Class: PulsarSdk::Producer::Router

Inherits:
Object
  • Object
show all
Includes:
Tweaks::CleanInspect
Defined in:
lib/pulsar_sdk/producer/router.rb

Instance Method Summary collapse

Methods included from Tweaks::CleanInspect

#inspect

Constructor Details

#initialize(scheme = :string_hash) ⇒ Router

Returns a new instance of Router.



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# 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

Instance Method Details

#murmur3_hash ⇒ Object 



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# 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) ⇒ Object 



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# 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 ⇒ Object

将hash值限制在32位内，防止key过长导致过多内存占用



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# 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