private object ReadLargeObject(NpgsqlRowDescription.FieldData field_descr, int field_value_size)
{
var cms = new LargeMemoryStream(Stream, field_value_size);
try
{
return
(NpgsqlTypesHelper.ConvertBackendStringToSystemType(
field_descr.TypeInfo,
new StreamReader(cms, Encoding.UTF8),
field_descr.TypeSize,
field_descr.TypeModifier));
}
catch (InvalidCastException ice)
{
return(ice);
}
catch (Exception ex)
{
return(new InvalidCastException(ex.Message, ex));
}
}
protected override object ReadNext()
{
int fieldSize = GetThisFieldCount();
if (fieldSize >= _messageSize)
{
AbandonShip();
}
_nextFieldSize = null;
// Check if this field is null
if (fieldSize == -1) // Null value
{
return(DBNull.Value);
}
NpgsqlRowDescription.FieldData field_descr = FieldData;
if (fieldSize >= 32768)
{
return(ReadLargeObject(field_descr, fieldSize));
}
try
{
if (field_descr.FormatCode == FormatCode.Text)
{
PGUtil.CheckedStreamRead(Stream, bytes.Large, 0, fieldSize);
var str = UTF8Encoding.GetString(bytes.Large, 0, fieldSize);
return
(NpgsqlTypesHelper.ConvertBackendStringToSystemType(
field_descr.TypeInfo,
str,
field_descr.TypeSize,
field_descr.TypeModifier));
}
else
{
var buffer = new byte[fieldSize];
PGUtil.CheckedStreamRead(Stream, buffer, 0, fieldSize);
return
(NpgsqlTypesHelper.ConvertBackendBytesToSystemType(
field_descr.TypeInfo,
buffer,
fieldSize,
field_descr.TypeModifier));
}
}
catch (IOException)
{
throw;
}
catch (InvalidCastException ice)
{
return(ice);
}
catch (Exception ex)
{
return(new InvalidCastException(ex.Message, ex));
}
}
/// <summary>
/// Creates a prepared version of the command on a PostgreSQL server.
/// </summary>
public override void Prepare()
{
// Check the connection state.
CheckConnectionState();
// reset any responses just before getting new ones
Connector.Mediator.ResetResponses();
// Set command timeout.
m_Connector.Mediator.CommandTimeout = CommandTimeout;
if (!m_Connector.SupportsPrepare)
{
return; // Do nothing.
}
using (m_Connector.BlockNotificationThread())
{
try
{
// Use the extended query parsing...
planName = m_Connector.NextPlanName();
String portalName = m_Connector.NextPortalName();
parse = new NpgsqlParse(planName, GetParseCommandText(), new Int32[] { });
m_Connector.Parse(parse);
// We need that because Flush() doesn't cause backend to send
// ReadyForQuery on error. Without ReadyForQuery, we don't return
// from query extended processing.
// We could have used Connector.Flush() which sends us back a
// ReadyForQuery, but on postgresql server below 8.1 there is an error
// with extended query processing which hinders us from using it.
m_Connector.RequireReadyForQuery = false;
m_Connector.Flush();
// Description...
NpgsqlDescribe describe = new NpgsqlDescribe('S', planName);
m_Connector.Describe(describe);
NpgsqlRowDescription returnRowDesc = m_Connector.Sync();
Int16[] resultFormatCodes;
if (returnRowDesc != null)
{
resultFormatCodes = new Int16[returnRowDesc.NumFields];
for (int i = 0; i < returnRowDesc.NumFields; i++)
{
NpgsqlRowDescription.FieldData returnRowDescData = returnRowDesc[i];
if (returnRowDescData.TypeInfo != null && returnRowDescData.TypeInfo.NpgsqlDbType == NpgsqlDbType.Bytea)
{
// Binary format
resultFormatCodes[i] = (Int16)FormatCode.Binary;
}
else
{
// Text Format
resultFormatCodes[i] = (Int16)FormatCode.Text;
}
}
}
else
{
resultFormatCodes = new Int16[] { 0 };
}
bind = new NpgsqlBind("", planName, new Int16[Parameters.Count], null, resultFormatCodes);
}
catch (IOException e)
{
throw ClearPoolAndCreateException(e);
}
catch
{
// As per documentation:
// "[...] When an error is detected while processing any extended-query message,
// the backend issues ErrorResponse, then reads and discards messages until a
// Sync is reached, then issues ReadyForQuery and returns to normal message processing.[...]"
// So, send a sync command if we get any problems.
m_Connector.Sync();
throw;
}
}
}
