internal T Read <T>(NpgsqlBuffer buf, int len, FieldDescription fieldDescription = null)
{
T result;
var asSimpleReader = this as ISimpleTypeReader <T>;
if (asSimpleReader != null)
{
buf.Ensure(len);
result = asSimpleReader.Read(buf, len, fieldDescription);
}
else
{
var asChunkingReader = this as IChunkingTypeReader <T>;
if (asChunkingReader == null)
{
if (fieldDescription == null)
{
throw new InvalidCastException("Can't cast database type to " + typeof(T).Name);
}
throw new InvalidCastException(String.Format("Can't cast database type {0} to {1}", fieldDescription.Handler.PgName, typeof(T).Name));
}
asChunkingReader.PrepareRead(buf, len, fieldDescription);
while (!asChunkingReader.Read(out result))
{
buf.ReadMore();
}
}
return(result);
}
internal override DataRowMessage Load(NpgsqlBuffer buf)
{
buf.Ensure(sizeof(short));
NumColumns = buf.ReadInt16();
Buffer = buf;
Column = -1;
ColumnLen = -1;
PosInColumn = 0;
return this;
}
void ReadHeader()
{
_leftToReadInDataMsg = _connector.ReadExpecting <CopyDataMessage>().Length;
var headerLen = NpgsqlRawCopyStream.BinarySignature.Length + 4 + 4;
_buf.Ensure(headerLen);
if (NpgsqlRawCopyStream.BinarySignature.Any(t => _buf.ReadByte() != t))
{
throw new Exception("Invalid COPY binary signature at beginning!");
}
var flags = _buf.ReadInt32();
if (flags != 0)
{
throw new NotSupportedException("Unsupported flags in COPY operation (OID inclusion?)");
}
_buf.ReadInt32(); // Header extensions, currently unused
_leftToReadInDataMsg -= headerLen;
}
internal NpgsqlBuffer EnsureOrAllocateTemp(int count)
{
if (count <= Size) {
Ensure(count);
return this;
}
// Worst case: our buffer isn't big enough. For now, allocate a new buffer
// and copy into it
// TODO: Optimize with a pool later?
var tempBuf = new NpgsqlBuffer(Underlying, count, TextEncoding);
CopyTo(tempBuf);
Clear();
tempBuf.Ensure(count);
return tempBuf;
}
/// <summary>
/// Reads in the requested bytes into the buffer, or if the buffer isn't big enough, allocates a new
/// temporary buffer and reads into it. Returns the buffer that contains the data (either itself or the
/// temp buffer). Used in cases where we absolutely have to have an entire value in memory and cannot
/// read it in sequentially.
/// </summary>
internal NpgsqlBuffer EnsureOrAllocateTemp(int count)
{
if (count <= Size) {
Ensure(count);
return this;
}
// Worst case: our buffer isn't big enough. For now, allocate a new buffer
// and copy into it
// TODO: Optimize with a pool later?
var tempBuf = new NpgsqlBuffer(Underlying, count, TextEncoding);
CopyTo(tempBuf);
Clear();
tempBuf.Ensure(count);
return tempBuf;
}
