xref: /sqlite-3.40.0/src/status.c (revision b2a0f75c)
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_PARSER_STACK );
126   if( newValue>wsdStat.mxValue[op] ){
127     wsdStat.mxValue[op] = newValue;
128   }
129 }
130 
131 /*
132 ** Query status information.
133 */
134 int sqlite3_status64(
135   int op,
136   sqlite3_int64 *pCurrent,
137   sqlite3_int64 *pHighwater,
138   int resetFlag
139 ){
140   sqlite3_mutex *pMutex;
141   wsdStatInit;
142   if( op<0 || op>=ArraySize(wsdStat.nowValue) ){
143     return SQLITE_MISUSE_BKPT;
144   }
145 #ifdef SQLITE_ENABLE_API_ARMOR
146   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
147 #endif
148   pMutex = statMutex[op] ? sqlite3Pcache1Mutex() : sqlite3MallocMutex();
149   sqlite3_mutex_enter(pMutex);
150   *pCurrent = wsdStat.nowValue[op];
151   *pHighwater = wsdStat.mxValue[op];
152   if( resetFlag ){
153     wsdStat.mxValue[op] = wsdStat.nowValue[op];
154   }
155   sqlite3_mutex_leave(pMutex);
156   (void)pMutex;  /* Prevent warning when SQLITE_THREADSAFE=0 */
157   return SQLITE_OK;
158 }
159 int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag){
160   sqlite3_int64 iCur = 0, iHwtr = 0;
161   int rc;
162 #ifdef SQLITE_ENABLE_API_ARMOR
163   if( pCurrent==0 || pHighwater==0 ) return SQLITE_MISUSE_BKPT;
164 #endif
165   rc = sqlite3_status64(op, &iCur, &iHwtr, resetFlag);
166   if( rc==0 ){
167     *pCurrent = (int)iCur;
168     *pHighwater = (int)iHwtr;
169   }
170   return rc;
171 }
172 
173 /*
174 ** Query status information for a single database connection
175 */
176 int sqlite3_db_status(
177   sqlite3 *db,          /* The database connection whose status is desired */
178   int op,               /* Status verb */
179   int *pCurrent,        /* Write current value here */
180   int *pHighwater,      /* Write high-water mark here */
181   int resetFlag         /* Reset high-water mark if true */
182 ){
183   int rc = SQLITE_OK;   /* Return code */
184 #ifdef SQLITE_ENABLE_API_ARMOR
185   if( !sqlite3SafetyCheckOk(db) || pCurrent==0|| pHighwater==0 ){
186     return SQLITE_MISUSE_BKPT;
187   }
188 #endif
189   sqlite3_mutex_enter(db->mutex);
190   switch( op ){
191     case SQLITE_DBSTATUS_LOOKASIDE_USED: {
192       *pCurrent = db->lookaside.nOut;
193       *pHighwater = db->lookaside.mxOut;
194       if( resetFlag ){
195         db->lookaside.mxOut = db->lookaside.nOut;
196       }
197       break;
198     }
199 
200     case SQLITE_DBSTATUS_LOOKASIDE_HIT:
201     case SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE:
202     case SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL: {
203       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_HIT );
204       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE );
205       testcase( op==SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL );
206       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)>=0 );
207       assert( (op-SQLITE_DBSTATUS_LOOKASIDE_HIT)<3 );
208       *pCurrent = 0;
209       *pHighwater = db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT];
210       if( resetFlag ){
211         db->lookaside.anStat[op - SQLITE_DBSTATUS_LOOKASIDE_HIT] = 0;
212       }
213       break;
214     }
215 
216     /*
217     ** Return an approximation for the amount of memory currently used
218     ** by all pagers associated with the given database connection.  The
219     ** highwater mark is meaningless and is returned as zero.
220     */
221     case SQLITE_DBSTATUS_CACHE_USED_SHARED:
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           int nByte = sqlite3PagerMemUsed(pPager);
231           if( op==SQLITE_DBSTATUS_CACHE_USED_SHARED ){
232             nByte = nByte / sqlite3BtreeConnectionCount(pBt);
233           }
234           totalUsed += nByte;
235         }
236       }
237       sqlite3BtreeLeaveAll(db);
238       *pCurrent = totalUsed;
239       *pHighwater = 0;
240       break;
241     }
242 
243     /*
244     ** *pCurrent gets an accurate estimate of the amount of memory used
245     ** to store the schema for all databases (main, temp, and any ATTACHed
246     ** databases.  *pHighwater is set to zero.
247     */
248     case SQLITE_DBSTATUS_SCHEMA_USED: {
249       int i;                      /* Used to iterate through schemas */
250       int nByte = 0;              /* Used to accumulate return value */
251 
252       sqlite3BtreeEnterAll(db);
253       db->pnBytesFreed = &nByte;
254       for(i=0; i<db->nDb; i++){
255         Schema *pSchema = db->aDb[i].pSchema;
256         if( ALWAYS(pSchema!=0) ){
257           HashElem *p;
258 
259           nByte += sqlite3GlobalConfig.m.xRoundup(sizeof(HashElem)) * (
260               pSchema->tblHash.count
261             + pSchema->trigHash.count
262             + pSchema->idxHash.count
263             + pSchema->fkeyHash.count
264           );
265           nByte += sqlite3_msize(pSchema->tblHash.ht);
266           nByte += sqlite3_msize(pSchema->trigHash.ht);
267           nByte += sqlite3_msize(pSchema->idxHash.ht);
268           nByte += sqlite3_msize(pSchema->fkeyHash.ht);
269 
270           for(p=sqliteHashFirst(&pSchema->trigHash); p; p=sqliteHashNext(p)){
271             sqlite3DeleteTrigger(db, (Trigger*)sqliteHashData(p));
272           }
273           for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
274             sqlite3DeleteTable(db, (Table *)sqliteHashData(p));
275           }
276         }
277       }
278       db->pnBytesFreed = 0;
279       sqlite3BtreeLeaveAll(db);
280 
281       *pHighwater = 0;
282       *pCurrent = nByte;
283       break;
284     }
285 
286     /*
287     ** *pCurrent gets an accurate estimate of the amount of memory used
288     ** to store all prepared statements.
289     ** *pHighwater is set to zero.
290     */
291     case SQLITE_DBSTATUS_STMT_USED: {
292       struct Vdbe *pVdbe;         /* Used to iterate through VMs */
293       int nByte = 0;              /* Used to accumulate return value */
294 
295       db->pnBytesFreed = &nByte;
296       for(pVdbe=db->pVdbe; pVdbe; pVdbe=pVdbe->pNext){
297         sqlite3VdbeClearObject(db, pVdbe);
298         sqlite3DbFree(db, pVdbe);
299       }
300       db->pnBytesFreed = 0;
301 
302       *pHighwater = 0;  /* IMP: R-64479-57858 */
303       *pCurrent = nByte;
304 
305       break;
306     }
307 
308     /*
309     ** Set *pCurrent to the total cache hits or misses encountered by all
310     ** pagers the database handle is connected to. *pHighwater is always set
311     ** to zero.
312     */
313     case SQLITE_DBSTATUS_CACHE_HIT:
314     case SQLITE_DBSTATUS_CACHE_MISS:
315     case SQLITE_DBSTATUS_CACHE_WRITE:{
316       int i;
317       int nRet = 0;
318       assert( SQLITE_DBSTATUS_CACHE_MISS==SQLITE_DBSTATUS_CACHE_HIT+1 );
319       assert( SQLITE_DBSTATUS_CACHE_WRITE==SQLITE_DBSTATUS_CACHE_HIT+2 );
320 
321       for(i=0; i<db->nDb; i++){
322         if( db->aDb[i].pBt ){
323           Pager *pPager = sqlite3BtreePager(db->aDb[i].pBt);
324           sqlite3PagerCacheStat(pPager, op, resetFlag, &nRet);
325         }
326       }
327       *pHighwater = 0; /* IMP: R-42420-56072 */
328                        /* IMP: R-54100-20147 */
329                        /* IMP: R-29431-39229 */
330       *pCurrent = nRet;
331       break;
332     }
333 
334     /* Set *pCurrent to non-zero if there are unresolved deferred foreign
335     ** key constraints.  Set *pCurrent to zero if all foreign key constraints
336     ** have been satisfied.  The *pHighwater is always set to zero.
337     */
338     case SQLITE_DBSTATUS_DEFERRED_FKS: {
339       *pHighwater = 0;  /* IMP: R-11967-56545 */
340       *pCurrent = db->nDeferredImmCons>0 || db->nDeferredCons>0;
341       break;
342     }
343 
344     default: {
345       rc = SQLITE_ERROR;
346     }
347   }
348   sqlite3_mutex_leave(db->mutex);
349   return rc;
350 }
351