/// <summary>
/// If this return it will read exactly length bytes, and unlike the
/// regular read method fails if it cannot.
/// </summary>
/// <param name="s">The stream</param>
/// <param name="buff">The buffer into which to write the data.</param>
/// <param name="offset">The offset of the output array into which to write.</param>
/// <param name="length">The number of bytes to read.</param>
public static void ReadBlock(this Stream s, byte[] buff, int offset, int length)
{
int pos = 0;
int read;
while (pos != length)
{
read = s.Read(buff, offset + pos, length - pos);
Contracts.CheckIO(read > 0, "Unexpected failure to read");
pos += read;
}
}
// Utilities for writing.
/// <summary>
/// Initialize the header and writer for writing. The value of fpMin and header
/// should be passed to the other utility methods here.
/// </summary>
public static void BeginWrite(BinaryWriter writer, out long fpMin, out ModelHeader header)
{
Contracts.Assert(Marshal.SizeOf(typeof(ModelHeader)) == Size);
Contracts.CheckValue(writer, nameof(writer));
fpMin = writer.FpCur();
header = default(ModelHeader);
header.Signature = SignatureValue;
header.VerWritten = VerWrittenCur;
header.VerReadable = VerReadableCur;
header.FpModel = ModelHeader.Size;
// Write a blank header - the correct information is written by WriteHeaderAndTail.
byte[] headerBytes = new byte[ModelHeader.Size];
writer.Write(headerBytes);
Contracts.CheckIO(writer.FpCur() == fpMin + ModelHeader.Size);
}