Add metadata objects and tests for them

include/cppkafka/metadata.h

@@ -0,0 +1,72 @@
+#ifndef CPPKAFKA_METADATA_H
+#define CPPKAFKA_METADATA_H
+
+#include <memory>
+#include <string>
+#include <vector>
+#include <cstdint>
+#include <unordered_set>
+#include <librdkafka/rdkafka.h>
+
+namespace cppkafka {
+
+class PartitionMetadata {
+public:
+    PartitionMetadata(const rd_kafka_metadata_partition& partition);
+
+    uint32_t get_id() const;
+    rd_kafka_resp_err_t get_error() const;
+    int32_t get_leader() const;
+    const std::vector<int32_t>& get_replicas() const;
+    const std::vector<int32_t>& get_in_sync_replica_brokers() const;
+private:
+    int32_t id_;
+    rd_kafka_resp_err_t error_;
+    int32_t leader_;
+    std::vector<int32_t> replicas_;
+    std::vector<int32_t> isrs_;
+};
+
+class TopicMetadata {
+public:
+    TopicMetadata(const rd_kafka_metadata_topic& topic);
+
+    const std::string& get_topic() const;
+    rd_kafka_resp_err_t get_error() const;
+    const std::vector<PartitionMetadata>& get_partitions() const;
+private:
+    std::string topic_;
+    rd_kafka_resp_err_t error_;
+    std::vector<PartitionMetadata> partitions_;
+};
+
+class BrokerMetadata {
+public:
+    BrokerMetadata(const rd_kafka_metadata_broker_t& broker);
+
+    const std::string& get_host() const;
+    int32_t get_id() const;
+    uint16_t get_port() const;
+private:
+    const std::string host_;
+    int32_t id_;
+    uint16_t port_;
+};
+
+class Metadata {
+public:
+    Metadata(const rd_kafka_metadata_t* ptr);
+
+    std::vector<BrokerMetadata> get_brokers() const;
+    std::vector<TopicMetadata> get_topics() const;
+    std::vector<TopicMetadata> get_topics(const std::unordered_set<std::string>& topics) const;
+    std::vector<TopicMetadata> get_topics(const std::string& prefix) const;
+private:
+    using HandlePtr = std::unique_ptr<const rd_kafka_metadata_t, decltype(&rd_kafka_metadata_destroy)>;
+
+    HandlePtr handle_;
+};
+
+} // cppkafka
+
+#endif // CPPKAFKA_METADATA_H