Add the SQLITE_DB_STATUS_CACHE_HIT and MISS options. For querying the number of cache hits and misses on a per-connection basis.

FossilOrigin-Name: 5100b6e9dc5107f0f835d0aac26fe6d4938ffc73

1 files changed, 22 insertions, 0 deletions

diff --git a/src/status.c b/src/status.c
index b8c1d58df..b23238bb1 100644
--- a/src/status.c
+++ b/src/status.c
@@ -218,6 +218,28 @@ int sqlite3_db_status(
       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;
     }