OW_WQLSelectStatement.cpp

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//%/////////////////////////////////////////////////////////////////////////////
//
// Copyright (c) 2000, 2001, 2002 BMC Software, Hewlett-Packard Company, IBM,
// The Open Group, Tivoli Systems
// Portions Copyright (C) 2003-2004 Vintela, Inc. All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
// ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
// "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
// ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
//==============================================================================
//
// Author: Mike Brasher (mbrasher@bmc.com)
//
// Modified By: Dan Nuffer
//
//%/////////////////////////////////////////////////////////////////////////////
#include "OW_config.h"
#include "OW_StringBuffer.hpp"
#include "OW_WQLSelectStatement.hpp"
#include "OW_Stack.hpp"
#include "OW_WQLCompile.hpp"
#include "OW_Assertion.hpp"

#if defined(OW_HAVE_OSTREAM)
#include <ostream>
#else
#include <iostream>
#endif

namespace OW_NAMESPACE
{

// TODO: Merge this code with WQLCompile.cpp, it's all duplicated.
//     Worse, it's an ODR violation, for which no diagnostic is
//     required, and which has undefined behavoir.
template<class T>
inline static bool _Compare(const T& x, const T& y, WQLOperation op)
{
   switch (op)
   {
      case WQL_EQ: 
         return x == y;
      case WQL_NE: 
         return x != y;
      case WQL_LT: 
         return x < y;
      case WQL_LE: 
         return x <= y;
      case WQL_GT: 
         return x > y;
      case WQL_GE: 
         return x >= y;
      default:
         OW_ASSERT(0);
   }
   return false;
}
static bool _Evaluate(
      const WQLOperand& lhs, 
      const WQLOperand& rhs, 
      WQLOperation op)
{
   switch (lhs.getType())
   {
      case WQLOperand::NULL_VALUE:
         {
            // return true if the op is WQL_EQ and the rhs is NULL
            // also if op is WQL_NE and rhs is not NULL
            return !(op == WQL_EQ) ^ (rhs.getType() == WQLOperand::NULL_VALUE);
            break;
         }
      case WQLOperand::INTEGER_VALUE:
         {
            return _Compare(
                  lhs.getIntegerValue(),
                  rhs.getIntegerValue(),
                  op);
         }
      case WQLOperand::DOUBLE_VALUE:
         {
            return _Compare(
                  lhs.getDoubleValue(),
                  rhs.getDoubleValue(),
                  op);
         }
      case WQLOperand::BOOLEAN_VALUE:
         {
            return _Compare(
                  lhs.getBooleanValue(),
                  rhs.getBooleanValue(),
                  op);
         }
      case WQLOperand::STRING_VALUE:
         {
            return _Compare(
                  lhs.getStringValue(),
                  rhs.getStringValue(),
                  op);
         }
      default:
         OW_ASSERT(0);
   }
   return false;
}
WQLSelectStatement::WQLSelectStatement()
{
   _operStack.reserve(32);
}
WQLSelectStatement::~WQLSelectStatement()
{
}
void WQLSelectStatement::clear()
{
   _className.erase();
   _selectPropertyNames.clear();
   _operStack.clear();
}
bool WQLSelectStatement::appendWherePropertyName(const String& x)
{
   //
   // Reject duplicate property names by returning false.
   //
   for (size_t i = 0, n = _wherePropertyNames.size(); i < n; i++)
   {
      if (_wherePropertyNames[i] == x)
      {
         return false;
      }
   }
   //
   // Append the new property.
   //
   _wherePropertyNames.append(x);
   return true;
}
static inline void _ResolveProperty(
      WQLOperand& op,
      const WQLPropertySource* source)
{
   //
   // Resolve the operand: if it's a property name, look up its value:
   //
   if (op.getType() == WQLOperand::PROPERTY_NAME)
   {
      const String& propertyName = op.getPropertyName();
      // it's up to the source to handle embedded properties.
      if (!source->getValue(propertyName, op))
      {
         OW_THROW(NoSuchPropertyException, propertyName.c_str());
      }
   }
}
bool WQLSelectStatement::evaluateWhereClause(
      const WQLPropertySource* source) const
{
   if (!hasWhereClause())
   {
      return true;
   }
   Stack<WQLOperand> stack;
   //
   // Process each of the operations:
   //
   for (UInt32 i = 0, n = _operStack.size(); i < n; i++)
   {
      const WQLSelectStatement::OperandOrOperation& curItem = _operStack[i];
      if (curItem.m_type == WQLSelectStatement::OperandOrOperation::OPERAND)
      {
         // put it onto the stack
         stack.push(curItem.m_operand);
      }
      else
      {
         WQLOperation op = curItem.m_operation;
         switch (op)
         {
            case WQL_OR:
               {
                  OW_ASSERT(stack.size() >= 2);
                  WQLOperand op1 = stack.top();
                  stack.pop();
                  WQLOperand& op2 = stack.top();
                  bool b1 = op1.getBooleanValue();
                  bool b2 = op2.getBooleanValue();
                  stack.top() = WQLOperand(b1 || b2, WQL_BOOLEAN_VALUE_TAG);
                  break;
               }
            case WQL_AND:
               {
                  OW_ASSERT(stack.size() >= 2);
                  WQLOperand op1 = stack.top();
                  stack.pop();
                  WQLOperand& op2 = stack.top();
                  bool b1 = op1.getBooleanValue();
                  bool b2 = op2.getBooleanValue();
                  stack.top() = WQLOperand(b1 && b2, WQL_BOOLEAN_VALUE_TAG);
                  break;
               }
            case WQL_NOT:
               {
                  OW_ASSERT(stack.size() >= 1);
                  WQLOperand& op = stack.top();
                  bool b1 = op.getBooleanValue();
                  stack.top() = WQLOperand(!b1, WQL_BOOLEAN_VALUE_TAG);
                  break;
               }
            case WQL_EQ:
            case WQL_NE:
            case WQL_LT:
            case WQL_LE:
            case WQL_GT:
            case WQL_GE:
               {
                  OW_ASSERT(stack.size() >= 2);
                  //
                  // Resolve the left-hand-side to a value (if not already
                  // a value).
                  //
                  WQLOperand lhs = stack.top();
                  stack.pop();
                  _ResolveProperty(lhs, source);
                  //
                  // Resolve the right-hand-side to a value (if not already
                  // a value).
                  //
                  WQLOperand& rhs = stack.top();
                  _ResolveProperty(rhs, source);
                  //
                  // Check for a type mismatch:
                  //
                  if (rhs.getType() != lhs.getType())
                  {
                     OW_THROW(TypeMismatchException, "");
                  }
                  //
                  // Now that the types are known to be alike, apply the
                  // operation:
                  //
                  stack.top() = WQLOperand(_Evaluate(lhs, rhs, op), WQL_BOOLEAN_VALUE_TAG);
                  break;
               }
            case WQL_ISA:
               {
                  OW_ASSERT(stack.size() >= 2);
                  WQLOperand lhs = stack.top();
                  stack.pop();
                  if (lhs.getType() != WQLOperand::PROPERTY_NAME)
                  {
                     OW_THROW(TypeMismatchException, "First argument of ISA must be a property name");
                  }
                  WQLOperand& rhs = stack.top();
                  String className;
                  if (rhs.getType() == WQLOperand::PROPERTY_NAME)
                  {
                     className = rhs.getPropertyName();
                  }
                  else if (rhs.getType() == WQLOperand::STRING_VALUE)
                  {
                     className = rhs.getStringValue();
                  }
                  else
                  {
                     OW_THROW(TypeMismatchException, "Second argument of ISA must be a property name or string constant");
                  }
                  stack.top() = WQLOperand(source->evaluateISA(lhs.getPropertyName(), className), WQL_BOOLEAN_VALUE_TAG);
                  break;
                  break;
               }
            case WQL_DO_NOTHING:
               {
                  OW_ASSERT(0); // should never happen
                  break;
               }
         }
      }
   }
   OW_ASSERT(stack.size() == 1);
   return stack.top().getBooleanValue();
}
void WQLSelectStatement::print(std::ostream& ostr) const
{
   ostr << "WQLSelectStatement\n";
   ostr << "{\n";
   ostr << "   _className: \"" << _className << "\"\n";
   for (size_t i = 0; i < _selectPropertyNames.size(); i++)
   {
      if (i == 0)
      {
         ostr << '\n';
      }
      ostr << "   _selectPropertyNames[" << i << "]: ";
      ostr << '"' << _selectPropertyNames[i] << '"' << '\n';
   }
   // Print the operations/operands
   for (size_t i = 0; i < _operStack.size(); i++)
   {
      if (i == 0)
      {
         ostr << '\n';
      }
      ostr << "   _operStack[" << i << "]: ";
      ostr << '"' << _operStack[i].toString() << '"' << '\n';
   }
   ostr << "}" << std::endl;
}
String WQLSelectStatement::toString() const
{
   StringBuffer buf("select ");
   if (_selectPropertyNames.size())
   {
      for (size_t i = 0; i < _selectPropertyNames.size(); i++)
      {
         if (i != 0)
         {
            buf += ", ";
         }
         buf += _selectPropertyNames[i];
      }
   }
   else
   {
      // can this happen?
      buf += " *";
   }
   buf += " from ";
   buf += _className;
   // Print the operations/operands
   for (size_t i = 0; i < _operStack.size(); i++)
   {
      if (i == 0)
      {
         buf += "\n";
      }
      buf += " _operStack[" + String(UInt32(i)) + "]: ";
      buf += "\"" + _operStack[i].toString() + "\"\n";
   }
   buf += ")";
   return buf.toString();
}
void WQLSelectStatement::compileWhereClause(
      const WQLPropertySource* /*source*/, WQLCompile& wcl)
{
   wcl.compile(this);
}

} // end namespace OW_NAMESPACE

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