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-rw-r--r--src/v2_decoder.cpp142
1 files changed, 142 insertions, 0 deletions
diff --git a/src/v2_decoder.cpp b/src/v2_decoder.cpp
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+/*
+ Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file
+
+ This file is part of 0MQ.
+
+ 0MQ 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.
+
+ 0MQ 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 "platform.hpp"
+#ifdef ZMQ_HAVE_WINDOWS
+#include "windows.hpp"
+#endif
+
+#include "v2_protocol.hpp"
+#include "v2_decoder.hpp"
+#include "likely.hpp"
+#include "wire.hpp"
+#include "err.hpp"
+
+zmq::v2_decoder_t::v2_decoder_t (size_t bufsize_, int64_t maxmsgsize_) :
+ decoder_base_t <v2_decoder_t> (bufsize_),
+ msg_flags (0),
+ maxmsgsize (maxmsgsize_)
+{
+ int rc = in_progress.init ();
+ errno_assert (rc == 0);
+
+ // At the beginning, read one byte and go to flags_ready state.
+ next_step (tmpbuf, 1, &v2_decoder_t::flags_ready);
+}
+
+zmq::v2_decoder_t::~v2_decoder_t ()
+{
+ int rc = in_progress.close ();
+ errno_assert (rc == 0);
+}
+
+int zmq::v2_decoder_t::flags_ready ()
+{
+ msg_flags = 0;
+ if (tmpbuf [0] & v2_protocol_t::more_flag)
+ msg_flags |= msg_t::more;
+ if (tmpbuf [0] & v2_protocol_t::command_flag)
+ msg_flags |= msg_t::command;
+
+ // The payload length is either one or eight bytes,
+ // depending on whether the 'large' bit is set.
+ if (tmpbuf [0] & v2_protocol_t::large_flag)
+ next_step (tmpbuf, 8, &v2_decoder_t::eight_byte_size_ready);
+ else
+ next_step (tmpbuf, 1, &v2_decoder_t::one_byte_size_ready);
+
+ return 0;
+}
+
+int zmq::v2_decoder_t::one_byte_size_ready ()
+{
+ // Message size must not exceed the maximum allowed size.
+ if (maxmsgsize >= 0)
+ if (unlikely (tmpbuf [0] > static_cast <uint64_t> (maxmsgsize))) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ // in_progress is initialised at this point so in theory we should
+ // close it before calling zmq_msg_init_size, however, it's a 0-byte
+ // message and thus we can treat it as uninitialised...
+ int rc = in_progress.init_size (tmpbuf [0]);
+ if (unlikely (rc)) {
+ errno_assert (errno == ENOMEM);
+ rc = in_progress.init ();
+ errno_assert (rc == 0);
+ errno = ENOMEM;
+ return -1;
+ }
+
+ in_progress.set_flags (msg_flags);
+ next_step (in_progress.data (), in_progress.size (),
+ &v2_decoder_t::message_ready);
+
+ return 0;
+}
+
+int zmq::v2_decoder_t::eight_byte_size_ready ()
+{
+ // The payload size is encoded as 64-bit unsigned integer.
+ // The most significant byte comes first.
+ const uint64_t msg_size = get_uint64 (tmpbuf);
+
+ // Message size must not exceed the maximum allowed size.
+ if (maxmsgsize >= 0)
+ if (unlikely (msg_size > static_cast <uint64_t> (maxmsgsize))) {
+ errno = EMSGSIZE;
+ return -1;
+ }
+
+ // Message size must fit into size_t data type.
+ if (unlikely (msg_size != static_cast <size_t> (msg_size))) {
+ errno = EMSGSIZE;
+ return -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 (static_cast <size_t> (msg_size));
+ if (unlikely (rc)) {
+ errno_assert (errno == ENOMEM);
+ rc = in_progress.init ();
+ errno_assert (rc == 0);
+ errno = ENOMEM;
+ return -1;
+ }
+
+ in_progress.set_flags (msg_flags);
+ next_step (in_progress.data (), in_progress.size (),
+ &v2_decoder_t::message_ready);
+
+ return 0;
+}
+
+int zmq::v2_decoder_t::message_ready ()
+{
+ // Message is completely read. Signal this to the caller
+ // and prepare to decode next message.
+ next_step (tmpbuf, 1, &v2_decoder_t::flags_ready);
+ return 1;
+}