public static void InitializeDatabaseFieldMetadata(QueryResultFieldMetadata *meta, MYSQL_FIELD *field, int fieldIndex)
{
meta->TableName = (IntPtr)field->org_table;
meta->TableAlias = (IntPtr)field->table;
meta->Name = (IntPtr)field->org_name;
meta->Alias = (IntPtr)field->name;
meta->FieldType = field->type;
meta->Index = fieldIndex;
meta->Type = MySqlTypeToFieldType(field->type);
}
public QueryResult(IntPtr result, MYSQL_FIELD *fields, long rowCount, int fieldCount)
{
_result = result;
_fields = fields;
_rowCount = rowCount;
_fieldCount = fieldCount;
_fieldMetadata = (QueryResultFieldMetadata *)Marshal.AllocHGlobal(sizeof(QueryResultFieldMetadata) * _fieldCount);
_currentRow = (Field *)Marshal.AllocHGlobal(sizeof(Field) * _fieldCount);
for (int i = 0; i < _fieldCount; i++)
{
InitializeDatabaseFieldMetadata(&_fieldMetadata[i], &_fields[i], i);
_currentRow[i].SetMetadata(&_fieldMetadata[i]);
}
}
void CleanUp()
{
if (_currentRow != default)
{
Marshal.FreeHGlobal((IntPtr)_currentRow);
_currentRow = default;
}
if (_fieldMetadata != default)
{
Marshal.FreeHGlobal((IntPtr)_fieldMetadata);
_fieldMetadata = default;
}
if (_result != default)
{
mysql_free_result(_result);
_result = default;
}
}
public void SetMetadata(QueryResultFieldMetadata *fieldMeta)
{
_meta = fieldMeta;
}
public const int UNSIGNED_FLAG = 32; /**< Field is unsigned */
public PreparedQueryResult(IntPtr stmt, IntPtr result, long rowCount, int fieldCount)
{
_stmt = stmt;
_rowCount = rowCount;
_fieldCount = fieldCount;
_metadataResult = result;
if (_metadataResult == default)
{
return;
}
if (DatabaseLoader.IsMySQL8)
{
if (((MYSQL_STMT *)_stmt)->bind_result_done != 0)
{
Marshal.FreeHGlobal((IntPtr)((MYSQL_STMT *)_stmt)->bind->length);
Marshal.FreeHGlobal((IntPtr)((MYSQL_STMT *)_stmt)->bind->is_null);
}
}
else
{
if (((MYSQL_STMT_OLD *)_stmt)->bind_result_done != 0)
{
Marshal.FreeHGlobal((IntPtr)((MYSQL_STMT_OLD *)_stmt)->bind->length);
Marshal.FreeHGlobal((IntPtr)((MYSQL_STMT_OLD *)_stmt)->bind->is_null);
}
}
_rBind = (MYSQL_BIND *)Marshal.AllocHGlobal(sizeof(MYSQL_BIND) * _fieldCount);
//- for future readers wondering where the f**k this is freed - mysql_stmt_bind_result moves pointers to these
// from m_rBind to m_stmt->bind and it is later freed by the `if (m_stmt->bind_result_done)` block just above here
// MYSQL_STMT lifetime is equal to connection lifetime
var isNullBuffer = (bool *)Marshal.AllocHGlobal(sizeof(bool) * _fieldCount);
var lengthBuffer = (CULong *)Marshal.AllocHGlobal(sizeof(CULong) * _fieldCount);
new Span <byte>(_rBind, sizeof(MYSQL_BIND) * _fieldCount).Fill(0);
new Span <byte>(isNullBuffer, sizeof(bool) * _fieldCount).Fill(0);
new Span <byte>(lengthBuffer, sizeof(CULong) * _fieldCount).Fill(0);
//- This is where we store the (entire) resultset
if (mysql_stmt_store_result(_stmt) != 0)
{
FEL_LOG_WARN("sql.sql", "{0}:mysql_stmt_store_result, cannot bind result from MySQL server. Error: {1}", "PreparedQueryResult()", mysql_stmt_error(_stmt));
Marshal.FreeHGlobal((IntPtr)_rBind);
Marshal.FreeHGlobal((IntPtr)isNullBuffer);
Marshal.FreeHGlobal((IntPtr)lengthBuffer);
_rBind = default;
return;
}
_rowCount = mysql_stmt_num_rows(_stmt);
//- This is where we prepare the buffer based on metadata
MYSQL_FIELD *field = mysql_fetch_fields(_metadataResult);
_fieldMetadata = (QueryResultFieldMetadata *)Marshal.AllocHGlobal(sizeof(QueryResultFieldMetadata) * _fieldCount);
int rowSize = 0;
for (int i = 0; i < _fieldCount; ++i)
{
int size = SizeForType(&field[i]);
rowSize += size;
InitializeDatabaseFieldMetadata(&_fieldMetadata[i], &field[i], i);
_rBind[i].buffer_type = field[i].type;
_rBind[i].buffer_length = new CULong((uint)size);
_rBind[i].length = &lengthBuffer[i];
_rBind[i].is_null = &isNullBuffer[i];
_rBind[i].error = default;
_rBind[i].is_unsigned = (field[i].flags & UNSIGNED_FLAG) != 0;
}
var dataBuffer = (byte *)Marshal.AllocHGlobal(rowSize * (int)_rowCount);
for (int i = 0, offset = 0; i < _fieldCount; ++i)
{
_rBind[i].buffer = dataBuffer + offset;
offset += (int)_rBind[i].buffer_length.Value;
}
//- This is where we bind the bind the buffer to the statement
if (mysql_stmt_bind_result(_stmt, _rBind))
{
FEL_LOG_WARN("sql.sql", "{0}:mysql_stmt_bind_result, cannot bind result from MySQL server. Error: {1}", "PreparedQueryResult()", mysql_stmt_error(_stmt));
mysql_stmt_free_result(_stmt);
CleanUp();
Marshal.FreeHGlobal((IntPtr)isNullBuffer);
Marshal.FreeHGlobal((IntPtr)lengthBuffer);
return;
}
_rows = (Field *)Marshal.AllocHGlobal(sizeof(Field) * _fieldCount * (int)_rowCount);
while (_NextRow())
{
for (int fIndex = 0; fIndex < _fieldCount; ++fIndex)
{
_rows[(int)_rowPosition * _fieldCount + fIndex].SetMetadata(&_fieldMetadata[fIndex]);
var buffer_length = (int)_rBind[fIndex].buffer_length.Value;
var fetched_length = (int)(*_rBind[fIndex].length).Value;
if (!*_rBind[fIndex].is_null)
{
void *buffer = DatabaseLoader.IsMySQL8 ? ((MYSQL_STMT *)_stmt)->bind[fIndex].buffer : ((MYSQL_STMT_OLD *)_stmt)->bind[fIndex].buffer;
switch (_rBind[fIndex].buffer_type)
{
case MYSQL_TYPE_TINY_BLOB:
case MYSQL_TYPE_MEDIUM_BLOB:
case MYSQL_TYPE_LONG_BLOB:
case MYSQL_TYPE_BLOB:
case MYSQL_TYPE_STRING:
case MYSQL_TYPE_VAR_STRING:
// warning - the string will not be null-terminated if there is no space for it in the buffer
// when mysql_stmt_fetch returned MYSQL_DATA_TRUNCATED
// we cannot blindly null-terminate the data either as it may be retrieved as binary blob and not specifically a string
// in this case using Field::GetCString will result in garbage
if (fetched_length < buffer_length)
{
*((byte *)buffer + fetched_length) = 0;
}
break;
default:
break;
}
_rows[(int)_rowPosition * _fieldCount + fIndex].SetByteValue((byte *)buffer, fetched_length);
// move buffer pointer to next part
if (DatabaseLoader.IsMySQL8)
{
((MYSQL_STMT *)_stmt)->bind[fIndex].buffer = (byte *)buffer + rowSize;
}
else
{
((MYSQL_STMT_OLD *)_stmt)->bind[fIndex].buffer = (byte *)buffer + rowSize;
}
}
else
{
_rows[(int)_rowPosition * _fieldCount + fIndex].SetByteValue(default, (int)(*_rBind[fIndex].length).Value);