Improved comments. Fewer opcodes for integrity_check on strict tables.

FossilOrigin-Name: 4ee57fb588b41ab76649c605f57c7bcf5b7b638435af458d69f69a8ccbb121e8

1 files changed, 34 insertions, 10 deletions

diff --git a/src/insert.c b/src/insert.c
index 1148257ad..9617e54e7 100644
--- a/src/insert.c
+++ b/src/insert.c
@@ -110,24 +110,44 @@ const char *sqlite3IndexAffinityStr(sqlite3 *db, Index *pIdx){
 }
 
 /*
+** Make changes to the evolving bytecode to do affinity transformations
+** of values that are about to be gathered into a row for table pTab.
+**
+** For ordinary (legacy, non-strict) tables:
+** -----------------------------------------
+**
 ** Compute the affinity string for table pTab, if it has not already been
 ** computed.  As an optimization, omit trailing SQLITE_AFF_BLOB affinities.
 **
-** If the affinity exists (if it is not entirely SQLITE_AFF_BLOB values) and
-** if iReg>0 then code an OP_Affinity opcode that will set the affinities
-** for register iReg and following.  Or if affinities exists and iReg==0,
+** If the affinity string is empty (because it was all SQLITE_AFF_BLOB entries
+** which were then optimized out) then this routine becomes a no-op.
+**
+** Otherwise if iReg>0 then code an OP_Affinity opcode that will set the
+** affinities for register iReg and following.  Or if iReg==0,
 ** then just set the P4 operand of the previous opcode (which should  be
 ** an OP_MakeRecord) to the affinity string.
 **
 ** A column affinity string has one character per column:
 **
-**  Character      Column affinity
-**  ------------------------------
-**  'A'            BLOB
-**  'B'            TEXT
-**  'C'            NUMERIC
-**  'D'            INTEGER
-**  'E'            REAL
+**    Character      Column affinity
+**    ---------      ---------------
+**    'A'            BLOB
+**    'B'            TEXT
+**    'C'            NUMERIC
+**    'D'            INTEGER
+**    'E'            REAL
+**
+** For STRICT tables:
+** ------------------
+**
+** Generate an appropropriate OP_TypeCheck opcode that will verify the
+** datatypes against the column definitions in pTab.  If iReg==0, that
+** means an OP_MakeRecord opcode has already been generated and should be
+** the last opcode generated.  The new OP_TypeCheck needs to be inserted
+** before the OP_MakeRecord.  The new OP_TypeCheck should use the same
+** register set as the OP_MakeRecord.  If iReg>0 then register iReg is
+** the first of a series of registers that will form the new record.
+** Apply the type checking to that array of registers.
 */
 void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
   int i, j;
@@ -140,6 +160,8 @@ void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
       VdbeOp *pPrev;
       sqlite3VdbeAppendP4(v, pTab, P4_TABLE);
       pPrev = sqlite3VdbeGetOp(v, -1);
+      assert( pPrev!=0 );
+      assert( pPrev->opcode==OP_MakeRecord || sqlite3VdbeDb(v)->mallocFailed );
       pPrev->opcode = OP_TypeCheck;
       sqlite3VdbeAddOp3(v, OP_MakeRecord, pPrev->p1, pPrev->p2, pPrev->p3);
     }else{
@@ -175,6 +197,8 @@ void sqlite3TableAffinity(Vdbe *v, Table *pTab, int iReg){
     if( iReg ){
       sqlite3VdbeAddOp4(v, OP_Affinity, iReg, i, 0, zColAff, i);
     }else{
+      assert( sqlite3VdbeGetOp(v, -1)->opcode==OP_MakeRecord
+              || sqlite3VdbeDb(v)->mallocFailed );
       sqlite3VdbeChangeP4(v, -1, zColAff, i);
     }
   }