row0purge.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

/******************************************************
Purge obsolete records

(c) 1997 Innobase Oy

Created 3/14/1997 Heikki Tuuri
*******************************************************/

#include "row0purge.h"

#ifdef UNIV_NONINL
#include "row0purge.ic"
#endif

#include "fsp0fsp.h"
#include "mach0data.h"
#include "trx0rseg.h"
#include "trx0trx.h"
#include "trx0roll.h"
#include "trx0undo.h"
#include "trx0purge.h"
#include "trx0rec.h"
#include "que0que.h"
#include "row0row.h"
#include "row0upd.h"
#include "row0vers.h"
#include "row0mysql.h"
#include "log0log.h"

/************************************************************************
Creates a purge node to a query graph. */

purge_node_t*
row_purge_node_create(
/*==================*/
				/* out, own: purge node */
	que_thr_t*	parent,	/* in: parent node, i.e., a thr node */
	mem_heap_t*	heap)	/* in: memory heap where created */
{
	purge_node_t*	node;

	ut_ad(parent && heap);

	node = mem_heap_alloc(heap, sizeof(purge_node_t));

	node->common.type = QUE_NODE_PURGE;
	node->common.parent = parent;

	node->heap = mem_heap_create(256);

	return(node);
}

/***************************************************************
Repositions the pcur in the purge node on the clustered index record,
if found. */
static
ibool
row_purge_reposition_pcur(
/*======================*/
				/* out: TRUE if the record was found */
	ulint		mode,	/* in: latching mode */
	purge_node_t*	node,	/* in: row purge node */
	mtr_t*		mtr)	/* in: mtr */
{
	ibool	found;

	if (node->found_clust) {
		found = btr_pcur_restore_position(mode, &(node->pcur), mtr);

		return(found);
	}

	found = row_search_on_row_ref(&(node->pcur), mode, node->table,
							node->ref, mtr);
	node->found_clust = found;

	if (found) {
		btr_pcur_store_position(&(node->pcur), mtr);
	}

	return(found);
}

/***************************************************************
Removes a delete marked clustered index record if possible. */
static
ibool
row_purge_remove_clust_if_poss_low(
/*===============================*/
				/* out: TRUE if success, or if not found, or
				if modified after the delete marking */
	purge_node_t*	node,	/* in: row purge node */
	ulint		mode)	/* in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */
{
	dict_index_t*	index;
	btr_pcur_t*	pcur;
	btr_cur_t*	btr_cur;
	ibool		success;
	ulint		err;
	mtr_t		mtr;
	rec_t*		rec;
	mem_heap_t*	heap		= NULL;
	ulint		offsets_[REC_OFFS_NORMAL_SIZE];
	*offsets_ = (sizeof offsets_) / sizeof *offsets_;

	index = dict_table_get_first_index(node->table);
	
	pcur = &(node->pcur);
	btr_cur = btr_pcur_get_btr_cur(pcur);

	mtr_start(&mtr);

	success = row_purge_reposition_pcur(mode, node, &mtr);

	if (!success) {
		/* The record is already removed */

		btr_pcur_commit_specify_mtr(pcur, &mtr);

		return(TRUE);
	}

	rec = btr_pcur_get_rec(pcur);

	if (0 != ut_dulint_cmp(node->roll_ptr,
		row_get_rec_roll_ptr(rec, index, rec_get_offsets(
			rec, index, offsets_, ULINT_UNDEFINED, &heap)))) {
		if (UNIV_LIKELY_NULL(heap)) {
			mem_heap_free(heap);
		}
		/* Someone else has modified the record later: do not remove */
		btr_pcur_commit_specify_mtr(pcur, &mtr);

		return(TRUE);
	}

	if (UNIV_LIKELY_NULL(heap)) {
		mem_heap_free(heap);
	}

	if (mode == BTR_MODIFY_LEAF) {
		success = btr_cur_optimistic_delete(btr_cur, &mtr);
	} else {
		ut_ad(mode == BTR_MODIFY_TREE);
		btr_cur_pessimistic_delete(&err, FALSE, btr_cur, FALSE, &mtr);

		if (err == DB_SUCCESS) {
			success = TRUE;
		} else if (err == DB_OUT_OF_FILE_SPACE) {
			success = FALSE;
		} else {
			ut_error;
		}
	}

	btr_pcur_commit_specify_mtr(pcur, &mtr);

	return(success);
}
		
/***************************************************************
Removes a clustered index record if it has not been modified after the delete
marking. */
static
void
row_purge_remove_clust_if_poss(
/*===========================*/
	purge_node_t*	node)	/* in: row purge node */
{
	ibool	success;
	ulint	n_tries	= 0;
	
/*	fputs("Purge: Removing clustered record\n", stderr); */

	success = row_purge_remove_clust_if_poss_low(node, BTR_MODIFY_LEAF);
	if (success) {

		return;
	}
retry:
	success = row_purge_remove_clust_if_poss_low(node, BTR_MODIFY_TREE);
	/* The delete operation may fail if we have little
	file space left: TODO: easiest to crash the database
	and restart with more file space */

	if (!success && n_tries < BTR_CUR_RETRY_DELETE_N_TIMES) {
		n_tries++;

		os_thread_sleep(BTR_CUR_RETRY_SLEEP_TIME);
			
		goto retry;
	}

	ut_a(success);
}
 						
/***************************************************************
Removes a secondary index entry if possible. */
static
ibool
row_purge_remove_sec_if_poss_low(
/*=============================*/
				/* out: TRUE if success or if not found */
	purge_node_t*	node,	/* in: row purge node */
	dict_index_t*	index,	/* in: index */
	dtuple_t*	entry,	/* in: index entry */
	ulint		mode)	/* in: latch mode BTR_MODIFY_LEAF or
				BTR_MODIFY_TREE */	
{
	btr_pcur_t	pcur;
	btr_cur_t*	btr_cur;
	ibool		success;
	ibool		old_has = 0; /* remove warning */
	ibool		found;
	ulint		err;
	mtr_t		mtr;
	mtr_t*		mtr_vers;
	
	log_free_check();
	mtr_start(&mtr);
	
	found = row_search_index_entry(index, entry, mode, &pcur, &mtr);

	if (!found) {
		/* Not found */

		/* fputs("PURGE:........sec entry not found\n", stderr); */
		/* dtuple_print(entry); */

		btr_pcur_close(&pcur);
		mtr_commit(&mtr);

		return(TRUE);
	}

	btr_cur = btr_pcur_get_btr_cur(&pcur);
	
	/* We should remove the index record if no later version of the row,
	which cannot be purged yet, requires its existence. If some requires,
	we should do nothing. */

	mtr_vers = mem_alloc(sizeof(mtr_t));
	
	mtr_start(mtr_vers);

	success = row_purge_reposition_pcur(BTR_SEARCH_LEAF, node, mtr_vers);

	if (success) {		
		old_has = row_vers_old_has_index_entry(TRUE,
					btr_pcur_get_rec(&(node->pcur)),
					mtr_vers, index, entry);
	}

	btr_pcur_commit_specify_mtr(&(node->pcur), mtr_vers);

	mem_free(mtr_vers);
	
	if (!success || !old_has) {
		/* Remove the index record */

		if (mode == BTR_MODIFY_LEAF) {		
			success = btr_cur_optimistic_delete(btr_cur, &mtr);
		} else {
			ut_ad(mode == BTR_MODIFY_TREE);
			btr_cur_pessimistic_delete(&err, FALSE, btr_cur,
							FALSE, &mtr);
			if (err == DB_SUCCESS) {
				success = TRUE;
			} else if (err == DB_OUT_OF_FILE_SPACE) {
				success = FALSE;
			} else {
				ut_error;
			}
		}
	}

	btr_pcur_close(&pcur);
	mtr_commit(&mtr);

	return(success);
}

/***************************************************************
Removes a secondary index entry if possible. */
UNIV_INLINE
void
row_purge_remove_sec_if_poss(
/*=========================*/
	purge_node_t*	node,	/* in: row purge node */
	dict_index_t*	index,	/* in: index */
	dtuple_t*	entry)	/* in: index entry */
{
	ibool	success;
	ulint	n_tries		= 0;
	
/*	fputs("Purge: Removing secondary record\n", stderr); */

	success = row_purge_remove_sec_if_poss_low(node, index, entry,
							BTR_MODIFY_LEAF);
	if (success) {

		return;
	}
retry:
	success = row_purge_remove_sec_if_poss_low(node, index, entry,
							BTR_MODIFY_TREE);
	/* The delete operation may fail if we have little
	file space left: TODO: easiest to crash the database
	and restart with more file space */

	if (!success && n_tries < BTR_CUR_RETRY_DELETE_N_TIMES) {
				
		n_tries++;

		os_thread_sleep(BTR_CUR_RETRY_SLEEP_TIME);
							
		goto retry;
	}

	ut_a(success);
}

/***************************************************************
Purges a delete marking of a record. */
static
void
row_purge_del_mark(
/*===============*/
	purge_node_t*	node)	/* in: row purge node */
{
	mem_heap_t*	heap;
	dtuple_t*	entry;
	dict_index_t*	index;
	
	ut_ad(node);