Allow getting config options and add multiple overloads for set

include/cppkafka/configuration.h

@@ -10,6 +10,7 @@
 #include "topic_partition_list.h"
 #include "topic_configuration.h"
 #include "clonable_ptr.h"
+#include "configuration_base.h"
 
 namespace cppkafka {
 
@@ -18,7 +19,7 @@ class Producer;
 class Consumer;
 class KafkaHandleBase;
 
-class Configuration {
+class Configuration : public ConfigurationBase<Configuration> {
 public:
     using DeliveryReportCallback = std::function<void(Producer& producer, const Message&)>;
     using OffsetCommitCallback = std::function<void(Consumer& consumer, rd_kafka_resp_err_t,
@@ -35,6 +36,8 @@ public:
     using StatsCallback = std::function<void(KafkaHandleBase& handle, const std::string& json)>;
     using SocketCallback = std::function<int(int domain, int type, int protoco)>;
 
+    using ConfigurationBase<Configuration>::set;
+
     Configuration();
 
     void set(const std::string& name, const std::string& value);
@@ -48,6 +51,7 @@ public:
     void set_default_topic_configuration(boost::optional<TopicConfiguration> config);
 
     rd_kafka_conf_t* get_handle() const;
+    std::string get(const std::string& name) const;
     const DeliveryReportCallback& get_delivery_report_callback() const;
     const OffsetCommitCallback& get_offset_commit_callback() const;
     const ErrorCallback& get_error_callback() const;

include/cppkafka/configuration_base.h

@@ -0,0 +1,33 @@
+#ifndef CPPKAFKA_CONFIGURATION_BASE_H
+#define CPPKAFKA_CONFIGURATION_BASE_H
+
+#include <string>
+
+namespace cppkafka {
+
+template <typename Concrete>
+class ConfigurationBase {
+public:
+    void set(const std::string& name, bool value) {
+        proxy_set(name, value ? "true" : "false");
+    }
+
+    // Overload for any integral value
+    template <typename T,
+              typename = typename std::enable_if<std::is_integral<T>::value>::type>
+    void set(const std::string& name, T value) {
+        proxy_set(name, std::to_string(value));
+    }
+
+    void set(const std::string& name, const char* value) {
+        proxy_set(name, value);
+    }
+private:
+    void proxy_set(const std::string& name, const std::string& value) {
+        static_cast<Concrete&>(*this).set(name, value);
+    }
+};
+
+} // cppkafka
+
+#endif // CPPKAFKA_CONFIGURATION_BASE_H

include/cppkafka/exceptions.h

@@ -21,6 +21,11 @@ public:
     ConfigException(const std::string& config_name, const std::string& error);
 };
 
+class ConfigOptionNotFound : public Exception {
+public:
+    ConfigOptionNotFound(const std::string& config_name);
+};
+
 class HandleException : public Exception {
 public:
     HandleException(rd_kafka_resp_err_t error_code);

include/cppkafka/topic_configuration.h

@@ -5,17 +5,20 @@
 #include <functional>
 #include <librdkafka/rdkafka.h>
 #include "clonable_ptr.h"
+#include "configuration_base.h"
 
 namespace cppkafka {
 
 class Topic;
 class Buffer;
 
-class TopicConfiguration {
+class TopicConfiguration : public ConfigurationBase<TopicConfiguration> {
 public:
     using PartitionerCallback = std::function<int32_t(const Topic&, const Buffer& key,
                                                       int32_t partition_count)>;
 
+    using ConfigurationBase<TopicConfiguration>::set;
+
     TopicConfiguration();
 
     void set(const std::string& name, const std::string& value);
@@ -26,6 +29,7 @@ public:
 
     const PartitionerCallback& get_partitioner_callback() const;
     rd_kafka_topic_conf_t* get_handle() const;
+    std::string get(const std::string& name) const;
 private:
     using HandlePtr = ClonablePtr<rd_kafka_topic_conf_t,
                                   decltype(&rd_kafka_topic_conf_destroy),

src/configuration.cpp

@@ -1,4 +1,5 @@
 #include "configuration.h"
+#include <vector>
 #include <librdkafka/rdkafka.h>
 #include "exceptions.h"
 #include "message.h"
@@ -7,6 +8,7 @@
 
 using std::string;
 using std::move;
+using std::vector;
 
 using boost::optional;
 
@@ -146,6 +148,17 @@ rd_kafka_conf_t* Configuration::get_handle() const {
     return handle_.get();
 }
 
+string Configuration::get(const string& name) const {
+    size_t size = 0;
+    auto result = rd_kafka_conf_get(handle_.get(), name.data(), nullptr, &size);
+    if (result != RD_KAFKA_CONF_OK) {
+        throw ConfigOptionNotFound(name);
+    }
+    vector<char> buffer(size);
+    rd_kafka_conf_get(handle_.get(), name.data(), buffer.data(), &size);
+    return string(buffer.data());
+}
+
 const Configuration::DeliveryReportCallback& Configuration::get_delivery_report_callback() const {
     return delivery_report_callback_;
 }

src/exceptions.cpp

@@ -22,6 +22,13 @@ ConfigException::ConfigException(const string& config_name, const string& error)
 
 }
 
+// ConfigOptionNotFound
+
+ConfigOptionNotFound::ConfigOptionNotFound(const string& config_name) 
+: Exception(config_name + " not found") {
+
+}
+
 // HandleException
 
 HandleException::HandleException(rd_kafka_resp_err_t error_code) 

src/topic_configuration.cpp

@@ -1,10 +1,12 @@
 #include "topic_configuration.h"
+#include <vector>
 #include <librdkafka/rdkafka.h>
 #include "exceptions.h"
 #include "topic.h"
 #include "buffer.h"
 
 using std::string;
+using std::vector;
 
 namespace cppkafka {
 
@@ -63,6 +65,17 @@ rd_kafka_topic_conf_t* TopicConfiguration::get_handle() const {
     return handle_.get();
 }
 
+string TopicConfiguration::get(const string& name) const {
+    size_t size = 0;
+    auto result = rd_kafka_topic_conf_get(handle_.get(), name.data(), nullptr, &size);
+    if (result != RD_KAFKA_CONF_OK) {
+        throw ConfigOptionNotFound(name);
+    }
+    vector<char> buffer(size);
+    rd_kafka_topic_conf_get(handle_.get(), name.data(), buffer.data(), &size);
+    return string(buffer.data());
+}
+
 TopicConfiguration::HandlePtr TopicConfiguration::make_handle(rd_kafka_topic_conf_t* ptr) {
     return HandlePtr(ptr, &rd_kafka_topic_conf_destroy, &rd_kafka_topic_conf_dup);
 }     

tests/CMakeLists.txt

@@ -18,3 +18,4 @@ create_test(consumer)
 create_test(producer)
 create_test(kafka_handle_base)
 create_test(topic_partition_list)
+create_test(configuration)

tests/configuration_test.cpp

@@ -0,0 +1,35 @@
+#include <gtest/gtest.h>
+#include "cppkafka/configuration.h"
+#include "cppkafka/exceptions.h"
+
+using namespace cppkafka;
+
+class ConfigurationTest : public testing::Test {
+public:
+    
+};
+
+TEST_F(ConfigurationTest, GetSetConfig) {
+    Configuration config;
+    config.set("group.id", "foo");
+    EXPECT_EQ("foo", config.get("group.id"));
+
+    EXPECT_THROW(config.get("asd"), ConfigOptionNotFound);
+}
+
+TEST_F(ConfigurationTest, GetSetTopicConfig) {
+    TopicConfiguration config;
+    config.set("auto.commit.enable", "true");
+    EXPECT_EQ("true", config.get("auto.commit.enable"));
+
+    EXPECT_THROW(config.get("asd"), ConfigOptionNotFound);
+}
+
+TEST_F(ConfigurationTest, SetOverloads) {
+    Configuration config;
+    config.set("enable.auto.commit", true);
+    config.set("auto.commit.interval.ms", 100);
+
+    EXPECT_EQ("true", config.get("enable.auto.commit"));
+    EXPECT_EQ("100", config.get("auto.commit.interval.ms"));
+}

tests/consumer_test.cpp

@@ -93,7 +93,7 @@ public:
     Configuration make_consumer_config(const string& group_id = "consumer_test") {
         Configuration config;
         config.set("metadata.broker.list", KAFKA_TEST_INSTANCE);
-        config.set("enable.auto.commit", "false");
+        config.set("enable.auto.commit", false);
         config.set("group.id", group_id);
         return config;
     }

tests/producer_test.cpp

@@ -93,7 +93,7 @@ public:
     Configuration make_consumer_config() {
         Configuration config;
         config.set("metadata.broker.list", KAFKA_TEST_INSTANCE);
-        config.set("enable.auto.commit", "false");
+        config.set("enable.auto.commit", false);
         config.set("group.id", "producer_test");
         return config;
     }