tra.h

firebird源代码

/*
 *	PROGRAM:	JRD Access Method
 *	MODULE:		tra.h
 *	DESCRIPTION:	Transaction block definitions
 *
 * The contents of this file are subject to the Interbase Public
 * License Version 1.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy
 * of the License at http://www.Inprise.com/IPL.html
 *
 * Software distributed under the License is distributed on an
 * "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express
 * or implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * The Original Code was created by Inprise Corporation
 * and its predecessors. Portions created by Inprise Corporation are
 * Copyright (C) Inprise Corporation.
 *
 * All Rights Reserved.
 * Contributor(s): ______________________________________.
 * 2001.6.25 Claudio Valderrama: add dfw_delete_generator and dfw_delete_udf
 * to the dfw_t enumeration.
 */

#ifndef _JRD_TRA_H_
#define _JRD_TRA_H_

/* Transaction block */

typedef struct tra {
    struct blk	tra_header;
    struct att	*tra_attachment;		/* database attachment */
    SLONG	tra_number;		/* transaction number */
    SLONG	tra_top;		/* highest transaction in snapshot */
    SLONG	tra_oldest;		/* oldest interesting transaction */
    SLONG	tra_oldest_active;	/* record versions older than this can be
					   gargage-collected by this tx */
    struct tra	*tra_next;		/* next transaction in database */
    struct tra	*tra_sibling;		/* next transaction in group */
    struct plb	*tra_pool;		/* pool for transaction */
    struct blb	*tra_blobs;		/* Linked list of active blobs */
    struct arr	*tra_arrays;		/* Linked list of active arrays */
    struct lck	*tra_lock;		/* lock for transaction */
    struct vec	*tra_relation_locks;	/* locks for relations */
    struct sbm	*tra_commit_sub_trans;	/* commited sub-transactions */
    struct sav  *tra_save_point;        /* list of savepoints  */
    struct sav  *tra_save_free;         /* free savepoints */
    SLONG	tra_save_point_number;	/* next save point number to use */
    ULONG	tra_flags;
#ifdef PC_ENGINE
    SLONG	tra_range_id;		/* unique id of cache range within transaction */
#endif
    struct dfw	*tra_deferred_work;	/* work deferred to commit time */
    struct rsc	*tra_resources;		/* resource existence list */
    UCHAR	tra_use_count;		/* use count for safe AST delivery */
    UCHAR	tra_callback_count;	/* callback count for 'execute varchar' */
    UCHAR	tra_transactions[1];
} *TRA;

#define TRA_system		1L	/* system transaction */
#define TRA_update		2L	/* update is permitted */
#define TRA_prepared		4L	/* transaction is in limbo */
#define TRA_reconnected		8L	/* reconnect in progress */
#define TRA_reserving		16L	/* relations explicityly locked */
#define TRA_degree3		32L	/* serializeable transaction */
#define TRA_committing		64L	/* commit in progress */
#define TRA_write		128L	/* transaction has written */
#define TRA_readonly		256L	/* transaction is readonly */
#define TRA_nowait		512L	/* don't wait on relations, give up */
#define TRA_prepare2		1024L	/* transaction has updated RDB$TRANSACTIONS */
#define TRA_ignore_limbo	2048L	/* ignore transactions in limbo */
#define TRA_invalidated 	4096L	/* transaction invalidated by failed write */
#define TRA_deferred_meta 	8192L	/* deferred meta work posted */
#define TRA_add_log		16384L	/* write ahead log file was added */
#define TRA_delete_log		32768L	/* write ahead log file was deleted */
#define TRA_read_committed	65536L	/* can see latest committed records */
#define TRA_autocommit		131072L	/* autocommits all updates */
#define TRA_perform_autocommit	262144L	/* indicates autocommit is necessary */
#define TRA_rec_version		524288L	/* don't wait for uncommitted versions */
#define TRA_restart_requests	1048576L /* restart all requests in attachment */
#define TRA_no_auto_undo	2097152L /* don't start a savepoint in TRA_start*/
#define TRA_sweep_at_startup    4194304L /* sweep done at startup */
#define TRA_precommitted	8388608L /* transaction committed at startup */

#define TRA_MASK		3
#define TRA_BITS_PER_TRANS	2
#define TRA_TRANS_PER_BYTE	4
#define TRA_SHIFT		2

#define TRANS_SHIFT(number)	(((number) & TRA_MASK) << 1)
#define TRANS_OFFSET(number)	((number) >> TRA_SHIFT)

/* Transaction cleanup. If a database is never quiescent, look
   for "dead" active transactions every so often at transaction
   startup */

#define TRA_ACTIVE_CLEANUP	100

/* Transaction states.  The first four are states found
   in the transaction inventory page; the last two are
   returned internally */

#define tra_active	    0	/* Transaction is active */
#define tra_limbo	    1
#define tra_dead	    2
#define tra_committed	    3
#define tra_us		    4	/* Transaction is us */
#define tra_precommitted    5	/* Transaction is precommitted */

/* The highest transaction number possible.  This is 0x7fffffff if SLONG is 32 bits. */
#define MAX_TRA_NUMBER		 (~(1L << (BITS_PER_LONG - 1)))
/* Savepoint block */

typedef struct sav {
    struct blk	sav_header;
    struct vct	*sav_verb_actions;	/* verb action list */
    struct vct	*sav_verb_free;		/* free verb action block */
    USHORT	sav_verb_count;		/* Active verb count */
    SLONG	sav_number;		/* save point number */
    struct sav  *sav_next;
    USHORT      sav_flags;
} *SAV;

/* Savepoint block flags. */

#define SAV_trans_level		1   /* savepoint was started by TRA_start */
#define SAV_event_post		2   /* event posted in the save point */

/* Deferred work blocks are used by the meta data handler to keep track
   of work deferred to commit time.  This are usually used to perform
   meta data updates */

ENUM dfw_t {
   dfw_null,
   dfw_create_relation,
   dfw_delete_relation,
   dfw_update_format,
   dfw_create_index,
   dfw_delete_index,
   dfw_compute_security,
   dfw_add_file,
   dfw_add_shadow,
   dfw_delete_shadow,
   dfw_modify_file,
   dfw_erase_file,
   dfw_delete_field,
   dfw_delete_global,
   dfw_delete_rfr,
   dfw_post_event,
   dfw_create_trigger,
   dfw_delete_trigger,
   dfw_modify_trigger,
   dfw_load_triggers,
   dfw_grant,
   dfw_revoke,
   dfw_scan_relation,
   dfw_create_expression_index,
   dfw_delete_expression_index,
   dfw_delete_log,
   dfw_create_log,
   dfw_create_procedure,
   dfw_modify_procedure,
   dfw_delete_procedure,
   dfw_delete_prm,
   dfw_delete_exception,
   dfw_unlink_file,
   dfw_delete_generator,
   dfw_delete_udf
};

typedef struct dfw {
    struct blk	dfw_header;
    ENUM dfw_t	dfw_type;		/* type of work deferred */
    struct dfw	*dfw_next;		/* next block in transaction */
    struct lck	*dfw_lock;		/* relation creation lock */
    SLONG	dfw_sav_number;		/* save point number */
    USHORT	dfw_name_length;	/* length of object name */
    USHORT	dfw_id;			/* object id, if appropriate */
    USHORT	dfw_count;		/* count of block posts */
    SCHAR	dfw_name [2];		/* name of object */
} *DFW;

/* Verb actions */

typedef struct vct {
    struct blk	vct_header;
    struct vct	*vct_next;		/* Next action within verb */
    struct rel	*vct_relation;		/* Relation involved */
    struct sbm	*vct_records;		/* Record involved */
    struct sbm	*vct_undo;		/* Record involved that have to be replaced */
    struct lls	*vct_data;		/* Data for undo records */
} *VCT;

#endif /* _JRD_TRA_H_ */