)
#endif

/*
 * Actions to __db_lget
 */
#define	LCK_ALWAYS		1	/* Lock even for off page dup cursors */
#define	LCK_COUPLE		2	/* Lock Couple */
#define	LCK_COUPLE_ALWAYS	3	/* Lock Couple even in txn. */
#define	LCK_DOWNGRADE		4	/* Downgrade the lock. (internal) */
#define	LCK_ROLLBACK		5	/* Lock even if in rollback */

/*
 * If doing transactions we have to hold the locks associated with a data item
 * from a page for the entire transaction.  However, we don't have to hold the
 * locks associated with walking the tree.  Distinguish between the two so that
 * we don't tie up the internal pages of the tree longer than necessary.
 */
#define	__LPUT(dbc, lock)						\
	__ENV_LPUT((dbc)->env, lock)

#define	__ENV_LPUT(env, lock)						\
	(LOCK_ISSET(lock) ? __lock_put(env, &(lock)) : 0)

/*
 * __TLPUT -- transactional lock put
 *	If the lock is valid then
 *	   If we are not in a transaction put the lock.
 *	   Else if the cursor is doing dirty reads and this was a read then
 *		put the lock.
 *	   Else if the db is supporting dirty reads and this is a write then
 *		downgrade it.
 *	Else do nothing.
 */
#define	__TLPUT(dbc, lock)						\
	(LOCK_ISSET(lock) ? __db_lput(dbc, &(lock)) : 0)

/*
 * A database should be required to be readonly if it's been explicitly
 * specified as such or if we're a client in a replicated environment
 * and the user did not specify DB_TXN_NOT_DURABLE.
 */
#define	DB_IS_READONLY(dbp)						\
    (F_ISSET(dbp, DB_AM_RDONLY) ||					\
    (IS_REP_CLIENT((dbp)->env) && !F_ISSET((dbp), DB_AM_NOT_DURABLE)))

/*
 * We copy the key out if there's any chance the key in the database is not
 * the same as the user-specified key.  If there is a custom comparator we
 * return a key, as the user-specified key might be a partial key, containing
 * only the unique identifier.  [#13572] [#15770]
 *
 * The test for (flags != 0) is necessary for Db.{get,pget}, but it's not
 * legal to pass a non-zero flags value to Dbc.{get,pget}.
 *
 * We need to split out the hash component, since it is possible to build
 * without hash support enabled. Which would result in a null pointer access.
 */
#ifdef HAVE_HASH
#define DB_RETURNS_A_KEY_HASH(dbp)					\
	((HASH *)(dbp)->h_internal)->h_compare != NULL
#else
#define DB_RETURNS_A_KEY_HASH(dbp)	0
#endif
#define	DB_RETURNS_A_KEY(dbp, flags)					\
	(((flags) != 0 && (flags) != DB_GET_BOTH &&			\
	    (flags) != DB_GET_BOTH_RANGE && (flags) != DB_SET) ||	\
	    ((BTREE *)(dbp)->bt_internal)->bt_compare != __bam_defcmp ||\
	    DB_RETURNS_A_KEY_HASH(dbp))

/*
 * For portability, primary keys that are record numbers are stored in
 * secondaries in the same byte order as the secondary database.  As a
 * consequence, we need to swap the byte order of these keys before attempting
 * to use them for lookups in the primary.  We also need to swap user-supplied
 * primary keys that are used in secondary lookups (for example, with the
 * DB_GET_BOTH flag on a secondary get).
 */
#include "dbinc/db_swap.h"

#define	SWAP_IF_NEEDED(sdbp, pkey)					\
	do {								\
		if (((sdbp)->s_primary->type == DB_QUEUE ||		\
		    (sdbp)->s_primary->type == DB_RECNO) &&		\
		    F_ISSET((sdbp), DB_AM_SWAP))			\
			P_32_SWAP((pkey)->data);			\
	} while (0)

/*
 * Cursor adjustment:
 *	Return the first DB handle in the sorted ENV list of DB
 *	handles that has a matching file ID.
 */
#define	FIND_FIRST_DB_MATCH(env, dbp, tdbp) do {			\
	for ((tdbp) = (dbp);						\
	    TAILQ_PREV((tdbp), __dblist, dblistlinks) != NULL &&	\
	    TAILQ_PREV((tdbp),						\
		__dblist, dblistlinks)->adj_fileid == (dbp)->adj_fileid;\
	    (tdbp) = TAILQ_PREV((tdbp), __dblist, dblistlinks))		\
		;							\
} while (0)

/*
 * Macros used to implement a binary search algorithm. Shared between the
 * btree and hash implementations.
 */
#define	DB_BINARY_SEARCH_FOR(base, limit, page, adjust)			\
	for (base = 0, limit = NUM_ENT(page) / (db_indx_t)(adjust);	\
	    (limit) != 0; (limit) >>= 1)

#define	DB_BINARY_SEARCH_INCR(index, base, limit, adjust)		\
	index = (base) + (((limit) >> 1) * (adjust))

#define	DB_BINARY_SEARCH_SHIFT_BASE(index, base, limit, adjust)	do {	\
	base = (index) + (adjust);					\
	--(limit);							\
} while (0)

/*
 * Sequence macros, shared between sequence.c and seq_stat.c
 */
#define	SEQ_IS_OPEN(seq)	((seq)->seq_key.data != NULL)

#define	SEQ_ILLEGAL_AFTER_OPEN(seq, name)				\
	if (SEQ_IS_OPEN(seq))						\
		return (__db_mi_open((seq)->seq_dbp->env, name, 1));

#define	SEQ_ILLEGAL_BEFORE_OPEN(seq, name)				\
	if (!SEQ_IS_OPEN(seq))						\
		return (__db_mi_open((seq)->seq_dbp->env, name, 0));

/*
 * Flags to __db_chk_meta.
 */
#define	DB_CHK_META	0x01	/* Checksum the meta page. */
#define	DB_CHK_NOLSN	0x02	/* Don't check the LSN. */

#if defined(__cplusplus)
}
#endif

#include "dbinc/db_dispatch.h"
#include "dbinc_auto/db_auto.h"
#include "dbinc_auto/crdel_auto.h"
#include "dbinc_auto/db_ext.h"
#endif /* !_DB_AM_H_ */