95 lines
3.1 KiB
C
95 lines
3.1 KiB
C
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// Copyright 2015-2018 The NATS Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "examples.h"
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static const char *usage = ""\
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"-gd use global message delivery thread pool\n" \
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"-queue use a queue subscriber with this name\n" \
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"-timeout <ms> timeout in milliseconds (default is 10sec)\n" \
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"-count number of expected messages\n";
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static volatile bool done = false;
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static void
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onMsg(natsConnection *nc, natsSubscription *sub, natsMsg *msg, void *closure)
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{
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// This callback will be invoked with a NULL message when the
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// subscription times out.
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if (print && (msg != NULL))
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printf("Received msg: %s - %.*s\n",
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natsMsg_GetSubject(msg),
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natsMsg_GetDataLength(msg),
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natsMsg_GetData(msg));
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// We should be using a mutex to protect those variables since
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// they are used from the subscription's delivery and the main
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// threads. For demo purposes, this is fine.
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if ((msg == NULL) || (++count == total))
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{
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printf("%s, destroying subscription\n",
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(msg == NULL ? "Subscription timed-out" : "All messages received"));
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natsSubscription_Destroy(sub);
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done = true;
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}
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// It is safe to call natsMsg_Destroy() with a NULL message.
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natsMsg_Destroy(msg);
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}
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int main(int argc, char **argv)
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{
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natsConnection *conn = NULL;
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natsOptions *opts = NULL;
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natsSubscription *sub = NULL;
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natsStatus s;
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opts = parseArgs(argc, argv, usage);
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printf("Listening asynchronously on '%s' with a timeout of %d ms.\n",
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subj, (int) timeout);
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s = natsConnection_Connect(&conn, opts);
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if (s == NATS_OK)
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{
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if (name != NULL)
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s = natsConnection_QueueSubscribeTimeout(&sub, conn, subj, name,
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timeout, onMsg, NULL);
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else
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s = natsConnection_SubscribeTimeout(&sub, conn, subj,
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timeout, onMsg, NULL);
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}
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// Check every half a second for end of test.
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while ((s == NATS_OK) && !done)
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{
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nats_Sleep(500);
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}
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if (s != NATS_OK)
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{
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printf("Error: %u - %s\n", s, natsStatus_GetText(s));
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nats_PrintLastErrorStack(stderr);
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}
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// Destroy all our objects to avoid report of memory leak
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// Do not destroy subscription since it is done in the callback
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natsConnection_Destroy(conn);
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natsOptions_Destroy(opts);
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// To silence reports of memory still in used with valgrind
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nats_Close();
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return 0;
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}
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