protected override int ReadInternal(byte[] dest, int timeoutMillis)
{
if (false)//(mEnableAsyncReads)
{
UsbRequest request = new UsbRequest();
try
{
request.Initialize(Connection, mReadEndpoint);
ByteBuffer buf = ByteBuffer.Wrap(dest);
if (!request.Queue(buf, dest.Length))
{
throw new IOException("Error queueing request.");
}
UsbRequest response = Connection.RequestWait();
if (response == null)
{
throw new IOException("Null response");
}
int nread = buf.Position();
if (nread > 0)
{
//Log.Debug(Tag, HexDump.DumpHexString(dest, 0, Math.Min(32, dest.Length)));
return nread;
}
else
{
return 0;
}
}
finally
{
request.Close();
}
}
int numBytesRead;
lock (mInternalReadBufferLock)
{
int readAmt = Math.Min(dest.Length, mInternalReadBuffer.Length);
numBytesRead = Connection.BulkTransfer(mReadEndpoint, mInternalReadBuffer, readAmt,
timeoutMillis);
if (numBytesRead < 0)
{
// This sucks: we get -1 on timeout, not 0 as preferred.
// We *should* use UsbRequest, except it has a bug/api oversight
// where there is no way to determine the number of bytes read
// in response :\ -- http://b.android.com/28023
if (timeoutMillis == int.MaxValue)
{
// Hack: Special case "~infinite timeout" as an error.
return -1;
}
return 0;
}
Array.Copy(mInternalReadBuffer, 0, dest, 0, numBytesRead);
}
return numBytesRead;
}
protected override int ReadInternal(byte[] dest, int timeoutMillis)
{
UsbEndpoint endpoint = UsbDevice.GetInterface(0).GetEndpoint(0);
if (ENABLE_ASYNC_READS)
{
int readAmt;
lock (mInternalReadBufferLock)
{
// mReadBuffer is only used for maximum read size.
readAmt = Math.Min(dest.Length, mInternalReadBuffer.Length);
}
UsbRequest request = new UsbRequest();
request.Initialize(Connection, endpoint);
ByteBuffer buf = ByteBuffer.Wrap(dest);
if (!request.Queue(buf, readAmt))
{
throw new IOException("Error queueing request.");
}
UsbRequest response = Connection.RequestWait();
if (response == null)
{
throw new IOException("Null response");
}
int payloadBytesRead = buf.Position() - MODEM_STATUS_HEADER_LENGTH;
if (payloadBytesRead > 0)
{
//Log.Debug(TAG, HexDump.DumpHexString(dest, 0, Math.Min(32, dest.Length)));
return payloadBytesRead;
}
else
{
return 0;
}
}
else
{
int totalBytesRead;
lock (mInternalReadBufferLock)
{
int readAmt = Math.Min(dest.Length, mInternalReadBuffer.Length);
totalBytesRead = Connection.BulkTransfer(endpoint, mInternalReadBuffer,
readAmt, timeoutMillis);
if (totalBytesRead < MODEM_STATUS_HEADER_LENGTH)
{
throw new IOException("Expected at least " + MODEM_STATUS_HEADER_LENGTH + " bytes");
}
return FilterStatusBytes(mInternalReadBuffer, dest, totalBytesRead, endpoint.MaxPacketSize);
}
}
}
