xref: /sqlite-3.40.0/src/status.c (revision 2b4905c8)
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 ** Set the value of a status to X.  The highwater mark is adjusted if
112 ** necessary.  The caller must hold the appropriate mutex.
113 */
114 void sqlite3StatusSet(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   wsdStat.nowValue[op] = X;
121   if( wsdStat.nowValue[op]>wsdStat.mxValue[op] ){
122     wsdStat.mxValue[op] = wsdStat.nowValue[op];
123   }
124 }
125 
126 /*
127 ** Query status information.
128 */
129 int sqlite3_status64(
130   int op,
131   sqlite3_int64 *pCurrent,
132   sqlite3_int64 *pHighwater,
133   int resetFlag
134 ){
135   wsdStatInit;
136   sqlite3_mutex *pMutex;
137   if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
138     return SQLITE_MISUSE_BKPT;
139   }
140 #ifdef SQLITE_ENABLE_API_ARMOR
141   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
142 #endif
143   pMutex = statMutex[op] ? sqlite3Pcache1Mutex() : sqlite3MallocMutex();
144   sqlite3_mutex_enter(pMutex);
145   *pCurrent = wsdStat.nowValue[op];
146   *pHighwater = wsdStat.mxValue[op];
147   if( resetFlag ){
148     wsdStat.mxValue[op] = wsdStat.nowValue[op];
149   }
150   sqlite3_mutex_leave(pMutex);
151   return SQLITE_OK;
152 }
153 int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
154   sqlite3_int64 iCur, iHwtr;
155   int rc;
156 #ifdef SQLITE_ENABLE_API_ARMOR
157   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
158 #endif
159   rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag);
160   if( rc==0 ){
161     *pCurrent = (int)iCur;
162     *pHighwater = (int)iHwtr;
163   }
164   return rc;
165 }
166 
167 /*
168 ** Query status information for a single database connection
169 */
170 int sqlite3_db_status(
171   sqlite3 *db,          /* The database connection whose status is desired */
172   int op,               /* Status verb */
173   int *pCurrent,        /* Write current value here */
174   int *pHighwater,      /* Write high-water mark here */
175   int resetFlag         /* Reset high-water mark if true */
176 ){
177   int rc = SQLITE_OK;   /* Return code */
178 #ifdef SQLITE_ENABLE_API_ARMOR
179   if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){
180     return SQLITE_MISUSE_BKPT;
181   }
182 #endif
183   sqlite3_mutex_enter(db->mutex);
184   switch( op ){
185     case SQLITE_DBSTATUS_LOOKASIDE_USED: {
186       *pCurrent = db->lookaside.nOut;
187       *pHighwater = db->lookaside.mxOut;
188       if( resetFlag ){
189         db->lookaside.mxOut = db->lookaside.nOut;
190       }
191       break;
192     }
193 
194     case SQLITE_DBSTATUS_LOOKASIDE_HIT:
195     case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:
196     case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {
197       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_HIT );
198       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE );
199       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL );
200       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)>=0 );
201       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)<3 );
202       *pCurrent = 0;
203       *pHighwater = db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT];
204       if( resetFlag ){
205         db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT] = 0;
206       }
207       break;
208     }
209 
210     /*
211     ** Return an approximation for the amount of memory currently used
212     ** by all pagers associated with the given database connection.  The
213     ** highwater mark is meaningless and is returned as zero.
214     */
215     case SQLITE_DBSTATUS_CACHE_USED: {
216       int totalUsed = 0;
217       int i;
218       sqlite3BtreeEnterAll(db);
219       for(i=0; i<db->nDb; i++){
220         Btree *pBt = db->aDb[i].pBt;
221         if( pBt ){
222           Pager *pPager = sqlite3BtreePager(pBt);
223           totalUsed += sqlite3PagerMemUsed(pPager);
224         }
225       }
226       sqlite3BtreeLeaveAll(db);
227       *pCurrent = totalUsed;
228       *pHighwater = 0;
229       break;
230     }
231 
232     /*
233     ** *pCurrent gets an accurate estimate of the amount of memory used
234     ** to store the schema for all databases (main, temp, and any ATTACHed
235     ** databases.  *pHighwater is set to zero.
236     */
237     case SQLITE_DBSTATUS_SCHEMA_USED: {
238       int i;                      /* Used to iterate through schemas */
239       int nByte = 0;              /* Used to accumulate return value */
240 
241       sqlite3BtreeEnterAll(db);
242       db->pnBytesFreed = &nByte;
243       for(i=0; i<db->nDb; i++){
244         Schema *pSchema = db->aDb[i].pSchema;
245         if( ALWAYS(pSchema!=0) ){
246           HashElem *p;
247 
248           nByte += sqlite3GlobalConfig.m.xRoundup(sizeof(HashElem)) * (
249               pSchema->tblHash.count
250             + pSchema->trigHash.count
251             + pSchema->idxHash.count
252             + pSchema->fkeyHash.count
253           );
254           nByte += sqlite3MallocSize(pSchema->tblHash.ht);
255           nByte += sqlite3MallocSize(pSchema->trigHash.ht);
256           nByte += sqlite3MallocSize(pSchema->idxHash.ht);
257           nByte += sqlite3MallocSize(pSchema->fkeyHash.ht);
258 
259           for(p=sqliteHashFirst(&pSchema->trigHash); p; p=sqliteHashNext(p)){
260             sqlite3DeleteTrigger(db, (Trigger*)sqliteHashData(p));
261           }
262           for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
263             sqlite3DeleteTable(db, (Table *)sqliteHashData(p));
264           }
265         }
266       }
267       db->pnBytesFreed = 0;
268       sqlite3BtreeLeaveAll(db);
269 
270       *pHighwater = 0;
271       *pCurrent = nByte;
272       break;
273     }
274 
275     /*
276     ** *pCurrent gets an accurate estimate of the amount of memory used
277     ** to store all prepared statements.
278     ** *pHighwater is set to zero.
279     */
280     case SQLITE_DBSTATUS_STMT_USED: {
281       struct Vdbe *pVdbe;         /* Used to iterate through VMs */
282       int nByte = 0;              /* Used to accumulate return value */
283 
284       db->pnBytesFreed = &nByte;
285       for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
286         sqlite3VdbeClearObject(db, pVdbe);
287         sqlite3DbFree(db, pVdbe);
288       }
289       db->pnBytesFreed = 0;
290 
291       *pHighwater = 0;  /* IMP: R-64479-57858 */
292       *pCurrent = nByte;
293 
294       break;
295     }
296 
297     /*
298     ** Set *pCurrent to the total cache hits or misses encountered by all
299     ** pagers the database handle is connected to. *pHighwater is always set
300     ** to zero.
301     */
302     case SQLITE_DBSTATUS_CACHE_HIT:
303     case SQLITE_DBSTATUS_CACHE_MISS:
304     case SQLITE_DBSTATUS_CACHE_WRITE:{
305       int i;
306       int nRet = 0;
307       assert( SQLITE_DBSTATUS_CACHE_MISS==SQLITE_DBSTATUS_CACHE_HIT+1 );
308       assert( SQLITE_DBSTATUS_CACHE_WRITE==SQLITE_DBSTATUS_CACHE_HIT+2 );
309 
310       for(i=0; i<db->nDb; i++){
311         if( db->aDb[i].pBt ){
312           Pager *pPager = sqlite3BtreePager(db->aDb[i].pBt);
313           sqlite3PagerCacheStat(pPager, op, resetFlag, &nRet);
314         }
315       }
316       *pHighwater = 0; /* IMP: R-42420-56072 */
317                        /* IMP: R-54100-20147 */
318                        /* IMP: R-29431-39229 */
319       *pCurrent = nRet;
320       break;
321     }
322 
323     /* Set *pCurrent to non-zero if there are unresolved deferred foreign
324     ** key constraints.  Set *pCurrent to zero if all foreign key constraints
325     ** have been satisfied.  The *pHighwater is always set to zero.
326     */
327     case SQLITE_DBSTATUS_DEFERRED_FKS: {
328       *pHighwater = 0;  /* IMP: R-11967-56545 */
329       *pCurrent = db->nDeferredImmCons>0 || db->nDeferredCons>0;
330       break;
331     }
332 
333     default: {
334       rc = SQLITE_ERROR;
335     }
336   }
337   sqlite3_mutex_leave(db->mutex);
338   return rc;
339 }
340