Add the SQLITE_OMIT_MERGE_SORT pre-processor directive. To omit the code in vdbesort.c.

FossilOrigin-Name: 4ced2394b10d0a4f86422ff893bcdf3cf32591e3

6 files changed, 61 insertions, 20 deletions

diff --git a/src/build.c b/src/build.c
index 7152ab8eb..91fe039c0 100644
--- a/src/build.c
+++ b/src/build.c
@@ -2308,7 +2308,7 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   Table *pTab = pIndex->pTable;  /* The table that is indexed */
   int iTab = pParse->nTab++;     /* Btree cursor used for pTab */
   int iIdx = pParse->nTab++;     /* Btree cursor used for pIndex */
-  int iSorter = pParse->nTab++;  /* Btree cursor used for sorting */
+  int iSorter = iTab;            /* Cursor opened by OpenSorter (if in use) */
   int addr1;                     /* Address of top of loop */
   int tnum;                      /* Root page of index */
   Vdbe *v;                       /* Generate code into this virtual machine */
@@ -2318,6 +2318,15 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   sqlite3 *db = pParse->db;      /* The database connection */
   int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
 
+  /* Set bUseSorter to use OP_OpenSorter, or clear it to insert directly 
+  ** into the index. The sorter is used unless either OMIT_MERGE_SORT is
+  ** defined or the system is configured to store temp files in-memory. */
+#ifdef SQLITE_OMIT_MERGE_SORT
+  static const int bUseSorter = 0;
+#else
+  const int bUseSorter = !sqlite3TempInMemory(pParse->db);
+#endif
+
 #ifndef SQLITE_OMIT_AUTHORIZATION
   if( sqlite3AuthCheck(pParse, SQLITE_REINDEX, pIndex->zName, 0,
       db->aDb[iDb].zName ) ){
@@ -2343,8 +2352,11 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
     sqlite3VdbeChangeP5(v, 1);
   }
 
-  /* Open the sorter cursor. */
-  sqlite3VdbeAddOp4(v, OP_OpenSorter, iSorter, 0, 0, (char*)pKey, P4_KEYINFO);
+  /* Open the sorter cursor if we are to use one. */
+  if( bUseSorter ){
+    iSorter = pParse->nTab++;
+    sqlite3VdbeAddOp4(v, OP_OpenSorter, iSorter, 0, 0, (char*)pKey, P4_KEYINFO);
+  }
 
   /* Open the table. Loop through all rows of the table, inserting index
   ** records into the sorter. */
@@ -2352,13 +2364,14 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
   regRecord = sqlite3GetTempReg(pParse);
   regIdxKey = sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);
-  sqlite3VdbeAddOp2(v, OP_IdxInsert, iSorter, regRecord);
-  sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
-  sqlite3VdbeJumpHere(v, addr1);
 
-  /* Rewind the sorter. Loop through index records in sorted order. */
-  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSorter, 0);
-  sqlite3VdbeAddOp2(v, OP_RowKey, iSorter, regRecord);
+  if( bUseSorter ){
+    sqlite3VdbeAddOp2(v, OP_IdxInsert, iSorter, regRecord);
+    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
+    sqlite3VdbeJumpHere(v, addr1);
+    addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iSorter, 0);
+    sqlite3VdbeAddOp2(v, OP_RowKey, iSorter, regRecord);
+  }
 
   if( pIndex->onError!=OE_None ){
     const int regRowid = regIdxKey + pIndex->nColumn;
@@ -2378,15 +2391,15 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
     sqlite3HaltConstraint(
         pParse, OE_Abort, "indexed columns are not unique", P4_STATIC);
   }
-  sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, 1);
+  sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, bUseSorter);
   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
   sqlite3ReleaseTempReg(pParse, regRecord);
   sqlite3VdbeAddOp2(v, OP_Next, iSorter, addr1+1);
   sqlite3VdbeJumpHere(v, addr1);
 
   sqlite3VdbeAddOp1(v, OP_Close, iTab);
-  sqlite3VdbeAddOp1(v, OP_Close, iSorter);
   sqlite3VdbeAddOp1(v, OP_Close, iIdx);
+  sqlite3VdbeAddOp1(v, OP_Close, iSorter);
 }
 
 /*
diff --git a/src/ctime.c b/src/ctime.c
index a128f61a6..9d31596bb 100644
--- a/src/ctime.c
+++ b/src/ctime.c
@@ -257,6 +257,9 @@ static const char * const azCompileOpt[] = {
 #ifdef SQLITE_OMIT_MEMORYDB
   "OMIT_MEMORYDB",
 #endif
+#ifdef SQLITE_OMIT_MERGE_SORT
+  "OMIT_MERGE_SORT",
+#endif
 #ifdef SQLITE_OMIT_OR_OPTIMIZATION
   "OMIT_OR_OPTIMIZATION",
 #endif
diff --git a/src/test_config.c b/src/test_config.c
index e8d6f88f6..5b0ffaa69 100644
--- a/src/test_config.c
+++ b/src/test_config.c
@@ -363,6 +363,12 @@ Tcl_SetVar2(interp, "sqlite_options", "long_double",
   Tcl_SetVar2(interp, "sqlite_options", "memorymanage", "0", TCL_GLOBAL_ONLY);
 #endif
 
+#ifdef SQLITE_OMIT_MERGE_SORT
+  Tcl_SetVar2(interp, "sqlite_options", "mergesort", "0", TCL_GLOBAL_ONLY);
+#else
+  Tcl_SetVar2(interp, "sqlite_options", "mergesort", "1", TCL_GLOBAL_ONLY);
+#endif
+
 #ifdef SQLITE_OMIT_OR_OPTIMIZATION
   Tcl_SetVar2(interp, "sqlite_options", "or_opt", "0", TCL_GLOBAL_ONLY);
 #else
diff --git a/src/vdbe.c b/src/vdbe.c
index 97edf90f0..857881413 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -157,6 +157,13 @@ int sqlite3_found_count = 0;
 */
 #define ExpandBlob(P) (((P)->flags&MEM_Zero)?sqlite3VdbeMemExpandBlob(P):0)
 
+/* Return true if the cursor was opened using the OP_OpenSorter opcode. */
+#ifdef SQLITE_OMIT_MERGE_SORT
+# define isSorter(x) 0
+#else
+# define isSorter(x) ((x)->pSorter!=0)
+#endif
+
 /*
 ** Argument pMem points at a register that will be passed to a
 ** user-defined function or returned to the user as the result of a query.
@@ -3155,13 +3162,12 @@ case OP_OpenEphemeral: {
       SQLITE_OPEN_DELETEONCLOSE |
       SQLITE_OPEN_TRANSIENT_DB;
 
-  int btflags = BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5;
-
   assert( pOp->p1>=0 );
   pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
   if( pCx==0 ) goto no_mem;
   pCx->nullRow = 1;
-  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBt, btflags, vfsFlags);
+  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBt, 
+                        BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5, vfsFlags);
   if( rc==SQLITE_OK ){
     rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
   }
@@ -3180,7 +3186,7 @@ case OP_OpenEphemeral: {
         rc = sqlite3BtreeCursor(pCx->pBt, pgno, 1, 
                                 (KeyInfo*)pOp->p4.z, pCx->pCursor);
         pCx->pKeyInfo = pOp->p4.pKeyInfo;
-        pCx->pKeyInfo->enc = ENC(db);
+        pCx->pKeyInfo->enc = ENC(p->db);
       }
       pCx->isTable = 0;
     }else{
@@ -3190,9 +3196,11 @@ case OP_OpenEphemeral: {
   }
   pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
   pCx->isIndex = !pCx->isTable;
+#ifndef SQLITE_OMIT_MERGE_SORT
   if( rc==SQLITE_OK && pOp->opcode==OP_OpenSorter ){
     rc = sqlite3VdbeSorterInit(db, pCx);
   }
+#endif
   break;
 }
 
@@ -4083,7 +4091,8 @@ case OP_RowData: {
   assert( pC->nullRow==0 );
   assert( pC->pseudoTableReg==0 );
 
-  if( pC->pSorter ){
+  if( isSorter(pC) ){
+    assert( pOp->opcode==OP_RowKey );
     rc = sqlite3VdbeSorterRowkey(db, pC, pOut);
     break;
   }
@@ -4268,7 +4277,7 @@ case OP_Rewind: {        /* jump */
   pC = p->apCsr[pOp->p1];
   assert( pC!=0 );
   res = 1;
-  if( pC->pSorter ){
+  if( isSorter(pC) ){
     rc = sqlite3VdbeSorterRewind(db, pC, &res);
   }else if( (pCrsr = pC->pCursor)!=0 ){
     rc = sqlite3BtreeFirst(pCrsr, &res);
@@ -4324,7 +4333,7 @@ case OP_Next: {        /* jump */
   if( pC==0 ){
     break;  /* See ticket #2273 */
   }
-  if( pC->pSorter ){
+  if( isSorter(pC) ){
     assert( pOp->opcode==OP_Next );
     rc = sqlite3VdbeSorterNext(db, pC, &res);
   }else{
@@ -4340,7 +4349,6 @@ case OP_Next: {        /* jump */
   }
   pC->nullRow = (u8)res;
   pC->cacheStatus = CACHE_STALE;
-
   if( res==0 ){
     pc = pOp->p2 - 1;
     if( pOp->p5 ) p->aCounter[pOp->p5-1]++;
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index b2f5ef661..1574f1d57 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -392,13 +392,21 @@ void sqlite3VdbeFrameDelete(VdbeFrame*);
 int sqlite3VdbeFrameRestore(VdbeFrame *);
 void sqlite3VdbeMemStoreType(Mem *pMem);
 
+#ifdef SQLITE_OMIT_MERGE_SORT
+# define sqlite3VdbeSorterInit(Y,Z)      SQLITE_OK
+# define sqlite3VdbeSorterWrite(X,Y,Z)   SQLITE_OK
+# define sqlite3VdbeSorterClose(Y,Z)
+# define sqlite3VdbeSorterRowkey(X,Y,Z)  SQLITE_OK
+# define sqlite3VdbeSorterRewind(X,Y,Z)  SQLITE_OK
+# define sqlite3VdbeSorterNext(X,Y,Z)    SQLITE_OK
+#else
 int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);
 int sqlite3VdbeSorterWrite(sqlite3 *, VdbeCursor *, int);
 void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
-
 int sqlite3VdbeSorterRowkey(sqlite3 *, VdbeCursor *, Mem *);
 int sqlite3VdbeSorterRewind(sqlite3 *, VdbeCursor *, int *);
 int sqlite3VdbeSorterNext(sqlite3 *, VdbeCursor *, int *);
+#endif
 
 #if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
   void sqlite3VdbeEnter(Vdbe*);
diff --git a/src/vdbesort.c b/src/vdbesort.c
index e7cb3aae0..0292ea933 100644
--- a/src/vdbesort.c
+++ b/src/vdbesort.c
@@ -18,6 +18,8 @@
 #include "sqliteInt.h"
 #include "vdbeInt.h"
 
+#ifndef SQLITE_OMIT_MERGE_SORT
+
 typedef struct VdbeSorterIter VdbeSorterIter;
 
 /*
@@ -684,3 +686,4 @@ int sqlite3VdbeSorterRowkey(sqlite3 *db, VdbeCursor *pCsr, Mem *pOut){
   return SQLITE_OK;
 }
 
+#endif /* #ifndef SQLITE_OMIT_MERGE_SORT */