4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
11 *************************************************************************
13 ** This module implements the sqlite3_status() interface and related
16 ** $Id: status.c,v 1.7 2008/08/05 17:53:23 drh Exp $
18 #include "sqliteInt.h"
21 ** Variables in which to record status information.
24 int nowValue[9]; /* Current value */
25 int mxValue[9]; /* Maximum value */
30 ** Reset the status records. This routine is called by
31 ** sqlite3_initialize().
33 void sqlite3StatusReset(void){
34 memset(&sqlite3Stat, 0, sizeof(sqlite3Stat));
38 ** Return the current value of a status parameter.
40 int sqlite3StatusValue(int op){
41 assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
42 return sqlite3Stat.nowValue[op];
46 ** Add N to the value of a status record. It is assumed that the
47 ** caller holds appropriate locks.
49 void sqlite3StatusAdd(int op, int N){
50 assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
51 sqlite3Stat.nowValue[op] += N;
52 if( sqlite3Stat.nowValue[op]>sqlite3Stat.mxValue[op] ){
53 sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
58 ** Set the value of a status to X.
60 void sqlite3StatusSet(int op, int X){
61 assert( op>=0 && op<ArraySize(sqlite3Stat.nowValue) );
62 sqlite3Stat.nowValue[op] = X;
63 if( sqlite3Stat.nowValue[op]>sqlite3Stat.mxValue[op] ){
64 sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
69 ** Query status information.
71 ** This implementation assumes that reading or writing an aligned
72 ** 32-bit integer is an atomic operation. If that assumption is not true,
73 ** then this routine is not threadsafe.
75 int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
76 if( op<0 || op>=ArraySize(sqlite3Stat.nowValue) ){
79 *pCurrent = sqlite3Stat.nowValue[op];
80 *pHighwater = sqlite3Stat.mxValue[op];
82 sqlite3Stat.mxValue[op] = sqlite3Stat.nowValue[op];
88 ** Query status information for a single database connection
90 int sqlite3_db_status(
91 sqlite3 *db, /* The database connection whose status is desired */
92 int op, /* Status verb */
93 int *pCurrent, /* Write current value here */
94 int *pHighwater, /* Write high-water mark here */
95 int resetFlag /* Reset high-water mark if true */
98 case SQLITE_DBSTATUS_LOOKASIDE_USED: {
99 *pCurrent = db->lookaside.nOut;
100 *pHighwater = db->lookaside.mxOut;
102 db->lookaside.mxOut = db->lookaside.nOut;