/// <param name="buf">the buffer into which to write the message.</param> /// <param name="directBuf"> /// an option buffer that, if returned, will be written to the server directly, bypassing our /// NpgsqlBuffer. This is an optimization hack for bytea. /// </param> /// <returns> /// Whether there was enough space in the buffer to contain the entire message. /// If false, the buffer should be flushed and write should be called again. /// </returns> internal abstract bool Write(NpgsqlBuffer buf, ref DirectBuffer directBuf);
void DoWrite <T>(TypeHandler handler, T value)
{
if (_buf.WriteSpaceLeft < 4)
{
Flush();
}
EnsureDataMessage();
var asObject = (object)value; // TODO: Implement boxless writing in the future
if (asObject == null)
{
_buf.WriteInt32(-1);
_column++;
return;
}
var asSimple = handler as ISimpleTypeWriter;
if (asSimple != null)
{
var len = asSimple.ValidateAndGetLength(asObject);
_buf.WriteInt32(len);
if (_buf.WriteSpaceLeft < len)
{
Contract.Assume(_buf.Size >= len);
FlushAndStartDataMessage();
}
asSimple.Write(asObject, _buf);
_column++;
return;
}
var asChunking = handler as IChunkingTypeWriter;
if (asChunking != null)
{
_lengthCache.Clear();
var len = asChunking.ValidateAndGetLength(asObject, ref _lengthCache);
_buf.WriteInt32(len);
_lengthCache.Rewind();
_lengthCache.Get(); // Hack
asChunking.PrepareWrite(asObject, _buf, _lengthCache);
var directBuf = new DirectBuffer();
while (!asChunking.Write(ref directBuf))
{
FlushAndStartDataMessage();
// The following is an optimization hack for writing large byte arrays without passing
// through our buffer
if (directBuf.Buffer != null)
{
len = directBuf.Size == 0 ? directBuf.Buffer.Length : directBuf.Size;
_buf.WriteInt32(len);
Flush();
_buf.Underlying.Write(directBuf.Buffer, directBuf.Offset, len);
directBuf.Buffer = null;
directBuf.Size = 0;
}
}
_column++;
return;
}
throw PGUtil.ThrowIfReached();
}
public override bool Write(ref DirectBuffer directBuf)
{
Contract.Ensures(Contract.Result <bool>() == false || directBuf.Buffer == null);
return(default(bool));
}
void DoWrite <T>(TypeHandler handler, T value)
{
try
{
if (_buf.WriteSpaceLeft < 4)
{
FlushAndStartDataMessage();
}
var asObject = (object)value; // TODO: Implement boxless writing in the future
if (asObject == null)
{
_buf.WriteInt32(-1);
_column++;
return;
}
_dummyParam.ConvertedValue = null;
var asSimple = handler as ISimpleTypeWriter;
if (asSimple != null)
{
var len = asSimple.ValidateAndGetLength(asObject, _dummyParam);
_buf.WriteInt32(len);
if (_buf.WriteSpaceLeft < len)
{
Contract.Assume(_buf.Size >= len);
FlushAndStartDataMessage();
}
asSimple.Write(asObject, _buf, _dummyParam);
_column++;
return;
}
var asChunking = handler as IChunkingTypeWriter;
if (asChunking != null)
{
_lengthCache.Clear();
var len = asChunking.ValidateAndGetLength(asObject, ref _lengthCache, _dummyParam);
_buf.WriteInt32(len);
// If the type handler used the length cache, rewind it to skip the first position:
// it contains the entire value length which we already have in len.
if (_lengthCache.Position > 0)
{
_lengthCache.Rewind();
_lengthCache.Position++;
}
asChunking.PrepareWrite(asObject, _buf, _lengthCache, _dummyParam);
var directBuf = new DirectBuffer();
while (!asChunking.Write(ref directBuf))
{
Flush();
// The following is an optimization hack for writing large byte arrays without passing
// through our buffer
if (directBuf.Buffer != null)
{
len = directBuf.Size == 0 ? directBuf.Buffer.Length : directBuf.Size;
_buf.WritePosition = 1;
_buf.WriteInt32(len + 4);
_buf.Flush();
_writingDataMsg = false;
_buf.Underlying.Write(directBuf.Buffer, directBuf.Offset, len);
directBuf.Buffer = null;
directBuf.Size = 0;
}
EnsureDataMessage();
}
_column++;
return;
}
throw PGUtil.ThrowIfReached();
}
catch
{
_connector.Break();
Cleanup();
throw;
}
}
public abstract bool Write(ref DirectBuffer directBuf);