Class: Kafka::OffsetManager

Inherits:
Object
  • Object
show all
Defined in:
lib/kafka/offset_manager.rb

Instance Method Summary collapse

Constructor Details

#initialize(cluster:, group:, logger:, commit_interval:, commit_threshold:) ⇒ OffsetManager

Returns a new instance of OffsetManager.



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# File 'lib/kafka/offset_manager.rb', line 3

def initialize(cluster:, group:, logger:, commit_interval:, commit_threshold:)
  @cluster = cluster
  @group = group
  @logger = logger
  @commit_interval = commit_interval
  @commit_threshold = commit_threshold

  @uncommitted_offsets = 0
  @processed_offsets = {}
  @default_offsets = {}
  @committed_offsets = nil
  @resolved_offsets = {}
  @last_commit = Time.now
end

Instance Method Details

#clear_offsets ⇒ Object 



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# File 'lib/kafka/offset_manager.rb', line 75

def clear_offsets
  @processed_offsets.clear
  @resolved_offsets.clear

  # Clear the cached commits from the brokers.
  @committed_offsets = nil
end

#clear_offsets_excluding(excluded) ⇒ Object 



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# File 'lib/kafka/offset_manager.rb', line 83

def clear_offsets_excluding(excluded)
  # Clear all offsets that aren't in `excluded`.
  @processed_offsets.each do |topic, partitions|
    partitions.keep_if do |partition, _|
      excluded.fetch(topic, []).include?(partition)
    end
  end

  # Clear the cached commits from the brokers.
  @committed_offsets = nil
  @resolved_offsets.clear
end

#commit_offsets ⇒ Object 



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# File 'lib/kafka/offset_manager.rb', line 52

def commit_offsets
  unless @processed_offsets.empty?
    pretty_offsets = @processed_offsets.flat_map {|topic, partitions|
      partitions.map {|partition, offset| "#{topic}/#{partition}:#{offset}" }
    }.join(", ")

    @logger.info "Committing offsets: #{pretty_offsets}"

    @group.commit_offsets(@processed_offsets)

    @last_commit = Time.now

    @uncommitted_offsets = 0
    @committed_offsets = nil
  end
end

#commit_offsets_if_necessary ⇒ Object 



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# File 'lib/kafka/offset_manager.rb', line 69

def commit_offsets_if_necessary
  if commit_timeout_reached? || commit_threshold_reached?
    commit_offsets
  end
end

#mark_as_processed(topic, partition, offset) ⇒ Object 



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# File 'lib/kafka/offset_manager.rb', line 22

def mark_as_processed(topic, partition, offset)
  @uncommitted_offsets += 1
  @processed_offsets[topic] ||= {}

  # The committed offset should always be the offset of the next message that the
  # application will read, thus adding one to the last message processed
  @processed_offsets[topic][partition] = offset + 1
  @logger.debug "Marking #{topic}/#{partition}:#{offset} as committed"
end

#next_offset_for(topic, partition) ⇒ Object 



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# File 'lib/kafka/offset_manager.rb', line 37

def next_offset_for(topic, partition)
  offset = @processed_offsets.fetch(topic, {}).fetch(partition) {
    committed_offset_for(topic, partition)
  }

  # A negative offset means that no offset has been committed, so we need to
  # resolve the default offset for the topic.
  if offset < 0
    resolve_offset(topic, partition)
  else
    # The next offset is the last offset.
    offset
  end
end

#seek_to_default(topic, partition) ⇒ Object 



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# File 'lib/kafka/offset_manager.rb', line 32

def seek_to_default(topic, partition)
  @processed_offsets[topic] ||= {}
  @processed_offsets[topic][partition] = -1
end

#set_default_offset(topic, default_offset) ⇒ Object 



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# File 'lib/kafka/offset_manager.rb', line 18

def set_default_offset(topic, default_offset)
  @default_offsets[topic] = default_offset
end