Re: [Boost-users] [asio] socket::read_some() splits data into two parts.

Subject: Re: [Boost-users] [asio] socket::read_some() splits data into two parts.
From: Igor R (boost.lists_at_[hidden])
Date: 2011-05-11 10:39:17

> I sent 8004 bytes to server through TCP connection and successfully read it
> like this:
>
> Â Â Â  int readBytes;
> Â Â Â  const int BUFFER_SIZE = 128;
> Â Â Â  char charBuf[BUFFER_SIZE];
> Â Â Â  do
> Â Â Â  {
> Â Â Â  Â Â Â  readBytes = socket.read_some(boost::asio::buffer(charBuf,
> BUFFER_SIZE));
> Â Â Â  }
> Â Â Â  while(readBytes >= BUFFER_SIZE);
>
> But sometimes this code reads just 3752 (precisely) bytes and returns. After
> that it handles another async_read and reads 4525 bytes (which in sum gives
> 8004 bytes).
> Do I use "read_some()" function in the right way?

This is exactly what "read_some" does --  it reads SOME data. It may
read even 1 byte.
If you know exactly how many bytes you expect to get, use read() free
function with the appropriate completion condition:
http://www.boost.org/doc/libs/1_46_1/doc/html/boost_asio/reference/read.html