Improved comments and function names. No logic changes.

FossilOrigin-Name: 8f460b3b15bf4b88a224907d2f83e4ed6bf84d6b3f480008a1b187ea49c6ce1d

diff --git a/manifest b/manifest
index cf96d243eb779d95d162dd5324544fc8d44ee74b..99d55d9f43337a212263d400dd96b05469ab2e28 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Get\sthe\sindexed\sexpression\soptimization\sworking\sfor\svirtual\sgenerated\scolumns.
-D 2022-10-17T14:30:01.606
+C Improved\scomments\sand\sfunction\snames.\s\sNo\slogic\schanges.
+D 2022-10-17T14:46:39.146
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -569,7 +569,7 @@ F src/date.c 94ce83b4cd848a387680a5f920c9018c16655db778c4d36525af0a0f34679ac5
 F src/dbpage.c 5808e91bc27fa3981b028000f8fadfdc10ce9e59a34ce7dc4e035a69be3906ec
 F src/dbstat.c 861e08690fcb0f2ee1165eff0060ea8d4f3e2ea10f80dab7d32ad70443a6ff2d
 F src/delete.c 86573edae75e3d3e9a8b590d87db8e47222103029df4f3e11fa56044459b514e
-F src/expr.c 4a13a0e5c30be801b0adc295ef74e0f1aa8c041aefdcb5d0d424337ecefa2806
+F src/expr.c ba67701bd7621ebba9c472fcc2dbd4f6444260530e694fa9d87281f9aedec93c
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 722f20779f5342a787922deded3628d8c74b5249cab04098cf17ee2f2aaff002
 F src/func.c fe2a795ad647ce42054873ac91c43beb7b5d204892903a67f6e7e314379b9d4a
@@ -624,7 +624,7 @@ F src/shell.c.in 2915eaf22bda89ad6533851a051de4773c249185360fe1fc7b4477b8f9063b2
 F src/sqlite.h.in d9c8a6243fc0a1c270d69db33758e34b810af3462f9bc5b4af113b347e07c69d
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 5336beea1868d99d2f62e628dbea55e97267dbff8193291ab175e960c5df9141
-F src/sqliteInt.h 2a182a906ac614eb240a68abba8eaf4b018693fd2410ddaa133c08de00507e0a
+F src/sqliteInt.h ed402c12a8b0920ae28cf79631d31490376ca3eed76b386b646712a1dda9e945
 F src/sqliteLimit.h d7323ffea5208c6af2734574bae933ca8ed2ab728083caa117c9738581a31657
 F src/status.c 160c445d7d28c984a0eae38c144f6419311ed3eace59b44ac6dafc20db4af749
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
@@ -706,7 +706,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c b9df133a705093da8977da5eb202eaadb844839f1c7297c08d33471f5491843d
 F src/wal.h c3aa7825bfa2fe0d85bef2db94655f99870a285778baa36307c0a16da32b226a
 F src/walker.c f890a3298418d7cba3b69b8803594fdc484ea241206a8dfa99db6dd36f8cbb3b
-F src/where.c 5d687c1f910b9b52284e0f7881a4d9b0ea9e9902b222dcc38e07a02ebeea3550
+F src/where.c 3ab52180ad3a4eea7a2061bd804850f443298adbdc9264642d0a28affe26fb4c
 F src/whereInt.h 70cd30de9ed784aa33fa6bd1245f060617de7a00d992469b6d8e419eed915743
 F src/wherecode.c 8ec5a413f12af06638dcca36d0954be2151eea6f293d3c67397cef6a90d6adf1
 F src/whereexpr.c bf8c155212c886621d71c951053660de6fcc4ee907b17aa02da0a96a39aa9405
@@ -2033,8 +2033,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 56ef97e64efb84176df570819474901d492209ff80ce4355ff896dea9d2b8a51
-R de79047dd54e7d5b7736aaaf7de5ad42
+P 8a510cb0880349370ad19b0852f270ca072bff7871f0dc272964af31c32a7c37
+R 2b7b8043aec8092eea598ea28e3a1178
 U drh
-Z 08d869d5cc79e1976c4600c81c421785
+Z e241a4932bd8de7b16432b2f0cb5fca6
 # Remove this line to create a well-formed Fossil manifest.

diff --git a/manifest.uuid b/manifest.uuid
index 8e5d83ed475128f082b8a00051a7193335d37f6f..6dd4259d17aa8ac16ab20b4229e711a44ce243aa 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-8a510cb0880349370ad19b0852f270ca072bff7871f0dc272964af31c32a7c37
\ No newline at end of file
+8f460b3b15bf4b88a224907d2f83e4ed6bf84d6b3f480008a1b187ea49c6ce1d
\ No newline at end of file

diff --git a/src/expr.c b/src/expr.c
index 4bff0041194ea3f844e697858ab86bbe76385483..30f9031e212086fcaa83071f6b06ebdfe989f23c 100644 (file)
--- a/src/expr.c
+++ b/src/expr.c
@@ -4044,17 +4044,17 @@ static int exprCodeInlineFunction(
 }
 
 /*
-** Check to see if pExpr is one of the indexed expression on pParse->pIdxExpr.
+** Check to see if pExpr is one of the indexed expressions on pParse->pIdxExpr.
 ** If it is, then resolve the expression by reading from the index and
-** return the register into which the value has been read.  If there is
-** no match, return negative.
+** return the register into which the value has been read.  If pExpr is
+** not an indexed expression, then return negative.
 */
-static SQLITE_NOINLINE int sqlite3ExprIndexLookup(
+static SQLITE_NOINLINE int sqlite3IndexedExprLookup(
   Parse *pParse,   /* The parsing context */
   Expr *pExpr,     /* The expression to potentially bypass */
   int target       /* Where to store the result of the expression */
 ){
-  IndexExpr *p;
+  IndexedExpr *p;
   Vdbe *v;
   for(p=pParse->pIdxExpr; p; p=p->pIENext){
     if( p->iDataCur<0 ) continue;
@@ -4111,7 +4111,7 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
   if( pParse->pIdxExpr!=0 
    && pExpr!=0
    && !ExprHasProperty(pExpr, EP_Leaf)
-   && (r1 = sqlite3ExprIndexLookup(pParse, pExpr, target))>=0
+   && (r1 = sqlite3IndexedExprLookup(pParse, pExpr, target))>=0
   ){
     return r1;
   }

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 8b9bdf474a3e00390880c36096e88215ea8fb3be..0e02db8cc8fce7a534de6e811c0b3447a590c615 100644 (file)
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1189,7 +1189,7 @@ typedef struct FuncDef FuncDef;
 typedef struct FuncDefHash FuncDefHash;
 typedef struct IdList IdList;
 typedef struct Index Index;
-typedef struct IndexExpr IndexExpr;
+typedef struct IndexedExpr IndexedExpr;
 typedef struct IndexSample IndexSample;
 typedef struct KeyClass KeyClass;
 typedef struct KeyInfo KeyInfo;
@@ -2617,7 +2617,8 @@ struct Index {
   unsigned bNoQuery:1;     /* Do not use this index to optimize queries */
   unsigned bAscKeyBug:1;   /* True if the bba7b69f9849b5bf bug applies */
   unsigned bHasVCol:1;     /* Index references one or more VIRTUAL columns */
-  unsigned bHasExpr:1;     /* This is an index on an expression */
+  unsigned bHasExpr:1;     /* Index contains an expression, either a literal
+                           ** expression, or a reference to a VIRTUAL column */
 #ifdef SQLITE_ENABLE_STAT4
   int nSample;             /* Number of elements in aSample[] */
   int nSampleCol;          /* Size of IndexSample.anEq[] and so on */
@@ -3566,21 +3567,22 @@ struct TriggerPrg {
 #endif
 
 /*
-** If there is an index on an expression in scope such that the value
-** of the expression pExpr can be read out of the index with cursor iCur
-** at column iCol, then an instance of this object records that fact.
+** For each index X that has as one of its arguments either an expression
+** or the name of a virtual generated column, and if X is in scope such that
+** the value of the expression can simply be read from the index, then
+** there is an instance of this object on the Parse.pIdxExpr list.
 **
-** A linked list of these objects is attached to Parse and records all
-** expressions that can be short-circuited by extracting a valid from
-** an index.
+** During code generation, while generating code to evaluate expressions,
+** this list is consulted and if a matching expression is found, the value
+** is read from the index rather than being recomputed.
 */
-struct IndexExpr {
+struct IndexedExpr {
   Expr *pExpr;            /* The expression contained in the index */
   int iDataCur;           /* The data cursor associated with the index */
   int iIdxCur;            /* The index cursor */
-  int iIdxCol;            /* The column of the index that contains pExpr */
+  int iIdxCol;            /* The index column that contains value of pExpr */
   u8 bMaybeNullRow;       /* True if we need an OP_IfNullRow check */
-  IndexExpr *pIENext;     /* Next in a list of all indexed expressions */
+  IndexedExpr *pIENext;   /* Next in a list of all indexed expressions */
 };
 
 /*
@@ -3641,7 +3643,7 @@ struct Parse {
   int nLabelAlloc;     /* Number of slots in aLabel */
   int *aLabel;         /* Space to hold the labels */
   ExprList *pConstExpr;/* Constant expressions */
-  IndexExpr *pIdxExpr; /* List of all expression in active indexes */
+  IndexedExpr *pIdxExpr;/* List of expressions used by active indexes */
   Token constraintName;/* Name of the constraint currently being parsed */
   yDbMask writeMask;   /* Start a write transaction on these databases */
   yDbMask cookieMask;  /* Bitmask of schema verified databases */

diff --git a/src/where.c b/src/where.c
index 32daa6e80ea6f6602505665efe1956f9341c1ab8..39bbf7d64cddb2b4c3b09bdffa5ae84d394bf117 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -5384,10 +5384,10 @@ static SQLITE_NOINLINE void whereCheckIfBloomFilterIsUseful(
 ** This is an sqlite3ParserAddCleanup() callback that is invoked to
 ** free the Parse->pIdxExpr list when the Parse object is destroyed.
 */
-static void whereIndexExprCleanup(sqlite3 *db, void *pObject){
+static void whereIndexedExprCleanup(sqlite3 *db, void *pObject){
   Parse *pParse = (Parse*)pObject;
   while( pParse->pIdxExpr!=0 ){
-    IndexExpr *p = pParse->pIdxExpr;
+    IndexedExpr *p = pParse->pIdxExpr;
     pParse->pIdxExpr = p->pIENext;
     sqlite3ExprDelete(db, p->pExpr);
     sqlite3DbFreeNN(db, p);
@@ -5400,19 +5400,19 @@ static void whereIndexExprCleanup(sqlite3 *db, void *pObject){
 ** number for the index and iDataCur is the cursor number for the corresponding
 ** table.
 **
-** This routine adds IndexExpr entries to the Parse->pIdxExpr field for
+** This routine adds IndexedExpr entries to the Parse->pIdxExpr field for
 ** each of the expressions in the index so that the expression code generator
 ** will know to replace occurrences of the indexed expression with
 ** references to the corresponding column of the index.
 */
-static SQLITE_NOINLINE void whereAddIndexExpr(
-  Parse *pParse,     /* Add IndexExpr entries to pParse->pIdxExpr */
+static SQLITE_NOINLINE void whereAddIndexedExpr(
+  Parse *pParse,     /* Add IndexedExpr entries to pParse->pIdxExpr */
   Index *pIdx,       /* The index-on-expression that contains the expressions */
   int iIdxCur,       /* Cursor number for pIdx */
   SrcItem *pTabItem  /* The FROM clause entry for the table */
 ){
   int i;
-  IndexExpr *p;
+  IndexedExpr *p;
   Table *pTab;
   assert( pIdx->bHasExpr );
   pTab = pIdx->pTable;
@@ -5426,7 +5426,7 @@ static SQLITE_NOINLINE void whereAddIndexExpr(
     }else{
       continue;
     }
-    p = sqlite3DbMallocRaw(pParse->db,  sizeof(IndexExpr));
+    p = sqlite3DbMallocRaw(pParse->db,  sizeof(IndexedExpr));
     if( p==0 ) break;
     p->pIENext = pParse->pIdxExpr;
     p->pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
@@ -5436,7 +5436,7 @@ static SQLITE_NOINLINE void whereAddIndexExpr(
     p->bMaybeNullRow = (pTabItem->fg.jointype & (JT_LEFT|JT_LTORJ))!=0;
     pParse->pIdxExpr = p;
     if( p->pIENext==0 ){
-      sqlite3ParserAddCleanup(pParse, whereIndexExprCleanup, pParse);
+      sqlite3ParserAddCleanup(pParse, whereIndexedExprCleanup, pParse);
     }
   }
 }
@@ -5987,7 +5987,7 @@ WhereInfo *sqlite3WhereBegin(
       }else{
         iIndexCur = pParse->nTab++;
         if( pIx->bHasExpr ){
-          whereAddIndexExpr(pParse, pIx, iIndexCur, pTabItem);
+          whereAddIndexedExpr(pParse, pIx, iIndexCur, pTabItem);
         }
       }
       pLevel->iIdxCur = iIndexCur;
@@ -6386,7 +6386,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
         last = pWInfo->iEndWhere;
       }
       if( pIdx->bHasExpr ){
-        IndexExpr *p = pParse->pIdxExpr;
+        IndexedExpr *p = pParse->pIdxExpr;
         while( p ){
           if( p->iIdxCur==pLevel->iIdxCur ){
             p->iDataCur = -1;