From: drh <drh@noemail.net>
Date: Wed, 13 Feb 2019 13:48:48 +0000 (+0000)
Subject: Performance optimization in the VDBE, and a fix for a harmless compiler
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=refs%2Fheads%2Freuse-schema-vdbe-opt;p=thirdparty%2Fsqlite.git

Performance optimization in the VDBE, and a fix for a harmless compiler
warning.

FossilOrigin-Name: e002666ac79c3452a772323c6ecc696104341cd842e77541553ec028f188096b
---

diff --git a/manifest b/manifest
index 77f938b151..9aa847208d 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\sproblem\swith\sOPEN_REUSE_SCHEMA\sconnections\sreloading\sthe\stemp\sschema.
-D 2019-02-13T08:40:34.055
+C Performance\soptimization\sin\sthe\sVDBE,\sand\sa\sfix\sfor\sa\sharmless\scompiler\nwarning.
+D 2019-02-13T13:48:48.604
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 56456706c4da271309914c756c9c8ea537685f1c79f8785afa72f968d6810482
@@ -521,7 +521,7 @@ F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 960f1b86c3610fa23cb6a267572a97dcf286e77aa0dd3b9b23292ffaa1ea8683
 F src/sqliteInt.h 6173e47d1cddb8c9aa5ccfaa0f40b9f62635050d503245e6439b3cd96fb6a53d
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
-F src/status.c 41d9cc5d5f9d2a470dcf0a28432c66e25c15b86e51535283e9aef632adf02ac8
+F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
 F src/tclsqlite.c b17e7c1629311de001887ad5afa4ed9bfddd85be0bbb7e6fdf16352162c98081
 F src/test1.c 353b066e7ec761c4c715c1c20b888e0e7a0b0c0eda7f68c110e032d63713cade
@@ -586,7 +586,7 @@ F src/upsert.c 0dd81b40206841814d46942a7337786932475f085716042d0cb2fc7791bf8ca4
 F src/utf.c 810fbfebe12359f10bc2a011520a6e10879ab2a163bcb26c74768eab82ea62a5
 F src/util.c 82a2e3f691a3b654be872e305dab1f455e565dedf5e6a90c818c1ab307c00432
 F src/vacuum.c 7dbed4a756f014f3ce54e6ae3c403ee725e8179cf73fc6dd5c064e5627649f9f
-F src/vdbe.c a9a47fee453e93a725469b3c6d9b58425178658ed3ec50709a08408a293773b3
+F src/vdbe.c 5f0e3dc94889a4e68497127d0bca320401797c7107035bc0408e6b5e49d6d733
 F src/vdbe.h 323218c4bfd64c719ba85d05fbc87cdd126991cadb39e73ccac7b59f30c3d53e
 F src/vdbeInt.h a76d5eed62c76bcd8de7afd3147fac1bc40c5a870582664bcd7d071ef437c37f
 F src/vdbeapi.c 57a2d794a8833f269b878dbc24e955369bdb379af6c4e93ebc5ce1a20fa3daf4
@@ -1808,7 +1808,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 8c07b609fccc43795498b942c733896defd8887e4ddd9e0ef48c124dfcf9fd7f
-R 765b6e0bdb51edd5b378e5259607a03d
-U dan
-Z c13672cd797193c9057764ed19647533
+P 7c2ec2d4cfcda9c0aa6d57bd9a12ff98b78e648533d49da27f91d5a37bf1e001
+R 874fe30becc1a5c03c09070b47052542
+T *branch * reuse-schema-vdbe-opt
+T *sym-reuse-schema-vdbe-opt *
+T -sym-reuse-schema *
+U drh
+Z 98b88b6e43c9abf2e2da117ac8e7a62c
diff --git a/manifest.uuid b/manifest.uuid
index c092348ad2..82b709ee6a 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-7c2ec2d4cfcda9c0aa6d57bd9a12ff98b78e648533d49da27f91d5a37bf1e001
\ No newline at end of file
+e002666ac79c3452a772323c6ecc696104341cd842e77541553ec028f188096b
\ No newline at end of file
diff --git a/src/status.c b/src/status.c
index d0dc0b734f..a5a39f4c18 100644
--- a/src/status.c
+++ b/src/status.c
@@ -282,7 +282,6 @@ int sqlite3_db_status(
         Schema *pSchema = db->aDb[i].pSchema;
         if( ALWAYS(pSchema!=0) ){
           HashElem *p;
-          int nStart = nByte;
 
           nByte += sqlite3GlobalConfig.m.xRoundup(sizeof(HashElem)) * (
               pSchema->tblHash.count 
diff --git a/src/vdbe.c b/src/vdbe.c
index 456b6e98d1..2f65d708f0 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -412,6 +412,86 @@ static u16 numericType(Mem *pMem){
   return 0;
 }
 
+/*
+** This is the implementation of the OP_ParseSchema opcode.  It is factored
+** out of the main sqlite3VdbeExec() routine because it is not a performance-
+** critical opcode and by factoring it out, it frees up registers in order
+** to help the compiler optimizer do a better job with the other opcodes
+** that are performance critical.
+*/
+static SQLITE_NOINLINE int parseSchemaOp(Vdbe *p, VdbeOp *pOp, sqlite3 *db){
+  int iDb;
+  const char *zMaster;
+  char *zSql;
+  InitData initData;
+  int bRelease;
+  int rc = SQLITE_OK;
+
+  /* Any prepared statement that invokes this opcode will hold mutexes
+  ** on every btree.  This is a prerequisite for invoking 
+  ** sqlite3InitCallback().
+  */
+#ifdef SQLITE_DEBUG
+  for(iDb=0; iDb<db->nDb; iDb++){
+    assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
+  }
+#endif
+
+  iDb = pOp->p1;
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( DbHasProperty(db, iDb, DB_SchemaLoaded) );
+
+#ifndef SQLITE_OMIT_ALTERTABLE
+  if( pOp->p4.z==0 ){
+    assert( !IsReuseSchema(db) || iDb==1 );
+    sqlite3SchemaClear(db->aDb[iDb].pSchema);
+    db->mDbFlags &= ~DBFLAG_SchemaKnownOk;
+    rc = sqlite3InitOne(db, iDb, &p->zErrMsg, INITFLAG_AlterTable);
+    db->mDbFlags |= DBFLAG_SchemaChange;
+    p->expired = 0;
+  }else
+#endif
+  {
+    zMaster = MASTER_NAME;
+    initData.db = db;
+    initData.iDb = iDb;
+    initData.pzErrMsg = &p->zErrMsg;
+    initData.mInitFlags = 0;
+    zSql = sqlite3MPrintf(db,
+       "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s ORDER BY rowid",
+       db->aDb[iDb].zDbSName, zMaster, pOp->p4.z);
+    if( zSql==0 ){
+      rc = SQLITE_NOMEM_BKPT;
+    }else{
+      bRelease = sqlite3LockReusableSchema(db);
+      if( IsReuseSchema(db) ){
+        rc = sqlite3Init(db, &p->zErrMsg);
+        if( rc ){
+          sqlite3UnlockReusableSchema(db, bRelease);
+          return rc;
+        }
+      }
+      assert( db->init.busy==0 );
+      db->init.busy = 1;
+      initData.rc = SQLITE_OK;
+      initData.nInitRow = 0;
+      assert( !db->mallocFailed );
+      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
+      sqlite3UnlockReusableSchema(db, bRelease);
+      if( rc==SQLITE_OK ) rc = initData.rc;
+      if( rc==SQLITE_OK && initData.nInitRow==0 ){
+        /* The OP_ParseSchema opcode with a non-NULL P4 argument should parse
+        ** at least one SQL statement. Any less than that indicates that
+        ** the sqlite_master table is corrupt. */
+        rc = SQLITE_CORRUPT_BKPT;
+      }
+      sqlite3DbFreeNN(db, zSql);
+      db->init.busy = 0;
+    }
+  }
+  return rc;
+}
+
 #ifdef SQLITE_DEBUG
 /*
 ** Write a nice string representation of the contents of cell pMem
@@ -5757,74 +5837,7 @@ case OP_SqlExec: {
 ** then runs the new virtual machine.  It is thus a re-entrant opcode.
 */
 case OP_ParseSchema: {
-  int iDb;
-  const char *zMaster;
-  char *zSql;
-  InitData initData;
-  int bRelease;
-
-  /* Any prepared statement that invokes this opcode will hold mutexes
-  ** on every btree.  This is a prerequisite for invoking 
-  ** sqlite3InitCallback().
-  */
-#ifdef SQLITE_DEBUG
-  for(iDb=0; iDb<db->nDb; iDb++){
-    assert( iDb==1 || sqlite3BtreeHoldsMutex(db->aDb[iDb].pBt) );
-  }
-#endif
-
-  iDb = pOp->p1;
-  assert( iDb>=0 && iDb<db->nDb );
-  assert( DbHasProperty(db, iDb, DB_SchemaLoaded) );
-
-#ifndef SQLITE_OMIT_ALTERTABLE
-  if( pOp->p4.z==0 ){
-    assert( !IsReuseSchema(db) || iDb==1 );
-    sqlite3SchemaClear(db->aDb[iDb].pSchema);
-    db->mDbFlags &= ~DBFLAG_SchemaKnownOk;
-    rc = sqlite3InitOne(db, iDb, &p->zErrMsg, INITFLAG_AlterTable);
-    db->mDbFlags |= DBFLAG_SchemaChange;
-    p->expired = 0;
-  }else
-#endif
-  {
-    zMaster = MASTER_NAME;
-    initData.db = db;
-    initData.iDb = iDb;
-    initData.pzErrMsg = &p->zErrMsg;
-    initData.mInitFlags = 0;
-    zSql = sqlite3MPrintf(db,
-       "SELECT name, rootpage, sql FROM '%q'.%s WHERE %s ORDER BY rowid",
-       db->aDb[iDb].zDbSName, zMaster, pOp->p4.z);
-    if( zSql==0 ){
-      rc = SQLITE_NOMEM_BKPT;
-    }else{
-      bRelease = sqlite3LockReusableSchema(db);
-      if( IsReuseSchema(db) ){
-        rc = sqlite3Init(db, &p->zErrMsg);
-        if( rc ){
-          sqlite3UnlockReusableSchema(db, bRelease);
-          goto abort_due_to_error;
-        }
-      }
-      assert( db->init.busy==0 );
-      db->init.busy = 1;
-      initData.rc = SQLITE_OK;
-      initData.nInitRow = 0;
-      assert( !db->mallocFailed );
-      rc = sqlite3_exec(db, zSql, sqlite3InitCallback, &initData, 0);
-      sqlite3UnlockReusableSchema(db, bRelease);
-      if( rc==SQLITE_OK ) rc = initData.rc;
-      if( rc==SQLITE_OK && initData.nInitRow==0 ){
-        /* The OP_ParseSchema opcode with a non-NULL P4 argument should parse
-        ** at least one SQL statement. Any less than that indicates that
-        ** the sqlite_master table is corrupt. */
-        rc = SQLITE_CORRUPT_BKPT;
-      }
-      sqlite3DbFreeNN(db, zSql);
-      db->init.busy = 0;
-    }
-  }
+  rc = parseSchemaOp(p, pOp, db);
   if( rc ){
     sqlite3ResetAllSchemasOfConnection(db);
     if( rc==SQLITE_NOMEM ){