Class: TurboStreamer::OjEncoder

Inherits:
Object
  • Object
show all
Defined in:
lib/turbostreamer/encoders/oj.rb

Constant Summary collapse

BUFFER_SIZE = 
4096

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io, options = {}) ⇒ OjEncoder

Returns a new instance of OjEncoder.



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# File 'lib/turbostreamer/encoders/oj.rb', line 10

def initialize(io, options={})
  @stack = []
  @indexes = []

  @options = {mode: :json, buffer_size: BUFFER_SIZE}.merge(options)

  @output = io
  @stream_writer = ::Oj::StreamWriter.new(io, @options)
  @write_comma_on_next_push = false
end

Instance Attribute Details

#output ⇒ Object (readonly)

Returns the value of attribute output.



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# File 'lib/turbostreamer/encoders/oj.rb', line 6

def output
  @output
end

Instance Method Details

#array_close ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 67

def array_close
  @indexes.pop
  @stack.pop
  @stream_writer.pop
end

#array_open ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 58

def array_open
  @stack << :array
  @indexes << 0
  if @write_comma_on_next_push
    @write_comma_on_next_push = false
  end
  @stream_writer.push_array
end

#capture(to = nil) ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 105

def capture(to=nil)
  @stream_writer.flush

  old_writer = @stream_writer
  old_output = @output
  @indexes << 0

  @output = (to || ::StringIO.new)
  @stream_writer = ::Oj::StreamWriter.new(@output, @options)

  # This is to prevent error from OJ streamer
  # We will strip the brackets afterward
  if @stack.last == :map
    @stream_writer.push_object
  elsif @stack.last == :array
    @stream_writer.push_array
  end

  yield

  @stream_writer.pop_all
  @stream_writer.flush
  result = output.string.sub(/\A,/, ''.freeze).chomp(",".freeze).strip

  # Strip brackets as promised above
  if @stack.last == :map
    result = result.sub(/\A{/, ''.freeze).chomp("}".freeze)
  elsif @stack.last == :array
    result = result.sub(/\A\[/, ''.freeze).chomp("]".freeze)
  end

  # Possible for `output.string` to have value like
  # `[,{"key":"value"}]\n`
  # Thus the comma must be removed here
  result.sub(/\A,/, ''.freeze)
ensure
  @indexes.pop
  @stream_writer = old_writer
  @output = old_output
end

#flush ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 146

def flush
  @stream_writer.flush
end

#inject(string) ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 73

def inject(string)
  @stream_writer.flush

  # It's possible to have
  # `@write_comma_on_next_push == true` and `@indexes.last > 0`
  # So there might be double comma written without this flag
  comma_written = false
  if @write_comma_on_next_push
    @output.write(",".freeze)
    @write_comma_on_next_push = false
    comma_written = true
  end

  if @stack.last == :array && !string.empty?
    if @indexes.last > 0
      self.output.write(",") unless comma_written
    else
      @write_comma_on_next_push = true
    end
    @indexes[-1] += 1
  elsif @stack.last == :map && !string.empty?
    if @indexes.last > 0
      self.output.write(",") unless comma_written
    else
      @write_comma_on_next_push = true
    end
    @indexes[-1] += 1
  end

  self.output.write(string.sub(/\A,/, ''.freeze).chomp(",".freeze).strip)
end

#key(k) ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 21

def key(k)
  if @write_comma_on_next_push && (@stack.last == :array || @stack.last == :map)
    @stream_writer.flush
    @output.write(",".freeze)
    @write_comma_on_next_push = false
  end
  @stream_writer.push_key(k)
end

#map_close ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 52

def map_close
  @indexes.pop
  @stack.pop
  @stream_writer.pop
end

#map_open ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 43

def map_open
  @stack << :map
  @indexes << 0
  if @write_comma_on_next_push
    @write_comma_on_next_push = false
  end
  @stream_writer.push_object
end

#value(v) ⇒ Object 



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# File 'lib/turbostreamer/encoders/oj.rb', line 30

def value(v)
  if @stack.last == :array || @stack.last == :map
    @indexes[-1] += 1

    if @write_comma_on_next_push
      @stream_writer.flush
      @output.write(",".freeze)
      @write_comma_on_next_push = false
    end
  end
  @stream_writer.push_value(v)
end