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/*
** 2008 June 18
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
**
** This module implements the sqlite3_status() interface and related
** functionality.
**
** $Id: status.c,v 1.7 2008/08/05 17:53:23 drh Exp $
*/
#include "sqliteInt.h"
/*
** Variables in which to record status information.
*/
static struct {
int nowValue[9]; /* Current value */
int mxValue[9]; /* Maximum value */
} sqlite3Stat;
/*
** Reset the status records. This routine is called by
** sqlite3_initialize().
*/
void sqlite3StatusReset(void){
memset(&sqlite3Stat, 0, sizeof(sqlite3Stat));
}
/*
** Return the current value of a status parameter.
*/
int sqlite3StatusValue(int op){
assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
return sqlite3Stat.nowValue[op];
}
/*
** Add N to the value of a status record. It is assumed that the
** caller holds appropriate locks.
*/
void sqlite3StatusAdd(int op, int N){
assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
sqlite3Stat.nowValue[op] += N;
if( sqlite3Stat.nowValue[op]>sqlite3Stat.mxValue[op] ){
sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
}
}
/*
** Set the value of a status to X.
*/
void sqlite3StatusSet(int op, int X){
assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
sqlite3Stat.nowValue[op] = X;
if( sqlite3Stat.nowValue[op]>sqlite3Stat.mxValue[op] ){
sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
}
}
/*
** Query status information.
**
** This implementation assumes that reading or writing an aligned
** 32-bit integer is an atomic operation. If that assumption is not true,
** then this routine is not threadsafe.
*/
int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
if( op<0 || op>=ArraySize(sqlite3Stat.nowValue) ){
return SQLITE_MISUSE;
}
*pCurrent = sqlite3Stat.nowValue[op];
*pHighwater = sqlite3Stat.mxValue[op];
if( resetFlag ){
sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
}
return SQLITE_OK;
}
/*
** Query status information for a single database connection
*/
int sqlite3_db_status(
sqlite3 *db, /* The database connection whose status is desired */
int op, /* Status verb */
int *pCurrent, /* Write current value here */
int *pHighwater, /* Write high-water mark here */
int resetFlag /* Reset high-water mark if true */
){
switch( op ){
case SQLITE_DBSTATUS_LOOKASIDE_USED: {
*pCurrent = db->lookaside.nOut;
*pHighwater = db->lookaside.mxOut;
if( resetFlag ){
db->lookaside.mxOut = db->lookaside.nOut;
}
break;
}
default: {
return SQLITE_ERROR;
}
}
return SQLITE_OK;
}
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