wasCSharpSQLite – Rev 1
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using System;
using System.Diagnostics;
using System.Text;
using Bitmask = System.UInt64;
using u32 = System.UInt32;
namespace Community.CsharpSqlite
{
public partial class Sqlite3
{
/*
** 2008 August 16
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for walking the parser tree for
** an SQL statement.
*************************************************************************
** Included in SQLite3 port to C#-SQLite; 2008 Noah B Hart
** C#-SQLite is an independent reimplementation of the SQLite software library
**
** SQLITE_SOURCE_ID: 2010-08-23 18:52:01 42537b60566f288167f1b5864a5435986838e3a3
**
*************************************************************************
*/
//#include "sqliteInt.h"
//#include <stdlib.h>
//#include <string.h>
/*
** Walk an expression tree. Invoke the callback once for each node
** of the expression, while decending. (In other words, the callback
** is invoked before visiting children.)
**
** The return value from the callback should be one of the WRC_*
** constants to specify how to proceed with the walk.
**
** WRC_Continue Continue descending down the tree.
**
** WRC_Prune Do not descend into child nodes. But allow
** the walk to continue with sibling nodes.
**
** WRC_Abort Do no more callbacks. Unwind the stack and
** return the top-level walk call.
**
** The return value from this routine is WRC_Abort to abandon the tree walk
** and WRC_Continue to continue.
*/
static int sqlite3WalkExpr( Walker pWalker, ref Expr pExpr )
{
int rc;
if ( pExpr == null )
return WRC_Continue;
testcase( ExprHasProperty( pExpr, EP_TokenOnly ) );
testcase( ExprHasProperty( pExpr, EP_Reduced ) );
rc = pWalker.xExprCallback( pWalker, ref pExpr );
if ( rc == WRC_Continue
&& !ExprHasAnyProperty( pExpr, EP_TokenOnly ) )
{
if ( sqlite3WalkExpr( pWalker, ref pExpr.pLeft ) != 0 )
return WRC_Abort;
if ( sqlite3WalkExpr( pWalker, ref pExpr.pRight ) != 0 )
return WRC_Abort;
if ( ExprHasProperty( pExpr, EP_xIsSelect ) )
{
if ( sqlite3WalkSelect( pWalker, pExpr.x.pSelect ) != 0 )
return WRC_Abort;
}
else
{
if ( sqlite3WalkExprList( pWalker, pExpr.x.pList ) != 0 )
return WRC_Abort;
}
}
return rc & WRC_Abort;
}
/*
** Call sqlite3WalkExpr() for every expression in list p or until
** an abort request is seen.
*/
static int sqlite3WalkExprList( Walker pWalker, ExprList p )
{
int i;
ExprList_item pItem;
if ( p != null )
{
for ( i = p.nExpr; i > 0; i-- )
{//, pItem++){
pItem = p.a[p.nExpr - i];
if ( sqlite3WalkExpr( pWalker, ref pItem.pExpr ) != 0 )
return WRC_Abort;
}
}
return WRC_Continue;
}
/*
** Walk all expressions associated with SELECT statement p. Do
** not invoke the SELECT callback on p, but do (of course) invoke
** any expr callbacks and SELECT callbacks that come from subqueries.
** Return WRC_Abort or WRC_Continue.
*/
static int sqlite3WalkSelectExpr( Walker pWalker, Select p )
{
if ( sqlite3WalkExprList( pWalker, p.pEList ) != 0 )
return WRC_Abort;
if ( sqlite3WalkExpr( pWalker, ref p.pWhere ) != 0 )
return WRC_Abort;
if ( sqlite3WalkExprList( pWalker, p.pGroupBy ) != 0 )
return WRC_Abort;
if ( sqlite3WalkExpr( pWalker, ref p.pHaving ) != 0 )
return WRC_Abort;
if ( sqlite3WalkExprList( pWalker, p.pOrderBy ) != 0 )
return WRC_Abort;
if ( sqlite3WalkExpr( pWalker, ref p.pLimit ) != 0 )
return WRC_Abort;
if ( sqlite3WalkExpr( pWalker, ref p.pOffset ) != 0 )
return WRC_Abort;
return WRC_Continue;
}
/*
** Walk the parse trees associated with all subqueries in the
** FROM clause of SELECT statement p. Do not invoke the select
** callback on p, but do invoke it on each FROM clause subquery
** and on any subqueries further down in the tree. Return
** WRC_Abort or WRC_Continue;
*/
static int sqlite3WalkSelectFrom( Walker pWalker, Select p )
{
SrcList pSrc;
int i;
SrcList_item pItem;
pSrc = p.pSrc;
if ( ALWAYS( pSrc ) )
{
for ( i = pSrc.nSrc; i > 0; i-- )// pItem++ )
{
pItem = pSrc.a[pSrc.nSrc - i];
if ( sqlite3WalkSelect( pWalker, pItem.pSelect ) != 0 )
{
return WRC_Abort;
}
}
}
return WRC_Continue;
}
/*
** Call sqlite3WalkExpr() for every expression in Select statement p.
** Invoke sqlite3WalkSelect() for subqueries in the FROM clause and
** on the compound select chain, p.pPrior.
**
** Return WRC_Continue under normal conditions. Return WRC_Abort if
** there is an abort request.
**
** If the Walker does not have an xSelectCallback() then this routine
** is a no-op returning WRC_Continue.
*/
static int sqlite3WalkSelect( Walker pWalker, Select p )
{
int rc;
if ( p == null || pWalker.xSelectCallback == null )
return WRC_Continue;
rc = WRC_Continue;
while ( p != null )
{
rc = pWalker.xSelectCallback( pWalker, p );
if ( rc != 0 )
break;
if ( sqlite3WalkSelectExpr( pWalker, p ) != 0 )
return WRC_Abort;
if ( sqlite3WalkSelectFrom( pWalker, p ) != 0 )
return WRC_Abort;
p = p.pPrior;
}
return rc & WRC_Abort;
}
}
}