Simplifications to the initialization of the sqlite3_index_info structure

that is used to communicate with virtual table modules.  Avoid adding
unused constraints to the sqlite3_index_info structure.  Extra constraints
are harmless, but might be confusing to people trying to understand the code.

FossilOrigin-Name: 5e6357fc953a955d8ebb5c1fcd72e04e4ae5e8bf5941810015c2fbc50de70535

diff --git a/manifest b/manifest
index c6cebb057e8e74b33188870ca27328f70bdf44ff..6fa51ebc179e2225110e5a49e6283ea976d6a397 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C If\sthe\s".wheretrace\s0x10000"\sbit\sis\sset,\sprint\sWhereTerm.prereqAll\nand\s.prereqRight\sfields\sin\sthe\sWhereTerm\strace\soutput.
-D 2019-12-28T12:33:35.974
+C Simplifications\sto\sthe\sinitialization\sof\sthe\ssqlite3_index_info\sstructure\s\nthat\sis\sused\sto\scommunicate\swith\svirtual\stable\smodules.\s\sAvoid\sadding\nunused\sconstraints\sto\sthe\ssqlite3_index_info\sstructure.\s\sExtra\sconstraints\nare\sharmless,\sbut\smight\sbe\sconfusing\sto\speople\strying\sto\sunderstand\sthe\scode.
+D 2019-12-28T13:01:52.507
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -614,7 +614,7 @@ F src/vxworks.h d2988f4e5a61a4dfe82c6524dd3d6e4f2ce3cdb9
 F src/wal.c 15a2845769f51ba132f9cf0b2c7a6887a91fc8437892dbcce9fcdc68b66d60a1
 F src/wal.h 606292549f5a7be50b6227bd685fa76e3a4affad71bb8ac5ce4cb5c79f6a176a
 F src/walker.c a137468bf36c92e64d2275caa80c83902e3a0fc59273591b96c6416d3253d05d
-F src/where.c 476c0091eb27c99fb481730621838f646fba6d9ebc6e76a97e8caa9b7f08d933
+F src/where.c 230995f73eded5c3b46cdd6dd9b1862930df2bc402f5e8d2b4bfe64779411685
 F src/whereInt.h 4a296fd4fa79fdcbc2b5e8c1b898901617655811223e1082b899c23ecb092217
 F src/wherecode.c d42d3e0fe93786621b84dec8065e1dc6b324d7c5934df52f141555843b6aef4e
 F src/whereexpr.c 4b34be1434183e7bb8a05d4bf42bd53ea53021b0b060936fbd12062b4ff6b396
@@ -1853,7 +1853,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 1be2c18f4021e1d0b8412ecb68a599475c717dd97c7db209fc4203358957fd70
-R 1077f4eb4d5b48d5e8fb352c3adc1164
+P a4f330b133a36356681dce7d2a65d8ab792620494d6cd4ef4934a97cf3a8e6fc
+R 9d791d568d34e1fbcc680abee9092a25
 U drh
-Z 26ea5bdabbe48f1cef138e8164f2fb1d
+Z 381500a973c5168ce8cc649911e2754b

diff --git a/manifest.uuid b/manifest.uuid
index 556a07d0a298be6bccf490e0ac90e20dd4c2590d..745651a863fbba719d5e463f98bd2dffcd61a453 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a4f330b133a36356681dce7d2a65d8ab792620494d6cd4ef4934a97cf3a8e6fc
\ No newline at end of file
+5e6357fc953a955d8ebb5c1fcd72e04e4ae5e8bf5941810015c2fbc50de70535
\ No newline at end of file

diff --git a/src/where.c b/src/where.c
index 0ea0026f489e816743169abf2525c9593d9a2091..69784bc1cc1e028d31ad3a5ffd1c7964e91fc4d7 100644 (file)
--- a/src/where.c
+++ b/src/where.c
@@ -605,7 +605,7 @@ static void translateColumnToCopy(
 ** are no-ops.
 */
 #if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)
-static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
+static void whereTraceIndexInfoInputs(sqlite3_index_info *p){
   int i;
   if( !sqlite3WhereTrace ) return;
   for(i=0; i<p->nConstraint; i++){
@@ -623,7 +623,7 @@ static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
        p->aOrderBy[i].desc);
   }
 }
-static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
+static void whereTraceIndexInfoOutputs(sqlite3_index_info *p){
   int i;
   if( !sqlite3WhereTrace ) return;
   for(i=0; i<p->nConstraint; i++){
@@ -639,8 +639,8 @@ static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
   sqlite3DebugPrintf("  estimatedRows=%lld\n", p->estimatedRows);
 }
 #else
-#define TRACE_IDX_INPUTS(A)
-#define TRACE_IDX_OUTPUTS(A)
+#define whereTraceIndexInfoInputs(A)
+#define whereTraceIndexInfoOutputs(A)
 #endif
 
 #ifndef SQLITE_OMIT_AUTOMATIC_INDEX
@@ -950,23 +950,14 @@ static sqlite3_index_info *allocateIndexInfo(
     sqlite3ErrorMsg(pParse, "out of memory");
     return 0;
   }
-
-  /* Initialize the structure.  The sqlite3_index_info structure contains
-  ** many fields that are declared "const" to prevent xBestIndex from
-  ** changing them.  We have to do some funky casting in order to
-  ** initialize those fields.
-  */
   pHidden = (struct HiddenIndexInfo*)&pIdxInfo[1];
   pIdxCons = (struct sqlite3_index_constraint*)&pHidden[1];
   pIdxOrderBy = (struct sqlite3_index_orderby*)&pIdxCons[nTerm];
   pUsage = (struct sqlite3_index_constraint_usage*)&pIdxOrderBy[nOrderBy];
-  *(int*)&pIdxInfo->nConstraint = nTerm;
-  *(int*)&pIdxInfo->nOrderBy = nOrderBy;
-  *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint = pIdxCons;
-  *(struct sqlite3_index_orderby**)&pIdxInfo->aOrderBy = pIdxOrderBy;
-  *(struct sqlite3_index_constraint_usage**)&pIdxInfo->aConstraintUsage =
-                                                                   pUsage;
-
+  pIdxInfo->nOrderBy = nOrderBy;
+  pIdxInfo->aConstraint = pIdxCons;
+  pIdxInfo->aOrderBy = pIdxOrderBy;
+  pIdxInfo->aConstraintUsage = pUsage;
   pHidden->pWC = pWC;
   pHidden->pParse = pParse;
   for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
@@ -1026,6 +1017,7 @@ static sqlite3_index_info *allocateIndexInfo(
 
     j++;
   }
+  pIdxInfo->nConstraint = j;
   for(i=0; i<nOrderBy; i++){
     Expr *pExpr = pOrderBy->a[i].pExpr;
     pIdxOrderBy[i].iColumn = pExpr->iColumn;
@@ -1056,9 +1048,9 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
   sqlite3_vtab *pVtab = sqlite3GetVTable(pParse->db, pTab)->pVtab;
   int rc;
 
-  TRACE_IDX_INPUTS(p);
+  whereTraceIndexInfoInputs(p);
   rc = pVtab->pModule->xBestIndex(pVtab, p);
-  TRACE_IDX_OUTPUTS(p);
+  whereTraceIndexInfoOutputs(p);
 
   if( rc!=SQLITE_OK && rc!=SQLITE_CONSTRAINT ){
     if( rc==SQLITE_NOMEM ){