Class: Spark::Serializer::AutoBatched

Inherits:
Batched show all
Defined in:
lib/spark/serializer/auto_batched.rb

Overview

AutoBatched serializator

Batch size is computed automatically. Simillar to Python’s AutoBatchedSerializer.

Constant Summary collapse

MAX_RATIO = 
10

Instance Attribute Summary

Attributes inherited from Batched

#serializer

Instance Method Summary collapse

Methods inherited from Batched

#batched?, #dump, #load, #load_from_io, #to_s, #unbatch!

Methods inherited from Base

#==, #batched?, #check_each, #error, #inspect, #load_from_file, #load_from_io, #to_s, #unbatch!

Constructor Details

#initialize(serializer, best_size = 65536) ⇒ AutoBatched

Returns a new instance of AutoBatched.



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# File 'lib/spark/serializer/auto_batched.rb', line 12

def initialize(serializer, best_size=65536)
  @serializer = serializer
  @best_size = best_size.to_i

  error('Batch size must be greater than 1') if @best_size < 2
end

Instance Method Details

#dump_to_io(data, io) ⇒ Object 



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# File 'lib/spark/serializer/auto_batched.rb', line 23

def dump_to_io(data, io)
  check_each(data)

  # Only Array have .slice
  data = data.to_a

  index = 0
  batch = 2
  max = @best_size * MAX_RATIO

  loop do
    chunk = data.slice(index, batch)
    if chunk.nil? || chunk.empty?
      break
    end

    serialized = @serializer.dump(chunk)
    io.write_string(serialized)

    index += batch

    size = serialized.bytesize
    if size < @best_size
      batch *= 2
    elsif size > max && batch > 1
      batch /= 2
    end
  end

  io.flush
end

#name ⇒ Object 



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# File 'lib/spark/serializer/auto_batched.rb', line 19

def name
  "AutoBatched(#{@best_size})"
end