Attempt to parse the NULLS LAST clause more efficiently. A few cycles were

saved, but at the expense of more code.  And there is a bug was introduced
somewhere.  Not worth continuing down this line.

FossilOrigin-Name: 12d2cf88714d8b61a0c6a0733406436100d84671d7aa7229eb9d815b0eeb77a1

diff --git a/manifest b/manifest
index 7dcd24ab83e6c70d1c90aec66244dd0636ca1c1d..b45cc39be6f87eefc50b4c0177789124048659a5 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Move\ssome\sthings\sin\sparse.y\sso\sthat\sTK_COLUMN\sand\sTK_AGG_COLUMN\sare\sassigned\sthe\ssame\svalues\sas\sthey\sare\son\strunk\sfor\sa\svery\ssmall\sspeedup.
-D 2019-08-23T20:33:01.837
+C Attempt\sto\sparse\sthe\sNULLS\sLAST\sclause\smore\sefficiently.\s\sA\sfew\scycles\swere\nsaved,\sbut\sat\sthe\sexpense\sof\smore\scode.\s\sAnd\sthere\sis\sa\sbug\swas\sintroduced\nsomewhere.\s\sNot\sworth\scontinuing\sdown\sthis\sline.
+D 2019-08-23T21:11:11.924
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -467,7 +467,7 @@ F src/btmutex.c 8acc2f464ee76324bf13310df5692a262b801808984c1b79defb2503bbafadb6
 F src/btree.c 5cf994516c1b74928b9d15971573a8bc8595e1afec129184099976da603402de
 F src/btree.h c11446f07ec0e9dc85af8041cb0855c52f5359c8b2a43e47e02a685282504d89
 F src/btreeInt.h 6111c15868b90669f79081039d19e7ea8674013f907710baa3c814dc3f8bfd3f
-F src/build.c da5d5d82eb53cb004e9120277cfe93a9c3dd294871eae3d728ebd0faee84d969
+F src/build.c 86827bdbc275ade579e778e2d430c252659fffa25ea88f45884cbe5d32f36de2
 F src/callback.c 25dda5e1c2334a367b94a64077b1d06b2553369f616261ca6783c48bcb6bda73
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 1b0724e66f95f33b160b1af85caaf9cceb325d22abf39bd24df4f54a73982251
@@ -475,7 +475,7 @@ F src/date.c e1d8ac7102f3f283e63e13867acb0efa33861cf34f0faf4cdbaf9fa7a1eb7041
 F src/dbpage.c 135eb3b5e74f9ef74bde5cec2571192c90c86984fa534c88bf4a055076fa19b7
 F src/dbstat.c c12833de69cb655751487d2c5a59607e36be1c58ba1f4bd536609909ad47b319
 F src/delete.c d08c9e01a2664afd12edcfa3a9c6578517e8ff8735f35509582693adbe0edeaf
-F src/expr.c e5f0cf649eb1477c7a57c9e30516aeead9d9d3f8229f4bbf782365665eb0f556
+F src/expr.c 1ed0847f4842c56a2f18e9b096526297b85fdb7b7c058e59ac77dc4cec621b4a
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 6b79f4c2447691aa9ac86e2a6a774b65f3b3dd053d4220a4893051a0de20f82e
 F src/func.c 4ee36219698d50d672a28eca4adb0fd6b92e607a1883d318315e0d2fd5044467
@@ -512,7 +512,7 @@ F src/os_win.c 035a813cbd17f355bdcad7ab894af214a9c13a1db8aeac902365350b98cd45a7
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
 F src/pager.c 422fd8cfa59fb9173eff36a95878904a0eeb0dcc62ba49350acc8b1e51c4dc7b
 F src/pager.h 217921e81eb5fe455caa5cda96061959706bcdd29ddb57166198645ef7822ac3
-F src/parse.y d127bf3f79f9f5baccfdfa00c7898df3eafa027ac58c35fd673bf81b008b2374
+F src/parse.y 1e469e2b5164d38ae3356314616fb5dcde840732cae4250e83e56082904683c8
 F src/pcache.c 385ff064bca69789d199a98e2169445dc16e4291fa807babd61d4890c3b34177
 F src/pcache.h 4f87acd914cef5016fae3030343540d75f5b85a1877eed1a2a19b9f284248586
 F src/pcache1.c 62714cbd1b7299a6e6a27a587b66b4fd3a836a84e1181e7f96f5c34a50917848
@@ -528,7 +528,7 @@ F src/shell.c.in e0f0758b6ab506d8ab12502fd2b8c55546bb9e4bb772374344a5a1b73f5bc2b
 F src/sqlite.h.in 50fc0914ccd347437db9a0278a47d7541df3a45eb6e641e9680750c6f98dad27
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h cef696ce3293242c67b2339763608427bf72ee66f1f3a05389ac2a7b46001c31
-F src/sqliteInt.h 6c5293a35a4377e3dcce476e86f6d023328d1e770d2943c4cf260131a3e0d175
+F src/sqliteInt.h f5a9c61f976a171654f429e4dac452b27a40a4250148d14a7ca3a918a4d9b31b
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
 F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
@@ -1837,7 +1837,11 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P bfe793780fa6fc7a1e7d0ee60606dda272985de9573887dca118e9510fc609f2
-R 65f7f5b095c6143834951d2d50e30b05
-U dan
-Z 741541dbd05afd6dd401231ece81d5cb
+P d26fdfa3bc5f8d9c4a6000462080b0dd508e5cae9a83e0d126be48195224da8c
+R e3fe5b60b5f6618296725ebf365cf8d1
+T *branch * dead-end
+T *sym-dead-end *
+T +closed *
+T -sym-nulls-last *
+U drh
+Z d85e52aacc1f69d8551de2fefb926b64

diff --git a/manifest.uuid b/manifest.uuid
index 130c1ae43339b274c427cf99c7d2f40a645e0f96..545c51ca516afc7936a6bdda2a18619cb2eae35c 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d26fdfa3bc5f8d9c4a6000462080b0dd508e5cae9a83e0d126be48195224da8c
\ No newline at end of file
+12d2cf88714d8b61a0c6a0733406436100d84671d7aa7229eb9d815b0eeb77a1
\ No newline at end of file

diff --git a/src/build.c b/src/build.c
index 106b995d31ad4abfd000c7d0e9d61f35117058f9..ad9ae6a05b9aeaee994a091dce03925f8ea71e81 100644 (file)
--- a/src/build.c
+++ b/src/build.c
@@ -3162,10 +3162,11 @@ int sqlite3HasExplicitNulls(Parse *pParse, ExprList *pList){
   if( pList ){
     int i;
     for(i=0; i<pList->nExpr; i++){
-      if( pList->a[i].bNulls ){
-        u8 sf = pList->a[i].sortFlags;
+      u8 sf = pList->a[i].sortFlags;
+      if( sf & (SQLITE_SO_BIGNULL|SQLITE_SO_SMALLNULL) ){
         sqlite3ErrorMsg(pParse, "unsupported use of NULLS %s", 
-            (sf==0 || sf==3) ? "FIRST" : "LAST"
+            (sf & SQLITE_SO_BIGNULL)==(sf & SQLITE_SO_DESC) ?
+                "FIRST" : "LAST"
         );
         return 1;
       }
@@ -3392,7 +3393,7 @@ void sqlite3CreateIndex(
               sqlite3ExprAlloc(db, TK_ID, &prevCol, 0));
     if( pList==0 ) goto exit_create_index;
     assert( pList->nExpr==1 );
-    sqlite3ExprListSetSortOrder(pList, sortOrder, SQLITE_SO_UNDEFINED);
+    sqlite3ExprListSetSortOrder(pList, sortOrder);
   }else{
     sqlite3ExprListCheckLength(pParse, pList, "index");
     if( pParse->nErr ) goto exit_create_index;

diff --git a/src/expr.c b/src/expr.c
index d19ee92a0d2a4288eb766baa38477eb6356d6684..a4a93b0a0a8232e67ef0323dcca7d7175a977689 100644 (file)
--- a/src/expr.c
+++ b/src/expr.c
@@ -1413,7 +1413,6 @@ ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
     pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
     pItem->sortFlags = pOldItem->sortFlags;
     pItem->done = 0;
-    pItem->bNulls = pOldItem->bNulls;
     pItem->bSpanIsTab = pOldItem->bSpanIsTab;
     pItem->bSorterRef = pOldItem->bSorterRef;
     pItem->u = pOldItem->u;
@@ -1665,34 +1664,15 @@ vector_append_error:
 /*
 ** Set the sort order for the last element on the given ExprList.
 */
-void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder, int eNulls){
+void sqlite3ExprListSetSortOrder(ExprList *p, int iSortOrder){
   struct ExprList_item *pItem;
   if( p==0 ) return;
   assert( p->nExpr>0 );
-
-  assert( SQLITE_SO_UNDEFINED<0 && SQLITE_SO_ASC==0 && SQLITE_SO_DESC>0 );
-  assert( iSortOrder==SQLITE_SO_UNDEFINED 
-       || iSortOrder==SQLITE_SO_ASC 
-       || iSortOrder==SQLITE_SO_DESC 
-  );
-  assert( eNulls==SQLITE_SO_UNDEFINED 
-       || eNulls==SQLITE_SO_ASC 
-       || eNulls==SQLITE_SO_DESC 
-  );
+  assert( SQLITE_SO_DESC==KEYINFO_ORDER_DESC );
+  assert( SQLITE_SO_BIGNULL==KEYINFO_ORDER_BIGNULL );
 
   pItem = &p->a[p->nExpr-1];
-  assert( pItem->bNulls==0 );
-  if( iSortOrder==SQLITE_SO_UNDEFINED ){
-    iSortOrder = SQLITE_SO_ASC;
-  }
   pItem->sortFlags = (u8)iSortOrder;
-
-  if( eNulls!=SQLITE_SO_UNDEFINED ){
-    pItem->bNulls = 1;
-    if( iSortOrder!=eNulls ){
-      pItem->sortFlags |= KEYINFO_ORDER_BIGNULL;
-    }
-  }
 }
 
 /*

diff --git a/src/parse.y b/src/parse.y
index 92be672a3178a77ffd0c9629bb913a08f6a67f22..5800ee7c61f9ee277e11cd929add822615663db2 100644 (file)
--- a/src/parse.y
+++ b/src/parse.y
@@ -782,25 +782,26 @@ using_opt(U) ::= .                        {U = 0;}
 
 orderby_opt(A) ::= .                          {A = 0;}
 orderby_opt(A) ::= ORDER BY sortlist(X).      {A = X;}
-sortlist(A) ::= sortlist(A) COMMA expr(Y) sortorder(Z) nulls(X). {
+sortlist(A) ::= sortlist(A) COMMA expr(Y) sortorder(Z). {
   A = sqlite3ExprListAppend(pParse,A,Y);
-  sqlite3ExprListSetSortOrder(A,Z,X);
+  sqlite3ExprListSetSortOrder(A,Z);
 }
-sortlist(A) ::= expr(Y) sortorder(Z) nulls(X). {
+sortlist(A) ::= expr(Y) sortorder(Z). {
   A = sqlite3ExprListAppend(pParse,0,Y); /*A-overwrites-Y*/
-  sqlite3ExprListSetSortOrder(A,Z,X);
+  sqlite3ExprListSetSortOrder(A,Z);
 }
 
 %type sortorder {int}
 
-sortorder(A) ::= ASC.           {A = SQLITE_SO_ASC;}
-sortorder(A) ::= DESC.          {A = SQLITE_SO_DESC;}
-sortorder(A) ::= .              {A = SQLITE_SO_UNDEFINED;}
-
-%type nulls {int}
-nulls(A) ::= NULLS FIRST.       {A = SQLITE_SO_ASC;}
-nulls(A) ::= NULLS LAST.        {A = SQLITE_SO_DESC;}
-nulls(A) ::= .                  {A = SQLITE_SO_UNDEFINED;}
+sortorder(A) ::= ASC.               {A = SQLITE_SO_XASC;}
+sortorder(A) ::= ASC NULLS FIRST.   {A = SQLITE_SO_XASC|SQLITE_SO_SMALLNULL;}
+sortorder(A) ::= ASC NULLS LAST.    {A = SQLITE_SO_XASC|SQLITE_SO_BIGNULL;}
+sortorder(A) ::= DESC.              {A = SQLITE_SO_DESC;}
+sortorder(A) ::= DESC NULLS FIRST.  {A = SQLITE_SO_DESC|SQLITE_SO_BIGNULL;}
+sortorder(A) ::= DESC NULLS LAST.   {A = SQLITE_SO_DESC|SQLITE_SO_SMALLNULL;}
+sortorder(A) ::= .                  {A = SQLITE_SO_ASC;}
+sortorder(A) ::= NULLS FIRST.       {A = SQLITE_SO_XASC|SQLITE_SO_SMALLNULL;}
+sortorder(A) ::= NULLS LAST.        {A = SQLITE_SO_XASC|SQLITE_SO_BIGNULL;}
 
 %type groupby_opt {ExprList*}
 %destructor groupby_opt {sqlite3ExprListDelete(pParse->db, $$);}
@@ -1347,7 +1348,7 @@ uniqueflag(A) ::= .        {A = OE_None;}
     int sortOrder
   ){
     ExprList *p = sqlite3ExprListAppend(pParse, pPrior, 0);
-    if( (hasCollate || sortOrder!=SQLITE_SO_UNDEFINED)
+    if( (hasCollate || sortOrder!=SQLITE_SO_ASC)
         && pParse->db->init.busy==0
     ){
       sqlite3ErrorMsg(pParse, "syntax error after column name \"%.*s\"",

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index b2e17c40b77552a5db1d1b69dc8607f634fca9d3..d135058a7babd953c38074bf7a5fe71aa7fc82cb 100644 (file)
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1847,9 +1847,11 @@ struct CollSeq {
 /*
 ** A sort order can be either ASC or DESC.
 */
-#define SQLITE_SO_ASC       0  /* Sort in ascending order */
-#define SQLITE_SO_DESC      1  /* Sort in ascending order */
-#define SQLITE_SO_UNDEFINED -1 /* No sort order specified */
+#define SQLITE_SO_ASC       0  /* Sort in ascending order by default */
+#define SQLITE_SO_DESC      1  /* Sort in descending order */
+#define SQLITE_SO_BIGNULL   2  /* NULLs larger than all other values */
+#define SQLITE_SO_SMALLNULL 4  /* NULLs smaller, explicitly stated */
+#define SQLITE_SO_XASC      8  /* Actually holds the ASC keyword */
 
 /*
 ** Column affinity types.
@@ -2610,7 +2612,6 @@ struct ExprList {
     unsigned bSpanIsTab :1; /* zSpan holds DB.TABLE.COLUMN */
     unsigned reusable :1;   /* Constant expression is reusable */
     unsigned bSorterRef :1; /* Defer evaluation until after sorting */
-    unsigned bNulls: 1;     /* True if explicit "NULLS FIRST/LAST" */
     union {
       struct {
         u16 iOrderByCol;      /* For ORDER BY, column number in result set */
@@ -3891,7 +3892,7 @@ void sqlite3ExprDelete(sqlite3*, Expr*);
 void sqlite3ExprUnmapAndDelete(Parse*, Expr*);
 ExprList *sqlite3ExprListAppend(Parse*,ExprList*,Expr*);
 ExprList *sqlite3ExprListAppendVector(Parse*,ExprList*,IdList*,Expr*);
-void sqlite3ExprListSetSortOrder(ExprList*,int,int);
+void sqlite3ExprListSetSortOrder(ExprList*,int);
 void sqlite3ExprListSetName(Parse*,ExprList*,Token*,int);
 void sqlite3ExprListSetSpan(Parse*,ExprList*,const char*,const char*);
 void sqlite3ExprListDelete(sqlite3*, ExprList*);