Use the VList object to replace Parse.azVar for tracking the mapping between

SQL parameter names and parameter numbers.  There is a performance
improvement, though there are still a few hiccups in the current code.

FossilOrigin-Name: 68ecafa1425a41358c88f41efea3262f1b4490f2

manifest

@@ -1,5 +1,5 @@
-C Fix\sharmless\scompiler\swarnings.
+C Use\sthe\sVList\sobject\sto\sreplace\sParse.azVar\sfor\stracking\sthe\smapping\sbetween\nSQL\sparameter\snames\sand\sparameter\snumbers.\s\sThere\sis\sa\sperformance\nimprovement,\sthough\sthere\sare\sstill\sa\sfew\shiccups\sin\sthe\scurrent\scode.
-D 2016-12-22T14:53:25.934
+D 2016-12-23T03:59:31.797
 F Makefile.in 41bd4cad981487345c4a84081074bcdb876e4b2e
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
@@ -341,7 +341,7 @@ F src/ctime.c 9f2296a4e5d26ebf0e0d95a0af4628f1ea694e7a
 F src/date.c b48378aeac68fa20c811404955a9b62108df47d8
 F src/dbstat.c 19ee7a4e89979d4df8e44cfac7a8f905ec89b77d
 F src/delete.c c8bc10d145c9666a34ae906250326fdaa8d58fa5
-F src/expr.c c7c11fbe8bd4d27d04f1370efcce5a05b4fca229
+F src/expr.c e640b1c82b0f22f6c00b75989b0c13503bd5083e
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
 F src/fkey.c 2e9aabe1aee76273aff8a84ee92c464e095400ae
 F src/func.c 43916c1d8e6da5d107d91d2b212577d4f69a876a
@@ -393,7 +393,7 @@ F src/shell.c bf79a69d1f9b53de958498752b78e9906c5d0aff
 F src/sqlite.h.in e8e2d108d82647f0a812fdb74accf91c1ec08ddc
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 8648034aa702469afb553231677306cc6492a1ae
-F src/sqliteInt.h adbe80409c2926d91e5485789e5bf69313cd54b0
+F src/sqliteInt.h 2075e22d50833ca2d9956d0b7a6bfb845ad05dd2
 F src/sqliteLimit.h c0373387c287c8d0932510b5547ecde31b5da247
 F src/status.c a9e66593dfb28a9e746cba7153f84d49c1ddc4b1
 F src/table.c 5226df15ab9179b9ed558d89575ea0ce37b03fc9
@@ -448,18 +448,18 @@ F src/test_windirent.c 600398db0198ca1c77ca183831bf456746b6f5c4
 F src/test_windirent.h 7edc57e2faa727026dbd5d010dd0e2e665d5aa01
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/threads.c 4ae07fa022a3dc7c5beb373cf744a85d3c5c6c3c
-F src/tokenize.c 6eb0752c4fd191f789190c3708ee5b0060fd2829
+F src/tokenize.c 5c2f516876fc27fbd7753913f032f49eb89e83b5
 F src/treeview.c 4e44ade3bfe59d82005039f72e09333ce2b4162c
 F src/trigger.c c9f0810043b265724fdb1bdd466894f984dfc182
 F src/update.c 1da7c462110bffed442a42884cb0d528c1db46d8
 F src/utf.c 699001c79f28e48e9bcdf8a463da029ea660540c
-F src/util.c e68e8ced7328f22d2cf7b4c898c394a0de34cdf1
+F src/util.c adf5ff9e457b69d3cab2afa45c9c4ce5da83da06
 F src/vacuum.c 33c174b28886b2faf26e503b5a49a1c01a9b1c16
-F src/vdbe.c 0106e0d4f0d39aced35c150a6919d2878df6b1e0
+F src/vdbe.c 54b12d95dbf10533ab2584acbf31ae12b8bfe171
 F src/vdbe.h 50ee139f9c68fff91be1d717ed3a6abbd496919c
-F src/vdbeInt.h 42e498dbe96475dbb3fda3d85d8fd2a87eff60a2
+F src/vdbeInt.h 281cb70332dc8b593b8c7afe776f3a2ba7d4255e
-F src/vdbeapi.c 129a2a1103e29fe839e137c641ff42b8066667b5
+F src/vdbeapi.c d6ebaa465f070eb1af8ba4e7b34583ece87bdd24
-F src/vdbeaux.c 7f67112cc57b2fa37b777fbf03eb32c96b337cfe
+F src/vdbeaux.c 1e2840804828d32332565485b7faa755a3acabdb
 F src/vdbeblob.c f4f98ea672b242f807c08c92c7faaa79e5091b65
 F src/vdbemem.c d3fd85b7b7ef3eb75de29c6d7e1d10d3ca78b4fd
 F src/vdbesort.c eda25cb2d1727efca6f7862fea32b8aa33c0face
@@ -1539,7 +1539,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 52a12e47de88744187bd1c71f2820885cde414a8
+P fa86db2f915c0a189c3be02b1aaa7f24d339d7d6
-R d04805544fe17af2729028773b1348a0
+R 4ff4f0f6aea9a4ccf6f07bfaa8f513d5
+T *branch * VList
+T *sym-VList *
+T -sym-trunk *
 U drh
-Z 33ba125ec9059ffd904b774699d11e2c
+Z d52e7f32e7ed6699ecd9b8a5a1a7ee92

manifest.uuid

@@ -1 +1 @@
-fa86db2f915c0a189c3be02b1aaa7f24d339d7d6
+68ecafa1425a41358c88f41efea3262f1b4490f2

src/expr.c

@@ -934,7 +934,7 @@ Expr *sqlite3ExprFunction(Parse *pParse, ExprList *pList, Token *pToken){
 ** variable number.
 **
 ** Wildcards of the form "?nnn" are assigned the number "nnn".  We make
-** sure "nnn" is not too be to avoid a denial of service attack when
+** sure "nnn" is not too big to avoid a denial of service attack when
 ** the SQL statement comes from an external source.
 **
 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
@@ -981,30 +981,13 @@ void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr, u32 n){
       ** number as the prior appearance of the same name, or if the name
       ** has never appeared before, reuse the same variable number
       */
-      ynVar i;
+      x = (ynVar)sqlite3VListNameToNum(pParse->pVList, z, n);
-      for(i=x=0; i<pParse->nzVar; i++){
+      if( x==0 ){
-        if( pParse->azVar[i] && strcmp(pParse->azVar[i],z)==0 ){
+        x = (ynVar)(++pParse->nVar);
-          x = (ynVar)i+1;
+        pParse->pVList = sqlite3VListAdd(db, pParse->pVList, z, n, x);
-          break;
       }
     }
-      if( x==0 ) x = (ynVar)(++pParse->nVar);
-    }
     pExpr->iColumn = x;
-    if( x>pParse->nzVar ){
-      char **a;
-      a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
-      if( a==0 ){
-        assert( db->mallocFailed ); /* Error reported through mallocFailed */
-        return;
-      }
-      pParse->azVar = a;
-      memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
-      pParse->nzVar = x;
-    }
-    if( pParse->azVar[x-1]==0 ){
-      pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
-    }
   } 
   if( pParse->nVar>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
     sqlite3ErrorMsg(pParse, "too many SQL variables");
@@ -3430,9 +3413,11 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       assert( pExpr->u.zToken[0]!=0 );
       sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
       if( pExpr->u.zToken[1]!=0 ){
-        assert( pExpr->u.zToken[0]=='?' 
+        const char *z = sqlite3VListNumToName(pParse->pVList, pExpr->iColumn);
-             || strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 );
+        if( z ){
-        sqlite3VdbeAppendP4(v, pParse->azVar[pExpr->iColumn-1], P4_STATIC);
+          assert( pExpr->u.zToken[0]=='?' || strcmp(pExpr->u.zToken, z)==0 );
+          sqlite3VdbeAppendP4(v, (char*)z, P4_STATIC);
+        }
       }
       return target;
     }

src/sqliteInt.h

@@ -1046,6 +1046,14 @@ typedef struct Walker Walker;
 typedef struct WhereInfo WhereInfo;
 typedef struct With With;
 
+/* A VList object records a mapping between parameters/variables/wildcards
+** in the SQL statement (such as $abc, @pqr, or :xyz) and the integer
+** variable number associated with that parameter.  See the format description
+** on the sqlite3VListAdd() routine for more information.  A VList is really
+** just an array of integers.
+*/
+typedef int VList;
+
 /*
 ** Defer sourcing vdbe.h and btree.h until after the "u8" and
 ** "BusyHandler" typedefs. vdbe.h also requires a few of the opaque
@@ -2952,7 +2960,6 @@ struct Parse {
 
   Token sLastToken;       /* The last token parsed */
   ynVar nVar;               /* Number of '?' variables seen in the SQL so far */
-  int nzVar;                /* Number of available slots in azVar[] */
   u8 iPkSortOrder;          /* ASC or DESC for INTEGER PRIMARY KEY */
   u8 explain;               /* True if the EXPLAIN flag is found on the query */
 #ifndef SQLITE_OMIT_VIRTUALTABLE
@@ -2964,7 +2971,7 @@ struct Parse {
   int iSelectId;            /* ID of current select for EXPLAIN output */
   int iNextSelectId;        /* Next available select ID for EXPLAIN output */
 #endif
-  char **azVar;             /* Pointers to names of parameters */
+  VList *pVList;            /* Mapping between variable names and numbers */
   Vdbe *pReprepare;         /* VM being reprepared (sqlite3Reprepare()) */
   const char *zTail;        /* All SQL text past the last semicolon parsed */
   Table *pNewTable;         /* A table being constructed by CREATE TABLE */
@@ -3864,6 +3871,9 @@ LogEst sqlite3LogEstFromDouble(double);
     defined(SQLITE_EXPLAIN_ESTIMATED_ROWS)
 u64 sqlite3LogEstToInt(LogEst);
 #endif
+VList *sqlite3VListAdd(sqlite3*,VList*,const char*,int,int);
+const char *sqlite3VListNumToName(VList*,int);
+int sqlite3VListNameToNum(VList*,const char*,int);
 
 /*
 ** Routines to read and write variable-length integers.  These used to

src/tokenize.c

@@ -500,8 +500,7 @@ int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
   assert( pParse->pNewTable==0 );
   assert( pParse->pNewTrigger==0 );
   assert( pParse->nVar==0 );
-  assert( pParse->nzVar==0 );
+  assert( pParse->pVList==0 );
-  assert( pParse->azVar==0 );
   while( 1 ){
     assert( i>=0 );
     if( zSql[i]!=0 ){
@@ -588,8 +587,7 @@ int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
 
   if( pParse->pWithToFree ) sqlite3WithDelete(db, pParse->pWithToFree);
   sqlite3DeleteTrigger(db, pParse->pNewTrigger);
-  for(i=pParse->nzVar-1; i>=0; i--) sqlite3DbFree(db, pParse->azVar[i]);
+  sqlite3DbFree(db, pParse->pVList);
-  sqlite3DbFree(db, pParse->azVar);
   while( pParse->pAinc ){
     AutoincInfo *p = pParse->pAinc;
     pParse->pAinc = p->pNext;

src/util.c

@@ -1453,3 +1453,92 @@ u64 sqlite3LogEstToInt(LogEst x){
   return x>=3 ? (n+8)<<(x-3) : (n+8)>>(3-x);
 }
 #endif /* defined SCANSTAT or STAT4 or ESTIMATED_ROWS */
+
+/*
+** Add a new name/number pair to a VList.  This might require that the
+** VList object be reallocated, so return the new VList.  If an OOM
+** error occurs, the original VList freed, NULL is returned, and the
+** db->mallocFailed flag is set.
+**
+** A VList is really just an array of integers.  To destroy a VList,
+** simply pass it to sqlite3DbFree().
+**
+** The first integer is the number of integers allocated for the whole
+** VList.  The second integer is the number of integers actually used.
+** Each name/number pair is encoded by subsequent groups of 3 or more
+** integers.
+**
+** Each name/number pair starts with two integers which are the number
+** value for the pair and the size of the name/number pair, respectively.
+** The text name overlays one or more following integers.  The text name
+** is always zero-terminated.
+** 
+*/
+VList *sqlite3VListAdd(
+  sqlite3 *db,           /* The database connection used for malloc() */
+  VList *pIn,            /* The input VList.  Might be NULL */
+  const char *zName,     /* Name of symbol to add */
+  int nName,             /* Bytes of text in zName */
+  int iVal               /* Value to associate with zName */
+){
+  int nInt;              /* number of sizeof(int) objects needed for zName */
+  char *z;
+  int i;
+
+  nInt = nName/4 + 3;
+  if( pIn==0 || pIn[1]+nInt > pIn[0] ){
+    /* Enlarge the allocation */
+    int nAlloc = (pIn ? pIn[0]*2 : 10) + nInt;
+    VList *pOut = sqlite3DbRealloc(db, pIn, nAlloc*sizeof(int));
+    if( pOut==0 ){
+      sqlite3DbFree(db, pIn);
+      return 0;
+    }
+    if( pIn==0 ) pOut[1] = 2;
+    pIn = pOut;
+    pIn[0] = nAlloc;
+  }
+  i = pIn[1];
+  pIn[i] = iVal;
+  pIn[i+1] = nInt;
+  z = (char*)&pIn[i+2];
+  pIn[1] = i+nInt;
+  assert( pIn[1]<=pIn[0] );
+  memcpy(z, zName, nName);
+  z[nName] = 0;
+  return pIn;
+}
+
+/*
+** Return a pointer to the name of a variable in the given VList that
+** has the value iVal.  Or return a NULL if there is no such variable in
+** the list
+*/
+const char *sqlite3VListNumToName(VList *pIn, int iVal){
+  int i, mx;
+  if( pIn==0 ) return 0;
+  mx = pIn[1];
+  i = 2;
+  do{
+    if( pIn[i]==iVal ) return (char*)&pIn[i+2];
+    i += pIn[i+1];
+  }while( i<mx );
+  return 0;
+}
+
+/*
+** Return the number of the variable named zName, if it is in VList.
+** or return 0 if there is no such variable.
+*/
+int sqlite3VListNameToNum(VList *pIn, const char *zName, int nName){
+  int i, mx;
+  if( pIn==0 ) return 0;
+  mx = pIn[1];
+  i = 2;
+  do{
+    const char *z = (const char*)&pIn[i+2];
+    if( strncmp(z,zName,nName)==0 && z[nName]==0 ) return pIn[i];
+    i += pIn[i+1];
+  }while( i<mx );
+  return 0;
+}

src/vdbe.c

@@ -1190,7 +1190,7 @@ case OP_Variable: {            /* out2 */
   Mem *pVar;       /* Value being transferred */
 
   assert( pOp->p1>0 && pOp->p1<=p->nVar );
-  assert( pOp->p4.z==0 || pOp->p4.z==p->azVar[pOp->p1-1] );
+  assert( pOp->p4.z==0 || pOp->p4.z==sqlite3VListNumToName(p->pVList,pOp->p1) );
   pVar = &p->aVar[pOp->p1 - 1];
   if( sqlite3VdbeMemTooBig(pVar) ){
     goto too_big;

src/vdbeInt.h

@@ -346,7 +346,6 @@ struct Vdbe {
   Vdbe *pPrev,*pNext;     /* Linked list of VDBEs with the same Vdbe.db */
   Parse *pParse;          /* Parsing context used to create this Vdbe */
   ynVar nVar;             /* Number of entries in aVar[] */
-  ynVar nzVar;            /* Number of entries in azVar[] */
   u32 magic;              /* Magic number for sanity checking */
   int nMem;               /* Number of memory locations currently allocated */
   int nCursor;            /* Number of slots in apCsr[] */
@@ -371,7 +370,7 @@ struct Vdbe {
   char *zErrMsg;          /* Error message written here */
   VdbeCursor **apCsr;     /* One element of this array for each open cursor */
   Mem *aVar;              /* Values for the OP_Variable opcode. */
-  char **azVar;           /* Name of variables */
+  VList *pVList;          /* Name of variables */
 #ifndef SQLITE_OMIT_TRACE
   i64 startTime;          /* Time when query started - used for profiling */
 #endif

src/vdbeapi.c

@@ -1470,10 +1470,8 @@ int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
 */
 const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
   Vdbe *p = (Vdbe*)pStmt;
-  if( p==0 || i<1 || i>p->nzVar ){
+  if( p==0 ) return 0;
-    return 0;
+  return sqlite3VListNumToName(p->pVList, i);
-  }
-  return p->azVar[i-1];
 }
 
 /*
@@ -1482,19 +1480,8 @@ const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
 ** return 0.
 */
 int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
-  int i;
+  if( p==0 || zName==0 ) return 0;
-  if( p==0 ){
+  return sqlite3VListNameToNum(p->pVList, zName, nName);
-    return 0;
-  }
-  if( zName ){
-    for(i=0; i<p->nzVar; i++){
-      const char *z = p->azVar[i];
-      if( z && strncmp(z,zName,nName)==0 && z[nName]==0 ){
-        return i+1;
-      }
-    }
-  }
-  return 0;
 }
 int sqlite3_bind_parameter_index(sqlite3_stmt *pStmt, const char *zName){
   return sqlite3VdbeParameterIndex((Vdbe*)pStmt, zName, sqlite3Strlen30(zName));

src/vdbeaux.c

@@ -1975,10 +1975,8 @@ void sqlite3VdbeMakeReady(
     x.nFree = x.nNeeded;
   }while( !db->mallocFailed );
 
-  p->nzVar = pParse->nzVar;
+  p->pVList = pParse->pVList;
-  p->azVar = pParse->azVar;
+  pParse->pVList =  0;
-  pParse->nzVar =  0;
-  pParse->azVar = 0;
   p->explain = pParse->explain;
   if( db->mallocFailed ){
     p->nVar = 0;
@@ -2982,8 +2980,7 @@ void sqlite3VdbeClearObject(sqlite3 *db, Vdbe *p){
   }
   if( p->magic!=VDBE_MAGIC_INIT ){
     releaseMemArray(p->aVar, p->nVar);
-    for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
+    sqlite3DbFree(db, p->pVList);
-    sqlite3DbFree(db, p->azVar);
     sqlite3DbFree(db, p->pFree);
   }
   vdbeFreeOpArray(db, p->aOp, p->nOp);