Automatically close ephemeral b-trees when their last cursor is closed.

FossilOrigin-Name: 39b5af18c0580c8e92516d410f8c465bfec31b2d0be9df1cfd6a1d1a19b4fc14

manifest

@@ -1,5 +1,5 @@
-C Allow\sinstruction\sOP_OpenDup\sto\sduplicate\scursors\screated\sby\sOP_OpenDup,\sas\swell\sas\sby\sOP_OpenEphemeral.
-D 2021-03-18T13:42:53.871
+C Automatically\sclose\sephemeral\sb-trees\swhen\stheir\slast\scursor\sis\sclosed.
+D 2021-03-18T14:31:37.348
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -483,8 +483,8 @@ F src/auth.c 08954fdc4cc2da5264ba5b75cfd90b67a6fc7d1710a02ccf917c38eadec77853
 F src/backup.c 3014889fa06e20e6adfa0d07b60097eec1f6e5b06671625f476a714d2356513d
 F src/bitvec.c 17ea48eff8ba979f1f5b04cc484c7bb2be632f33
 F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
-F src/btree.c 83cb92554f14752d1446ecebf9d2b38292d36af23d1b422862653192b742e1b7
-F src/btree.h a25ab8dfe82764e0449e12091f4dbedcf2995a70db6a27e224d1f3772a0d640c
+F src/btree.c b048dcb502fd8abd5b161189150607d8ca9477b52fc5cba907246f795eb1fe36
+F src/btree.h 096cc53baa58be22b02c896d1cf933c38cfc6d65f9253c1367ece8cc88a24de5
 F src/btreeInt.h 7614cae30f95b6aed0c7cac7718276a55cfe2c77058cbfd8bef5b75329757331
 F src/build.c fec73c39d756f31d35ccbaa80fe1e040a8d675a318d4d30f41c444167bf3b860
 F src/callback.c d0b853dd413255d2e337b34545e54d888ea02f20da5ad0e63585b389624c4a6c
@@ -614,11 +614,11 @@ F src/upsert.c df8f1727d62b5987c4fd302cd4d7c0c84ae57cd65683c5a34a740dfe24039235
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
 F src/util.c 41c7a72da1df47864faa378a1c720b38adb288c6838cb6be5594511b6287a048
 F src/vacuum.c 492422c1463c076473bae1858799c7a0a5fe87a133d1223239447c422cd26286
-F src/vdbe.c ae4ebb8762fc1b30f11a0498eba74c193f052c6724f73ffb63548875200813c6
+F src/vdbe.c 819860625f65ebc1ad029fbef07b62c56904e057a6d76f0d5486e2c41d0fccd4
 F src/vdbe.h 25dabb25c7e157b84e59260cfb5b466c3ac103ede9f36f4db371332c47601abe
 F src/vdbeInt.h 3df118924e1711f1bbc8e30c46260d0ab6c3b029b32dd411f789111f76434f3c
 F src/vdbeapi.c 4a43e303ec3354c785f453e881521969378e85628278ab74ba4a9df790c0d93b
-F src/vdbeaux.c fb51483c2bcaf45c5de63c26cce8649ef37f1332e8e035867033d21ef5e7fc2c
+F src/vdbeaux.c 6df834c4ff0c86a62b94fe0762d0abb7dbda54a862f0fe82e35d22fc4490414d
 F src/vdbeblob.c 253ed82894924c362a7fa3079551d3554cd1cdace39aa833da77d3bc67e7c1b1
 F src/vdbemem.c 947f2a65910edb4014dc981d33e414a68c51f169f9df8c4c493a0ba840b6eb1f
 F src/vdbesort.c f5b5e473a7cee44e47a94817b042fd7172cf3aa2c0a7928a8339d612bcfdec5a
@@ -1910,10 +1910,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P ea80f3002f4120f5dcee76e8779dfdc88e1e096c5cdd06904c20fd26d50c3827
-R 5690d05e7243d41ceb9332de8bdd3707
-T *branch * opendup-fix
-T *sym-opendup-fix *
-T -sym-trunk *
+P b8de980b2fb78088ef74e053cb987bb84319d13dc96ce1e89baaaa3fe8cf1efc
+R d059e62ed2003127849996336a75bcfd
 U dan
-Z fd7ffe22c065e32af24a29a1b9c91b9f
+Z 5c6f726925b0e9cfdd8d4a838991a1a4

manifest.uuid

@@ -1 +1 @@
-b8de980b2fb78088ef74e053cb987bb84319d13dc96ce1e89baaaa3fe8cf1efc
+39b5af18c0580c8e92516d410f8c465bfec31b2d0be9df1cfd6a1d1a19b4fc14

src/btree.c

@@ -2742,6 +2742,7 @@ int sqlite3BtreeClose(Btree *p){
   /* Close all cursors opened via this handle.  */
   assert( sqlite3_mutex_held(p->db->mutex) );
   sqlite3BtreeEnter(p);
+  pBt->openFlags &= ~BTREE_SINGLE;
   pCur = pBt->pCursor;
   while( pCur ){
     BtCursor *pTmp = pCur;
@@ -4541,7 +4542,14 @@ int sqlite3BtreeCloseCursor(BtCursor *pCur){
     unlockBtreeIfUnused(pBt);
     sqlite3_free(pCur->aOverflow);
     sqlite3_free(pCur->pKey);
+    if( (pBt->openFlags & BTREE_SINGLE) && pBt->pCursor==0 ){
+      /* Since the BtShared is not sharable, there is no need to
+      ** worry about the missing sqlite3BtreeLeave() call here.  */
+      assert( pBtree->sharable==0 );
+      sqlite3BtreeClose(pBtree);
+    }else{
       sqlite3BtreeLeave(pBtree);
+    }
     pCur->pBtree = 0;
   }
   return SQLITE_OK;
@@ -10705,14 +10713,6 @@ int sqlite3BtreeIsReadonly(Btree *p){
 */
 int sqlite3HeaderSizeBtree(void){ return ROUND8(sizeof(MemPage)); }
 
-/*
-** Return the Btree object used to open the cursor provided as an
-** argument.
-*/
-Btree *sqlite3BtreeGetBtree(BtCursor *pCsr){
-  return pCsr->pBtree;
-}
-
 #if !defined(SQLITE_OMIT_SHARED_CACHE)
 /*
 ** Return true if the Btree passed as the only argument is sharable.

src/btree.h

@@ -363,7 +363,6 @@ void sqlite3BtreeCursorList(Btree*);
 #endif
 
 int sqlite3BtreeTransferRow(BtCursor*, BtCursor*, i64);
-Btree *sqlite3BtreeGetBtree(BtCursor*);
 
 /*
 ** If we are not using shared cache, then there is no need to

src/vdbe.c

@@ -3873,7 +3873,7 @@ case OP_OpenDup: {
 
   pOrig = p->apCsr[pOp->p2];
   assert( pOrig );
-  assert( pOrig->isEphemeral );  /* Only ephemeral cursors can be duplicated */
+  assert( pOrig->pBtx );  /* Only ephemeral cursors can be duplicated */
 
   pCx = allocateCursor(p, pOp->p1, pOrig->nField, -1, CURTYPE_BTREE);
   if( pCx==0 ) goto no_mem;
@@ -3883,9 +3883,9 @@ case OP_OpenDup: {
   pCx->isTable = pOrig->isTable;
   pCx->pgnoRoot = pOrig->pgnoRoot;
   pCx->isOrdered = pOrig->isOrdered;
-  rc = sqlite3BtreeCursor(sqlite3BtreeGetBtree(pOrig->uc.pCursor),
-      pCx->pgnoRoot, BTREE_WRCSR, pCx->pKeyInfo, pCx->uc.pCursor
-  );
+  pCx->pBtx = pOrig->pBtx;
+  rc = sqlite3BtreeCursor(pCx->pBtx, pCx->pgnoRoot, BTREE_WRCSR, 
+                          pCx->pKeyInfo, pCx->uc.pCursor);
   /* The sqlite3BtreeCursor() routine can only fail for the first cursor
   ** opened for a database.  Since there is already an open cursor when this
   ** opcode is run, the sqlite3BtreeCursor() cannot fail */
@@ -3966,7 +3966,6 @@ case OP_OpenEphemeral: {
                           vfsFlags);
     if( rc==SQLITE_OK ){
       rc = sqlite3BtreeBeginTrans(pCx->pBtx, 1, 0);
-    }
       if( rc==SQLITE_OK ){
         /* If a transient index is required, create it by calling
         ** sqlite3BtreeCreateTable() with the BTREE_BLOBKEY flag before
@@ -3993,6 +3992,10 @@ case OP_OpenEphemeral: {
         }
       }
       pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
+      if( rc ){
+        sqlite3BtreeClose(pCx->pBtx);
+      }
+    }
   }
   if( rc ) goto abort_due_to_error;
   pCx->nullRow = 1;

src/vdbeaux.c

@@ -2472,20 +2472,15 @@ void sqlite3VdbeFreeCursor(Vdbe *p, VdbeCursor *pCx){
     return;
   }
   assert( pCx->pBtx==0 || pCx->eCurType==CURTYPE_BTREE );
+  assert( pCx->pBtx==0 || pCx->isEphemeral );
   switch( pCx->eCurType ){
     case CURTYPE_SORTER: {
       sqlite3VdbeSorterClose(p->db, pCx);
       break;
     }
     case CURTYPE_BTREE: {
-      if( pCx->isEphemeral ){
-        if( pCx->pBtx ) sqlite3BtreeClose(pCx->pBtx);
-        /* The pCx->pCursor will be close automatically, if it exists, by
-        ** the call above. */
-      }else{
       assert( pCx->uc.pCursor!=0 );
       sqlite3BtreeCloseCursor(pCx->uc.pCursor);
-      }
       break;
     }
 #ifndef SQLITE_OMIT_VIRTUALTABLE