receive.c

Subscribes to the 'example' node and prints the message bodies received.

Subscribes to the 'example' node and prints the message bodies received.Can be used with broker.c, direct.c or an external AMQP broker.

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 */
 
#include <proton/connection.h>
#include <proton/condition.h>
#include <proton/delivery.h>
#include <proton/link.h>
#include <proton/message.h>
#include <proton/object.h>
#include <proton/proactor.h>
#include <proton/session.h>
#include <proton/transport.h>
 
#include <stdio.h>
#include <stdlib.h>
 
typedef struct app_data_t {
  const char *host, *port;
  const char *amqp_address;
  const char *container_id;
  int message_count;
 
  pn_proactor_t *proactor;
  int received;
  bool finished;
  pn_rwbytes_t msgin;       /* Partially received message */
} app_data_t;
 
static const int BATCH = 1000; /* Batch size for unlimited receive */
 
static int exit_code = 0;
 
static void check_condition(pn_event_t *e, pn_condition_t *cond) {
  if (pn_condition_is_set(cond)) {
    fprintf(stderr, "%s: %s: %s\n", pn_event_type_name(pn_event_type(e)),
            pn_condition_get_name(cond), pn_condition_get_description(cond));
    pn_connection_close(pn_event_connection(e));
    exit_code = 1;
  }
}
 
static void decode_message(pn_rwbytes_t data) {
  pn_message_t *m = pn_message();
  int err = pn_message_decode(m, data.start, data.size);
  if (!err) {
    /* Print the decoded message */
    char *s = pn_tostring(pn_message_body(m));
    printf("%s\n", s);
    free(s);
    pn_message_free(m);
    free(data.start);
  } else {
    fprintf(stderr, "decode_message: %s\n", pn_code(err));
    exit_code = 1;
  }
}
 
/* Return true to continue, false to exit */
static bool handle(app_data_t* app, pn_event_t* event) {
  switch (pn_event_type(event)) {
 
   case PN_CONNECTION_INIT: {
     pn_connection_t* c = pn_event_connection(event);
     pn_session_t* s = pn_session(c);
     pn_connection_set_container(c, app->container_id);
     pn_connection_open(c);
     pn_session_open(s);
     {
     pn_link_t* l = pn_receiver(s, "my_receiver");
     pn_terminus_set_address(pn_link_source(l), app->amqp_address);
     pn_link_open(l);
     /* cannot receive without granting credit: */
     pn_link_flow(l, app->message_count ? app->message_count : BATCH);
     }
   } break;
 
   case PN_DELIVERY: {
     /* A message (or part of a message) has been received */
     pn_delivery_t *d = pn_event_delivery(event);
     if (pn_delivery_readable(d)) {
       pn_link_t *l = pn_delivery_link(d);
       size_t size = pn_delivery_pending(d);
       pn_rwbytes_t* m = &app->msgin; /* Append data to incoming message buffer */
       int recv;
       size_t oldsize = m->size;
       m->size += size;
       m->start = (char*)realloc(m->start, m->size);
       recv = pn_link_recv(l, m->start + oldsize, m->size);
       if (recv == PN_ABORTED) {
         printf("Message aborted\n");
         m->size = 0;           /* Forget the data we accumulated */
         pn_delivery_settle(d); /* Free the delivery so we can receive the next message */
         pn_link_flow(l, 1);    /* Replace credit for aborted message */
       } else if (recv < 0 && recv != PN_EOS) {        /* Unexpected error */
         pn_condition_format(pn_link_condition(l), "broker", "PN_DELIVERY error: %s", pn_code(recv));
         pn_link_close(l);               /* Unexpected error, close the link */
       } else if (!pn_delivery_partial(d)) { /* Message is complete */
         decode_message(*m);
         *m = pn_rwbytes_null;  /* Reset the buffer for the next message*/
         /* Accept the delivery */
         pn_delivery_update(d, PN_ACCEPTED);
         pn_delivery_settle(d);  /* settle and free d */
         if (app->message_count == 0) {
           /* receive forever - see if more credit is needed */
           if (pn_link_credit(l) < BATCH/2) {
             /* Grant enough credit to bring it up to BATCH: */
             pn_link_flow(l, BATCH - pn_link_credit(l));
           }
         } else if (++app->received >= app->message_count) {
           pn_session_t *ssn = pn_link_session(l);
           printf("%d messages received\n", app->received);
           pn_link_close(l);
           pn_session_close(ssn);
           pn_connection_close(pn_session_connection(ssn));
         }
       }
     }
     break;
   }
 
   case PN_TRANSPORT_CLOSED:
    check_condition(event, pn_transport_condition(pn_event_transport(event)));
    break;
 
   case PN_CONNECTION_REMOTE_CLOSE:
    check_condition(event, pn_connection_remote_condition(pn_event_connection(event)));
    pn_connection_close(pn_event_connection(event));
    break;
 
   case PN_SESSION_REMOTE_CLOSE:
    check_condition(event, pn_session_remote_condition(pn_event_session(event)));
    pn_connection_close(pn_event_connection(event));
    break;
 
   case PN_LINK_REMOTE_CLOSE:
   case PN_LINK_REMOTE_DETACH:
    check_condition(event, pn_link_remote_condition(pn_event_link(event)));
    pn_connection_close(pn_event_connection(event));
    break;
 
   case PN_PROACTOR_INACTIVE:
    return false;
    break;
 
   default:
    break;
  }
    return true;
}
 
void run(app_data_t *app) {
  /* Loop and handle events */
  do {
    pn_event_batch_t *events = pn_proactor_wait(app->proactor);
    pn_event_t *e;
    for (e = pn_event_batch_next(events); e; e = pn_event_batch_next(events)) {
      if (!handle(app, e) || exit_code != 0) {
        return;
      }
    }
    pn_proactor_done(app->proactor, events);
  } while(true);
}
 
int main(int argc, char **argv) {
  struct app_data_t app = {0};
  char addr[PN_MAX_ADDR];
 
  app.container_id = argv[0];   /* Should be unique */
  app.host = (argc > 1) ? argv[1] : "";
  app.port = (argc > 2) ? argv[2] : "amqp";
  app.amqp_address = (argc > 3) ? argv[3] : "examples";
  app.message_count = (argc > 4) ? atoi(argv[4]) : 10;
 
  /* Create the proactor and connect */
  app.proactor = pn_proactor();
  pn_proactor_addr(addr, sizeof(addr), app.host, app.port);
  pn_proactor_connect2(app.proactor, NULL, NULL, addr);
  run(&app);
  pn_proactor_free(app.proactor);
  return exit_code;
}