xref: /sqlite-3.40.0/src/status.c (revision 3c060c2a)
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 typedef struct sqlite3StatType sqlite3StatType;
23 static SQLITE_WSD struct sqlite3StatType {
24 #if SQLITE_PTRSIZE>4
25   sqlite3_int64 nowValue[10];         /* Current value */
26   sqlite3_int64 mxValue[10];          /* Maximum value */
27 #else
28   u32 nowValue[10];                   /* Current value */
29   u32 mxValue[10];                    /* Maximum value */
30 #endif
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   wsdStatInit;
116   assert( op>=0 && op<ArraySize(wsdStat.nowValue) );
117   assert( op>=0 && op<ArraySize(statMutex) );
118   assert( sqlite3_mutex_held(statMutex[op] ? sqlite3Pcache1Mutex()
119                                            : sqlite3MallocMutex()) );
120   assert( op==SQLITE_STATUS_MALLOC_SIZE
121           || op==SQLITE_STATUS_PAGECACHE_SIZE
122           || op==SQLITE_STATUS_SCRATCH_SIZE
123           || op==SQLITE_STATUS_PARSER_STACK );
124   if( X>wsdStat.mxValue[op] ){
125     wsdStat.mxValue[op] = X;
126   }
127 }
128 
129 /*
130 ** Query status information.
131 */
132 int sqlite3_status64(
133   int op,
134   sqlite3_int64 *pCurrent,
135   sqlite3_int64 *pHighwater,
136   int resetFlag
137 ){
138   sqlite3_mutex *pMutex;
139   wsdStatInit;
140   if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
141     return SQLITE_MISUSE_BKPT;
142   }
143 #ifdef SQLITE_ENABLE_API_ARMOR
144   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
145 #endif
146   pMutex = statMutex[op] ? sqlite3Pcache1Mutex() : sqlite3MallocMutex();
147   sqlite3_mutex_enter(pMutex);
148   *pCurrent = wsdStat.nowValue[op];
149   *pHighwater = wsdStat.mxValue[op];
150   if( resetFlag ){
151     wsdStat.mxValue[op] = wsdStat.nowValue[op];
152   }
153   sqlite3_mutex_leave(pMutex);
154   (void)pMutex;  /* Prevent warning when SQLITE_THREADSAFE=0 */
155   return SQLITE_OK;
156 }
157 int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
158   sqlite3_int64 iCur, iHwtr;
159   int rc;
160 #ifdef SQLITE_ENABLE_API_ARMOR
161   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
162 #endif
163   rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag);
164   if( rc==0 ){
165     *pCurrent = (int)iCur;
166     *pHighwater = (int)iHwtr;
167   }
168   return rc;
169 }
170 
171 /*
172 ** Query status information for a single database connection
173 */
174 int sqlite3_db_status(
175   sqlite3 *db,          /* The database connection whose status is desired */
176   int op,               /* Status verb */
177   int *pCurrent,        /* Write current value here */
178   int *pHighwater,      /* Write high-water mark here */
179   int resetFlag         /* Reset high-water mark if true */
180 ){
181   int rc = SQLITE_OK;   /* Return code */
182 #ifdef SQLITE_ENABLE_API_ARMOR
183   if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){
184     return SQLITE_MISUSE_BKPT;
185   }
186 #endif
187   sqlite3_mutex_enter(db->mutex);
188   switch( op ){
189     case SQLITE_DBSTATUS_LOOKASIDE_USED: {
190       *pCurrent = db->lookaside.nOut;
191       *pHighwater = db->lookaside.mxOut;
192       if( resetFlag ){
193         db->lookaside.mxOut = db->lookaside.nOut;
194       }
195       break;
196     }
197 
198     case SQLITE_DBSTATUS_LOOKASIDE_HIT:
199     case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:
200     case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {
201       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_HIT );
202       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE );
203       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL );
204       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)>=0 );
205       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)<3 );
206       *pCurrent = 0;
207       *pHighwater = db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT];
208       if( resetFlag ){
209         db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT] = 0;
210       }
211       break;
212     }
213 
214     /*
215     ** Return an approximation for the amount of memory currently used
216     ** by all pagers associated with the given database connection.  The
217     ** highwater mark is meaningless and is returned as zero.
218     */
219     case SQLITE_DBSTATUS_CACHE_USED: {
220       int totalUsed = 0;
221       int i;
222       sqlite3BtreeEnterAll(db);
223       for(i=0; i<db->nDb; i++){
224         Btree *pBt = db->aDb[i].pBt;
225         if( pBt ){
226           Pager *pPager = sqlite3BtreePager(pBt);
227           totalUsed += sqlite3PagerMemUsed(pPager);
228         }
229       }
230       sqlite3BtreeLeaveAll(db);
231       *pCurrent = totalUsed;
232       *pHighwater = 0;
233       break;
234     }
235 
236     /*
237     ** *pCurrent gets an accurate estimate of the amount of memory used
238     ** to store the schema for all databases (main, temp, and any ATTACHed
239     ** databases.  *pHighwater is set to zero.
240     */
241     case SQLITE_DBSTATUS_SCHEMA_USED: {
242       int i;                      /* Used to iterate through schemas */
243       int nByte = 0;              /* Used to accumulate return value */
244 
245       sqlite3BtreeEnterAll(db);
246       db->pnBytesFreed = &nByte;
247       for(i=0; i<db->nDb; i++){
248         Schema *pSchema = db->aDb[i].pSchema;
249         if( ALWAYS(pSchema!=0) ){
250           HashElem *p;
251 
252           nByte += sqlite3GlobalConfig.m.xRoundup(sizeof(HashElem)) * (
253               pSchema->tblHash.count
254             + pSchema->trigHash.count
255             + pSchema->idxHash.count
256             + pSchema->fkeyHash.count
257           );
258           nByte += sqlite3_msize(pSchema->tblHash.ht);
259           nByte += sqlite3_msize(pSchema->trigHash.ht);
260           nByte += sqlite3_msize(pSchema->idxHash.ht);
261           nByte += sqlite3_msize(pSchema->fkeyHash.ht);
262 
263           for(p=sqliteHashFirst(&pSchema->trigHash); p; p=sqliteHashNext(p)){
264             sqlite3DeleteTrigger(db, (Trigger*)sqliteHashData(p));
265           }
266           for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
267             sqlite3DeleteTable(db, (Table *)sqliteHashData(p));
268           }
269         }
270       }
271       db->pnBytesFreed = 0;
272       sqlite3BtreeLeaveAll(db);
273 
274       *pHighwater = 0;
275       *pCurrent = nByte;
276       break;
277     }
278 
279     /*
280     ** *pCurrent gets an accurate estimate of the amount of memory used
281     ** to store all prepared statements.
282     ** *pHighwater is set to zero.
283     */
284     case SQLITE_DBSTATUS_STMT_USED: {
285       struct Vdbe *pVdbe;         /* Used to iterate through VMs */
286       int nByte = 0;              /* Used to accumulate return value */
287 
288       db->pnBytesFreed = &nByte;
289       for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
290         sqlite3VdbeClearObject(db, pVdbe);
291         sqlite3DbFree(db, pVdbe);
292       }
293       db->pnBytesFreed = 0;
294 
295       *pHighwater = 0;  /* IMP: R-64479-57858 */
296       *pCurrent = nByte;
297 
298       break;
299     }
300 
301     /*
302     ** Set *pCurrent to the total cache hits or misses encountered by all
303     ** pagers the database handle is connected to. *pHighwater is always set
304     ** to zero.
305     */
306     case SQLITE_DBSTATUS_CACHE_HIT:
307     case SQLITE_DBSTATUS_CACHE_MISS:
308     case SQLITE_DBSTATUS_CACHE_WRITE:{
309       int i;
310       int nRet = 0;
311       assert( SQLITE_DBSTATUS_CACHE_MISS==SQLITE_DBSTATUS_CACHE_HIT+1 );
312       assert( SQLITE_DBSTATUS_CACHE_WRITE==SQLITE_DBSTATUS_CACHE_HIT+2 );
313 
314       for(i=0; i<db->nDb; i++){
315         if( db->aDb[i].pBt ){
316           Pager *pPager = sqlite3BtreePager(db->aDb[i].pBt);
317           sqlite3PagerCacheStat(pPager, op, resetFlag, &nRet);
318         }
319       }
320       *pHighwater = 0; /* IMP: R-42420-56072 */
321                        /* IMP: R-54100-20147 */
322                        /* IMP: R-29431-39229 */
323       *pCurrent = nRet;
324       break;
325     }
326 
327     /* Set *pCurrent to non-zero if there are unresolved deferred foreign
328     ** key constraints.  Set *pCurrent to zero if all foreign key constraints
329     ** have been satisfied.  The *pHighwater is always set to zero.
330     */
331     case SQLITE_DBSTATUS_DEFERRED_FKS: {
332       *pHighwater = 0;  /* IMP: R-11967-56545 */
333       *pCurrent = db->nDeferredImmCons>0 || db->nDeferredCons>0;
334       break;
335     }
336 
337     default: {
338       rc = SQLITE_ERROR;
339     }
340   }
341   sqlite3_mutex_leave(db->mutex);
342   return rc;
343 }
344