Change sqlite3BtreeBeginTrans() to return the BTREE_SCHEMA_COOKIE, for a

small speed improvement when starting new transactions.

FossilOrigin-Name: a10662aa915ae2b5a78b3e10920350d32255b2d6b1a8aac0aba1ad173b07ed2b

manifest

@@ -1,5 +1,5 @@
-C Fix\sthe\s".archive"\scommand\sin\sthe\sCLI\s(and\sthe\scorresponding\s-A\scommand-line\noption)\sso\sthat\sit\ssilently\signores\sfilenames\sthat\scontain\s"../"\sin\stheir\nnames.\s\sThis\sprevents\sthe\s"Zip\sSlip"\sattack.
+C Change\ssqlite3BtreeBeginTrans()\sto\sreturn\sthe\sBTREE_SCHEMA_COOKIE,\sfor\sa\nsmall\sspeed\simprovement\swhen\sstarting\snew\stransactions.
-D 2018-06-06T01:18:01.520
+D 2018-06-06T16:28:40.777
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in bfc40f350586923e0419d2ea4b559c37ec10ee4b6e210e08c14401f8e340f0da
@@ -433,18 +433,18 @@ F src/alter.c cf7a8af45cb0ace672f47a1b29ab24092a9e8cd8d945a9974e3b5d925f548594
 F src/analyze.c 71fbbeb7b25417592f54d869fe90c28b48e4cecb9926ef9b06d90fb0aec48941
 F src/attach.c 4a3138bd771d5426ae4344d8d5e900440af29fabc5ec2f39f69a45010dfbccd7
 F src/auth.c a38f3c63c974787ecf75e3213f8cac6568b9a7af7591fb0372ec0517dd16dca8
-F src/backup.c faf17e60b43233c214aae6a8179d24503a61e83b
+F src/backup.c 78d3cecfbe28230a3a9a1793e2ead609f469be43e8f486ca996006be551857ab
 F src/bitvec.c 17ea48eff8ba979f1f5b04cc484c7bb2be632f33
 F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
-F src/btree.c 44405d03a05496e13b40b3a208bcf941c42c815da90d6ff4b04267a6985e5eb7
+F src/btree.c ae7687faa330562d36cede3375fdc316bff068e9216322d0dfbb3749333e5d3d
-F src/btree.h 448f15b98ea85dcf7e4eb76f731cadb89636c676ad25dfaac6de77cd66556598
+F src/btree.h ab639c4b9b210b8f4cd7a3a922af73df9a3f27c1d124267339fd73ef8619f488
 F src/btreeInt.h 620ab4c7235f43572cf3ac2ac8723cbdf68073be4d29da24897c7b77dda5fd96
 F src/build.c 5fc41458505331bfb0c175f40b9a13cb335f826bed3ae311aaae000c132d7b16
 F src/callback.c 36caff1e7eb7deb58572d59c41cee8f064a11d00297616995c5050ea0cfc1288
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 849d4cebe008cfc6e4799b034a172b4eaf8856b100739632a852732ba66eee48
 F src/date.c ebe1dc7c8a347117bb02570f1a931c62dd78f4a2b1b516f4837d45b7d6426957
-F src/dbpage.c 8db4c97f630e7d83f884ea75caf1ffd0988c160e9d530194d93721c80821e0f6
+F src/dbpage.c 4aa7f26198934dbd002e69418220eae3dbc71b010bbac32bd78faf86b52ce6c3
 F src/dbstat.c edabb82611143727511a45ca0859b8cd037851ebe756ae3db289859dd18b6f91
 F src/delete.c 4c8c7604277a2041647f96b78f4b9a47858e9217e4fb333d35e7b5ab32c5b57f
 F src/expr.c 16f90ae2af2a100bc430a89184afde54878d82f18267e8d00bc4f33e695a7c57
@@ -490,7 +490,7 @@ F src/pcache.h 072f94d29281cffd99e46c1539849f248c4b56ae7684c1f36626797fee375170
 F src/pcache1.c 716975564c15eb6679e97f734cec1bfd6c16ac3d4010f05f1f8e509fc7d19880
 F src/pragma.c c0d13c0e82a9197aef5533d63300c5b0c8a216ae1fd14ada64e1f12f398d7e82
 F src/pragma.h bb83728944b42f6d409c77f5838a8edbdb0fe83046c5496ffc9602b40340a324
-F src/prepare.c 95a9dba7a5d032039a77775188cb3b6fb17f2fa1a0b7cd915b30b4b823383ffa
+F src/prepare.c e966ecc97c3671ff0e96227c8c877b83f2d33ea371ee190bbf1698b36b5605c0
 F src/printf.c 7f6f3cba8e0c49c19e30a1ff4e9aeda6e06814dcbad4b664a69e1b6cb6e7e365
 F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 14602f46800ba182ea6a490e0f304127d29ac1f724bdadcc639e25d3223fcf6e
@@ -507,7 +507,7 @@ F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
 F src/tclsqlite.c 916a92de77ec5cbe27818ca194d8cf0c58aa7ad5b87527098f6aa5a6068800ce
 F src/test1.c 51aa5f3030217ca45eb62e90944838794d4faaae7a8f60e0330ae01f30bc997b
 F src/test2.c 3efb99ab7f1fc8d154933e02ae1378bac9637da5
-F src/test3.c b8434949dfb8aff8dfa082c8b592109e77844c2135ed3c492113839b6956255b
+F src/test3.c 61798bb0d38b915067a8c8e03f5a534b431181f802659a6616f9b4ff7d872644
 F src/test4.c 18ec393bb4d0ad1de729f0b94da7267270f3d8e6
 F src/test5.c 328aae2c010c57a9829d255dc099d6899311672d
 F src/test6.c e8d839fbc552ce044bec8234561a2d5b8819b48e29548ad0ba400471697946a8
@@ -564,8 +564,8 @@ F src/update.c 46dc24c6158446aaab45caee09b6d99327cb479268b83ffeb5b701823da3b67b
 F src/upsert.c 47edd408cc73f8d3c00a140550d1ad180b407c146285947969dd09874802bf88
 F src/utf.c 810fbfebe12359f10bc2a011520a6e10879ab2a163bcb26c74768eab82ea62a5
 F src/util.c d9eb0a6c4aae1b00a7369eadd7ca0bbe946cb4c953b6751aa20d357c2f482157
-F src/vacuum.c 37730af7540033135909ecaee3667dddec043293428d8718546d0d64ba4a5025
+F src/vacuum.c 36e7d21a20c0bf6ef4ef7c399d192b5239410b7c4d3c1070fba4e30810d0b855
-F src/vdbe.c fcec6e9ad743f92f0a557f0b61728d001581ee96e18c3e5c7d09702afde79b38
+F src/vdbe.c 6d399cc8e10a7c1b2103e5bc21874cbbb645bab39ae5839a124547de9c67281d
 F src/vdbe.h e3f43bcc27ff30b0f25a6104d0cb5657e1c4b5e1b5cd2dd2216d5bcc2156a746
 F src/vdbeInt.h 42d3e65ea0c664f6d9bc9a53de645c0baf8566ff0188409ff3b8d2abc327bc17
 F src/vdbeapi.c 765a0bbe01311626417de6cb743f7f25f9f98435c98a9df4bb0714d11014633d
@@ -1730,7 +1730,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 7598236c356cdb548c6188d69dfef99f7a08b89e512a3addfe1433ccd85e7b68
+P 27291f2d7fd4dadf2ee9b9a7d1373158cadfbaf83c3654b00d7030dc921770c6
-R e18f63662d0afb8275af32300ec3f6c3
+R 16b62aa5de77d5bb1612bf4110bec5fd
 U drh
-Z 67410ec210186d8a0784f53b2ab9e4b9
+Z 863a8fc1288d57d76620b26ae04bd21c

manifest.uuid

@@ -1 +1 @@
-27291f2d7fd4dadf2ee9b9a7d1373158cadfbaf83c3654b00d7030dc921770c6
+a10662aa915ae2b5a78b3e10920350d32255b2d6b1a8aac0aba1ad173b07ed2b

src/backup.c

@@ -382,7 +382,7 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
     ** before this function exits.
     */
     if( rc==SQLITE_OK && 0==sqlite3BtreeIsInReadTrans(p->pSrc) ){
-      rc = sqlite3BtreeBeginTrans(p->pSrc, 0);
+      rc = sqlite3BtreeBeginTrans(p->pSrc, 0, 0);
       bCloseTrans = 1;
     }
 
@@ -398,10 +398,10 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
 
     /* Lock the destination database, if it is not locked already. */
     if( SQLITE_OK==rc && p->bDestLocked==0
-     && SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2)) 
+     && SQLITE_OK==(rc = sqlite3BtreeBeginTrans(p->pDest, 2,
+                                                (int*)&p->iDestSchema)) 
     ){
       p->bDestLocked = 1;
-      sqlite3BtreeGetMeta(p->pDest, BTREE_SCHEMA_VERSION, &p->iDestSchema);
     }
 
     /* Do not allow backup if the destination database is in WAL mode

src/btree.c

@@ -3300,7 +3300,7 @@ int sqlite3BtreeNewDb(Btree *p){
 ** when A already has a read lock, we encourage A to give up and let B
 ** proceed.
 */
-int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
+int sqlite3BtreeBeginTrans(Btree *p, int wrflag, int *pSchemaVersion){
   BtShared *pBt = p->pBt;
   int rc = SQLITE_OK;
 
@@ -3428,12 +3428,17 @@ int sqlite3BtreeBeginTrans(Btree *p, int wrflag){
 
 
 trans_begun:
-  if( rc==SQLITE_OK && wrflag ){
+  if( rc==SQLITE_OK ){
-    /* This call makes sure that the pager has the correct number of
+    if( pSchemaVersion ){
-    ** open savepoints. If the second parameter is greater than 0 and
+      *pSchemaVersion = get4byte(&pBt->pPage1->aData[40]);
-    ** the sub-journal is not already open, then it will be opened here.
+    }
-    */
+    if( wrflag ){
-    rc = sqlite3PagerOpenSavepoint(pBt->pPager, p->db->nSavepoint);
+      /* This call makes sure that the pager has the correct number of
+      ** open savepoints. If the second parameter is greater than 0 and
+      ** the sub-journal is not already open, then it will be opened here.
+      */
+      rc = sqlite3PagerOpenSavepoint(pBt->pPager, p->db->nSavepoint);
+    }
   }
 
   btreeIntegrity(p);
@@ -10084,11 +10089,11 @@ int sqlite3BtreeSetVersion(Btree *pBtree, int iVersion){
   pBt->btsFlags &= ~BTS_NO_WAL;
   if( iVersion==1 ) pBt->btsFlags |= BTS_NO_WAL;
 
-  rc = sqlite3BtreeBeginTrans(pBtree, 0);
+  rc = sqlite3BtreeBeginTrans(pBtree, 0, 0);
   if( rc==SQLITE_OK ){
     u8 *aData = pBt->pPage1->aData;
     if( aData[18]!=(u8)iVersion || aData[19]!=(u8)iVersion ){
-      rc = sqlite3BtreeBeginTrans(pBtree, 2);
+      rc = sqlite3BtreeBeginTrans(pBtree, 2, 0);
       if( rc==SQLITE_OK ){
         rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
         if( rc==SQLITE_OK ){

src/btree.h

@@ -78,7 +78,7 @@ int sqlite3BtreeGetOptimalReserve(Btree*);
 int sqlite3BtreeGetReserveNoMutex(Btree *p);
 int sqlite3BtreeSetAutoVacuum(Btree *, int);
 int sqlite3BtreeGetAutoVacuum(Btree *);
-int sqlite3BtreeBeginTrans(Btree*,int);
+int sqlite3BtreeBeginTrans(Btree*,int,int*);
 int sqlite3BtreeCommitPhaseOne(Btree*, const char *zMaster);
 int sqlite3BtreeCommitPhaseTwo(Btree*, int);
 int sqlite3BtreeCommit(Btree*);

src/dbpage.c

@@ -369,7 +369,7 @@ static int dbpageBegin(sqlite3_vtab *pVtab){
   int i;
   for(i=0; i<db->nDb; i++){
     Btree *pBt = db->aDb[i].pBt;
-    if( pBt ) sqlite3BtreeBeginTrans(pBt, 1);
+    if( pBt ) sqlite3BtreeBeginTrans(pBt, 1, 0);
   }
   return SQLITE_OK;
 }

src/prepare.c

@@ -188,7 +188,7 @@ static int sqlite3InitOne(sqlite3 *db, int iDb, char **pzErrMsg){
   ** will be closed before this function returns.  */
   sqlite3BtreeEnter(pDb->pBt);
   if( !sqlite3BtreeIsInReadTrans(pDb->pBt) ){
-    rc = sqlite3BtreeBeginTrans(pDb->pBt, 0);
+    rc = sqlite3BtreeBeginTrans(pDb->pBt, 0, 0);
     if( rc!=SQLITE_OK ){
       sqlite3SetString(pzErrMsg, db, sqlite3ErrStr(rc));
       goto initone_error_out;
@@ -433,7 +433,7 @@ static void schemaIsValid(Parse *pParse){
     ** on the b-tree database, open one now. If a transaction is opened, it 
     ** will be closed immediately after reading the meta-value. */
     if( !sqlite3BtreeIsInReadTrans(pBt) ){
-      rc = sqlite3BtreeBeginTrans(pBt, 0);
+      rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
       if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
         sqlite3OomFault(db);
       }

src/test3.c

@@ -133,7 +133,7 @@ static int SQLITE_TCLAPI btree_begin_transaction(
   }
   pBt = sqlite3TestTextToPtr(argv[1]);
   sqlite3BtreeEnter(pBt);
-  rc = sqlite3BtreeBeginTrans(pBt, 1);
+  rc = sqlite3BtreeBeginTrans(pBt, 1, 0);
   sqlite3BtreeLeave(pBt);
   if( rc!=SQLITE_OK ){
     Tcl_AppendResult(interp, sqlite3ErrName(rc), 0);

src/vacuum.c

@@ -224,7 +224,7 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db, int iDb){
   */
   rc = execSql(db, pzErrMsg, "BEGIN");
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
-  rc = sqlite3BtreeBeginTrans(pMain, 2);
+  rc = sqlite3BtreeBeginTrans(pMain, 2, 0);
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
 
   /* Do not attempt to change the page size for a WAL database */

src/vdbe.c

@@ -3202,8 +3202,8 @@ case OP_AutoCommit: {
 */
 case OP_Transaction: {
   Btree *pBt;
-  int iMeta;
+  int iMeta = 0;
-  int iGen;
+  int iGen = 0;
 
   assert( p->bIsReader );
   assert( p->readOnly==0 || pOp->p2==0 );
@@ -3216,7 +3216,7 @@ case OP_Transaction: {
   pBt = db->aDb[pOp->p1].pBt;
 
   if( pBt ){
-    rc = sqlite3BtreeBeginTrans(pBt, pOp->p2);
+    rc = sqlite3BtreeBeginTrans(pBt, pOp->p2, &iMeta);
     testcase( rc==SQLITE_BUSY_SNAPSHOT );
     testcase( rc==SQLITE_BUSY_RECOVERY );
     if( rc!=SQLITE_OK ){
@@ -3255,10 +3255,7 @@ case OP_Transaction: {
     ** version is checked to ensure that the schema has not changed since the
     ** SQL statement was prepared.
     */
-    sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&iMeta);
     iGen = db->aDb[pOp->p1].pSchema->iGeneration;
-  }else{
-    iGen = iMeta = 0;
   }
   assert( pOp->p5==0 || pOp->p4type==P4_INT32 );
   if( pOp->p5 && (iMeta!=pOp->p3 || iGen!=pOp->p4.i) ){
@@ -3626,7 +3623,7 @@ case OP_OpenEphemeral: {
   rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBtx, 
                         BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5, vfsFlags);
   if( rc==SQLITE_OK ){
-    rc = sqlite3BtreeBeginTrans(pCx->pBtx, 1);
+    rc = sqlite3BtreeBeginTrans(pCx->pBtx, 1, 0);
   }
   if( rc==SQLITE_OK ){
     /* If a transient index is required, create it by calling