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/*
Copyright (c) 2009-2012 250bpm s.r.o.
Copyright (c) 2007-2009 iMatix Corporation
Copyright (c) 2007-2011 Other contributors as noted in the AUTHORS file
This file is part of Crossroads I/O project.
Crossroads I/O is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
Crossroads is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdlib.h>
#include <string.h>
#include <limits>
#include "decoder.hpp"
#include "session_base.hpp"
#include "likely.hpp"
#include "wire.hpp"
#include "err.hpp"
xs::decoder_t::decoder_t (size_t bufsize_, uint64_t maxmsgsize_) :
decoder_base_t <decoder_t> (bufsize_),
session (NULL),
maxmsgsize (maxmsgsize_)
{
int rc = in_progress.init ();
errno_assert (rc == 0);
// At the beginning, read one byte and go to one_byte_size_ready state.
next_step (tmpbuf, 1, &decoder_t::one_byte_size_ready);
}
xs::decoder_t::~decoder_t ()
{
int rc = in_progress.close ();
errno_assert (rc == 0);
}
void xs::decoder_t::set_session (session_base_t *session_)
{
session = session_;
}
bool xs::decoder_t::one_byte_size_ready ()
{
// First byte of size is read. If it is 0xff read 8-byte size.
// Otherwise allocate the buffer for message data and read the
// message data into it.
if (*tmpbuf == 0xff)
next_step (tmpbuf, 8, &decoder_t::eight_byte_size_ready);
else {
// There has to be at least one byte (the flags) in the message).
if (!*tmpbuf) {
decoding_error ();
return false;
}
// in_progress is initialised at this point so in theory we should
// close it before calling xs_msg_init_size, however, it's a 0-byte
// message and thus we can treat it as uninitialised...
int rc;
if (maxmsgsize >= 0 && (uint64_t) (*tmpbuf - 1) > maxmsgsize) {
rc = -1;
errno = ENOMEM;
}
else
rc = in_progress.init_size (*tmpbuf - 1);
if (rc != 0 && errno == ENOMEM) {
rc = in_progress.init ();
errno_assert (rc == 0);
decoding_error ();
return false;
}
errno_assert (rc == 0);
next_step (tmpbuf, 1, &decoder_t::flags_ready);
}
return true;
}
bool xs::decoder_t::eight_byte_size_ready ()
{
// 8-byte payload length is read. Allocate the buffer
// for message body and read the message data into it.
const uint64_t payload_length = get_uint64 (tmpbuf);
// There has to be at least one byte (the flags) in the message).
if (unlikely (payload_length == 0)) {
decoding_error ();
return false;
}
// Message size must not exceed the maximum allowed size.
if (unlikely (maxmsgsize >= 0 && payload_length - 1 > maxmsgsize)) {
decoding_error ();
return false;
}
// Message size must fit within range of size_t data type.
if (unlikely (payload_length - 1 > std::numeric_limits <size_t>::max ())) {
decoding_error ();
return false;
}
const size_t msg_size = static_cast <size_t> (payload_length - 1);
// in_progress is initialised at this point so in theory we should
// close it before calling init_size, however, it's a 0-byte
// message and thus we can treat it as uninitialised...
int rc = in_progress.init_size (msg_size);
if (rc != 0) {
errno_assert (errno == ENOMEM);
rc = in_progress.init ();
errno_assert (rc == 0);
decoding_error ();
return false;
}
errno_assert (rc == 0);
next_step (tmpbuf, 1, &decoder_t::flags_ready);
return true;
}
bool xs::decoder_t::flags_ready ()
{
// Store the flags from the wire into the message structure.
in_progress.set_flags (tmpbuf [0] & 0x01);
next_step (in_progress.data (), in_progress.size (),
&decoder_t::message_ready);
return true;
}
bool xs::decoder_t::message_ready ()
{
// Message is completely read. Push it further and start reading
// new message. (in_progress is a 0-byte message after this point.)
if (unlikely (!session))
return false;
int rc = session->write (&in_progress);
if (unlikely (rc != 0)) {
if (errno != EAGAIN)
decoding_error ();
return false;
}
next_step (tmpbuf, 1, &decoder_t::one_byte_size_ready);
return true;
}
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