Changes to the INSERT logic to make it simpler and faster and so that

it works with generated columns and BEFORE triggers.

FossilOrigin-Name: bc368cb090376d33d3844e3689c4f6bd19eed758e39b878ee67fef93b1c839ea

4 files changed, 115 insertions, 122 deletions

diff --git a/src/build.c b/src/build.c
index c688a68e0..4501d41d4 100644
--- a/src/build.c
+++ b/src/build.c
@@ -2329,7 +2329,7 @@ void sqlite3EndTable(
       pSelTab = sqlite3ResultSetOfSelect(pParse, pSelect, SQLITE_AFF_BLOB);
       if( pSelTab==0 ) return;
       assert( p->aCol==0 );
-      p->nCol = pSelTab->nCol;
+      p->nCol = p->nNVCol = pSelTab->nCol;
       p->aCol = pSelTab->aCol;
       pSelTab->nCol = 0;
       pSelTab->aCol = 0;
@@ -2617,7 +2617,7 @@ int sqlite3ViewGetColumnNames(Parse *pParse, Table *pTable){
       ** the column names from the SELECT statement that defines the view.
       */
       assert( pTable->aCol==0 );
-      pTable->nCol = pSelTab->nCol;
+      pTable->nCol = pTable->nNVCol = pSelTab->nCol;
       pTable->aCol = pSelTab->aCol;
       pSelTab->nCol = 0;
       pSelTab->aCol = 0;
diff --git a/src/expr.c b/src/expr.c
index b868ed969..1c562fdf5 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -4337,14 +4337,10 @@ void sqlite3ExprCode(Parse *pParse, Expr *pExpr, int target){
   int inReg;
 
   assert( target>0 && target<=pParse->nMem );
-  if( pExpr && pExpr->op==TK_REGISTER ){
-    sqlite3VdbeAddOp2(pParse->pVdbe, OP_Copy, pExpr->iTable, target);
-  }else{
-    inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
-    assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
-    if( inReg!=target && pParse->pVdbe ){
-      sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
-    }
+  inReg = sqlite3ExprCodeTarget(pParse, pExpr, target);
+  assert( pParse->pVdbe!=0 || pParse->db->mallocFailed );
+  if( inReg!=target && pParse->pVdbe ){
+    sqlite3VdbeAddOp2(pParse->pVdbe, OP_SCopy, inReg, target);
   }
 }
 
@@ -4375,30 +4371,6 @@ void sqlite3ExprCodeFactorable(Parse *pParse, Expr *pExpr, int target){
 }
 
 /*
-** Generate code that evaluates the given expression and puts the result
-** in register target.
-**
-** Also make a copy of the expression results into another "cache" register
-** and modify the expression so that the next time it is evaluated,
-** the result is a copy of the cache register.
-**
-** This routine is used for expressions that are used multiple 
-** times.  They are evaluated once and the results of the expression
-** are reused.
-*/
-void sqlite3ExprCodeAndCache(Parse *pParse, Expr *pExpr, int target){
-  Vdbe *v = pParse->pVdbe;
-  int iMem;
-
-  assert( target>0 );
-  assert( pExpr->op!=TK_REGISTER );
-  sqlite3ExprCode(pParse, pExpr, target);
-  iMem = ++pParse->nMem;
-  sqlite3VdbeAddOp2(v, OP_Copy, target, iMem);
-  exprToRegister(pExpr, iMem);
-}
-
-/*
 ** Generate code that pushes the value of every element of the given
 ** expression list into a sequence of registers beginning at target.
 **
diff --git a/src/insert.c b/src/insert.c
index 7eba08e95..8640a77b6 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -561,7 +561,7 @@ void sqlite3Insert(
   Parse *pParse,        /* Parser context */
   SrcList *pTabList,    /* Name of table into which we are inserting */
   Select *pSelect,      /* A SELECT statement to use as the data source */
-  IdList *pColumn,      /* Column names corresponding to IDLIST. */
+  IdList *pColumn,      /* Column names corresponding to IDLIST, or NULL. */
   int onError,          /* How to handle constraint errors */
   Upsert *pUpsert       /* ON CONFLICT clauses for upsert, or NULL */
 ){
@@ -694,8 +694,8 @@ void sqlite3Insert(
   */
   regAutoinc = autoIncBegin(pParse, iDb, pTab);
 
-  /* Allocate registers for holding the rowid of the new row,
-  ** the content of the new row, and the assembled row record.
+  /* Allocate a block registers to hold the rowid and the values
+  ** for all columns of the new row.
   */
   regRowid = regIns = pParse->nMem+1;
   pParse->nMem += pTab->nCol + 1;
@@ -714,7 +714,15 @@ void sqlite3Insert(
   ** the index into IDLIST of the primary key column.  ipkColumn is
   ** the index of the primary key as it appears in IDLIST, not as
   ** is appears in the original table.  (The index of the INTEGER
-  ** PRIMARY KEY in the original table is pTab->iPKey.)
+  ** PRIMARY KEY in the original table is pTab->iPKey.)  After this
+  ** loop, if ipkColumn==(-1), that means that integer primary key
+  ** is unspecified, and hence the table is either WITHOUT ROWID or
+  ** it will automatically generated an integer primary key.
+  **
+  ** bIdListInOrder is true if the columns in IDLIST are in storage
+  ** order.  This enables an optimization that avoids shuffling the
+  ** columns into storage order.  False negatives are harmless,
+  ** but false positives will cause database corruption.
   */
   bIdListInOrder = (pTab->tabFlags & (TF_OOOHidden|TF_HasStored))==0;
   if( pColumn ){
@@ -937,8 +945,88 @@ void sqlite3Insert(
     */
     addrInsTop = addrCont = sqlite3VdbeAddOp1(v, OP_Yield, dest.iSDParm);
     VdbeCoverage(v);
+    if( ipkColumn>=0 ){
+      /* tag-20191021-001: If the INTEGER PRIMARY KEY is being generated by the
+      ** SELECT, go ahead and copy the value into the rowid slot now, so that
+      ** the value does not get overwritten by a NULL at tag-20191021-002. */
+      sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
+    }
   }
 
+  /* Compute data for ordinary columns of the new entry.  Values
+  ** are written in storage order into registers starting with regData.
+  ** Only ordinary columns are computed in this loop. The rowid
+  ** (if there is one) is computed later and generated columns are
+  ** computed after the rowid since they might depend on the value
+  ** of the rowid.
+  */
+  nHidden = 0;
+  iRegStore = regData;  assert( regData==regRowid+1 );
+  for(i=0; i<pTab->nCol; i++, iRegStore++){
+    int k;
+    u32 colFlags;
+    assert( i>=nHidden );
+    if( i==pTab->iPKey ){
+      /* tag-20191021-002: References to the INTEGER PRIMARY KEY are filled
+      ** using the rowid. So put a NULL in the IPK slot of the record to avoid
+      ** using excess space.  The file format definition requires this extra
+      ** NULL - we cannot optimize further by skipping the column completely */
+      sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
+      continue;
+    }
+    if( ((colFlags = pTab->aCol[i].colFlags) & COLFLAG_NOINSERT)!=0 ){
+      nHidden++;
+      if( (colFlags & COLFLAG_VIRTUAL)!=0 ){
+        /* Virtual columns do not participate in OP_MakeRecord.  So back up
+        ** iRegStore by one slot to compensate for the iRegStore++ in the
+        ** outer for() loop */
+        iRegStore--;
+        continue;
+      }else if( (colFlags & COLFLAG_STORED)!=0 ){
+        /* Stored columns are computed later.  But if there are BEFORE
+        ** triggers, the slots used for stored columns will be OP_Copy-ed
+        ** to a second block of registers, so the register needs to be
+        ** initialized to NULL to avoid an uninitialized register read */
+        if( tmask & TRIGGER_BEFORE ){
+          sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
+        }
+        continue;
+      }else if( pColumn==0 ){
+        /* Hidden columns that are not explicitly named in the INSERT
+        ** get there default value */
+        sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
+        continue;
+      }
+    }
+    if( pColumn ){
+      for(j=0; j<pColumn->nId && pColumn->a[j].idx!=i; j++){}
+      if( j>=pColumn->nId ){
+        /* A column not named in the insert column list gets its
+        ** default value */
+        sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
+        continue;
+      }
+      k = j;
+    }else if( nColumn==0 ){
+      /* This is INSERT INTO ... DEFAULT VALUES.  Load the default value. */
+      sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
+      continue;
+    }else{
+      k = i - nHidden;
+    }
+
+    if( useTempTable ){
+      sqlite3VdbeAddOp3(v, OP_Column, srcTab, k, iRegStore); 
+    }else if( pSelect ){
+      if( regFromSelect!=regData ){
+        sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+k, iRegStore);
+      }
+    }else{
+      sqlite3ExprCode(pParse, pList->a[k].pExpr, iRegStore);
+    }
+  }
+
+
   /* Run the BEFORE and INSTEAD OF triggers, if there are any
   */
   endOfLoop = sqlite3VdbeMakeLabel(pParse);
@@ -973,25 +1061,19 @@ void sqlite3Insert(
     */
     assert( !IsVirtual(pTab) );
 
-    /* Create the new column data
-    */
-    for(i=j=0; i<pTab->nCol; i++){
-      if( pColumn ){
-        for(j=0; j<pColumn->nId; j++){
-          if( pColumn->a[j].idx==i ) break;
-        }
-      }
-      if( (!useTempTable && !pList) || (pColumn && j>=pColumn->nId)
-            || (pColumn==0 && IsOrdinaryHiddenColumn(&pTab->aCol[i])) ){
-        sqlite3ExprCode(pParse, pTab->aCol[i].pDflt, regCols+i+1);
-      }else if( useTempTable ){
-        sqlite3VdbeAddOp3(v, OP_Column, srcTab, j, regCols+i+1); 
-      }else{
-        assert( pSelect==0 ); /* Otherwise useTempTable is true */
-        sqlite3ExprCodeAndCache(pParse, pList->a[j].pExpr, regCols+i+1);
-      }
-      if( pColumn==0 && !IsOrdinaryHiddenColumn(&pTab->aCol[i]) ) j++;
+    /* Copy the new data already generated. */
+    assert( pTab->nNVCol>0 );
+    sqlite3VdbeAddOp3(v, OP_Copy, regRowid+1, regCols+1, pTab->nNVCol-1);
+
+#ifndef SQLITE_OMIT_GENERATED_COLUMNS
+    /* Compute the new value for generated columns after all other
+    ** columns have already been computed.  This must be done after
+    ** computing the ROWID in case one of the generated columns
+    ** refers to the ROWID. */
+    if( pTab->tabFlags & (TF_HasStored|TF_HasVirtual) ){
+      sqlite3ComputeGeneratedColumns(pParse, regCols+1, pTab);
     }
+#endif
 
     /* If this is an INSERT on a view with an INSTEAD OF INSERT trigger,
     ** do not attempt any conversions before assembling the record.
@@ -1009,19 +1091,17 @@ void sqlite3Insert(
     sqlite3ReleaseTempRange(pParse, regCols, pTab->nCol+1);
   }
 
-  /* Compute the content of the next row to insert into a range of
-  ** registers beginning at regIns.
-  */
   if( !isView ){
     if( IsVirtual(pTab) ){
       /* The row that the VUpdate opcode will delete: none */
       sqlite3VdbeAddOp2(v, OP_Null, 0, regIns);
     }
     if( ipkColumn>=0 ){
+      /* Compute the new rowid */
       if( useTempTable ){
         sqlite3VdbeAddOp3(v, OP_Column, srcTab, ipkColumn, regRowid);
       }else if( pSelect ){
-        sqlite3VdbeAddOp2(v, OP_Copy, regFromSelect+ipkColumn, regRowid);
+        /* Rowid already initialized at tag-20191021-001 */
       }else{
         Expr *pIpk = pList->a[ipkColumn].pExpr;
         if( pIpk->op==TK_NULL && !IsVirtual(pTab) ){
@@ -1054,69 +1134,11 @@ void sqlite3Insert(
     }
     autoIncStep(pParse, regAutoinc, regRowid);
 
-    /* Compute data for all columns of the new entry, beginning
-    ** with the first column.
-    */
-    nHidden = 0;
-    iRegStore = regRowid+1;
-    for(i=0; i<pTab->nCol; i++, iRegStore++){
-      int k;
-      u32 colFlags;
-      assert( i>=nHidden );
-      if( i==pTab->iPKey ){
-        /* The value of the INTEGER PRIMARY KEY column is always a NULL.
-        ** Whenever this column is read, the rowid will be substituted
-        ** in its place.  Hence, fill this column with a NULL to avoid
-        ** taking up data space with information that will never be used.
-        ** As there may be shallow copies of this value, make it a soft-NULL */
-        sqlite3VdbeAddOp1(v, OP_SoftNull, iRegStore);
-        continue;
-      }
-      if( ((colFlags = pTab->aCol[i].colFlags) & COLFLAG_NOINSERT)!=0 ){
-        nHidden++;
-        if( (colFlags & COLFLAG_VIRTUAL)!=0 ){
-          /* Virtual columns are no stored */
-          iRegStore--;
-          continue;
-        }else if( (colFlags & COLFLAG_STORED)!=0 ){
-          /* Stored columns are handled on the second pass */
-          continue;
-        }else if( pColumn==0 ){
-          /* Hidden columns that are not explicitly named in the INSERT */
-          sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
-          continue;
-        }
-      }
-      if( pColumn ){
-        for(j=0; j<pColumn->nId && pColumn->a[j].idx!=i; j++){}
-        if( j>=pColumn->nId ){
-          /* A column not named in the insert column list gets its
-          ** default value */
-          sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
-          continue;
-        }
-        k = j;
-      }else if( nColumn==0 ){
-        sqlite3ExprCodeFactorable(pParse, pTab->aCol[i].pDflt, iRegStore);
-        continue;
-      }else{
-        k = i - nHidden;
-      }
-
-      if( useTempTable ){
-        sqlite3VdbeAddOp3(v, OP_Column, srcTab, k, iRegStore); 
-      }else if( pSelect ){
-        if( regFromSelect!=regData ){
-          sqlite3VdbeAddOp2(v, OP_SCopy, regFromSelect+k, iRegStore);
-        }
-      }else{
-        sqlite3ExprCode(pParse, pList->a[k].pExpr, iRegStore);
-      }
-    }
-
 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
     /* Compute the new value for generated columns after all other
-    ** columns have already been computed */
+    ** columns have already been computed.  This must be done after
+    ** computing the ROWID in case one of the generated columns
+    ** refers to the ROWID. */
     if( pTab->tabFlags & (TF_HasStored|TF_HasVirtual) ){
       sqlite3ComputeGeneratedColumns(pParse, regRowid+1, pTab);
     }
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 00013bd17..e586674f9 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -4100,7 +4100,6 @@ void sqlite3ExprCodeFactorable(Parse*, Expr*, int);
 int sqlite3ExprCodeAtInit(Parse*, Expr*, int);
 int sqlite3ExprCodeTemp(Parse*, Expr*, int*);
 int sqlite3ExprCodeTarget(Parse*, Expr*, int);
-void sqlite3ExprCodeAndCache(Parse*, Expr*, int);
 int sqlite3ExprCodeExprList(Parse*, ExprList*, int, int, u8);
 #define SQLITE_ECEL_DUP      0x01  /* Deep, not shallow copies */
 #define SQLITE_ECEL_FACTOR   0x02  /* Factor out constant terms */