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How to read full bytes using port basestream

I am working on serial port communication. While using BaseStream I am writing and reading the port.
port.BaseStream.Write(dataItems, 0, dataItems.Length);
int receivedBytes = port.BaseStream.Read(buffer, 0, (int)buffer.Length);
Thread.Sleep(100);
var receiveData = BitConverter.ToString(buffer, 0, receivedBytes);
Hereafter write, I am sleeping the thread so that I will get full bytes. Is there any other way around that I can wait that all bytes are available?
Note
The last byte should be 22. Also the above code is running in Task named as public async Task PortHitmethod(Iterations iterations)

This is certainly a wrong way to use Stream.Read. The correct pattern is in the documentation:
Stream s = new MemoryStream();
...
// Now read s into a byte buffer with a little padding.
byte[] bytes = new byte[s.Length + 10];
int numBytesToRead = (int)s.Length;
int numBytesRead = 0;
do
{
// Read may return anything from 0 to 10.
int n = s.Read(bytes, numBytesRead, 10);
numBytesRead += n;
numBytesToRead -= n;
} while (numBytesToRead > 0);
s.Close();
P.S. If you think you should use Thread.Sleep then you can be sure you are certainly doing something wrong.

C# How to write bytes into the middle of a byte[] array

The function ReadPipe() below reads chunks of bytes, and I need each chunk to go to the next location in byte[] packet_buffer. But I can't figure out how to tell .ReadPipe to write bytes to within packet_buffer.
If it was C, I could just specify: *packet_buffer[ byte index of next chunk ]
How do I do this in C#?
public static int receive_SetStreamPipe_2( byte[] packet_buffer, int bytes_to_read )
{
uint received_chunk_bytes = 0;
int remaining_bytes = bytes_to_read;
int total_transferred_bytes = 0;
// Use DataPipeInformation to get the actual PipeID
ftStatus = USB_device_selection0.SetStreamPipe( FT_pipe_information.PipeId, (UInt32)bytes_to_read );
if (ftStatus != FTDI.FT_STATUS.FT_OK)
return -(int)ftStatus; // lookup: FTDI.FT_STATUS
// For each chunk 'o bytes:
for(;;)
{
// Read chunk of bytes from FPGA:
ftStatus = USB_device_selection0.ReadPipe( FT_pipe_information.PipeId,
packet_buffer( remaining_bytes ) , <<<<<<<<<<<<<< THIS WON'T WORK
(uint)remaining_bytes,
ref received_chunk_bytes );
if (ftStatus != FTDI.FT_STATUS.FT_OK)
return -(int)ftStatus; // lookup: FTDI.FT_STATUS
total_transferred_bytes += (int)received_chunk_bytes;
remaining_bytes -= (int)received_chunk_bytes;
// Get more if not done:
if( total_transferred_bytes < bytes_to_read )
{
continue; // go get more
}
return 0;
}
}

Based on CodeCaster's response, the best answer so far is that I have asked the FTDI company that makes the USB host driver to provide an overload with an offset.

Making the following assumption on your code, which I really shouldn't have to, please read [ask] and provide all relevant details:
receive_SetStreamPipe_2(byte[] packet_buffer, int bytes_to_read):
Is implemented by you
Receives in packet_buffer an array that is at least bytes_to_read long and needs to be filled with exactly bytes_to_read bytes
USB_device_selection0.ReadPipe(FT_pipe_information.PipeId, packet_buffer, (uint)remaining_bytes, ref received_chunk_bytes):
Fills packet_buffer from index 0 and doesn't have an overload with an offset (such as Stream.Write(buffer, offset, count))
Fills it up to at most remaining_bytes, but probably less
Assigns the received_chunk_bytes to how many bytes have been read
Then you need to introduce a temporary buffer that you copy to the final buffer. How large that buffer should optimally be should be obtainable from the API information, but let's take 1024 bytes:
uint received_chunk_bytes = 0;
int remaining_bytes = bytes_to_read;
int total_transferred_bytes = 0;
// Create a smaller buffer to hold each chunk
int chunkSize = 1024;
byte[] chunkBuffer = new byte[chunkSize];
// ...
for (;;)
{
// Read chunk of bytes from FPGA into chunkBuffer, chunk size being the the buffer size or the remaining number of bytes, whichever is less
ftStatus = USB_device_selection0.ReadPipe(FT_pipe_information.PipeId,
chunkBuffer
(uint)Math.Min(chunkSize, remaining_bytes),
ref received_chunk_bytes);
if (ftStatus != FTDI.FT_STATUS.FT_OK)
return -(int)ftStatus; // lookup: FTDI.FT_STATUS
// Copy the chunk into the output array
Array.Copy(chunkBuffer, 0, packet_buffer, total_transferred_bytes, received_chunk_bytes);
total_transferred_bytes += (int)received_chunk_bytes;
remaining_bytes -= (int)received_chunk_bytes;
// ...

Reading bytes from the serial port

Im building an application where i need to reed 15 byes from a serial device. (ScaleXtric c7042 powerbase) The bytes need to come in the right order, and the last one is a crc.
Using this code in an backgroundworker, I get the bytes:
byte[] data = new byte[_APB.ReadBufferSize];
_APB.Read(data, 0, data.Length);
The problem is that I don't get the first bytes first, Its like it stores some of the bytes in the buffer, so next time the DataRecieved event fires, I get the last x bytes from the previous message, and only the 15-x byte from the new. I write the bytes to a text box, and its all over the place, so some bytes are missing somewhere.
I have tried to clear the buffer after each read, but no luck.
_APB = new SerialPort(comboBoxCommAPB.SelectedItem.ToString());
_APB.BaudRate = 19200;
_APB.DataReceived += new SerialDataReceivedEventHandler(DataReceivedHandlerDataFromAPB);
_APB.Open();
_APB.DiscardInBuffer();
Hope any one can help me here

Use this Method to read fixed amout of bytes from serial port, for your case toread = 15;
public byte[] ReadFromSerialPort(SerialPort serialPort, int toRead)
{
byte[] buffer = new byte[toRead];
int offset = 0;
int read;
while (toRead > 0 && (read = serialPort.Read(buffer, offset, toRead)) > 0)
{
offset += read;
toRead -= read;
}
if (toRead > 0) throw new EndOfStreamException();
return buffer;
}

Copy all but the last 16 bytes of a stream? Early detection of end-of-stream?

This is C# related. We have a case where we need to copy the entire source stream into a destination stream except for the last 16 bytes.
EDIT: The streams can range upto 40GB, so can't do some static byte[] allocation (eg: .ToArray())
Looking at the MSDN documentation, it seems that we can reliably determine the end of stream only when the return value is 0. Return values between 0 and the requested size can imply bytes are "not currently available" (what does that really mean?)
Currently it copies every single byte as follows. inStream and outStream are generic - can be memory, disk or network streams (actually some more too).
public static void StreamCopy(Stream inStream, Stream outStream)
{
var buffer = new byte[8*1024];
var last16Bytes = new byte[16];
int bytesRead;
while ((bytesRead = inStream.Read(buffer, 0, buffer.Length)) > 0)
{
outStream.Write(buffer, 0, bytesRead);
}
// Issues:
// 1. We already wrote the last 16 bytes into
// outStream (possibly over the n/w)
// 2. last16Bytes = ? (inStream may not necessarily support rewinding)
}
What is a reliable way to ensure all but the last 16 are copied? I can think of using Position and Length on the inStream but there is a gotcha on MSDN that says
If a class derived from Stream does not support seeking, calls to Length, SetLength, Position, and Seek throw a NotSupportedException. .

Read between 1 and n bytes from the input stream.1
Append the bytes to a circular buffer.2
Write the first max(0, b - 16) bytes from the circular buffer to the output stream, where b is the number of bytes in the circular buffer.
Remove the bytes that you just have written from the circular buffer.
Go to step 1.
1This is what the Read method does – if you call int n = Read(buffer, 0, 500); it will read between 1 and 500 bytes into buffer and return the number of bytes read. If Read returns 0, you have reached the end of the stream.
2For maximum performance, you can read the bytes directly from the input stream into the circular buffer. This is a bit tricky, because you have to deal with the wraparound within the array underlying the buffer.

The following solution is fast and tested. Hope it's useful. It uses the double buffering idea you already had in mind. EDIT: simplified loop removing the conditional that separated the first iteration from the rest.
public static void StreamCopy(Stream inStream, Stream outStream) {
// Define the size of the chunk to copy during each iteration (1 KiB)
const int blockSize = 1024;
const int bytesToOmit = 16;
const int buffSize = blockSize + bytesToOmit;
// Generate working buffers
byte[] buffer1 = new byte[buffSize];
byte[] buffer2 = new byte[buffSize];
// Initialize first iteration
byte[] curBuffer = buffer1;
byte[] prevBuffer = null;
int bytesRead;
// Attempt to fully fill the buffer
bytesRead = inStream.Read(curBuffer, 0, buffSize);
if( bytesRead == buffSize ) {
// We succesfully retrieved a whole buffer, we will output
// only [blockSize] bytes, to avoid writing to the last
// bytes in the buffer in case the remaining 16 bytes happen to
// be the last ones
outStream.Write(curBuffer, 0, blockSize);
} else {
// We couldn't retrieve the whole buffer
int bytesToWrite = bytesRead - bytesToOmit;
if( bytesToWrite > 0 ) {
outStream.Write(curBuffer, 0, bytesToWrite);
}
// There's no more data to process
return;
}
curBuffer = buffer2;
prevBuffer = buffer1;
while( true ) {
// Attempt again to fully fill the buffer
bytesRead = inStream.Read(curBuffer, 0, buffSize);
if( bytesRead == buffSize ) {
// We retrieved the whole buffer, output first the last 16
// bytes of the previous buffer, and output just [blockSize]
// bytes from the current buffer
outStream.Write(prevBuffer, blockSize, bytesToOmit);
outStream.Write(curBuffer, 0, blockSize);
} else {
// We could not retrieve a complete buffer
if( bytesRead <= bytesToOmit ) {
// The bytes to output come solely from the previous buffer
outStream.Write(prevBuffer, blockSize, bytesRead);
} else {
// The bytes to output come from the previous buffer and
// the current buffer
outStream.Write(prevBuffer, blockSize, bytesToOmit);
outStream.Write(curBuffer, 0, bytesRead - bytesToOmit);
}
break;
}
// swap buffers for next iteration
byte[] swap = prevBuffer;
prevBuffer = curBuffer;
curBuffer = swap;
}
}
static void Assert(Stream inStream, Stream outStream) {
// Routine that tests the copy worked as expected
inStream.Seek(0, SeekOrigin.Begin);
outStream.Seek(0, SeekOrigin.Begin);
Debug.Assert(outStream.Length == Math.Max(inStream.Length - bytesToOmit, 0));
for( int i = 0; i < outStream.Length; i++ ) {
int byte1 = inStream.ReadByte();
int byte2 = outStream.ReadByte();
Debug.Assert(byte1 == byte2);
}
}
A much easier solution to code, yet slower since it would work at a byte level, would be to use an intermediate queue between the input stream and the output stream. The process would first read and enqueue 16 bytes from the input stream. Then it would iterate over the remaining input bytes, reading a single byte from the input stream, enqueuing it and then dequeuing a byte. The dequeued byte would be written to the output stream, until all bytes from the input stream are processed. The unwanted 16 bytes should linger in the intermediate queue.
Hope this helps!
=)

Use a circular buffer sounds great but there is no circular buffer class in .NET which means additional code anyways. I ended up with the following algorithm, a sort of map and copy - I think it's simple. The variable names are longer than usual for the sake of being self descriptive here.
This flows thru the buffers as
[outStream] <== [tailBuf] <== [mainBuf] <== [inStream]
public byte[] CopyStreamExtractLastBytes(Stream inStream, Stream outStream,
int extractByteCount)
{
//var mainBuf = new byte[1024*4]; // 4K buffer ok for network too
var mainBuf = new byte[4651]; // nearby prime for testing
int mainBufValidCount;
var tailBuf = new byte[extractByteCount];
int tailBufValidCount = 0;
while ((mainBufValidCount = inStream.Read(mainBuf, 0, mainBuf.Length)) > 0)
{
// Map: how much of what (passthru/tail) lives where (MainBuf/tailBuf)
// more than tail is passthru
int totalPassthruCount = Math.Max(0, tailBufValidCount +
mainBufValidCount - extractByteCount);
int tailBufPassthruCount = Math.Min(tailBufValidCount, totalPassthruCount);
int tailBufTailCount = tailBufValidCount - tailBufPassthruCount;
int mainBufPassthruCount = totalPassthruCount - tailBufPassthruCount;
int mainBufResidualCount = mainBufValidCount - mainBufPassthruCount;
// Copy: Passthru must be flushed per FIFO order (tailBuf then mainBuf)
outStream.Write(tailBuf, 0, tailBufPassthruCount);
outStream.Write(mainBuf, 0, mainBufPassthruCount);
// Copy: Now reassemble/compact tail into tailBuf
var tempResidualBuf = new byte[extractByteCount];
Array.Copy(tailBuf, tailBufPassthruCount, tempResidualBuf, 0,
tailBufTailCount);
Array.Copy(mainBuf, mainBufPassthruCount, tempResidualBuf,
tailBufTailCount, mainBufResidualCount);
tailBufValidCount = tailBufTailCount + mainBufResidualCount;
tailBuf = tempResidualBuf;
}
return tailBuf;
}

Setting the offset in a stream

It says here msdn.microsoft.com/en-us/library/system.io.stream.read.aspx that the Stream.Read and Stream.Write methods both advance the position/offset in the stream automatically so why is the examples here http://msdn.microsoft.com/en-us/library/system.io.stream.read.aspx and http://msdn.microsoft.com/en-us/library/system.io.filestream.read.aspx manually changing the offset?
Do you only set the offset in a loop if you know the size of the stream and set it to 0 if you don't know the size and using a buffer?
// Now read s into a byte buffer.
byte[] bytes = new byte[s.Length];
int numBytesToRead = (int) s.Length;
int numBytesRead = 0;
while (numBytesToRead > 0)
{
// Read may return anything from 0 to 10.
int n = s.Read(bytes, numBytesRead, 10);
// The end of the file is reached.
if (n == 0)
{
break;
}
numBytesRead += n;
numBytesToRead -= n;
}
and
using (GZipStream stream = new GZipStream(new MemoryStream(gzip), CompressionMode.Decompress))
{
const int size = 4096;
byte[] buffer = new byte[size];
using (MemoryStream memory = new MemoryStream())
{
int count = 0;
do
{
count = stream.Read(buffer, 0, size);
if (count > 0)
{
memory.Write(buffer, 0, count);
}
}
while (count > 0);
return memory.ToArray();
}
}

The offset is actually the offset of the buffer, not the stream. Streams are advanced automatically as they are read.

Edit (to the edited question):
In none of the code snippets you pasted into the question I see any stream offset being set.
I think you are mistaking the calculation of bytes to read vs. bytes received. This protocol may seem funny (why would you receive fewer bytes than requested?) but it makes sense when you consider that you might be reading from a high-latency packet oriented source (think: network sockets).
You might be receiving 6 characters in one burst (from a TCP packet) and only receive the remaining 4 characters in your next read (when the next packet has arrived).
Edit In response to your linked example from the comment:
using (GZipStream stream = new GZipStream(new MemoryStream(gzip), CompressionMode.Decompress))
{
// ... snip
count = stream.Read(buffer, 0, size);
if (count > 0)
{
memory.Write(buffer, 0, count);
}
It appears that the coders use prior knowledge about the underlying stream implementation, that stream.Read will always return 0 OR the size requested. That seems like a risky bet, to me. But if the docs for GZipStream do state that, it could be alright. However, since the MSDN samples use a generic Stream variable, it is (way) more correct to check the exact number of bytes read.
The first linked example uses a MemoryStream in both Write and Read fashion. The position is reset in between, so the data that was written first will be read:
Stream s = new MemoryStream();
for (int i = 0; i < 100; i++)
{
s.WriteByte((byte)i);
}
s.Position = 0;
The second example linked does not set the stream position. You'd typically have seen a call to Seek if it did. You maybe confusing the offsets into the data buffer with the stream position?