Merge branch 'chapter4-wip' of github.com:imatix/zguide

.gitignore

@@ -1,3 +1,4 @@
 wdtemp.txt
 tmp_*
+*.wd
 

examples/C/mdcliapi.c

@@ -0,0 +1,178 @@
+/*  =========================================================================
+    mdcliapi.c
+
+    Majordomo Protocol Client API
+    Implements the MDP/Client spec at http://rfc.zeromq.org/spec:7.
+
+    Follows the ZFL class conventions and is further developed as the ZFL
+    mdcli class.  See http://zfl.zeromq.org for more details.
+
+    -------------------------------------------------------------------------
+    Copyright (c) 1991-2011 iMatix Corporation <www.imatix.com>
+    Copyright other contributors as noted in the AUTHORS file.
+
+    This file is part of the ZeroMQ Guide: http://zguide.zeromq.org
+
+    This 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.
+
+    This software is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABIL-
+    ITY 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 __MDCLIAPI_H_INCLUDED__
+#define __MDCLIAPI_H_INCLUDED__
+
+#include "zhelpers.h"
+#include "zmsg.c"
+
+//  This is the version of MDP/Client we implement
+#define MDPC_HEADER         "MDPC01"
+
+//  Reliability parameters
+#define REQUEST_TIMEOUT     2500    //  msecs, (> 1000!)
+#define REQUEST_RETRIES     3       //  Before we abandon
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+//  Opaque class structure
+typedef struct _mdcli_t mdcli_t;
+
+mdcli_t *mdcli_new     (char *broker);
+void     mdcli_destroy (mdcli_t **self_p);
+zmsg_t  *mdcli_send    (mdcli_t *self, char *service, zmsg_t *request);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+//  Structure of our class
+//  We access these properties only via class methods
+
+struct _mdcli_t {
+    char *broker;
+    void *context;
+    void *client;               //  Socket to broker
+};
+
+
+//  --------------------------------------------------------------------------
+//  Connect or reconnect to broker
+
+void s_connect_to_broker (mdcli_t *self)
+{
+    if (self->client)
+        zmq_close (self->client);
+    self->client = zmq_socket (self->context, ZMQ_REQ);
+    int linger = 0;
+    zmq_setsockopt (self->client, ZMQ_LINGER, &linger, sizeof (linger));
+    zmq_connect (self->client, self->broker);
+}
+
+
+//  --------------------------------------------------------------------------
+//  Constructor
+
+mdcli_t *
+mdcli_new (char *broker)
+{
+    mdcli_t
+        *self;
+
+    assert (broker);
+    s_version_assert (2, 1);
+    self = malloc (sizeof (mdcli_t));
+    memset (self, 0, sizeof (mdcli_t));
+
+    self->broker = strdup (broker);
+    self->context = zmq_init (1);
+    s_connect_to_broker (self);
+    return (self);
+}
+
+
+//  --------------------------------------------------------------------------
+//  Destructor
+
+void
+mdcli_destroy (mdcli_t **self_p)
+{
+    assert (self_p);
+    if (*self_p) {
+        mdcli_t *self = *self_p;
+        zmq_close (self->client);
+        zmq_term (self->context);
+        free (self->broker);
+        free (self);
+        *self_p = NULL;
+    }
+}
+
+
+//  --------------------------------------------------------------------------
+//  Send request to broker and get reply by hook or crook
+//  Returns the reply message or NULL if there was no reply.
+
+zmsg_t *
+mdcli_send (mdcli_t *self, char *service, zmsg_t *request)
+{
+    int retries_left = REQUEST_RETRIES;
+    while (retries_left) {
+        //  Prefix request with protocol frames
+        //  Frame 1: "MDPCxy" (six bytes, MDP/Client x.y)
+        //  Frame 2: Service name (printable string)
+        zmsg_t *msg = zmsg_dup (request);
+        zmsg_push (msg, service);
+        zmsg_push (msg, MDPC_HEADER);
+        zmsg_send (&msg, self->client);
+
+        while (1) {
+            //  Poll socket for a reply, with timeout
+            zmq_pollitem_t items [] = { { self->client, 0, ZMQ_POLLIN, 0 } };
+            zmq_poll (items, 1, REQUEST_TIMEOUT * 1000);
+
+            //  If we got a reply, process it
+            if (items [0].revents & ZMQ_POLLIN) {
+                zmsg_t *msg = zmsg_recv (self->client);
+
+                //  Don't try to handle errors, just assert noisily
+                assert (zmsg_parts (msg) >= 3);
+
+                char *header = zmsg_pop (msg);
+                assert (strcmp (header, MDPC_HEADER) == 0);
+                free (header);
+
+                char *service = zmsg_pop (msg);
+                assert (strcmp (service, service) == 0);
+                free (service);
+
+                return msg;     //  Success
+            }
+            else
+            if (--retries_left) {
+                //  Reconnect, and resend message
+                s_connect_to_broker (self);
+                zmsg_t *msg = zmsg_dup (request);
+                zmsg_push (msg, service);
+                zmsg_push (msg, MDPC_HEADER);
+                zmsg_send (&msg, self->client);
+            }
+            else
+                break;          //  Give up
+        }
+    }
+    return NULL;
+}
+

examples/C/mdclient.c

@@ -0,0 +1,18 @@
+//
+//  Majordomo client
+//
+#include "mdcliapi.c"
+
+int main (void)
+{
+    mdcli_t *mdcli;
+    int rc;
+
+    printf (" * mdcli: ");
+    mdcli = mdcli_new ("tcp://127.0.0.1:5055");
+
+    mdcli_destroy (&mdcli);
+    return 0;
+
+    return 0;
+}

examples/C/mdworker.c

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+//
+//  Majordomo worker
+//
+#include "mdwrkapi.c"
+
+
+
+
+int main (void)
+{