xref: /sqlite-3.40.0/src/status.c (revision 45f31be8)
1 /*
2 ** 2008 June 18
3 **
4 ** The author disclaims copyright to this source code.  In place of
5 ** a legal notice, here is a blessing:
6 **
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.
10 **
11 *************************************************************************
12 **
13 ** This module implements the sqlite3_status() interface and related
14 ** functionality.
15 */
16 #include "sqliteInt.h"
17 #include "vdbeInt.h"
18 
19 /*
20 ** Variables in which to record status information.
21 */
22 #if SQLITE_PTRSIZE>4
23 typedef sqlite3_int64 sqlite3StatValueType;
24 #else
25 typedef u32 sqlite3StatValueType;
26 #endif
27 typedef struct sqlite3StatType sqlite3StatType;
28 static SQLITE_WSD struct sqlite3StatType {
29   sqlite3StatValueType nowValue[10];  /* Current value */
30   sqlite3StatValueType mxValue[10];   /* Maximum value */
31 } sqlite3Stat = { {0,}, {0,} };
32 
33 /*
34 ** Elements of sqlite3Stat[] are protected by either the memory allocator
35 ** mutex, or by the pcache1 mutex.  The following array determines which.
36 */
37 static const char statMutex[] = {
38   0,  /* SQLITE_STATUS_MEMORY_USED */
39   1,  /* SQLITE_STATUS_PAGECACHE_USED */
40   1,  /* SQLITE_STATUS_PAGECACHE_OVERFLOW */
41   0,  /* SQLITE_STATUS_SCRATCH_USED */
42   0,  /* SQLITE_STATUS_SCRATCH_OVERFLOW */
43   0,  /* SQLITE_STATUS_MALLOC_SIZE */
44   0,  /* SQLITE_STATUS_PARSER_STACK */
45   1,  /* SQLITE_STATUS_PAGECACHE_SIZE */
46   0,  /* SQLITE_STATUS_SCRATCH_SIZE */
47   0,  /* SQLITE_STATUS_MALLOC_COUNT */
48 };
49 
50 
51 /* The "wsdStat" macro will resolve to the status information
52 ** state vector.  If writable static data is unsupported on the target,
53 ** we have to locate the state vector at run-time.  In the more common
54 ** case where writable static data is supported, wsdStat can refer directly
55 ** to the "sqlite3Stat" state vector declared above.
56 */
57 #ifdef SQLITE_OMIT_WSD
58 # define wsdStatInit  sqlite3StatType *x = &GLOBAL(sqlite3StatType,sqlite3Stat)
59 # define wsdStat x[0]
60 #else
61 # define wsdStatInit
62 # define wsdStat sqlite3Stat
63 #endif
64 
65 /*
66 ** Return the current value of a status parameter.  The caller must
67 ** be holding the appropriate mutex.
68 */
69 sqlite3_int64 sqlite3StatusValue(int op){
70   wsdStatInit;
71   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
72   assert( op>=0 && op<ArraySize(statMutex) );
73   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
74                                            : sqlite3MallocMutex()) );
75   return wsdStat.nowValue[op];
76 }
77 
78 /*
79 ** Add N to the value of a status record.  The caller must hold the
80 ** appropriate mutex.  (Locking is checked by assert()).
81 **
82 ** The StatusUp() routine can accept positive or negative values for N.
83 ** The value of N is added to the current status value and the high-water
84 ** mark is adjusted if necessary.
85 **
86 ** The StatusDown() routine lowers the current value by N.  The highwater
87 ** mark is unchanged.  N must be non-negative for StatusDown().
88 */
89 void sqlite3StatusUp(int op, int N){
90   wsdStatInit;
91   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
92   assert( op>=0 && op<ArraySize(statMutex) );
93   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
94                                            : sqlite3MallocMutex()) );
95   wsdStat.nowValue[op] += N;
96   if( wsdStat.nowValue[op]>wsdStat.mxValue[op] ){
97     wsdStat.mxValue[op] = wsdStat.nowValue[op];
98   }
99 }
100 void sqlite3StatusDown(int op, int N){
101   wsdStatInit;
102   assert( N>=0 );
103   assert( op>=0 && op<ArraySize(statMutex) );
104   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
105                                            : sqlite3MallocMutex()) );
106   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
107   wsdStat.nowValue[op] -= N;
108 }
109 
110 /*
111 ** Adjust the highwater mark if necessary.
112 ** The caller must hold the appropriate mutex.
113 */
114 void sqlite3StatusHighwater(int op, int X){
115   sqlite3StatValueType newValue;
116   wsdStatInit;
117   assert( X>=0 );
118   newValue = (sqlite3StatValueType)X;
119   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
120   assert( op>=0 && op<ArraySize(statMutex) );
121   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
122                                            : sqlite3MallocMutex()) );
123   assert( op==SQLITE_STATUS_MALLOC_SIZE
124           || op==SQLITE_STATUS_PAGECACHE_SIZE
125           || op==SQLITE_STATUS_SCRATCH_SIZE
126           || op==SQLITE_STATUS_PARSER_STACK );
127   if( newValue>wsdStat.mxValue[op] ){
128     wsdStat.mxValue[op] = newValue;
129   }
130 }
131 
132 /*
133 ** Query status information.
134 */
135 int sqlite3_status64(
136   int op,
137   sqlite3_int64 *pCurrent,
138   sqlite3_int64 *pHighwater,
139   int resetFlag
140 ){
141   sqlite3_mutex *pMutex;
142   wsdStatInit;
143   if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
144     return SQLITE_MISUSE_BKPT;
145   }
146 #ifdef SQLITE_ENABLE_API_ARMOR
147   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
148 #endif
149   pMutex = statMutex[op] ? sqlite3Pcache1Mutex() : sqlite3MallocMutex();
150   sqlite3_mutex_enter(pMutex);
151   *pCurrent = wsdStat.nowValue[op];
152   *pHighwater = wsdStat.mxValue[op];
153   if( resetFlag ){
154     wsdStat.mxValue[op] = wsdStat.nowValue[op];
155   }
156   sqlite3_mutex_leave(pMutex);
157   (void)pMutex;  /* Prevent warning when SQLITE_THREADSAFE=0 */
158   return SQLITE_OK;
159 }
160 int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
161   sqlite3_int64 iCur, iHwtr;
162   int rc;
163 #ifdef SQLITE_ENABLE_API_ARMOR
164   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
165 #endif
166   rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag);
167   if( rc==0 ){
168     *pCurrent = (int)iCur;
169     *pHighwater = (int)iHwtr;
170   }
171   return rc;
172 }
173 
174 /*
175 ** Query status information for a single database connection
176 */
177 int sqlite3_db_status(
178   sqlite3 *db,          /* The database connection whose status is desired */
179   int op,               /* Status verb */
180   int *pCurrent,        /* Write current value here */
181   int *pHighwater,      /* Write high-water mark here */
182   int resetFlag         /* Reset high-water mark if true */
183 ){
184   int rc = SQLITE_OK;   /* Return code */
185 #ifdef SQLITE_ENABLE_API_ARMOR
186   if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){
187     return SQLITE_MISUSE_BKPT;
188   }
189 #endif
190   sqlite3_mutex_enter(db->mutex);
191   switch( op ){
192     case SQLITE_DBSTATUS_LOOKASIDE_USED: {
193       *pCurrent = db->lookaside.nOut;
194       *pHighwater = db->lookaside.mxOut;
195       if( resetFlag ){
196         db->lookaside.mxOut = db->lookaside.nOut;
197       }
198       break;
199     }
200 
201     case SQLITE_DBSTATUS_LOOKASIDE_HIT:
202     case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:
203     case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {
204       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_HIT );
205       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE );
206       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL );
207       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)>=0 );
208       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)<3 );
209       *pCurrent = 0;
210       *pHighwater = db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT];
211       if( resetFlag ){
212         db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT] = 0;
213       }
214       break;
215     }
216 
217     /*
218     ** Return an approximation for the amount of memory currently used
219     ** by all pagers associated with the given database connection.  The
220     ** highwater mark is meaningless and is returned as zero.
221     */
222     case SQLITE_DBSTATUS_CACHE_USED: {
223       int totalUsed = 0;
224       int i;
225       sqlite3BtreeEnterAll(db);
226       for(i=0; i<db->nDb; i++){
227         Btree *pBt = db->aDb[i].pBt;
228         if( pBt ){
229           Pager *pPager = sqlite3BtreePager(pBt);
230           totalUsed += sqlite3PagerMemUsed(pPager);
231         }
232       }
233       sqlite3BtreeLeaveAll(db);
234       *pCurrent = totalUsed;
235       *pHighwater = 0;
236       break;
237     }
238 
239     /*
240     ** *pCurrent gets an accurate estimate of the amount of memory used
241     ** to store the schema for all databases (main, temp, and any ATTACHed
242     ** databases.  *pHighwater is set to zero.
243     */
244     case SQLITE_DBSTATUS_SCHEMA_USED: {
245       int i;                      /* Used to iterate through schemas */
246       int nByte = 0;              /* Used to accumulate return value */
247 
248       sqlite3BtreeEnterAll(db);
249       db->pnBytesFreed = &nByte;
250       for(i=0; i<db->nDb; i++){
251         Schema *pSchema = db->aDb[i].pSchema;
252         if( ALWAYS(pSchema!=0) ){
253           HashElem *p;
254 
255           nByte += sqlite3GlobalConfig.m.xRoundup(sizeof(HashElem)) * (
256               pSchema->tblHash.count
257             + pSchema->trigHash.count
258             + pSchema->idxHash.count
259             + pSchema->fkeyHash.count
260           );
261           nByte += sqlite3_msize(pSchema->tblHash.ht);
262           nByte += sqlite3_msize(pSchema->trigHash.ht);
263           nByte += sqlite3_msize(pSchema->idxHash.ht);
264           nByte += sqlite3_msize(pSchema->fkeyHash.ht);
265 
266           for(p=sqliteHashFirst(&pSchema->trigHash); p; p=sqliteHashNext(p)){
267             sqlite3DeleteTrigger(db, (Trigger*)sqliteHashData(p));
268           }
269           for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
270             sqlite3DeleteTable(db, (Table *)sqliteHashData(p));
271           }
272         }
273       }
274       db->pnBytesFreed = 0;
275       sqlite3BtreeLeaveAll(db);
276 
277       *pHighwater = 0;
278       *pCurrent = nByte;
279       break;
280     }
281 
282     /*
283     ** *pCurrent gets an accurate estimate of the amount of memory used
284     ** to store all prepared statements.
285     ** *pHighwater is set to zero.
286     */
287     case SQLITE_DBSTATUS_STMT_USED: {
288       struct Vdbe *pVdbe;         /* Used to iterate through VMs */
289       int nByte = 0;              /* Used to accumulate return value */
290 
291       db->pnBytesFreed = &nByte;
292       for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
293         sqlite3VdbeClearObject(db, pVdbe);
294         sqlite3DbFree(db, pVdbe);
295       }
296       db->pnBytesFreed = 0;
297 
298       *pHighwater = 0;  /* IMP: R-64479-57858 */
299       *pCurrent = nByte;
300 
301       break;
302     }
303 
304     /*
305     ** Set *pCurrent to the total cache hits or misses encountered by all
306     ** pagers the database handle is connected to. *pHighwater is always set
307     ** to zero.
308     */
309     case SQLITE_DBSTATUS_CACHE_HIT:
310     case SQLITE_DBSTATUS_CACHE_MISS:
311     case SQLITE_DBSTATUS_CACHE_WRITE:{
312       int i;
313       int nRet = 0;
314       assert( SQLITE_DBSTATUS_CACHE_MISS==SQLITE_DBSTATUS_CACHE_HIT+1 );
315       assert( SQLITE_DBSTATUS_CACHE_WRITE==SQLITE_DBSTATUS_CACHE_HIT+2 );
316 
317       for(i=0; i<db->nDb; i++){
318         if( db->aDb[i].pBt ){
319           Pager *pPager = sqlite3BtreePager(db->aDb[i].pBt);
320           sqlite3PagerCacheStat(pPager, op, resetFlag, &nRet);
321         }
322       }
323       *pHighwater = 0; /* IMP: R-42420-56072 */
324                        /* IMP: R-54100-20147 */
325                        /* IMP: R-29431-39229 */
326       *pCurrent = nRet;
327       break;
328     }
329 
330     /* Set *pCurrent to non-zero if there are unresolved deferred foreign
331     ** key constraints.  Set *pCurrent to zero if all foreign key constraints
332     ** have been satisfied.  The *pHighwater is always set to zero.
333     */
334     case SQLITE_DBSTATUS_DEFERRED_FKS: {
335       *pHighwater = 0;  /* IMP: R-11967-56545 */
336       *pCurrent = db->nDeferredImmCons>0 || db->nDeferredCons>0;
337       break;
338     }
339 
340     default: {
341       rc = SQLITE_ERROR;
342     }
343   }
344   sqlite3_mutex_leave(db->mutex);
345   return rc;
346 }
347