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rdkafkacpp.h
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rdkafkacpp.h
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/*
* librdkafka - Apache Kafka C/C++ library
*
* Copyright (c) 2014 Magnus Edenhill
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _RDKAFKACPP_H_
#define _RDKAFKACPP_H_
/**
* @file rdkafkacpp.h
* @brief Apache Kafka C/C++ consumer and producer client library.
*
* rdkafkacpp.h contains the public C++ API for librdkafka.
* The API is documented in this file as comments prefixing the class,
* function, type, enum, define, etc.
* For more information, see the C interface in rdkafka.h and read the
* manual in INTRODUCTION.md.
* The C++ interface is STD C++ '03 compliant and adheres to the
* Google C++ Style Guide.
* @sa For the C interface see rdkafka.h
*
* @tableofcontents
*/
/**@cond NO_DOC*/
#include <string>
#include <list>
#include <vector>
#include <stdint.h>
#ifdef _MSC_VER
#undef RD_EXPORT
#ifdef LIBRDKAFKA_STATICLIB
#define RD_EXPORT
#else
#ifdef LIBRDKAFKACPP_EXPORTS
#define RD_EXPORT __declspec(dllexport)
#else
#define RD_EXPORT __declspec(dllimport)
#endif
#endif
#else
#define RD_EXPORT
#endif
/**@endcond*/
extern "C" {
/* Forward declarations */
struct rd_kafka_s;
struct rd_kafka_topic_s;
struct rd_kafka_message_s;
}
namespace RdKafka {
/**
* @name Miscellaneous APIs
* @{
*/
/**
* @brief librdkafka version
*
* Interpreted as hex \c MM.mm.rr.xx:
* - MM = Major
* - mm = minor
* - rr = revision
* - xx = pre-release id (0xff is the final release)
*
* E.g.: \c 0x000801ff = 0.8.1
*
* @remark This value should only be used during compile time,
* for runtime checks of version use RdKafka::version()
*/
#define RD_KAFKA_VERSION 0x01000002
/**
* @brief Returns the librdkafka version as integer.
*
* @sa See RD_KAFKA_VERSION for how to parse the integer format.
*/
RD_EXPORT
int version ();
/**
* @brief Returns the librdkafka version as string.
*/
RD_EXPORT
std::string version_str();
/**
* @brief Returns a CSV list of the supported debug contexts
* for use with Conf::Set("debug", ..).
*/
RD_EXPORT
std::string get_debug_contexts();
/**
* @brief Wait for all rd_kafka_t objects to be destroyed.
*
* @returns 0 if all kafka objects are now destroyed, or -1 if the
* timeout was reached.
* Since RdKafka handle deletion is an asynch operation the
* \p wait_destroyed() function can be used for applications where
* a clean shutdown is required.
*/
RD_EXPORT
int wait_destroyed(int timeout_ms);
/**@}*/
/**
* @name Constants, errors, types
* @{
*
*
*/
/**
* @brief Error codes.
*
* The negative error codes delimited by two underscores
* (\c _ERR__..) denotes errors internal to librdkafka and are
* displayed as \c \"Local: \<error string..\>\", while the error codes
* delimited by a single underscore (\c ERR_..) denote broker
* errors and are displayed as \c \"Broker: \<error string..\>\".
*
* @sa Use RdKafka::err2str() to translate an error code a human readable string
*/
enum ErrorCode {
/* Internal errors to rdkafka: */
/** Begin internal error codes */
ERR__BEGIN = -200,
/** Received message is incorrect */
ERR__BAD_MSG = -199,
/** Bad/unknown compression */
ERR__BAD_COMPRESSION = -198,
/** Broker is going away */
ERR__DESTROY = -197,
/** Generic failure */
ERR__FAIL = -196,
/** Broker transport failure */
ERR__TRANSPORT = -195,
/** Critical system resource */
ERR__CRIT_SYS_RESOURCE = -194,
/** Failed to resolve broker */
ERR__RESOLVE = -193,
/** Produced message timed out*/
ERR__MSG_TIMED_OUT = -192,
/** Reached the end of the topic+partition queue on
* the broker. Not really an error. */
ERR__PARTITION_EOF = -191,
/** Permanent: Partition does not exist in cluster. */
ERR__UNKNOWN_PARTITION = -190,
/** File or filesystem error */
ERR__FS = -189,
/** Permanent: Topic does not exist in cluster. */
ERR__UNKNOWN_TOPIC = -188,
/** All broker connections are down. */
ERR__ALL_BROKERS_DOWN = -187,
/** Invalid argument, or invalid configuration */
ERR__INVALID_ARG = -186,
/** Operation timed out */
ERR__TIMED_OUT = -185,
/** Queue is full */
ERR__QUEUE_FULL = -184,
/** ISR count < required.acks */
ERR__ISR_INSUFF = -183,
/** Broker node update */
ERR__NODE_UPDATE = -182,
/** SSL error */
ERR__SSL = -181,
/** Waiting for coordinator to become available. */
ERR__WAIT_COORD = -180,
/** Unknown client group */
ERR__UNKNOWN_GROUP = -179,
/** Operation in progress */
ERR__IN_PROGRESS = -178,
/** Previous operation in progress, wait for it to finish. */
ERR__PREV_IN_PROGRESS = -177,
/** This operation would interfere with an existing subscription */
ERR__EXISTING_SUBSCRIPTION = -176,
/** Assigned partitions (rebalance_cb) */
ERR__ASSIGN_PARTITIONS = -175,
/** Revoked partitions (rebalance_cb) */
ERR__REVOKE_PARTITIONS = -174,
/** Conflicting use */
ERR__CONFLICT = -173,
/** Wrong state */
ERR__STATE = -172,
/** Unknown protocol */
ERR__UNKNOWN_PROTOCOL = -171,
/** Not implemented */
ERR__NOT_IMPLEMENTED = -170,
/** Authentication failure*/
ERR__AUTHENTICATION = -169,
/** No stored offset */
ERR__NO_OFFSET = -168,
/** Outdated */
ERR__OUTDATED = -167,
/** Timed out in queue */
ERR__TIMED_OUT_QUEUE = -166,
/** Feature not supported by broker */
ERR__UNSUPPORTED_FEATURE = -165,
/** Awaiting cache update */
ERR__WAIT_CACHE = -164,
/** Operation interrupted */
ERR__INTR = -163,
/** Key serialization error */
ERR__KEY_SERIALIZATION = -162,
/** Value serialization error */
ERR__VALUE_SERIALIZATION = -161,
/** Key deserialization error */
ERR__KEY_DESERIALIZATION = -160,
/** Value deserialization error */
ERR__VALUE_DESERIALIZATION = -159,
/** Partial response */
ERR__PARTIAL = -158,
/** Modification attempted on read-only object */
ERR__READ_ONLY = -157,
/** No such entry / item not found */
ERR__NOENT = -156,
/** Read underflow */
ERR__UNDERFLOW = -155,
/** Invalid type */
ERR__INVALID_TYPE = -154,
/** Retry operation */
ERR__RETRY = -153,
/** Purged in queue */
ERR__PURGE_QUEUE = -152,
/** Purged in flight */
ERR__PURGE_INFLIGHT = -151,
/** Fatal error: see ::fatal_error() */
ERR__FATAL = -150,
/** Inconsistent state */
ERR__INCONSISTENT = -149,
/** Gap-less ordering would not be guaranteed if proceeding */
ERR__GAPLESS_GUARANTEE = -148,
/** Maximum poll interval exceeded */
ERR__MAX_POLL_EXCEEDED = -147,
/** End internal error codes */
ERR__END = -100,
/* Kafka broker errors: */
/** Unknown broker error */
ERR_UNKNOWN = -1,
/** Success */
ERR_NO_ERROR = 0,
/** Offset out of range */
ERR_OFFSET_OUT_OF_RANGE = 1,
/** Invalid message */
ERR_INVALID_MSG = 2,
/** Unknown topic or partition */
ERR_UNKNOWN_TOPIC_OR_PART = 3,
/** Invalid message size */
ERR_INVALID_MSG_SIZE = 4,
/** Leader not available */
ERR_LEADER_NOT_AVAILABLE = 5,
/** Not leader for partition */
ERR_NOT_LEADER_FOR_PARTITION = 6,
/** Request timed out */
ERR_REQUEST_TIMED_OUT = 7,
/** Broker not available */
ERR_BROKER_NOT_AVAILABLE = 8,
/** Replica not available */
ERR_REPLICA_NOT_AVAILABLE = 9,
/** Message size too large */
ERR_MSG_SIZE_TOO_LARGE = 10,
/** StaleControllerEpochCode */
ERR_STALE_CTRL_EPOCH = 11,
/** Offset metadata string too large */
ERR_OFFSET_METADATA_TOO_LARGE = 12,
/** Broker disconnected before response received */
ERR_NETWORK_EXCEPTION = 13,
/** Group coordinator load in progress */
ERR_GROUP_LOAD_IN_PROGRESS = 14,
/** Group coordinator not available */
ERR_GROUP_COORDINATOR_NOT_AVAILABLE = 15,
/** Not coordinator for group */
ERR_NOT_COORDINATOR_FOR_GROUP = 16,
/** Invalid topic */
ERR_TOPIC_EXCEPTION = 17,
/** Message batch larger than configured server segment size */
ERR_RECORD_LIST_TOO_LARGE = 18,
/** Not enough in-sync replicas */
ERR_NOT_ENOUGH_REPLICAS = 19,
/** Message(s) written to insufficient number of in-sync replicas */
ERR_NOT_ENOUGH_REPLICAS_AFTER_APPEND = 20,
/** Invalid required acks value */
ERR_INVALID_REQUIRED_ACKS = 21,
/** Specified group generation id is not valid */
ERR_ILLEGAL_GENERATION = 22,
/** Inconsistent group protocol */
ERR_INCONSISTENT_GROUP_PROTOCOL = 23,
/** Invalid group.id */
ERR_INVALID_GROUP_ID = 24,
/** Unknown member */
ERR_UNKNOWN_MEMBER_ID = 25,
/** Invalid session timeout */
ERR_INVALID_SESSION_TIMEOUT = 26,
/** Group rebalance in progress */
ERR_REBALANCE_IN_PROGRESS = 27,
/** Commit offset data size is not valid */
ERR_INVALID_COMMIT_OFFSET_SIZE = 28,
/** Topic authorization failed */
ERR_TOPIC_AUTHORIZATION_FAILED = 29,
/** Group authorization failed */
ERR_GROUP_AUTHORIZATION_FAILED = 30,
/** Cluster authorization failed */
ERR_CLUSTER_AUTHORIZATION_FAILED = 31,
/** Invalid timestamp */
ERR_INVALID_TIMESTAMP = 32,
/** Unsupported SASL mechanism */
ERR_UNSUPPORTED_SASL_MECHANISM = 33,
/** Illegal SASL state */
ERR_ILLEGAL_SASL_STATE = 34,
/** Unuspported version */
ERR_UNSUPPORTED_VERSION = 35,
/** Topic already exists */
ERR_TOPIC_ALREADY_EXISTS = 36,
/** Invalid number of partitions */
ERR_INVALID_PARTITIONS = 37,
/** Invalid replication factor */
ERR_INVALID_REPLICATION_FACTOR = 38,
/** Invalid replica assignment */
ERR_INVALID_REPLICA_ASSIGNMENT = 39,
/** Invalid config */
ERR_INVALID_CONFIG = 40,
/** Not controller for cluster */
ERR_NOT_CONTROLLER = 41,
/** Invalid request */
ERR_INVALID_REQUEST = 42,
/** Message format on broker does not support request */
ERR_UNSUPPORTED_FOR_MESSAGE_FORMAT = 43,
/** Isolation policy volation */
ERR_POLICY_VIOLATION = 44,
/** Broker received an out of order sequence number */
ERR_OUT_OF_ORDER_SEQUENCE_NUMBER = 45,
/** Broker received a duplicate sequence number */
ERR_DUPLICATE_SEQUENCE_NUMBER = 46,
/** Producer attempted an operation with an old epoch */
ERR_INVALID_PRODUCER_EPOCH = 47,
/** Producer attempted a transactional operation in an invalid state */
ERR_INVALID_TXN_STATE = 48,
/** Producer attempted to use a producer id which is not
* currently assigned to its transactional id */
ERR_INVALID_PRODUCER_ID_MAPPING = 49,
/** Transaction timeout is larger than the maximum
* value allowed by the broker's max.transaction.timeout.ms */
ERR_INVALID_TRANSACTION_TIMEOUT = 50,
/** Producer attempted to update a transaction while another
* concurrent operation on the same transaction was ongoing */
ERR_CONCURRENT_TRANSACTIONS = 51,
/** Indicates that the transaction coordinator sending a
* WriteTxnMarker is no longer the current coordinator for a
* given producer */
ERR_TRANSACTION_COORDINATOR_FENCED = 52,
/** Transactional Id authorization failed */
ERR_TRANSACTIONAL_ID_AUTHORIZATION_FAILED = 53,
/** Security features are disabled */
ERR_SECURITY_DISABLED = 54,
/** Operation not attempted */
ERR_OPERATION_NOT_ATTEMPTED = 55,
/** Disk error when trying to access log file on the disk */
ERR_KAFKA_STORAGE_ERROR = 56,
/** The user-specified log directory is not found in the broker config */
ERR_LOG_DIR_NOT_FOUND = 57,
/** SASL Authentication failed */
ERR_SASL_AUTHENTICATION_FAILED = 58,
/** Unknown Producer Id */
ERR_UNKNOWN_PRODUCER_ID = 59,
/** Partition reassignment is in progress */
ERR_REASSIGNMENT_IN_PROGRESS = 60,
/** Delegation Token feature is not enabled */
ERR_DELEGATION_TOKEN_AUTH_DISABLED = 61,
/** Delegation Token is not found on server */
ERR_DELEGATION_TOKEN_NOT_FOUND = 62,
/** Specified Principal is not valid Owner/Renewer */
ERR_DELEGATION_TOKEN_OWNER_MISMATCH = 63,
/** Delegation Token requests are not allowed on this connection */
ERR_DELEGATION_TOKEN_REQUEST_NOT_ALLOWED = 64,
/** Delegation Token authorization failed */
ERR_DELEGATION_TOKEN_AUTHORIZATION_FAILED = 65,
/** Delegation Token is expired */
ERR_DELEGATION_TOKEN_EXPIRED = 66,
/** Supplied principalType is not supported */
ERR_INVALID_PRINCIPAL_TYPE = 67,
/** The group is not empty */
ERR_NON_EMPTY_GROUP = 68,
/** The group id does not exist */
ERR_GROUP_ID_NOT_FOUND = 69,
/** The fetch session ID was not found */
ERR_FETCH_SESSION_ID_NOT_FOUND = 70,
/** The fetch session epoch is invalid */
ERR_INVALID_FETCH_SESSION_EPOCH = 71,
/** No matching listener */
ERR_LISTENER_NOT_FOUND = 72,
/** Topic deletion is disabled */
ERR_TOPIC_DELETION_DISABLED = 73
};
/**
* @brief Returns a human readable representation of a kafka error.
*/
RD_EXPORT
std::string err2str(RdKafka::ErrorCode err);
/**@} */
/**@cond NO_DOC*/
/* Forward declarations */
class Producer;
class Message;
class Queue;
class Event;
class Topic;
class TopicPartition;
class Metadata;
class KafkaConsumer;
/**@endcond*/
/**
* @name Callback classes
* @{
*
*
* librdkafka uses (optional) callbacks to propagate information and
* delegate decisions to the application logic.
*
* An application must call RdKafka::poll() at regular intervals to
* serve queued callbacks.
*/
/**
* @brief Delivery Report callback class
*
* The delivery report callback will be called once for each message
* accepted by RdKafka::Producer::produce() (et.al) with
* RdKafka::Message::err() set to indicate the result of the produce request.
*
* The callback is called when a message is succesfully produced or
* if librdkafka encountered a permanent failure, or the retry counter for
* temporary errors has been exhausted.
*
* An application must call RdKafka::poll() at regular intervals to
* serve queued delivery report callbacks.
*/
class RD_EXPORT DeliveryReportCb {
public:
/**
* @brief Delivery report callback.
*/
virtual void dr_cb (Message &message) = 0;
virtual ~DeliveryReportCb() { }
};
/**
* @brief Partitioner callback class
*
* Generic partitioner callback class for implementing custom partitioners.
*
* @sa RdKafka::Conf::set() \c "partitioner_cb"
*/
class RD_EXPORT PartitionerCb {
public:
/**
* @brief Partitioner callback
*
* Return the partition to use for \p key in \p topic.
*
* The \p msg_opaque is the same \p msg_opaque provided in the
* RdKafka::Producer::produce() call.
*
* @remark \p key may be NULL or the empty.
*
* @returns Must return a value between 0 and \p partition_cnt (non-inclusive).
* May return RD_KAFKA_PARTITION_UA (-1) if partitioning failed.
*
* @sa The callback may use RdKafka::Topic::partition_available() to check
* if a partition has an active leader broker.
*/
virtual int32_t partitioner_cb (const Topic *topic,
const std::string *key,
int32_t partition_cnt,
void *msg_opaque) = 0;
virtual ~PartitionerCb() { }
};
/**
* @brief Variant partitioner with key pointer
*
*/
class PartitionerKeyPointerCb {
public:
/**
* @brief Variant partitioner callback that gets \p key as pointer and length
* instead of as a const std::string *.
*
* @remark \p key may be NULL or have \p key_len 0.
*
* @sa See RdKafka::PartitionerCb::partitioner_cb() for exact semantics
*/
virtual int32_t partitioner_cb (const Topic *topic,
const void *key,
size_t key_len,
int32_t partition_cnt,
void *msg_opaque) = 0;
virtual ~PartitionerKeyPointerCb() { }
};
/**
* @brief Event callback class
*
* Events are a generic interface for propagating errors, statistics, logs, etc
* from librdkafka to the application.
*
* @sa RdKafka::Event
*/
class RD_EXPORT EventCb {
public:
/**
* @brief Event callback
*
* @sa RdKafka::Event
*/
virtual void event_cb (Event &event) = 0;
virtual ~EventCb() { }
};
/**
* @brief Event object class as passed to the EventCb callback.
*/
class RD_EXPORT Event {
public:
/** @brief Event type */
enum Type {
EVENT_ERROR, /**< Event is an error condition */
EVENT_STATS, /**< Event is a statistics JSON document */
EVENT_LOG, /**< Event is a log message */
EVENT_THROTTLE /**< Event is a throttle level signaling from the broker */
};
/** @brief EVENT_LOG severities (conforms to syslog(3) severities) */
enum Severity {
EVENT_SEVERITY_EMERG = 0,
EVENT_SEVERITY_ALERT = 1,
EVENT_SEVERITY_CRITICAL = 2,
EVENT_SEVERITY_ERROR = 3,
EVENT_SEVERITY_WARNING = 4,
EVENT_SEVERITY_NOTICE = 5,
EVENT_SEVERITY_INFO = 6,
EVENT_SEVERITY_DEBUG = 7
};
virtual ~Event () { }
/*
* Event Accessor methods
*/
/**
* @returns The event type
* @remark Applies to all event types
*/
virtual Type type () const = 0;
/**
* @returns Event error, if any.
* @remark Applies to all event types except THROTTLE
*/
virtual ErrorCode err () const = 0;
/**
* @returns Log severity level.
* @remark Applies to LOG event type.
*/
virtual Severity severity () const = 0;
/**
* @returns Log facility string.
* @remark Applies to LOG event type.
*/
virtual std::string fac () const = 0;
/**
* @returns Log message string.
*
* \c EVENT_LOG: Log message string.
* \c EVENT_STATS: JSON object (as string).
*
* @remark Applies to LOG event type.
*/
virtual std::string str () const = 0;
/**
* @returns Throttle time in milliseconds.
* @remark Applies to THROTTLE event type.
*/
virtual int throttle_time () const = 0;
/**
* @returns Throttling broker's name.
* @remark Applies to THROTTLE event type.
*/
virtual std::string broker_name () const = 0;
/**
* @returns Throttling broker's id.
* @remark Applies to THROTTLE event type.
*/
virtual int broker_id () const = 0;
/**
* @returns true if this is a fatal error.
* @remark Applies to ERROR event type.
* @sa RdKafka::Handle::fatal_error()
*/
virtual bool fatal () const = 0;
};
/**
* @brief Consume callback class
*/
class RD_EXPORT ConsumeCb {
public:
/**
* @brief The consume callback is used with
* RdKafka::Consumer::consume_callback()
* methods and will be called for each consumed \p message.
*
* The callback interface is optional but provides increased performance.
*/
virtual void consume_cb (Message &message, void *opaque) = 0;
virtual ~ConsumeCb() { }
};
/**
* @brief \b KafkaConsunmer: Rebalance callback class
*/
class RD_EXPORT RebalanceCb {
public:
/**
* @brief Group rebalance callback for use with RdKafka::KafkaConsunmer
*
* Registering a \p rebalance_cb turns off librdkafka's automatic
* partition assignment/revocation and instead delegates that responsibility
* to the application's \p rebalance_cb.
*
* The rebalance callback is responsible for updating librdkafka's
* assignment set based on the two events: RdKafka::ERR__ASSIGN_PARTITIONS
* and RdKafka::ERR__REVOKE_PARTITIONS but should also be able to handle
* arbitrary rebalancing failures where \p err is neither of those.
* @remark In this latter case (arbitrary error), the application must
* call unassign() to synchronize state.
*
* Without a rebalance callback this is done automatically by librdkafka
* but registering a rebalance callback gives the application flexibility
* in performing other operations along with the assinging/revocation,
* such as fetching offsets from an alternate location (on assign)
* or manually committing offsets (on revoke).
*
* The following example show's the application's responsibilities:
* @code
* class MyRebalanceCb : public RdKafka::RebalanceCb {
* public:
* void rebalance_cb (RdKafka::KafkaConsumer *consumer,
* RdKafka::ErrorCode err,
* std::vector<RdKafka::TopicPartition*> &partitions) {
* if (err == RdKafka::ERR__ASSIGN_PARTITIONS) {
* // application may load offets from arbitrary external
* // storage here and update \p partitions
*
* consumer->assign(partitions);
*
* } else if (err == RdKafka::ERR__REVOKE_PARTITIONS) {
* // Application may commit offsets manually here
* // if auto.commit.enable=false
*
* consumer->unassign();
*
* } else {
* std::cerr << "Rebalancing error: <<
* RdKafka::err2str(err) << std::endl;
* consumer->unassign();
* }
* }
* }
* @endcode
*/
virtual void rebalance_cb (RdKafka::KafkaConsumer *consumer,
RdKafka::ErrorCode err,
std::vector<TopicPartition*>&partitions) = 0;
virtual ~RebalanceCb() { }
};
/**
* @brief Offset Commit callback class
*/
class RD_EXPORT OffsetCommitCb {
public:
/**
* @brief Set offset commit callback for use with consumer groups
*
* The results of automatic or manual offset commits will be scheduled
* for this callback and is served by RdKafka::KafkaConsumer::consume().
*
* If no partitions had valid offsets to commit this callback will be called
* with \p err == ERR__NO_OFFSET which is not to be considered an error.
*
* The \p offsets list contains per-partition information:
* - \c topic The topic committed
* - \c partition The partition committed
* - \c offset: Committed offset (attempted)
* - \c err: Commit error
*/
virtual void offset_commit_cb(RdKafka::ErrorCode err,
std::vector<TopicPartition*>&offsets) = 0;
virtual ~OffsetCommitCb() { }
};
/**
* @brief \b Portability: SocketCb callback class
*
*/
class RD_EXPORT SocketCb {
public:
/**
* @brief Socket callback
*
* The socket callback is responsible for opening a socket
* according to the supplied \p domain, \p type and \p protocol.
* The socket shall be created with \c CLOEXEC set in a racefree fashion, if
* possible.
*
* It is typically not required to register an alternative socket
* implementation
*
* @returns The socket file descriptor or -1 on error (\c errno must be set)
*/
virtual int socket_cb (int domain, int type, int protocol) = 0;
virtual ~SocketCb() { }
};
/**
* @brief \b Portability: OpenCb callback class
*
*/
class RD_EXPORT OpenCb {
public:
/**
* @brief Open callback
* The open callback is responsible for opening the file specified by
* \p pathname, using \p flags and \p mode.
* The file shall be opened with \c CLOEXEC set in a racefree fashion, if
* possible.
*
* It is typically not required to register an alternative open implementation
*
* @remark Not currently available on native Win32
*/
virtual int open_cb (const std::string &path, int flags, int mode) = 0;
virtual ~OpenCb() { }
};
/**@}*/
/**
* @name Configuration interface
* @{
*
*/
/**
* @brief Configuration interface
*
* Holds either global or topic configuration that are passed to
* RdKafka::Consumer::create(), RdKafka::Producer::create(),
* RdKafka::KafkaConsumer::create(), etc.
*
* @sa CONFIGURATION.md for the full list of supported properties.
*/
class RD_EXPORT Conf {
public:
/**
* @brief Configuration object type
*/
enum ConfType {
CONF_GLOBAL, /**< Global configuration */
CONF_TOPIC /**< Topic specific configuration */
};
/**
* @brief RdKafka::Conf::Set() result code
*/
enum ConfResult {
CONF_UNKNOWN = -2, /**< Unknown configuration property */
CONF_INVALID = -1, /**< Invalid configuration value */
CONF_OK = 0 /**< Configuration property was succesfully set */
};
/**
* @brief Create configuration object
*/
static Conf *create (ConfType type);
virtual ~Conf () { }
/**
* @brief Set configuration property \p name to value \p value.
*
* Fallthrough:
* Topic-level configuration properties may be set using this interface
* in which case they are applied on the \c default_topic_conf.
* If no \c default_topic_conf has been set one will be created.
* Any sub-sequent set("default_topic_conf", ..) calls will
* replace the current default topic configuration.
* @returns CONF_OK on success, else writes a human readable error
* description to \p errstr on error.
*/
virtual Conf::ConfResult set (const std::string &name,
const std::string &value,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"dr_cb\" */
virtual Conf::ConfResult set (const std::string &name,
DeliveryReportCb *dr_cb,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"event_cb\" */
virtual Conf::ConfResult set (const std::string &name,
EventCb *event_cb,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"default_topic_conf\"
*
* Sets the default topic configuration to use for for automatically
* subscribed topics.
*
* @sa RdKafka::KafkaConsumer::subscribe()
*/
virtual Conf::ConfResult set (const std::string &name,
const Conf *topic_conf,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"partitioner_cb\" */
virtual Conf::ConfResult set (const std::string &name,
PartitionerCb *partitioner_cb,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"partitioner_key_pointer_cb\" */
virtual Conf::ConfResult set (const std::string &name,
PartitionerKeyPointerCb *partitioner_kp_cb,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"socket_cb\" */
virtual Conf::ConfResult set (const std::string &name, SocketCb *socket_cb,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"open_cb\" */
virtual Conf::ConfResult set (const std::string &name, OpenCb *open_cb,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"rebalance_cb\" */
virtual Conf::ConfResult set (const std::string &name,
RebalanceCb *rebalance_cb,
std::string &errstr) = 0;
/** @brief Use with \p name = \c \"offset_commit_cb\" */
virtual Conf::ConfResult set (const std::string &name,
OffsetCommitCb *offset_commit_cb,
std::string &errstr) = 0;
/** @brief Query single configuration value
*
* Do not use this method to get callbacks registered by the configuration file.
* Instead use the specific get() methods with the specific callback parameter in the signature.
*
* Fallthrough:
* Topic-level configuration properties from the \c default_topic_conf
* may be retrieved using this interface.
*
* @returns CONF_OK if the property was set previously set and
* returns the value in \p value. */
virtual Conf::ConfResult get(const std::string &name,
std::string &value) const = 0;
/** @brief Query single configuration value
* @returns CONF_OK if the property was set previously set and
* returns the value in \p dr_cb. */
virtual Conf::ConfResult get(DeliveryReportCb *&dr_cb) const = 0;
/** @brief Query single configuration value
* @returns CONF_OK if the property was set previously set and
* returns the value in \p event_cb. */
virtual Conf::ConfResult get(EventCb *&event_cb) const = 0;
/** @brief Query single configuration value
* @returns CONF_OK if the property was set previously set and
* returns the value in \p partitioner_cb. */
virtual Conf::ConfResult get(PartitionerCb *&partitioner_cb) const = 0;
/** @brief Query single configuration value
* @returns CONF_OK if the property was set previously set and
* returns the value in \p partitioner_kp_cb. */
virtual Conf::ConfResult get(PartitionerKeyPointerCb *&partitioner_kp_cb) const = 0;
/** @brief Query single configuration value
* @returns CONF_OK if the property was set previously set and
* returns the value in \p socket_cb. */
virtual Conf::ConfResult get(SocketCb *&socket_cb) const = 0;
/** @brief Query single configuration value
* @returns CONF_OK if the property was set previously set and
* returns the value in \p open_cb. */
virtual Conf::ConfResult get(OpenCb *&open_cb) const = 0;
/** @brief Query single configuration value
* @returns CONF_OK if the property was set previously set and
* returns the value in \p rebalance_cb. */
virtual Conf::ConfResult get(RebalanceCb *&rebalance_cb) const = 0;
/** @brief Query single configuration value
* @returns CONF_OK if the property was set previously set and
* returns the value in \p offset_commit_cb. */
virtual Conf::ConfResult get(OffsetCommitCb *&offset_commit_cb) const = 0;
/** @brief Dump configuration names and values to list containing
* name,value tuples */
virtual std::list<std::string> *dump () = 0;
/** @brief Use with \p name = \c \"consume_cb\" */
virtual Conf::ConfResult set (const std::string &name, ConsumeCb *consume_cb,
std::string &errstr) = 0;
};