added test case for polling strategy refactored the strategy class

tests/test_utils.cpp

@@ -1,91 +0,0 @@
-#include <mutex>
-#include <chrono>
-#include <condition_variable>
-#include "test_utils.h"
-#include "cppkafka/utils/consumer_dispatcher.h"
-
-using std::vector;
-using std::move;
-using std::thread;
-using std::mutex;
-using std::lock_guard;
-using std::unique_lock;
-using std::condition_variable;
-using std::chrono::system_clock;
-using std::chrono::milliseconds;
-using std::chrono::seconds;
-
-using cppkafka::Consumer;
-using cppkafka::ConsumerDispatcher;
-using cppkafka::Message;
-using cppkafka::MessageList;
-using cppkafka::TopicPartition;
-
-ConsumerRunner::ConsumerRunner(Consumer& consumer, size_t expected, size_t partitions) 
-: consumer_(consumer) {
-    bool booted = false;
-    mutex mtx;
-    condition_variable cond;
-    thread_ = thread([&, expected, partitions]() {
-        consumer_.set_timeout(milliseconds(500));
-        size_t number_eofs = 0;
-        auto start = system_clock::now();
-        ConsumerDispatcher dispatcher(consumer_);
-        dispatcher.run(
-            // Message callback
-            [&](Message msg) {
-                if (number_eofs == partitions) {
-                    messages_.push_back(move(msg));
-                }
-            },
-            // EOF callback
-            [&](ConsumerDispatcher::EndOfFile, const TopicPartition& topic_partition) {
-                if (number_eofs != partitions) {
-                    number_eofs++;
-                    if (number_eofs == partitions) {
-                        lock_guard<mutex> _(mtx);
-                        booted = true;
-                        cond.notify_one();
-                    }
-                }
-            },
-            // Every time there's any event callback
-            [&](ConsumerDispatcher::Event) {
-                if (expected > 0 && messages_.size() == expected) {
-                    dispatcher.stop();
-                }
-                if (expected == 0 && number_eofs >= partitions) {
-                    dispatcher.stop();
-                }
-                if (system_clock::now() - start >= seconds(20)) {
-                    dispatcher.stop();
-                }
-            }
-        );
-        if (number_eofs < partitions) {
-            lock_guard<mutex> _(mtx);
-            booted = true;
-            cond.notify_one();
-        }
-    });
-
-    unique_lock<mutex> lock(mtx);
-    while (!booted) {
-        cond.wait(lock);
-    }
-}
-
-ConsumerRunner::~ConsumerRunner() {
-    try_join();
-}
-
-const MessageList& ConsumerRunner::get_messages() const {
-    return messages_;
-}
-
-void ConsumerRunner::try_join() {
-    if (thread_.joinable()) {
-        thread_.join();
-    }
-}
-