本文整理汇总了C#中Expr.Copy方法的典型用法代码示例。如果您正苦于以下问题：C# Expr.Copy方法的具体用法？C# Expr.Copy怎么用？C# Expr.Copy使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Expr的用法示例。
在下文中一共展示了Expr.Copy方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C#代码示例。
示例1: exprDup
/*
** This function is similar to sqlite3ExprDup(), except that if pzBuffer
** is not NULL then *pzBuffer is assumed to point to a buffer large enough
** to store the copy of expression p, the copies of p->u.zToken
** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
** if any. Before returning, *pzBuffer is set to the first byte passed the
** portion of the buffer copied into by this function.
*/
static Expr exprDup( sqlite3 db, Expr p, int flags, ref Expr pzBuffer )
{
Expr pNew = null; /* Value to return */
if ( p != null )
{
bool isReduced = ( flags & EXPRDUP_REDUCE ) != 0;
Expr zAlloc = new Expr();
u32 staticFlag = 0;
Debug.Assert( pzBuffer == null || isReduced );
/* Figure out where to write the new Expr structure. */
//if ( pzBuffer !=null)
//{
// zAlloc = pzBuffer;
// staticFlag = EP_Static;
//}
//else
//{
///Expr zAlloc = new Expr();//sqlite3DbMallocRaw( db, dupedExprSize( p, flags ) );
//}
// (Expr)zAlloc;
//if ( pNew != null )
{
/* Set nNewSize to the size allocated for the structure pointed to
** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
** by the copy of the p->u.zToken string (if any).
*/
int nStructSize = dupedExprStructSize( p, flags );
int nNewSize = nStructSize & 0xfff;
int nToken;
if ( !ExprHasProperty( p, EP_IntValue ) && !String.IsNullOrEmpty( p.u.zToken ) )
{
nToken = sqlite3Strlen30( p.u.zToken );
}
else
{
nToken = 0;
}
if ( isReduced )
{
Debug.Assert( !ExprHasProperty( p, EP_Reduced ) );
pNew = p.Copy( EXPR_TOKENONLYSIZE );//memcpy( zAlloc, p, nNewSize );
}
else
{
int nSize = exprStructSize( p );
//memcpy( zAlloc, p, nSize );
pNew = p.Copy();
//memset( &zAlloc[nSize], 0, EXPR_FULLSIZE - nSize );
}
/* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
unchecked
{
pNew.flags &= (ushort)( ~( EP_Reduced | EP_TokenOnly | EP_Static ) );
}
pNew.flags |= (ushort)( nStructSize & ( EP_Reduced | EP_TokenOnly ) );
pNew.flags |= (ushort)staticFlag;
/* Copy the p->u.zToken string, if any. */
if ( nToken != 0 )
{
string zToken;// = pNew.u.zToken = (char)&zAlloc[nNewSize];
zToken = p.u.zToken.Substring( 0, nToken );// memcpy( zToken, p.u.zToken, nToken );
}
if ( 0 == ( ( p.flags | pNew.flags ) & EP_TokenOnly ) )
{
/* Fill in the pNew.x.pSelect or pNew.x.pList member. */
if ( ExprHasProperty( p, EP_xIsSelect ) )
{
pNew.x.pSelect = sqlite3SelectDup( db, p.x.pSelect, isReduced ? 1 : 0 );
}
else
{
pNew.x.pList = sqlite3ExprListDup( db, p.x.pList, isReduced ? 1 : 0 );
}
}
/* Fill in pNew.pLeft and pNew.pRight. */
if ( ExprHasAnyProperty( pNew, EP_Reduced | EP_TokenOnly ) )
{
//zAlloc += dupedExprNodeSize( p, flags );
if ( ExprHasProperty( pNew, EP_Reduced ) )
{
pNew.pLeft = exprDup( db, p.pLeft, EXPRDUP_REDUCE, ref pzBuffer );
pNew.pRight = exprDup( db, p.pRight, EXPRDUP_REDUCE, ref pzBuffer );
}
//if ( pzBuffer != null )
//.........这里部分代码省略.........
示例2: exprDup
/*
** This function is similar to sqlite3ExprDup(), except that if pzBuffer
** is not NULL then *pzBuffer is assumed to point to a buffer large enough
** to store the copy of expression p, the copies of p->u.zToken
** (if applicable), and the copies of the p->pLeft and p->pRight expressions,
** if any. Before returning, *pzBuffer is set to the first byte passed the
** portion of the buffer copied into by this function.
*/
static Expr exprDup(sqlite3 db, Expr p, int flags, ref Expr pzBuffer)
{
Expr pNew = null; /* Value to return */
if (p != null)
{
bool isReduced = (flags & EXPRDUP_REDUCE) != 0;
u32 staticFlag = 0;
Debug.Assert(pzBuffer == null || isReduced);
/* Figure out where to write the new Expr structure. */
{
/* Set nNewSize to the size allocated for the structure pointed to
** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
** by the copy of the p->u.zToken string (if any).
*/
int nStructSize = dupedExprStructSize(p, flags);
if (isReduced)
{
Debug.Assert(!ExprHasProperty(p, EP_Reduced));
pNew = p.Copy(EXPR_TOKENONLYSIZE);//memcpy( zAlloc, p, nNewSize );
}
else
{
pNew = p.Copy();
}
/* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
unchecked
{
pNew.flags &= (ushort)(~(EP_Reduced | EP_TokenOnly | EP_Static));
}
pNew.flags |= (ushort)(nStructSize & (EP_Reduced | EP_TokenOnly));
pNew.flags |= (ushort)staticFlag;
if (0 == ((p.flags | pNew.flags) & EP_TokenOnly))
{
/* Fill in the pNew.x.pSelect or pNew.x.pList member. */
if (ExprHasProperty(p, EP_xIsSelect))
{
pNew.x.pSelect = sqlite3SelectDup(db, p.x.pSelect, isReduced ? 1 : 0);
}
else
{
pNew.x.pList = sqlite3ExprListDup(db, p.x.pList, isReduced ? 1 : 0);
}
}
/* Fill in pNew.pLeft and pNew.pRight. */
if (ExprHasAnyProperty(pNew, EP_Reduced | EP_TokenOnly))
{
if (ExprHasProperty(pNew, EP_Reduced))
{
pNew.pLeft = exprDup(db, p.pLeft, EXPRDUP_REDUCE, ref pzBuffer);
pNew.pRight = exprDup(db, p.pRight, EXPRDUP_REDUCE, ref pzBuffer);
}
}
else
{
pNew.flags2 = 0;
if (!ExprHasAnyProperty(p, EP_TokenOnly))
{
pNew.pLeft = sqlite3ExprDup(db, p.pLeft, 0);
pNew.pRight = sqlite3ExprDup(db, p.pRight, 0);
}
}
}
}
return pNew;
}