#ifndef _SQMYSQL_HANDLE_RESULT_HPP_
#define _SQMYSQL_HANDLE_RESULT_HPP_
// ------------------------------------------------------------------------------------------------
#include "Handle/Statement.hpp"
// ------------------------------------------------------------------------------------------------
#include <Base/Buffer.hpp>
// ------------------------------------------------------------------------------------------------
#include <unordered_map>
// ------------------------------------------------------------------------------------------------
namespace SqMod {
/* ------------------------------------------------------------------------------------------------
* Manages a reference counted result set handle.
*/
class ResHnd
{
// --------------------------------------------------------------------------------------------
friend class Connection;
friend class Statement;
friend class ResultSet;
public:
// --------------------------------------------------------------------------------------------
typedef MYSQL_RES Type; // The managed type.
// --------------------------------------------------------------------------------------------
typedef Type* Pointer; // Pointer to the managed type.
typedef const Type* ConstPtr; // Constant pointer to the managed type.
// --------------------------------------------------------------------------------------------
typedef Type& Reference; // Reference to the managed type.
typedef const Type& ConstRef; // Constant reference to the managed type.
// --------------------------------------------------------------------------------------------
typedef unsigned int Counter; // Reference counter type.
// --------------------------------------------------------------------------------------------
typedef MYSQL_FIELD FieldType; // Database field type.
typedef MYSQL_BIND BindType; // Database bind type.
typedef MYSQL_TIME TimeType; // Database time type.
typedef MYSQL_ROW RowType; // Database row type.
typedef my_bool BoolType; // Database boolean type.
/* --------------------------------------------------------------------------------------------
* Validate the result set handle and throw an error if invalid.
*/
void Validate() const;
/* --------------------------------------------------------------------------------------------
* Validate the result set handle and specified index and throw an error if invalid.
*/
void ValidateIndex(Uint32 idx) const;
protected:
// --------------------------------------------------------------------------------------------
typedef std::unordered_map< String, Uint32 > IndexMap;
/* --------------------------------------------------------------------------------------------
* The structure that holds the data associated with a certain bind point.
*/
struct Bind
{
// ----------------------------------------------------------------------------------------
BoolType mIsNull; // Allows the database to specify if the field is null.
BoolType mError; // Allows the database if errors occured on this field.
Buffer mData; // Buffer to store non fundamental data for the field.
BindType * mBind; // The associated database bind point handle.
TimeType mTime; // Structure used to retrieve time data from database.
// ----------------------------------------------------------------------------------------
union
{
Uint64 mUint64; // Retrieve unsigned integer values from a field.
Int64 mInt64; // Retrieve signed integer values from a field.
Int32 mInt32[2]; // Retrieve 32 bit signed integer values from a field.
Float64 mFloat64; // Retrieve 32 bit floating point values from a field.
Float32 mFloat32[2]; // Retrieve 64 bit floating point values from the field.
};
/* ----------------------------------------------------------------------------------------
* Default constructor.
*/
Bind()
: mIsNull(0), mError(0), mData(), mBind(nullptr), mTime(), mUint64(0)
{
/* ... */
}
/* ----------------------------------------------------------------------------------------
* Copy constructor. (disabled)
*/
Bind(const Bind & o) = delete;
/* ----------------------------------------------------------------------------------------
* Move constructor. (disabled)
*/
Bind(Bind && o) = delete;
/* ----------------------------------------------------------------------------------------
* Copy assignment operator. (disabled)
*/
Bind & operator = (const Bind & o) = delete;
/* ----------------------------------------------------------------------------------------
* Move assignment operator. (disabled)
*/
Bind & operator = (Bind && o) = delete;
/* ----------------------------------------------------------------------------------------
* Retrieve the used buffer.
*/
CStr GetBuffer()
{
return mData ? mData.Data() : reinterpret_cast< CStr >(&mUint64);
}
/* ----------------------------------------------------------------------------------------
* Retrieve the buffer length.
*/
Ulong GetLength() const
{
return mBind == nullptr ? 0 : mBind->buffer_length;
}
/* ----------------------------------------------------------------------------------------
* Configure the output to match the requirements of a certain field.
*/
void SetOutput(const FieldType & field, BindType * bind);
};
/* --------------------------------------------------------------------------------------------
* The structure that holds the data associated with a certain result set handle.
*/
struct Handle
{
// ----------------------------------------------------------------------------------------
Pointer mPtr; // The managed result set handle.
Counter mRef; // Reference count to the managed handle.
// ----------------------------------------------------------------------------------------
Uint32 mFieldCount; // Number of fields in the result set.
Ulong * mLengths; // Data length when the result set came from a connection.
FieldType * mFields; // Fields in the results set.
Bind * mBinds; // Bind wrappers.
BindType * mMyBinds; // Bind points.
RowType mRow; // Row data.
// ----------------------------------------------------------------------------------------
StmtHnd mStatement; // Associated statement.
IndexMap mIndexes; // Field names and their associated index.
/* ----------------------------------------------------------------------------------------
* Connection constructor.
*/
Handle(const ConnHnd & conn);
/* ----------------------------------------------------------------------------------------
* Statement constructor.
*/
Handle(const StmtHnd & stmt);
/* ----------------------------------------------------------------------------------------
* Destructor.
*/
~Handle();
};
private:
// --------------------------------------------------------------------------------------------
Handle * m_Hnd; // The managed handle instance.
/* --------------------------------------------------------------------------------------------
* Grab a strong reference to a result set handle.
*/
void Grab()
{
if (m_Hnd)
{
++(m_Hnd->mRef);
}
}
/* --------------------------------------------------------------------------------------------
* Drop a strong reference to a result set handle.
*/
void Drop()
{
if (m_Hnd && --(m_Hnd->mRef) == 0)
{
delete m_Hnd; // Let the destructor take care of cleaning up (if necessary)
}
}
/* --------------------------------------------------------------------------------------------
* Connection constructor.
*/
ResHnd(const ConnHnd & conn)
: m_Hnd(conn ? new Handle(conn) : nullptr)
{
/* ... */
}
/* --------------------------------------------------------------------------------------------
* Connection constructor.
*/
ResHnd(const StmtHnd & stmt)
: m_Hnd(stmt ? new Handle(stmt) : nullptr)
{
/* ... */
}
public:
/* --------------------------------------------------------------------------------------------
* Default constructor (null).
*/
ResHnd()
: m_Hnd(nullptr)
{
/* ... */
}
/* --------------------------------------------------------------------------------------------
* Copy constructor.
*/
ResHnd(const ResHnd & o)
: m_Hnd(o.m_Hnd)
{
Grab();
}
/* --------------------------------------------------------------------------------------------
* Move constructor.
*/
ResHnd(ResHnd && o)
: m_Hnd(o.m_Hnd)
{
o.m_Hnd = nullptr;
}
/* --------------------------------------------------------------------------------------------
* Destructor.
*/
~ResHnd()
{
Drop();
}
/* --------------------------------------------------------------------------------------------
* Copy assignment operator.
*/
ResHnd & operator = (const ResHnd & o)
{
if (m_Hnd != o.m_Hnd)
{
Drop();
m_Hnd = o.m_Hnd;
Grab();
}
return *this;
}
/* --------------------------------------------------------------------------------------------
* Move assignment operator.
*/
ResHnd & operator = (ResHnd && o)
{
if (m_Hnd != o.m_Hnd)
{
m_Hnd = o.m_Hnd;
o.m_Hnd = nullptr;
}
return *this;
}
/* --------------------------------------------------------------------------------------------
* Perform an equality comparison between two result set handles.
*/
bool operator == (const ResHnd & o) const
{
return (m_Hnd == o.m_Hnd);
}
/* --------------------------------------------------------------------------------------------
* Perform an inequality comparison between two result set handles.
*/
bool operator != (const ResHnd & o) const
{
return (m_Hnd != o.m_Hnd);
}
/* --------------------------------------------------------------------------------------------
* Implicit conversion to boolean for use in boolean operations.
*/
operator bool () const
{
return (m_Hnd != nullptr) && (m_Hnd->mPtr != nullptr);
}
/* --------------------------------------------------------------------------------------------
* Implicit conversion to the managed instance.
*/
operator Pointer ()
{
return (m_Hnd != nullptr) ? m_Hnd->mPtr : nullptr;
}
/* --------------------------------------------------------------------------------------------
* Implicit conversion to the managed instance.
*/
operator Pointer () const
{
return (m_Hnd != nullptr) ? m_Hnd->mPtr : nullptr;
}
/* --------------------------------------------------------------------------------------------
* Implicit conversion to the managed instance.
*/
operator Reference ()
{
assert((m_Hnd != nullptr) && (m_Hnd->mPtr != nullptr));
return *(m_Hnd->mPtr);
}
/* --------------------------------------------------------------------------------------------
* Implicit conversion to the managed instance.
*/
operator ConstRef () const
{
assert((m_Hnd != nullptr) && (m_Hnd->mPtr != nullptr));
return *(m_Hnd->mPtr);
}
/* --------------------------------------------------------------------------------------------
* Member operator for dereferencing the managed pointer.
*/
Handle * operator -> () const
{
assert(m_Hnd != nullptr);
return m_Hnd;
}
/* --------------------------------------------------------------------------------------------
* Indirection operator for obtaining a reference of the managed pointer.
*/
Handle & operator * () const
{
assert(m_Hnd != nullptr);
return *m_Hnd;
}
/* --------------------------------------------------------------------------------------------
* Retrieve the raw handle structure pointer.
*/
Handle * HndPtr()
{
return m_Hnd;
}
/* --------------------------------------------------------------------------------------------
* Retrieve the raw handle structure pointer.
*/
Handle * HndPtr() const
{
return m_Hnd;
}
/* --------------------------------------------------------------------------------------------
* Retrieve the number of active references to the managed instance.
*/
Counter Count() const
{
return (m_Hnd != nullptr) ? m_Hnd->mRef : 0;
}
/* --------------------------------------------------------------------------------------------
* Retrieve the handle reference but only if valid.
*/
Handle & GetHnd()
{
// Validate the managed handle
Validate();
// Return the requesed information
return *m_Hnd;
}
/* --------------------------------------------------------------------------------------------
* Retrieve the handle reference but only if valid.
*/
const Handle & GetHnd() const
{
// Validate the managed handle
Validate();
// Return the requesed information
return *m_Hnd;
}
};
} // Namespace:: SqMod
#endif // _SQMYSQL_HANDLE_RESULT_HPP_