Improvements to gsim's SubscriptionManager:

 - auto-stop mode: run returns when all subscriptions cancelled.
 - flow control.

examples/topic_listener.cpp updated to use SubscriptionManager.


git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@591388 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 190 insertions, 0 deletions

diff --git a/cpp/src/qpid/client/SubscriptionManager.cpp b/cpp/src/qpid/client/SubscriptionManager.cpp
new file mode 100644
index 0000000000..4a4e3d0236
--- /dev/null
+++ b/cpp/src/qpid/client/SubscriptionManager.cpp
@@ -0,0 +1,97 @@
+/*
+ *
+ * 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.
+ *
+ */
+#ifndef _Subscription_
+#define _Subscription_
+
+#include "SubscriptionManager.h"
+#include <qpid/client/Dispatcher.h>
+#include <qpid/client/Session.h>
+#include <qpid/client/MessageListener.h>
+#include <set>
+#include <sstream>
+
+
+namespace qpid {
+namespace client {
+
+SubscriptionManager::SubscriptionManager(Session_0_10& s)
+    : dispatcher(s), session(s), messages(1), bytes(UNLIMITED), autoStop(true)
+{}
+
+std::string SubscriptionManager::uniqueTag(const std::string& tag) {
+    // Make unique tag.
+    int count=1;
+    std::string unique=tag;
+    while (subscriptions.find(tag) != subscriptions.end()) {
+        std::ostringstream s;
+        s << tag << "-" << count++;
+        unique=s.str();
+    }
+    subscriptions.insert(unique);
+    return tag;
+}
+
+std::string SubscriptionManager::subscribe(
+    MessageListener& listener, const std::string& q, const std::string& t)
+{
+    std::string tag=uniqueTag(t);
+    using namespace arg;
+    session.messageSubscribe(arg::queue=q, arg::destination=tag);
+    flowLimits(tag, messages, bytes);
+    dispatcher.listen(tag, &listener);
+    return tag;
+}
+
+void SubscriptionManager::flowLimits(
+    const std::string& tag, uint32_t messages,  uint32_t bytes) {
+    session.messageFlow(tag, 0, messages); 
+    session.messageFlow(tag, 1, bytes);
+}
+
+void SubscriptionManager::flowLimits(uint32_t m,  uint32_t b) {
+    messages=m;
+    bytes=b;
+}
+
+void SubscriptionManager::cancel(const std::string tag)
+{
+    if (subscriptions.erase(tag)) {
+        dispatcher.cancel(tag);
+        session.messageCancel(tag);
+        if (autoStop && subscriptions.empty()) stop();
+    }
+}
+
+void SubscriptionManager::run(bool autoStop_)
+{
+    autoStop=autoStop_;
+    if (autoStop && subscriptions.empty()) return;
+    dispatcher.run();
+}
+
+void SubscriptionManager::stop()
+{
+    dispatcher.stop();
+}
+
+}} // namespace qpid::client
+
+#endif
diff --git a/cpp/src/qpid/client/SubscriptionManager.h b/cpp/src/qpid/client/SubscriptionManager.h
new file mode 100644
index 0000000000..985b6ce222
--- /dev/null
+++ b/cpp/src/qpid/client/SubscriptionManager.h
@@ -0,0 +1,93 @@
+#ifndef QPID_CLIENT_SUBSCRIPTIONMANAGER_H
+#define QPID_CLIENT_SUBSCRIPTIONMANAGER_H
+
+/*
+ *
+ * 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 <qpid/client/Dispatcher.h>
+#include <qpid/client/Session_0_10.h>
+#include <qpid/client/MessageListener.h>
+#include <set>
+#include <sstream>
+
+namespace qpid {
+namespace client {
+
+struct TagNotUniqueException : public qpid::Exception {
+    TagNotUniqueException() {}
+};
+
+class SubscriptionManager
+{
+    std::set<std::string> subscriptions;
+    qpid::client::Dispatcher dispatcher;
+    qpid::client::Session_0_10& session;
+    std::string uniqueTag(const std::string&);
+    uint32_t messages;
+    uint32_t bytes;
+    bool autoStop;
+
+public:
+    SubscriptionManager(Session_0_10& session);
+    
+    /**
+     * Subscribe listener to receive messages from queue.
+     *@param listener Listener object to receive messages.
+     *@param queue Name of the queue to subscribe to.
+     *@param tag Unique destination tag for the listener.
+     * If not specified a unique tag will be generted based on the queue name.
+     *@return Destination tag.
+     *@exception TagNotUniqueException if there is already a subscription
+     * with the same tag.
+     */
+    std::string subscribe(MessageListener& listener,
+                          const std::string& queue,
+                          const std::string& tag=std::string());
+
+    /** Cancel a subscription. */
+    void cancel(const std::string tag);
+    
+    qpid::client::Dispatcher& getDispatcher() { return dispatcher; }
+    size_t size() { return subscriptions.size(); }
+
+    /** Deliver messages until stop() is called.
+     *@param autoStop If true, return when all subscriptions are cancelled.
+     */
+    void run(bool autoStop=true);
+
+    /** Cause run() to return */
+    void stop();
+
+    static const uint32_t UNLIMITED=0xFFFFFFFF;
+
+    /** Set the flow control limits for subscriber with tag.
+     * UNLIMITED means no limit.
+     */
+    void flowLimits(const std::string& tag, uint32_t messages,  uint32_t bytes);
+
+    /** Set the initial flow control limits for new subscribers */
+    void flowLimits(uint32_t messages,  uint32_t bytes);
+};
+
+
+}} // namespace qpid::client
+
+#endif  /*!QPID_CLIENT_SUBSCRIPTIONMANAGER_H*/