Introduce abstract interface for message encoder/decoder

src/decoder.hpp

@@ -29,6 +29,7 @@
 
 #include "err.hpp"
 #include "msg.hpp"
+#include "i_decoder.hpp"
 #include "stdint.hpp"
 
 namespace zmq
@@ -47,7 +48,7 @@ namespace zmq
     //  This class implements the state machine that parses the incoming buffer.
     //  Derived class should implement individual state machine actions.
 
-    template <typename T> class decoder_base_t
+    template <typename T> class decoder_base_t : public i_decoder
     {
     public:
 

src/encoder.hpp

@@ -29,6 +29,7 @@
 
 #include "err.hpp"
 #include "msg.hpp"
+#include "i_encoder.hpp"
 
 namespace zmq
 {
@@ -39,7 +40,7 @@ namespace zmq
     //  fills the outgoing buffer. Derived classes should implement individual
     //  state machine actions.
 
-    template <typename T> class encoder_base_t
+    template <typename T> class encoder_base_t : public i_encoder
     {
     public:
 

src/i_decoder.hpp

+/*
+    Copyright (c) 2007-2012 iMatix Corporation
+    Copyright (c) 2007-2012 Other 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/>.
+*/
+
+#ifndef __ZMQ_I_DECODER_HPP_INCLUDED__
+#define __ZMQ_I_DECODER_HPP_INCLUDED__
+
+#include <stdint.h>
+
+namespace zmq
+{
+
+    class i_msg_sink;
+
+    //  Interface to be implemented by message decoder.
+
+    struct i_decoder
+    {
+        virtual ~i_decoder () {}
+
+        virtual void set_msg_sink (i_msg_sink *msg_sink_) = 0;
+
+        virtual void get_buffer (unsigned char **data_, size_t *size_) = 0;
+
+        virtual size_t process_buffer (unsigned char *data_, size_t size_) = 0;
+
+        virtual bool stalled () const = 0;
+
+    };
+
+}
+
+#endif

src/i_encoder.hpp

+/*
+    Copyright (c) 2007-2012 iMatix Corporation
+    Copyright (c) 2007-2012 Other 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/>.
+*/
+
+#ifndef __ZMQ_I_ENCODER_HPP_INCLUDED__
+#define __ZMQ_I_ENCODER_HPP_INCLUDED__
+
+#include <stdint.h>
+
+namespace zmq
+{
+
+    //  Forward declaration
+    class i_msg_source;
+
+    //  Interface to be implemented by message encoder.
+
+    struct i_encoder
+    {
+        virtual ~i_encoder () {}
+
+        //  Set message producer.
+        virtual void set_msg_source (i_msg_source *msg_source_) = 0;
+
+        //  The function returns a batch of binary data. The data
+        //  are filled to a supplied buffer. If no buffer is supplied (data_
+        //  is NULL) encoder will provide buffer of its own.
+        //  If offset is not NULL, it is filled by offset of the first message
+        //  in the batch.If there's no beginning of a message in the batch,
+        //  offset is set to -1.
+        virtual void get_data (unsigned char **data_, size_t *size_,
+            int *offset_ = NULL) = 0;
+
+    };
+
+}
+
+#endif

src/stream_engine.cpp

@@ -38,6 +38,8 @@
 #include "stream_engine.hpp"
 #include "io_thread.hpp"
 #include "session_base.hpp"
+#include "encoder.hpp"
+#include "decoder.hpp"
 #include "config.hpp"
 #include "err.hpp"
 #include "ip.hpp"
@@ -48,11 +50,11 @@ zmq::stream_engine_t::stream_engine_t (fd_t fd_, const options_t &options_, cons
     s (fd_),
     inpos (NULL),
     insize (0),
-    decoder (in_batch_size, options_.maxmsgsize),
+    decoder (NULL),
     input_error (false),
     outpos (NULL),
     outsize (0),
-    encoder (out_batch_size),
+    encoder (NULL),
     handshaking (true),
     greeting_bytes_read (0),
     greeting_size (0),
@@ -106,6 +108,11 @@ zmq::stream_engine_t::~stream_engine_t ()
 #endif
 		s = retired_fd;
     }
+
+    if (encoder != NULL)
+        delete encoder;
+    if (decoder != NULL)
+        delete decoder;
 }
 
 void zmq::stream_engine_t::plug (io_thread_t *io_thread_,
@@ -156,8 +163,10 @@ void zmq::stream_engine_t::unplug ()
     io_object_t::unplug ();
 
     //  Disconnect from session object.
-    encoder.set_msg_source (NULL);
-    decoder.set_msg_sink (NULL);
+    if (encoder)
+        encoder->set_msg_source (NULL);
+    if (decoder)
+        decoder->set_msg_sink (NULL);
     session = NULL;
 }
 
@@ -174,6 +183,7 @@ void zmq::stream_engine_t::in_event ()
         if (!handshake ())
             return;
 
+    zmq_assert (decoder);
     bool disconnection = false;
 
     //  If there's no data to process in the buffer...
@@ -183,7 +193,7 @@ void zmq::stream_engine_t::in_event ()
         //  Note that buffer can be arbitrarily large. However, we assume
         //  the underlying TCP layer has fixed buffer size and thus the
         //  number of bytes read will be always limited.
-        decoder.get_buffer (&inpos, &insize);
+        decoder->get_buffer (&inpos, &insize);
         insize = read (inpos, insize);
 
         //  Check whether the peer has closed the connection.
@@ -194,7 +204,7 @@ void zmq::stream_engine_t::in_event ()
     }
 
     //  Push the data to the decoder.
-    size_t processed = decoder.process_buffer (inpos, insize);
+    size_t processed = decoder->process_buffer (inpos, insize);
 
     if (unlikely (processed == (size_t) -1)) {
         disconnection = true;
@@ -220,7 +230,7 @@ void zmq::stream_engine_t::in_event ()
     //  until after the session has accepted the message.
     if (disconnection) {
         input_error = true;
-        if (decoder.stalled ())
+        if (decoder->stalled ())
             reset_pollin (handle);
         else
             error ();
@@ -233,7 +243,8 @@ void zmq::stream_engine_t::out_event ()
     if (!outsize) {
 
         outpos = NULL;
-        encoder.get_data (&outpos, &outsize);
+        zmq_assert (encoder);
+        encoder->get_data (&outpos, &outsize);
 
         //  If there is no data to send, stop polling for output.
         if (outsize == 0) {
@@ -284,8 +295,9 @@ void zmq::stream_engine_t::activate_in ()
         //  There was an input error but the engine could not
         //  be terminated (due to the stalled decoder).
         //  Flush the pending message and terminate the engine now.
-        decoder.process_buffer (inpos, 0);
-        zmq_assert (!decoder.stalled ());
+        zmq_assert (decoder);
+        decoder->process_buffer (inpos, 0);
+        zmq_assert (!decoder->stalled ());
         session->flush ();
         error ();
         return;
@@ -379,8 +391,11 @@ bool zmq::stream_engine_t::handshake ()
     //  We have received either a header of identity message
     //  or the whole greeting.
 
-    encoder.set_msg_source (session);
-    decoder.set_msg_sink (session);
+    encoder = new (std::nothrow) encoder_t (out_batch_size);
+    decoder = new (std::nothrow) decoder_t (in_batch_size, options.maxmsgsize);
+
+    encoder->set_msg_source (session);
+    decoder->set_msg_sink (session);
 
     zmq_assert (greeting [0] != 0xff || greeting_bytes_read >= 10);
 
@@ -395,7 +410,7 @@ bool zmq::stream_engine_t::handshake ()
         const size_t header_size = options.identity_size + 1 >= 255 ? 10 : 2;
         unsigned char tmp [10], *bufferp = tmp;
         size_t buffer_size = header_size;
-        encoder.get_data (&bufferp, &buffer_size);
+        encoder->get_data (&bufferp, &buffer_size);
         zmq_assert (buffer_size == header_size);
 
         //  Make sure the decoder sees the data we have already received.
@@ -408,7 +423,7 @@ bool zmq::stream_engine_t::handshake ()
         //  message right after the identity message, we temporarily
         //  divert the message stream from session to ourselves.
         if (options.type == ZMQ_PUB || options.type == ZMQ_XPUB)
-            decoder.set_msg_sink (this);
+            decoder->set_msg_sink (this);
     }
 
     // Start polling for output if necessary.
@@ -441,7 +456,8 @@ int zmq::stream_engine_t::push_msg (msg_t *msg_)
 
     //  Once we have injected the subscription message, we can
     //  Divert the message flow back to the session.
-    decoder.set_msg_sink (session);
+    zmq_assert (decoder);
+    decoder->set_msg_sink (session);
 
     return rc;
 }

src/stream_engine.hpp

@@ -28,8 +28,8 @@
 #include "i_engine.hpp"
 #include "i_msg_sink.hpp"
 #include "io_object.hpp"
-#include "encoder.hpp"
-#include "decoder.hpp"
+#include "i_encoder.hpp"
+#include "i_decoder.hpp"
 #include "options.hpp"
 #include "../include/zmq.h"
 
@@ -105,12 +105,12 @@ namespace zmq
 
         unsigned char *inpos;
         size_t insize;
-        decoder_t decoder;
+        i_decoder *decoder;
         bool input_error;
 
         unsigned char *outpos;
         size_t outsize;
-        encoder_t encoder;
+        i_encoder *encoder;
 
         //  When true, we are still trying to determine whether
         //  the peer is using versioned protocol, and if so, which