class PulsarSdk::Producer::Router

Public Class Methods

new(scheme = :string_hash) click to toggle source
# File lib/pulsar_sdk/producer/router.rb, line 6
def initialize(scheme = :string_hash)
  case scheme.to_sym
  when :string_hash
    @handler = string_hash
  when :murmur_hash
    @handler = murmur3_hash
  else
    raise "Unknown hash scheme #{scheme}"
  end
end

Public Instance Methods

murmur3_hash() click to toggle source
# File lib/pulsar_sdk/producer/router.rb, line 38
def murmur3_hash
  Proc.new do |key, seed = 31|
    # Using 0x7fffffff was maintain compatibility with values used in Java client
    Murmur3.hash(key, seed) & 0x7fffffff
  end
end
route(key, total, delay = 0) click to toggle source
# File lib/pulsar_sdk/producer/router.rb, line 17
def route(key, total, delay = 0)
  return 0 if total <= 1

  return (@handler.call(key) % total) unless key.to_s.empty?

  Murmur3.int32_hash(TimeX.now.timestamp) % total
end
string_hash() click to toggle source

将hash值限制在32位内,防止key过长导致过多内存占用

# File lib/pulsar_sdk/producer/router.rb, line 26
def string_hash
  max_mod = 1 << 32
  Proc.new do |key|
    h = 0
    key.to_s.each_byte do |x|
      h = (31*h)%max_mod + x
    end

    h
  end
end