(cobra bots) add a utility class to factor out the common bots features (heartbeat) and move all bots to used it + convert cobra_subscribe to be a bot and add a unittest for it

ixbots/ixbots/IXCobraToStdoutBot.cpp

@@ -0,0 +1,106 @@
+/*
+ *  IXCobraToStdoutBot.cpp
+ *  Author: Benjamin Sergeant
+ *  Copyright (c) 2019 Machine Zone, Inc. All rights reserved.
+ */
+
+#include "IXCobraToStdoutBot.h"
+#include "IXCobraBot.h"
+#include "IXQueueManager.h"
+
+#include <chrono>
+#include <spdlog/spdlog.h>
+#include <sstream>
+#include <iostream>
+
+namespace ix
+{
+    using StreamWriterPtr = std::unique_ptr<Json::StreamWriter>;
+
+    StreamWriterPtr makeStreamWriter()
+    {
+        Json::StreamWriterBuilder builder;
+        builder["commentStyle"] = "None";
+        builder["indentation"] = ""; // will make the JSON object compact
+        std::unique_ptr<Json::StreamWriter> jsonWriter(builder.newStreamWriter());
+        return jsonWriter;
+    }
+
+    std::string timeSinceEpoch()
+    {
+        std::chrono::system_clock::time_point tp = std::chrono::system_clock::now();
+        std::chrono::system_clock::duration dtn = tp.time_since_epoch();
+
+        std::stringstream ss;
+        ss << dtn.count() * std::chrono::system_clock::period::num /
+                  std::chrono::system_clock::period::den;
+        return ss.str();
+    }
+
+    void writeToStdout(bool fluentd,
+                       const StreamWriterPtr& jsonWriter,
+                       const Json::Value& msg,
+                       const std::string& position)
+    {
+        Json::Value enveloppe;
+        if (fluentd)
+        {
+            enveloppe["producer"] = "cobra";
+            enveloppe["consumer"] = "fluentd";
+
+            Json::Value nestedMessage(msg);
+            nestedMessage["position"] = position;
+            nestedMessage["created_at"] = timeSinceEpoch();
+            enveloppe["message"] = nestedMessage;
+
+            jsonWriter->write(enveloppe, &std::cout);
+            std::cout << std::endl; // add lf and flush
+        }
+        else
+        {
+            enveloppe = msg;
+            std::cout << position << " ";
+            jsonWriter->write(enveloppe, &std::cout);
+            std::cout << std::endl;
+        }
+    }
+
+    int64_t cobra_to_stdout_bot(const CobraConfig& config,
+                                const std::string& channel,
+                                const std::string& filter,
+                                const std::string& position,
+                                bool fluentd,
+                                bool quiet,
+                                bool verbose,
+                                size_t maxQueueSize,
+                                bool enableHeartbeat,
+                                int runtime)
+    {
+        CobraBot bot;
+        auto jsonWriter = makeStreamWriter();
+
+        bot.setOnBotMessageCallback([&fluentd, &quiet, &jsonWriter](const Json::Value& msg,
+                                                                    const std::string& position,
+                                                                    const bool /*verbose*/,
+                                                                    std::atomic<bool>& /*throttled*/,
+                                                                    std::atomic<bool>& /*fatalCobraError*/) -> bool {
+            if (!quiet)
+            {
+                writeToStdout(fluentd, jsonWriter, msg, position);
+            }
+            return true;
+        });
+
+        bool useQueue = false;
+
+        return bot.run(config,
+                       channel,
+                       filter,
+                       position,
+                       verbose,
+                       maxQueueSize,
+                       useQueue,
+                       enableHeartbeat,
+                       runtime);
+    }
+} // namespace ix