/*
** 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.
*/
#include "sqliteInt.h"
#include "vdbeInt.h"
/*
** Variables in which to record status information.
*/
typedef struct sqlite3StatType sqlite3StatType;
static SQLITE_WSD struct sqlite3StatType {
int nowValue[10]; /* Current value */
int mxValue[10]; /* Maximum value */
} sqlite3Stat = { {0,}, {0,} };
/* The "wsdStat" macro will resolve to the status information
** state vector. If writable static data is unsupported on the target,
** we have to locate the state vector at run-time. In the more common
** case where writable static data is supported, wsdStat can refer directly
** to the "sqlite3Stat" state vector declared above.
*/
#ifdef SQLITE_OMIT_WSD
# define wsdStatInit sqlite3StatType *x = &GLOBAL(sqlite3StatType,sqlite3Stat)
# define wsdStat x[0]
#else
# define wsdStatInit
# define wsdStat sqlite3Stat
#endif
/*
** Return the current value of a status parameter.
*/
int sqlite3StatusValue(int op){
wsdStatInit;
assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
return wsdStat.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){
wsdStatInit;
assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
wsdStat.nowValue[op] += N;
if( wsdStat.nowValue[op]>wsdStat.mxValue[op] ){
wsdStat.mxValue[op] = wsdStat.nowValue[op];
}
}
/*
** Set the value of a status to X.
*/
void sqlite3StatusSet(int op, int X){
wsdStatInit;
assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
wsdStat.nowValue[op] = X;
if( wsdStat.nowValue[op]>wsdStat.mxValue[op] ){
wsdStat.mxValue[op] = wsdStat.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){
wsdStatInit;
if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
return SQLITE_MISUSE_BKPT;
}
*pCurrent = wsdStat.nowValue[op];
*pHighwater = wsdStat.mxValue[op];
if( resetFlag ){
wsdStat.mxValue[op] = wsdStat.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 */
){
int rc = SQLITE_OK; /* Return code */
sqlite3_mutex_enter(db->mutex);
switch( op ){
case SQLITE_DBSTATUS_LOOKASIDE_USED: {
*pCurrent = db->lookaside.nOut;
*pHighwater = db->lookaside.mxOut;
if( resetFlag ){
db->lookaside.mxOut = db->lookaside.nOut;
}
break;
}
case SQLITE_DBSTATUS_LOOKASIDE_HIT:
case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:
case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {
testcase( op==SQLITE_DBSTATUS_LOOKASIDE_HIT );
testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE );
testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL );
assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)>=0 );
assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)<3 );
*pCurrent = 0;
*pHighwater = db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT];
if( resetFlag ){
db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT] = 0;
}
break;
}
/*
** Return an approximation for the amount of memory currently used
** by all pagers associated with the given database connection. The
** highwater mark is meaningless and is returned as zero.
*/
case SQLITE_DBSTATUS_CACHE_USED: {
int totalUsed = 0;
int i;
sqlite3BtreeEnterAll(db);
for(i=0; i<db->nDb; i++){
Btree *pBt = db->aDb[i].pBt;
if( pBt ){
Pager *pPager = sqlite3BtreePager(pBt);
totalUsed += sqlite3PagerMemUsed(pPager);
}
}
sqlite3BtreeLeaveAll(db);
*pCurrent = totalUsed;
*pHighwater = 0;
break;
}
/*
** *pCurrent gets an accurate estimate of the amount of memory used
** to store the schema for all databases (main, temp, and any ATTACHed
** databases. *pHighwater is set to zero.
*/
case SQLITE_DBSTATUS_SCHEMA_USED: {
int i; /* Used to iterate through schemas */
int nByte = 0; /* Used to accumulate return value */
sqlite3BtreeEnterAll(db);
db->pnBytesFreed = &nByte;
for(i=0; i<db->nDb; i++){
Schema *pSchema = db->aDb[i].pSchema;
if( ALWAYS(pSchema!=0) ){
HashElem *p;
nByte += sqlite3GlobalConfig.m.xRoundup(sizeof(HashElem)) * (
pSchema->tblHash.count
+ pSchema->trigHash.count
+ pSchema->idxHash.count
+ pSchema->fkeyHash.count
);
nByte += sqlite3MallocSize(pSchema->tblHash.ht);
nByte += sqlite3MallocSize(pSchema->trigHash.ht);
nByte += sqlite3MallocSize(pSchema->idxHash.ht);
nByte += sqlite3MallocSize(pSchema->fkeyHash.ht);
for(p=sqliteHashFirst(&pSchema->trigHash); p; p=sqliteHashNext(p)){
sqlite3DeleteTrigger(db, (Trigger*)sqliteHashData(p));
}
for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
sqlite3DeleteTable(db, (Table *)sqliteHashData(p));
}
}
}
db->pnBytesFreed = 0;
sqlite3BtreeLeaveAll(db);
*pHighwater = 0;
*pCurrent = nByte;
break;
}
/*
** *pCurrent gets an accurate estimate of the amount of memory used
** to store all prepared statements.
** *pHighwater is set to zero.
*/
case SQLITE_DBSTATUS_STMT_USED: {
struct Vdbe *pVdbe; /* Used to iterate through VMs */
int nByte = 0; /* Used to accumulate return value */
db->pnBytesFreed = &nByte;
for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
sqlite3VdbeDeleteObject(db, pVdbe);
}
db->pnBytesFreed = 0;
*pHighwater = 0;
*pCurrent = nByte;
break;
}
/*
** Set *pCurrent to the total cache hits or misses encountered by all
** pagers the database handle is connected to. *pHighwater is always set
** to zero.
*/
case SQLITE_DBSTATUS_CACHE_HIT:
case SQLITE_DBSTATUS_CACHE_MISS: {
int i;
int nRet = 0;
assert( SQLITE_DBSTATUS_CACHE_MISS==SQLITE_DBSTATUS_CACHE_HIT+1 );
for(i=0; i<db->nDb; i++){
if( db->aDb[i].pBt ){
Pager *pPager = sqlite3BtreePager(db->aDb[i].pBt);
sqlite3PagerCacheStat(pPager, op, resetFlag, &nRet);
}
}
*pHighwater = 0;
*pCurrent = nRet;
break;
}
default: {
rc = SQLITE_ERROR;
}
}
sqlite3_mutex_leave(db->mutex);
return rc;
}