The former sqlite3ResetInternalSchema() routine was really two different

routines, selected by parameter, each with a confused mission.  So split
this routine up into three separate smaller routines, calling each
separately as needed.  Hopefully this will make further refactoring and
schema reset collateral damage containment easier.

FossilOrigin-Name: aa0c3493d3647d7efe527067e9fcccefda8e3008

manifest

@@ -1,5 +1,5 @@
-C When\sa\sconnection\sdisconnects\sfrom\sa\sshared-cache\sdatabase,\sonly\sdelete\sthe\sin-memory\sschema\sif\sthere\sare\sno\sother\sconnections.
-D 2012-05-15T17:15:34.812
+C The\sformer\ssqlite3ResetInternalSchema()\sroutine\swas\sreally\stwo\sdifferent\s\nroutines,\sselected\sby\sparameter,\seach\swith\sa\sconfused\smission.\s\sSo\ssplit\nthis\sroutine\sup\sinto\sthree\sseparate\ssmaller\sroutines,\scalling\seach\nseparately\sas\sneeded.\s\sHopefully\sthis\swill\smake\sfurther\srefactoring\sand\nschema\sreset\scollateral\sdamage\scontainment\seasier.
+D 2012-05-15T18:28:27.325
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 2f37e468503dbe79d35c9f6dffcf3fae1ae9ec20
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -113,15 +113,15 @@ F sqlite3.1 6be1ad09113570e1fc8dcaff84c9b0b337db5ffc
 F sqlite3.pc.in ae6f59a76e862f5c561eb32a380228a02afc3cad
 F src/alter.c 149cc80d9257971b0bff34e58fb2263e01998289
 F src/analyze.c 70c46504c0d2543ea5cdca01140b2cd3e1d886e7
-F src/attach.c 12c6957996908edc31c96d7c68d4942c2474405f
+F src/attach.c 577bf5675b0c50495fc28549f2fcbdb1bac71143
 F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
-F src/backup.c 6be23a344d3301ae38e92fddb3a33b91c309fce4
+F src/backup.c d7fb4c6d2ad3fe51a4ce1a897fde7b00f4de5fef
 F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
 F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
 F src/btree.c df800f10896bc2ddaa1125c532d6e7a7b9efc532
 F src/btree.h 48a013f8964f12d944d90e4700df47b72dd6d923
 F src/btreeInt.h 38a639c0542c29fe8331a221c4aed0cb8686249e
-F src/build.c 95fd8aa1bf81acf15e9ef46b07d1f70111ea88d0
+F src/build.c 6da3a261958d79805df198808b35209e93acf52d
 F src/callback.c 0cb4228cdcd827dcc5def98fb099edcc9142dbcd
 F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c a9c26822515f81ec21588cbb482ca6724be02e33
@@ -140,7 +140,7 @@ F src/journal.c 552839e54d1bf76fb8f7abe51868b66acacf6a0e
 F src/legacy.c a199d7683d60cef73089e892409113e69c23a99f
 F src/lempar.c 0ee69fca0be54cd93939df98d2aca4ca46f44416
 F src/loadext.c f20382fbaeec832438a1ba7797bee3d3c8a6d51d
-F src/main.c 62146c65069408bc66ad72954655c9cc14bd8f01
+F src/main.c 28804c01149c1e707418434a42dc36438acdc5c8
 F src/malloc.c 15afac5e59b6584efe072e9933aefb4230e74f97
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c b3677415e69603d6a0e7c5410a1b3731d55beda1
@@ -167,8 +167,8 @@ F src/parse.y f29df90bd3adc64b33114ab1de9fb7768fcf2099
 F src/pcache.c f8043b433a57aba85384a531e3937a804432a346
 F src/pcache.h 1b5dcc3dc8103d03e625b177023ee67764fa6b7c
 F src/pcache1.c b30b1c35908346ecc43d8d9d17f2ddf6817f8f60
-F src/pragma.c e708b3bb5704605816f617e0b1d63a5488060715
-F src/prepare.c 9a00a9612ebf80203fbb41f8a29ab8cb27a05f40
+F src/pragma.c 28d7955a9e9a27d41cb462690228d39e3cec231c
+F src/prepare.c ef197444dac110ee57a5f49745368b447a8c6bd1
 F src/printf.c 7ffb4ebb8b341f67e049695ba031da717b3d2699
 F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
 F src/resolve.c 748e75299faff345f34f0e5bd02a2bac8aa69fcd
@@ -177,7 +177,7 @@ F src/select.c d7b9018b7dd2e821183d69477ab55c39b8272335
 F src/shell.c 04399b2f9942bd02ed5ffee3b84bcdb39c52a1e6
 F src/sqlite.h.in 4f4d4792f6fb00387c877af013cb09d955643f12
 F src/sqlite3ext.h 6904f4aadf976f95241311fbffb00823075d9477
-F src/sqliteInt.h cef468b8f16c847c235cb9a3d06253389abe3bc9
+F src/sqliteInt.h 05b22e581622128168d786a7c852d1763dd45559
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 35939e7e03abf1b7577ce311f48f682c40de3208
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -233,8 +233,8 @@ F src/trigger.c ee7e178fb9188f44b532cebd449a7c1df90fb684
 F src/update.c d3076782c887c10e882996550345da9c4c9f9dea
 F src/utf.c 890c67dcfcc7a74623c95baac7535aadfe265e84
 F src/util.c 4f6cfad661b2e3454b0cdd5b1b9d39a54942d0e3
-F src/vacuum.c bfd53f9bd20a8fdb70b0fa8e77182b866875c0d8
-F src/vdbe.c e1d26b98288889c22f00cf4851ec351ee67ad8b9
+F src/vacuum.c 587a52bb8833d7ac15af8916f25437e2575028bd
+F src/vdbe.c 6ed3e89957a0dd55e9c4ab7842949051ba8eaaa9
 F src/vdbe.h 18f581cac1f4339ec3299f3e0cc6e11aec654cdb
 F src/vdbeInt.h 6ff4180a05683566a8835d12f7ec504b22932c82
 F src/vdbeapi.c 3662b6a468a2a4605a15dfab313baa6dff81ad91
@@ -243,7 +243,7 @@ F src/vdbeblob.c 32f2a4899d67f69634ea4dd93e3f651936d732cb
 F src/vdbemem.c cb55e84b8e2c15704968ee05f0fae25883299b74
 F src/vdbesort.c b25814d385895544ebc8118245c8311ded7f81c9
 F src/vdbetrace.c d6e50e04e1ec498150e519058f617d91b8f5c843
-F src/vtab.c 1fbe133809ae542a9cf3a3d8187774b68436fa85
+F src/vtab.c 4c1d7e7206aa330da12cfbed29bbe08a5fd2c08e
 F src/wal.c 7bb3ad807afc7973406c805d5157ec7a2f65e146
 F src/wal.h 29c197540b19044e6cd73487017e5e47a1d3dac6
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
@@ -998,10 +998,7 @@ F tool/tostr.awk e75472c2f98dd76e06b8c9c1367f4ab07e122d06
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings-clang.sh a8a0a3babda96dfb1ff51adda3cbbf3dfb7266c2
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
-P 736d6ea677f58e4aa2914fa79a3156b775c5a3f5
-R cdb1dff646b0010ea62b89ecb700e74c
-T *branch * shared-schema
-T *sym-shared-schema *
-T -sym-trunk *
-U dan
-Z 9910d0bfd0815b5cd0d4b52750333b7f
+P 46f4eb5430d7bc9a339cdf7124ff4bd518eaa39b
+R 3470c7e3b0ec734f279c648e5bd9b93d
+U drh
+Z 93dd6b08b78f998064cdd25b32f8367e

manifest.uuid

@@ -1 +1 @@
-46f4eb5430d7bc9a339cdf7124ff4bd518eaa39b
+aa0c3493d3647d7efe527067e9fcccefda8e3008

src/attach.c

@@ -216,7 +216,7 @@ static void attachFunc(
       db->aDb[iDb].pBt = 0;
       db->aDb[iDb].pSchema = 0;
     }
-    sqlite3ResetInternalSchema(db, -1);
+    sqlite3ResetAllSchemasOfConnection(db);
     db->nDb = iDb;
     if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
       db->mallocFailed = 1;
@@ -288,7 +288,7 @@ static void detachFunc(
   sqlite3BtreeClose(pDb->pBt);
   pDb->pBt = 0;
   pDb->pSchema = 0;
-  sqlite3ResetInternalSchema(db, -1);
+  sqlite3ResetAllSchemasOfConnection(db);
   return;
 
 detach_error:

src/backup.c

@@ -414,7 +414,7 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
       rc = sqlite3BtreeUpdateMeta(p->pDest,1,p->iDestSchema+1);
       if( rc==SQLITE_OK ){
         if( p->pDestDb ){
-          sqlite3ResetInternalSchema(p->pDestDb, -1);
+          sqlite3ResetAllSchemasOfConnection(p->pDestDb);
         }
         if( destMode==PAGER_JOURNALMODE_WAL ){
           rc = sqlite3BtreeSetVersion(p->pDest, 2);

src/build.c

@@ -394,58 +394,15 @@ void sqlite3UnlinkAndDeleteIndex(sqlite3 *db, int iDb, const char *zIdxName){
 }
 
 /*
-** Erase all schema information from the in-memory hash tables of
-** a single database.  This routine is called to reclaim memory
-** before the database closes.  It is also called during a rollback
-** if there were schema changes during the transaction or if a
-** schema-cookie mismatch occurs.
+** Look through the list of open database files in db->aDb[] and if
+** any have been closed, remove them from the list.  Reallocate the
+** db->aDb[] structure to a smaller size, if possible.
 **
-** If iDb<0 then reset the internal schema tables for all database
-** files.  If iDb>=0 then reset the internal schema for only the
-** single file indicated.
+** Entry 0 (the "main" database) and entry 1 (the "temp" database)
+** are never candidates for being collapsed.
 */
-void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
+void sqlite3CollapseDatabaseArray(sqlite3 *db){
   int i, j;
-  assert( iDb<db->nDb );
-
-  if( iDb>=0 ){
-    /* Case 1:  Reset the single schema identified by iDb */
-    Db *pDb = &db->aDb[iDb];
-    assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
-    assert( pDb->pSchema!=0 );
-    sqlite3SchemaClear(pDb->pSchema);
-
-    /* If any database other than TEMP is reset, then also reset TEMP
-    ** since TEMP might be holding triggers that reference tables in the
-    ** other database.
-    */
-    if( iDb!=1 ){
-      pDb = &db->aDb[1];
-      assert( pDb->pSchema!=0 );
-      sqlite3SchemaClear(pDb->pSchema);
-    }
-    return;
-  }
-  /* Case 2 (from here to the end): Reset all schemas for all attached
-  ** databases. */
-  assert( iDb<0 );
-  sqlite3BtreeEnterAll(db);
-  for(i=0; i<db->nDb; i++){
-    Db *pDb = &db->aDb[i];
-    if( pDb->pSchema ){
-      sqlite3SchemaClear(pDb->pSchema);
-    }
-  }
-  db->flags &= ~SQLITE_InternChanges;
-  sqlite3VtabUnlockList(db);
-  sqlite3BtreeLeaveAll(db);
-
-  /* If one or more of the auxiliary database files has been closed,
-  ** then remove them from the auxiliary database list.  We take the
-  ** opportunity to do this here since we have just deleted all of the
-  ** schema hash tables and therefore do not have to make any changes
-  ** to any of those tables.
-  */
   for(i=j=2; i<db->nDb; i++){
     struct Db *pDb = &db->aDb[i];
     if( pDb->pBt==0 ){
@@ -467,6 +424,50 @@ void sqlite3ResetInternalSchema(sqlite3 *db, int iDb){
   }
 }
 
+/*
+** Reset the schema for the database at index iDb.  Also reset the
+** TEMP schema.
+*/
+void sqlite3ResetOneSchema(sqlite3 *db, int iDb){
+  assert( iDb<db->nDb );
+
+  /* Case 1:  Reset the single schema identified by iDb */
+  Db *pDb = &db->aDb[iDb];
+  assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
+  assert( pDb->pSchema!=0 );
+  sqlite3SchemaClear(pDb->pSchema);
+
+  /* If any database other than TEMP is reset, then also reset TEMP
+  ** since TEMP might be holding triggers that reference tables in the
+  ** other database.
+  */
+  if( iDb!=1 ){
+    pDb = &db->aDb[1];
+    assert( pDb->pSchema!=0 );
+    sqlite3SchemaClear(pDb->pSchema);
+  }
+  return;
+}
+
+/*
+** Erase all schema information from all attached databases (including
+** "main" and "temp") for a single database connection.
+*/
+void sqlite3ResetAllSchemasOfConnection(sqlite3 *db){
+  int i;
+  sqlite3BtreeEnterAll(db);
+  for(i=0; i<db->nDb; i++){
+    Db *pDb = &db->aDb[i];
+    if( pDb->pSchema ){
+      sqlite3SchemaClear(pDb->pSchema);
+    }
+  }
+  db->flags &= ~SQLITE_InternChanges;
+  sqlite3VtabUnlockList(db);
+  sqlite3BtreeLeaveAll(db);
+  sqlite3CollapseDatabaseArray(db);
+}
+
 /*
 ** This routine is called when a commit occurs.
 */

src/main.c

@@ -806,7 +806,7 @@ int sqlite3_close(sqlite3 *db){
 
   /* This call frees the schema associated with the temp database only (if
   ** any). It also frees the db->aDb array, if required.  */
-  sqlite3ResetInternalSchema(db, -1);
+  sqlite3ResetAllSchemasOfConnection(db);
   assert( db->nDb<=2 );
   assert( db->aDb==db->aDbStatic );
 
@@ -901,7 +901,7 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
 
   if( db->flags&SQLITE_InternChanges ){
     sqlite3ExpirePreparedStatements(db);
-    sqlite3ResetInternalSchema(db, -1);
+    sqlite3ResetAllSchemasOfConnection(db);
   }
 
   /* Any deferred constraint violations have now been resolved. */

src/pragma.c

@@ -118,7 +118,7 @@ static int invalidateTempStorage(Parse *pParse){
     }
     sqlite3BtreeClose(db->aDb[1].pBt);
     db->aDb[1].pBt = 0;
-    sqlite3ResetInternalSchema(db, -1);
+    sqlite3ResetAllSchemasOfConnection(db);
   }
   return SQLITE_OK;
 }

src/prepare.c

@@ -342,7 +342,7 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   }
   if( db->mallocFailed ){
     rc = SQLITE_NOMEM;
-    sqlite3ResetInternalSchema(db, -1);
+    sqlite3ResetAllSchemasOfConnection(db);
   }
   if( rc==SQLITE_OK || (db->flags&SQLITE_RecoveryMode)){
     /* Black magic: If the SQLITE_RecoveryMode flag is set, then consider
@@ -395,7 +395,7 @@ int sqlite3Init(sqlite3 *db, char **pzErrMsg){
     if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;
     rc = sqlite3InitOne(db, i, pzErrMsg);
     if( rc ){
-      sqlite3ResetInternalSchema(db, i);
+      sqlite3ResetOneSchema(db, i);
     }
   }
 
@@ -408,7 +408,7 @@ int sqlite3Init(sqlite3 *db, char **pzErrMsg){
                     && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
     rc = sqlite3InitOne(db, 1, pzErrMsg);
     if( rc ){
-      sqlite3ResetInternalSchema(db, 1);
+      sqlite3ResetOneSchema(db, 1);
     }
   }
 #endif
@@ -476,7 +476,7 @@ static void schemaIsValid(Parse *pParse){
     sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&cookie);
     assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
     if( cookie!=db->aDb[iDb].pSchema->schema_cookie ){
-      sqlite3ResetInternalSchema(db, iDb);
+      sqlite3ResetOneSchema(db, iDb);
       pParse->rc = SQLITE_SCHEMA;
     }
 

src/sqliteInt.h

@@ -2696,7 +2696,9 @@ void sqlite3ExprListDelete(sqlite3*, ExprList*);
 int sqlite3Init(sqlite3*, char**);
 int sqlite3InitCallback(void*, int, char**, char**);
 void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
-void sqlite3ResetInternalSchema(sqlite3*, int);
+void sqlite3ResetAllSchemasOfConnection(sqlite3*);
+void sqlite3ResetOneSchema(sqlite3*,int);
+void sqlite3CollapseDatabaseArray(sqlite3*);
 void sqlite3BeginParse(Parse*,int);
 void sqlite3CommitInternalChanges(sqlite3*);
 Table *sqlite3ResultSetOfSelect(Parse*,Select*);

src/vacuum.c

@@ -339,7 +339,7 @@ end_of_vacuum:
 
   /* This both clears the schemas and reduces the size of the db->aDb[]
   ** array. */ 
-  sqlite3ResetInternalSchema(db, -1);
+  sqlite3ResetAllSchemasOfConnection(db);
 
   return rc;
 }

src/vdbe.c

@@ -2747,7 +2747,7 @@ case OP_Savepoint: {
         }
         if( p1==SAVEPOINT_ROLLBACK && (db->flags&SQLITE_InternChanges)!=0 ){
           sqlite3ExpirePreparedStatements(db);
-          sqlite3ResetInternalSchema(db, -1);
+          sqlite3ResetAllSchemasOfConnection(db);
           db->flags = (db->flags | SQLITE_InternChanges);
         }
       }
@@ -3051,7 +3051,7 @@ case OP_VerifyCookie: {
     ** a v-table method.
     */
     if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){
-      sqlite3ResetInternalSchema(db, pOp->p1);
+      sqlite3ResetOneSchema(db, pOp->p1);
     }
 
     p->expired = 1;
@@ -4864,7 +4864,7 @@ case OP_ParseSchema: {
       db->init.busy = 0;
     }
   }
-  if( rc ) sqlite3ResetInternalSchema(db, -1);
+  if( rc ) sqlite3ResetAllSchemasOfConnection(db);
   if( rc==SQLITE_NOMEM ){
     goto no_mem;
   }
@@ -6159,7 +6159,7 @@ vdbe_error_halt:
   if( rc==SQLITE_IOERR_NOMEM ) db->mallocFailed = 1;
   rc = SQLITE_ERROR;
   if( resetSchemaOnFault>0 ){
-    sqlite3ResetInternalSchema(db, resetSchemaOnFault-1);
+    sqlite3ResetOneSchema(db, resetSchemaOnFault-1);
   }
 
   /* This is the only way out of this procedure.  We have to

src/vtab.c

@@ -22,8 +22,8 @@
 ** are invoked only from within xCreate and xConnect methods.
 */
 struct VtabCtx {
-  Table *pTab;
-  VTable *pVTable;
+  VTable *pVTable;    /* The virtual table being constructed */
+  Table *pTab;        /* The Table object to which the virtual table belongs */
 };
 
 /*
@@ -54,7 +54,7 @@ static int createModule(
     pMod->xDestroy = xDestroy;
     pDel = (Module *)sqlite3HashInsert(&db->aModule, zCopy, nName, (void*)pMod);
     if( pDel && pDel->xDestroy ){
-      sqlite3ResetInternalSchema(db, -1);
+      sqlite3ResetAllSchemasOfConnection(db);
       pDel->xDestroy(pDel->pAux);
     }
     sqlite3DbFree(db, pDel);