WIP [VOL-2811] - Incorporate preliminary onu-adapter-go code into opencord repo
- reason "discovery-mibsync-complete" reached (via full MibUpload only, received data won't be stored yet)
- first review comments of patchset #4 considered
(please have a look into our inline-comments in Gerrit to know more about the current state)
- no refactoring done yet
Change-Id: Iac47817f8ce4bd28dd8132f530b0570d57ae99b8
Signed-off-by: Holger Hildebrandt <holger.hildebrandt@adtran.com>
diff --git a/vendor/github.com/Shopify/sarama/consumer.go b/vendor/github.com/Shopify/sarama/consumer.go
new file mode 100644
index 0000000..72c4d7c
--- /dev/null
+++ b/vendor/github.com/Shopify/sarama/consumer.go
@@ -0,0 +1,896 @@
+package sarama
+
+import (
+ "errors"
+ "fmt"
+ "math"
+ "sync"
+ "sync/atomic"
+ "time"
+
+ "github.com/rcrowley/go-metrics"
+)
+
+// ConsumerMessage encapsulates a Kafka message returned by the consumer.
+type ConsumerMessage struct {
+ Headers []*RecordHeader // only set if kafka is version 0.11+
+ Timestamp time.Time // only set if kafka is version 0.10+, inner message timestamp
+ BlockTimestamp time.Time // only set if kafka is version 0.10+, outer (compressed) block timestamp
+
+ Key, Value []byte
+ Topic string
+ Partition int32
+ Offset int64
+}
+
+// ConsumerError is what is provided to the user when an error occurs.
+// It wraps an error and includes the topic and partition.
+type ConsumerError struct {
+ Topic string
+ Partition int32
+ Err error
+}
+
+func (ce ConsumerError) Error() string {
+ return fmt.Sprintf("kafka: error while consuming %s/%d: %s", ce.Topic, ce.Partition, ce.Err)
+}
+
+// ConsumerErrors is a type that wraps a batch of errors and implements the Error interface.
+// It can be returned from the PartitionConsumer's Close methods to avoid the need to manually drain errors
+// when stopping.
+type ConsumerErrors []*ConsumerError
+
+func (ce ConsumerErrors) Error() string {
+ return fmt.Sprintf("kafka: %d errors while consuming", len(ce))
+}
+
+// Consumer manages PartitionConsumers which process Kafka messages from brokers. You MUST call Close()
+// on a consumer to avoid leaks, it will not be garbage-collected automatically when it passes out of
+// scope.
+type Consumer interface {
+ // Topics returns the set of available topics as retrieved from the cluster
+ // metadata. This method is the same as Client.Topics(), and is provided for
+ // convenience.
+ Topics() ([]string, error)
+
+ // Partitions returns the sorted list of all partition IDs for the given topic.
+ // This method is the same as Client.Partitions(), and is provided for convenience.
+ Partitions(topic string) ([]int32, error)
+
+ // ConsumePartition creates a PartitionConsumer on the given topic/partition with
+ // the given offset. It will return an error if this Consumer is already consuming
+ // on the given topic/partition. Offset can be a literal offset, or OffsetNewest
+ // or OffsetOldest
+ ConsumePartition(topic string, partition int32, offset int64) (PartitionConsumer, error)
+
+ // HighWaterMarks returns the current high water marks for each topic and partition.
+ // Consistency between partitions is not guaranteed since high water marks are updated separately.
+ HighWaterMarks() map[string]map[int32]int64
+
+ // Close shuts down the consumer. It must be called after all child
+ // PartitionConsumers have already been closed.
+ Close() error
+}
+
+type consumer struct {
+ conf *Config
+ children map[string]map[int32]*partitionConsumer
+ brokerConsumers map[*Broker]*brokerConsumer
+ client Client
+ lock sync.Mutex
+}
+
+// NewConsumer creates a new consumer using the given broker addresses and configuration.
+func NewConsumer(addrs []string, config *Config) (Consumer, error) {
+ client, err := NewClient(addrs, config)
+ if err != nil {
+ return nil, err
+ }
+ return newConsumer(client)
+}
+
+// NewConsumerFromClient creates a new consumer using the given client. It is still
+// necessary to call Close() on the underlying client when shutting down this consumer.
+func NewConsumerFromClient(client Client) (Consumer, error) {
+ // For clients passed in by the client, ensure we don't
+ // call Close() on it.
+ cli := &nopCloserClient{client}
+ return newConsumer(cli)
+}
+
+func newConsumer(client Client) (Consumer, error) {
+ // Check that we are not dealing with a closed Client before processing any other arguments
+ if client.Closed() {
+ return nil, ErrClosedClient
+ }
+
+ c := &consumer{
+ client: client,
+ conf: client.Config(),
+ children: make(map[string]map[int32]*partitionConsumer),
+ brokerConsumers: make(map[*Broker]*brokerConsumer),
+ }
+
+ return c, nil
+}
+
+func (c *consumer) Close() error {
+ return c.client.Close()
+}
+
+func (c *consumer) Topics() ([]string, error) {
+ return c.client.Topics()
+}
+
+func (c *consumer) Partitions(topic string) ([]int32, error) {
+ return c.client.Partitions(topic)
+}
+
+func (c *consumer) ConsumePartition(topic string, partition int32, offset int64) (PartitionConsumer, error) {
+ child := &partitionConsumer{
+ consumer: c,
+ conf: c.conf,
+ topic: topic,
+ partition: partition,
+ messages: make(chan *ConsumerMessage, c.conf.ChannelBufferSize),
+ errors: make(chan *ConsumerError, c.conf.ChannelBufferSize),
+ feeder: make(chan *FetchResponse, 1),
+ trigger: make(chan none, 1),
+ dying: make(chan none),
+ fetchSize: c.conf.Consumer.Fetch.Default,
+ }
+
+ if err := child.chooseStartingOffset(offset); err != nil {
+ return nil, err
+ }
+
+ var leader *Broker
+ var err error
+ if leader, err = c.client.Leader(child.topic, child.partition); err != nil {
+ return nil, err
+ }
+
+ if err := c.addChild(child); err != nil {
+ return nil, err
+ }
+
+ go withRecover(child.dispatcher)
+ go withRecover(child.responseFeeder)
+
+ child.broker = c.refBrokerConsumer(leader)
+ child.broker.input <- child
+
+ return child, nil
+}
+
+func (c *consumer) HighWaterMarks() map[string]map[int32]int64 {
+ c.lock.Lock()
+ defer c.lock.Unlock()
+
+ hwms := make(map[string]map[int32]int64)
+ for topic, p := range c.children {
+ hwm := make(map[int32]int64, len(p))
+ for partition, pc := range p {
+ hwm[partition] = pc.HighWaterMarkOffset()
+ }
+ hwms[topic] = hwm
+ }
+
+ return hwms
+}
+
+func (c *consumer) addChild(child *partitionConsumer) error {
+ c.lock.Lock()
+ defer c.lock.Unlock()
+
+ topicChildren := c.children[child.topic]
+ if topicChildren == nil {
+ topicChildren = make(map[int32]*partitionConsumer)
+ c.children[child.topic] = topicChildren
+ }
+
+ if topicChildren[child.partition] != nil {
+ return ConfigurationError("That topic/partition is already being consumed")
+ }
+
+ topicChildren[child.partition] = child
+ return nil
+}
+
+func (c *consumer) removeChild(child *partitionConsumer) {
+ c.lock.Lock()
+ defer c.lock.Unlock()
+
+ delete(c.children[child.topic], child.partition)
+}
+
+func (c *consumer) refBrokerConsumer(broker *Broker) *brokerConsumer {
+ c.lock.Lock()
+ defer c.lock.Unlock()
+
+ bc := c.brokerConsumers[broker]
+ if bc == nil {
+ bc = c.newBrokerConsumer(broker)
+ c.brokerConsumers[broker] = bc
+ }
+
+ bc.refs++
+
+ return bc
+}
+
+func (c *consumer) unrefBrokerConsumer(brokerWorker *brokerConsumer) {
+ c.lock.Lock()
+ defer c.lock.Unlock()
+
+ brokerWorker.refs--
+
+ if brokerWorker.refs == 0 {
+ close(brokerWorker.input)
+ if c.brokerConsumers[brokerWorker.broker] == brokerWorker {
+ delete(c.brokerConsumers, brokerWorker.broker)
+ }
+ }
+}
+
+func (c *consumer) abandonBrokerConsumer(brokerWorker *brokerConsumer) {
+ c.lock.Lock()
+ defer c.lock.Unlock()
+
+ delete(c.brokerConsumers, brokerWorker.broker)
+}
+
+// PartitionConsumer
+
+// PartitionConsumer processes Kafka messages from a given topic and partition. You MUST call one of Close() or
+// AsyncClose() on a PartitionConsumer to avoid leaks; it will not be garbage-collected automatically when it passes out
+// of scope.
+//
+// The simplest way of using a PartitionConsumer is to loop over its Messages channel using a for/range
+// loop. The PartitionConsumer will only stop itself in one case: when the offset being consumed is reported
+// as out of range by the brokers. In this case you should decide what you want to do (try a different offset,
+// notify a human, etc) and handle it appropriately. For all other error cases, it will just keep retrying.
+// By default, it logs these errors to sarama.Logger; if you want to be notified directly of all errors, set
+// your config's Consumer.Return.Errors to true and read from the Errors channel, using a select statement
+// or a separate goroutine. Check out the Consumer examples to see implementations of these different approaches.
+//
+// To terminate such a for/range loop while the loop is executing, call AsyncClose. This will kick off the process of
+// consumer tear-down & return immediately. Continue to loop, servicing the Messages channel until the teardown process
+// AsyncClose initiated closes it (thus terminating the for/range loop). If you've already ceased reading Messages, call
+// Close; this will signal the PartitionConsumer's goroutines to begin shutting down (just like AsyncClose), but will
+// also drain the Messages channel, harvest all errors & return them once cleanup has completed.
+type PartitionConsumer interface {
+ // AsyncClose initiates a shutdown of the PartitionConsumer. This method will return immediately, after which you
+ // should continue to service the 'Messages' and 'Errors' channels until they are empty. It is required to call this
+ // function, or Close before a consumer object passes out of scope, as it will otherwise leak memory. You must call
+ // this before calling Close on the underlying client.
+ AsyncClose()
+
+ // Close stops the PartitionConsumer from fetching messages. It will initiate a shutdown just like AsyncClose, drain
+ // the Messages channel, harvest any errors & return them to the caller. Note that if you are continuing to service
+ // the Messages channel when this function is called, you will be competing with Close for messages; consider
+ // calling AsyncClose, instead. It is required to call this function (or AsyncClose) before a consumer object passes
+ // out of scope, as it will otherwise leak memory. You must call this before calling Close on the underlying client.
+ Close() error
+
+ // Messages returns the read channel for the messages that are returned by
+ // the broker.
+ Messages() <-chan *ConsumerMessage
+
+ // Errors returns a read channel of errors that occurred during consuming, if
+ // enabled. By default, errors are logged and not returned over this channel.
+ // If you want to implement any custom error handling, set your config's
+ // Consumer.Return.Errors setting to true, and read from this channel.
+ Errors() <-chan *ConsumerError
+
+ // HighWaterMarkOffset returns the high water mark offset of the partition,
+ // i.e. the offset that will be used for the next message that will be produced.
+ // You can use this to determine how far behind the processing is.
+ HighWaterMarkOffset() int64
+}
+
+type partitionConsumer struct {
+ highWaterMarkOffset int64 // must be at the top of the struct because https://golang.org/pkg/sync/atomic/#pkg-note-BUG
+
+ consumer *consumer
+ conf *Config
+ broker *brokerConsumer
+ messages chan *ConsumerMessage
+ errors chan *ConsumerError
+ feeder chan *FetchResponse
+
+ trigger, dying chan none
+ closeOnce sync.Once
+ topic string
+ partition int32
+ responseResult error
+ fetchSize int32
+ offset int64
+ retries int32
+}
+
+var errTimedOut = errors.New("timed out feeding messages to the user") // not user-facing
+
+func (child *partitionConsumer) sendError(err error) {
+ cErr := &ConsumerError{
+ Topic: child.topic,
+ Partition: child.partition,
+ Err: err,
+ }
+
+ if child.conf.Consumer.Return.Errors {
+ child.errors <- cErr
+ } else {
+ Logger.Println(cErr)
+ }
+}
+
+func (child *partitionConsumer) computeBackoff() time.Duration {
+ if child.conf.Consumer.Retry.BackoffFunc != nil {
+ retries := atomic.AddInt32(&child.retries, 1)
+ return child.conf.Consumer.Retry.BackoffFunc(int(retries))
+ }
+ return child.conf.Consumer.Retry.Backoff
+}
+
+func (child *partitionConsumer) dispatcher() {
+ for range child.trigger {
+ select {
+ case <-child.dying:
+ close(child.trigger)
+ case <-time.After(child.computeBackoff()):
+ if child.broker != nil {
+ child.consumer.unrefBrokerConsumer(child.broker)
+ child.broker = nil
+ }
+
+ Logger.Printf("consumer/%s/%d finding new broker\n", child.topic, child.partition)
+ if err := child.dispatch(); err != nil {
+ child.sendError(err)
+ child.trigger <- none{}
+ }
+ }
+ }
+
+ if child.broker != nil {
+ child.consumer.unrefBrokerConsumer(child.broker)
+ }
+ child.consumer.removeChild(child)
+ close(child.feeder)
+}
+
+func (child *partitionConsumer) dispatch() error {
+ if err := child.consumer.client.RefreshMetadata(child.topic); err != nil {
+ return err
+ }
+
+ var leader *Broker
+ var err error
+ if leader, err = child.consumer.client.Leader(child.topic, child.partition); err != nil {
+ return err
+ }
+
+ child.broker = child.consumer.refBrokerConsumer(leader)
+
+ child.broker.input <- child
+
+ return nil
+}
+
+func (child *partitionConsumer) chooseStartingOffset(offset int64) error {
+ newestOffset, err := child.consumer.client.GetOffset(child.topic, child.partition, OffsetNewest)
+ if err != nil {
+ return err
+ }
+ oldestOffset, err := child.consumer.client.GetOffset(child.topic, child.partition, OffsetOldest)
+ if err != nil {
+ return err
+ }
+
+ switch {
+ case offset == OffsetNewest:
+ child.offset = newestOffset
+ case offset == OffsetOldest:
+ child.offset = oldestOffset
+ case offset >= oldestOffset && offset <= newestOffset:
+ child.offset = offset
+ default:
+ return ErrOffsetOutOfRange
+ }
+
+ return nil
+}
+
+func (child *partitionConsumer) Messages() <-chan *ConsumerMessage {
+ return child.messages
+}
+
+func (child *partitionConsumer) Errors() <-chan *ConsumerError {
+ return child.errors
+}
+
+func (child *partitionConsumer) AsyncClose() {
+ // this triggers whatever broker owns this child to abandon it and close its trigger channel, which causes
+ // the dispatcher to exit its loop, which removes it from the consumer then closes its 'messages' and
+ // 'errors' channel (alternatively, if the child is already at the dispatcher for some reason, that will
+ // also just close itself)
+ child.closeOnce.Do(func() {
+ close(child.dying)
+ })
+}
+
+func (child *partitionConsumer) Close() error {
+ child.AsyncClose()
+
+ var errors ConsumerErrors
+ for err := range child.errors {
+ errors = append(errors, err)
+ }
+
+ if len(errors) > 0 {
+ return errors
+ }
+ return nil
+}
+
+func (child *partitionConsumer) HighWaterMarkOffset() int64 {
+ return atomic.LoadInt64(&child.highWaterMarkOffset)
+}
+
+func (child *partitionConsumer) responseFeeder() {
+ var msgs []*ConsumerMessage
+ expiryTicker := time.NewTicker(child.conf.Consumer.MaxProcessingTime)
+ firstAttempt := true
+
+feederLoop:
+ for response := range child.feeder {
+ msgs, child.responseResult = child.parseResponse(response)
+
+ if child.responseResult == nil {
+ atomic.StoreInt32(&child.retries, 0)
+ }
+
+ for i, msg := range msgs {
+ messageSelect:
+ select {
+ case <-child.dying:
+ child.broker.acks.Done()
+ continue feederLoop
+ case child.messages <- msg:
+ firstAttempt = true
+ case <-expiryTicker.C:
+ if !firstAttempt {
+ child.responseResult = errTimedOut
+ child.broker.acks.Done()
+ remainingLoop:
+ for _, msg = range msgs[i:] {
+ select {
+ case child.messages <- msg:
+ case <-child.dying:
+ break remainingLoop
+ }
+ }
+ child.broker.input <- child
+ continue feederLoop
+ } else {
+ // current message has not been sent, return to select
+ // statement
+ firstAttempt = false
+ goto messageSelect
+ }
+ }
+ }
+
+ child.broker.acks.Done()
+ }
+
+ expiryTicker.Stop()
+ close(child.messages)
+ close(child.errors)
+}
+
+func (child *partitionConsumer) parseMessages(msgSet *MessageSet) ([]*ConsumerMessage, error) {
+ var messages []*ConsumerMessage
+ for _, msgBlock := range msgSet.Messages {
+ for _, msg := range msgBlock.Messages() {
+ offset := msg.Offset
+ timestamp := msg.Msg.Timestamp
+ if msg.Msg.Version >= 1 {
+ baseOffset := msgBlock.Offset - msgBlock.Messages()[len(msgBlock.Messages())-1].Offset
+ offset += baseOffset
+ if msg.Msg.LogAppendTime {
+ timestamp = msgBlock.Msg.Timestamp
+ }
+ }
+ if offset < child.offset {
+ continue
+ }
+ messages = append(messages, &ConsumerMessage{
+ Topic: child.topic,
+ Partition: child.partition,
+ Key: msg.Msg.Key,
+ Value: msg.Msg.Value,
+ Offset: offset,
+ Timestamp: timestamp,
+ BlockTimestamp: msgBlock.Msg.Timestamp,
+ })
+ child.offset = offset + 1
+ }
+ }
+ if len(messages) == 0 {
+ child.offset++
+ }
+ return messages, nil
+}
+
+func (child *partitionConsumer) parseRecords(batch *RecordBatch) ([]*ConsumerMessage, error) {
+ messages := make([]*ConsumerMessage, 0, len(batch.Records))
+
+ for _, rec := range batch.Records {
+ offset := batch.FirstOffset + rec.OffsetDelta
+ if offset < child.offset {
+ continue
+ }
+ timestamp := batch.FirstTimestamp.Add(rec.TimestampDelta)
+ if batch.LogAppendTime {
+ timestamp = batch.MaxTimestamp
+ }
+ messages = append(messages, &ConsumerMessage{
+ Topic: child.topic,
+ Partition: child.partition,
+ Key: rec.Key,
+ Value: rec.Value,
+ Offset: offset,
+ Timestamp: timestamp,
+ Headers: rec.Headers,
+ })
+ child.offset = offset + 1
+ }
+ if len(messages) == 0 {
+ child.offset++
+ }
+ return messages, nil
+}
+
+func (child *partitionConsumer) parseResponse(response *FetchResponse) ([]*ConsumerMessage, error) {
+ var (
+ metricRegistry = child.conf.MetricRegistry
+ consumerBatchSizeMetric metrics.Histogram
+ )
+
+ if metricRegistry != nil {
+ consumerBatchSizeMetric = getOrRegisterHistogram("consumer-batch-size", metricRegistry)
+ }
+
+ // If request was throttled and empty we log and return without error
+ if response.ThrottleTime != time.Duration(0) && len(response.Blocks) == 0 {
+ Logger.Printf(
+ "consumer/broker/%d FetchResponse throttled %v\n",
+ child.broker.broker.ID(), response.ThrottleTime)
+ return nil, nil
+ }
+
+ block := response.GetBlock(child.topic, child.partition)
+ if block == nil {
+ return nil, ErrIncompleteResponse
+ }
+
+ if block.Err != ErrNoError {
+ return nil, block.Err
+ }
+
+ nRecs, err := block.numRecords()
+ if err != nil {
+ return nil, err
+ }
+
+ consumerBatchSizeMetric.Update(int64(nRecs))
+
+ if nRecs == 0 {
+ partialTrailingMessage, err := block.isPartial()
+ if err != nil {
+ return nil, err
+ }
+ // We got no messages. If we got a trailing one then we need to ask for more data.
+ // Otherwise we just poll again and wait for one to be produced...
+ if partialTrailingMessage {
+ if child.conf.Consumer.Fetch.Max > 0 && child.fetchSize == child.conf.Consumer.Fetch.Max {
+ // we can't ask for more data, we've hit the configured limit
+ child.sendError(ErrMessageTooLarge)
+ child.offset++ // skip this one so we can keep processing future messages
+ } else {
+ child.fetchSize *= 2
+ // check int32 overflow
+ if child.fetchSize < 0 {
+ child.fetchSize = math.MaxInt32
+ }
+ if child.conf.Consumer.Fetch.Max > 0 && child.fetchSize > child.conf.Consumer.Fetch.Max {
+ child.fetchSize = child.conf.Consumer.Fetch.Max
+ }
+ }
+ }
+
+ return nil, nil
+ }
+
+ // we got messages, reset our fetch size in case it was increased for a previous request
+ child.fetchSize = child.conf.Consumer.Fetch.Default
+ atomic.StoreInt64(&child.highWaterMarkOffset, block.HighWaterMarkOffset)
+
+ // abortedProducerIDs contains producerID which message should be ignored as uncommitted
+ // - producerID are added when the partitionConsumer iterate over the offset at which an aborted transaction begins (abortedTransaction.FirstOffset)
+ // - producerID are removed when partitionConsumer iterate over an aborted controlRecord, meaning the aborted transaction for this producer is over
+ abortedProducerIDs := make(map[int64]struct{}, len(block.AbortedTransactions))
+ abortedTransactions := block.getAbortedTransactions()
+
+ messages := []*ConsumerMessage{}
+ for _, records := range block.RecordsSet {
+ switch records.recordsType {
+ case legacyRecords:
+ messageSetMessages, err := child.parseMessages(records.MsgSet)
+ if err != nil {
+ return nil, err
+ }
+
+ messages = append(messages, messageSetMessages...)
+ case defaultRecords:
+ // Consume remaining abortedTransaction up to last offset of current batch
+ for _, txn := range abortedTransactions {
+ if txn.FirstOffset > records.RecordBatch.LastOffset() {
+ break
+ }
+ abortedProducerIDs[txn.ProducerID] = struct{}{}
+ // Pop abortedTransactions so that we never add it again
+ abortedTransactions = abortedTransactions[1:]
+ }
+
+ recordBatchMessages, err := child.parseRecords(records.RecordBatch)
+ if err != nil {
+ return nil, err
+ }
+
+ // Parse and commit offset but do not expose messages that are:
+ // - control records
+ // - part of an aborted transaction when set to `ReadCommitted`
+
+ // control record
+ isControl, err := records.isControl()
+ if err != nil {
+ // I don't know why there is this continue in case of error to begin with
+ // Safe bet is to ignore control messages if ReadUncommitted
+ // and block on them in case of error and ReadCommitted
+ if child.conf.Consumer.IsolationLevel == ReadCommitted {
+ return nil, err
+ }
+ continue
+ }
+ if isControl {
+ controlRecord, err := records.getControlRecord()
+ if err != nil {
+ return nil, err
+ }
+
+ if controlRecord.Type == ControlRecordAbort {
+ delete(abortedProducerIDs, records.RecordBatch.ProducerID)
+ }
+ continue
+ }
+
+ // filter aborted transactions
+ if child.conf.Consumer.IsolationLevel == ReadCommitted {
+ _, isAborted := abortedProducerIDs[records.RecordBatch.ProducerID]
+ if records.RecordBatch.IsTransactional && isAborted {
+ continue
+ }
+ }
+
+ messages = append(messages, recordBatchMessages...)
+ default:
+ return nil, fmt.Errorf("unknown records type: %v", records.recordsType)
+ }
+ }
+
+ return messages, nil
+}
+
+type brokerConsumer struct {
+ consumer *consumer
+ broker *Broker
+ input chan *partitionConsumer
+ newSubscriptions chan []*partitionConsumer
+ subscriptions map[*partitionConsumer]none
+ wait chan none
+ acks sync.WaitGroup
+ refs int
+}
+
+func (c *consumer) newBrokerConsumer(broker *Broker) *brokerConsumer {
+ bc := &brokerConsumer{
+ consumer: c,
+ broker: broker,
+ input: make(chan *partitionConsumer),
+ newSubscriptions: make(chan []*partitionConsumer),
+ wait: make(chan none),
+ subscriptions: make(map[*partitionConsumer]none),
+ refs: 0,
+ }
+
+ go withRecover(bc.subscriptionManager)
+ go withRecover(bc.subscriptionConsumer)
+
+ return bc
+}
+
+// The subscriptionManager constantly accepts new subscriptions on `input` (even when the main subscriptionConsumer
+// goroutine is in the middle of a network request) and batches it up. The main worker goroutine picks
+// up a batch of new subscriptions between every network request by reading from `newSubscriptions`, so we give
+// it nil if no new subscriptions are available. We also write to `wait` only when new subscriptions is available,
+// so the main goroutine can block waiting for work if it has none.
+func (bc *brokerConsumer) subscriptionManager() {
+ var buffer []*partitionConsumer
+
+ for {
+ if len(buffer) > 0 {
+ select {
+ case event, ok := <-bc.input:
+ if !ok {
+ goto done
+ }
+ buffer = append(buffer, event)
+ case bc.newSubscriptions <- buffer:
+ buffer = nil
+ case bc.wait <- none{}:
+ }
+ } else {
+ select {
+ case event, ok := <-bc.input:
+ if !ok {
+ goto done
+ }
+ buffer = append(buffer, event)
+ case bc.newSubscriptions <- nil:
+ }
+ }
+ }
+
+done:
+ close(bc.wait)
+ if len(buffer) > 0 {
+ bc.newSubscriptions <- buffer
+ }
+ close(bc.newSubscriptions)
+}
+
+//subscriptionConsumer ensures we will get nil right away if no new subscriptions is available
+func (bc *brokerConsumer) subscriptionConsumer() {
+ <-bc.wait // wait for our first piece of work
+
+ for newSubscriptions := range bc.newSubscriptions {
+ bc.updateSubscriptions(newSubscriptions)
+
+ if len(bc.subscriptions) == 0 {
+ // We're about to be shut down or we're about to receive more subscriptions.
+ // Either way, the signal just hasn't propagated to our goroutine yet.
+ <-bc.wait
+ continue
+ }
+
+ response, err := bc.fetchNewMessages()
+
+ if err != nil {
+ Logger.Printf("consumer/broker/%d disconnecting due to error processing FetchRequest: %s\n", bc.broker.ID(), err)
+ bc.abort(err)
+ return
+ }
+
+ bc.acks.Add(len(bc.subscriptions))
+ for child := range bc.subscriptions {
+ child.feeder <- response
+ }
+ bc.acks.Wait()
+ bc.handleResponses()
+ }
+}
+
+func (bc *brokerConsumer) updateSubscriptions(newSubscriptions []*partitionConsumer) {
+ for _, child := range newSubscriptions {
+ bc.subscriptions[child] = none{}
+ Logger.Printf("consumer/broker/%d added subscription to %s/%d\n", bc.broker.ID(), child.topic, child.partition)
+ }
+
+ for child := range bc.subscriptions {
+ select {
+ case <-child.dying:
+ Logger.Printf("consumer/broker/%d closed dead subscription to %s/%d\n", bc.broker.ID(), child.topic, child.partition)
+ close(child.trigger)
+ delete(bc.subscriptions, child)
+ default:
+ // no-op
+ }
+ }
+}
+
+//handleResponses handles the response codes left for us by our subscriptions, and abandons ones that have been closed
+func (bc *brokerConsumer) handleResponses() {
+ for child := range bc.subscriptions {
+ result := child.responseResult
+ child.responseResult = nil
+
+ switch result {
+ case nil:
+ // no-op
+ case errTimedOut:
+ Logger.Printf("consumer/broker/%d abandoned subscription to %s/%d because consuming was taking too long\n",
+ bc.broker.ID(), child.topic, child.partition)
+ delete(bc.subscriptions, child)
+ case ErrOffsetOutOfRange:
+ // there's no point in retrying this it will just fail the same way again
+ // shut it down and force the user to choose what to do
+ child.sendError(result)
+ Logger.Printf("consumer/%s/%d shutting down because %s\n", child.topic, child.partition, result)
+ close(child.trigger)
+ delete(bc.subscriptions, child)
+ case ErrUnknownTopicOrPartition, ErrNotLeaderForPartition, ErrLeaderNotAvailable, ErrReplicaNotAvailable:
+ // not an error, but does need redispatching
+ Logger.Printf("consumer/broker/%d abandoned subscription to %s/%d because %s\n",
+ bc.broker.ID(), child.topic, child.partition, result)
+ child.trigger <- none{}
+ delete(bc.subscriptions, child)
+ default:
+ // dunno, tell the user and try redispatching
+ child.sendError(result)
+ Logger.Printf("consumer/broker/%d abandoned subscription to %s/%d because %s\n",
+ bc.broker.ID(), child.topic, child.partition, result)
+ child.trigger <- none{}
+ delete(bc.subscriptions, child)
+ }
+ }
+}
+
+func (bc *brokerConsumer) abort(err error) {
+ bc.consumer.abandonBrokerConsumer(bc)
+ _ = bc.broker.Close() // we don't care about the error this might return, we already have one
+
+ for child := range bc.subscriptions {
+ child.sendError(err)
+ child.trigger <- none{}
+ }
+
+ for newSubscriptions := range bc.newSubscriptions {
+ if len(newSubscriptions) == 0 {
+ <-bc.wait
+ continue
+ }
+ for _, child := range newSubscriptions {
+ child.sendError(err)
+ child.trigger <- none{}
+ }
+ }
+}
+
+func (bc *brokerConsumer) fetchNewMessages() (*FetchResponse, error) {
+ request := &FetchRequest{
+ MinBytes: bc.consumer.conf.Consumer.Fetch.Min,
+ MaxWaitTime: int32(bc.consumer.conf.Consumer.MaxWaitTime / time.Millisecond),
+ }
+ if bc.consumer.conf.Version.IsAtLeast(V0_9_0_0) {
+ request.Version = 1
+ }
+ if bc.consumer.conf.Version.IsAtLeast(V0_10_0_0) {
+ request.Version = 2
+ }
+ if bc.consumer.conf.Version.IsAtLeast(V0_10_1_0) {
+ request.Version = 3
+ request.MaxBytes = MaxResponseSize
+ }
+ if bc.consumer.conf.Version.IsAtLeast(V0_11_0_0) {
+ request.Version = 4
+ request.Isolation = bc.consumer.conf.Consumer.IsolationLevel
+ }
+
+ for child := range bc.subscriptions {
+ request.AddBlock(child.topic, child.partition, child.offset, child.fetchSize)
+ }
+
+ return bc.broker.Fetch(request)
+}