Class: IO

Inherits:
Object show all
Includes:
CosmosIO
Defined in:
lib/cosmos/core_ext/io.rb

Constant Summary collapse

SELECT_BASE_TIMEOUT = 
0.0004
SELECT_MAX_TIMEOUT = 
0.016

Class Method Summary collapse

Methods included from CosmosIO

#read_length_bytes

Class Method Details

.fast_read_select(read_sockets, timeout) ⇒ Object

fast_select



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# File 'lib/cosmos/core_ext/io.rb', line 68

def self.fast_read_select(read_sockets, timeout)
  return fast_select(read_sockets, nil, nil, timeout)
end

.fast_select(read_sockets = nil, write_sockets = nil, error_array = nil, timeout = nil) ⇒ Object 



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# File 'lib/cosmos/core_ext/io.rb', line 19

def self.fast_select(read_sockets = nil, write_sockets = nil, error_array = nil, timeout = nil)
  # Always try a zero timeout first
  current_timeout = SELECT_BASE_TIMEOUT
  total_timeout = 0.0

  while true
    result = IO.select(read_sockets, write_sockets, error_array, current_timeout)
    return result if result or current_timeout.nil?
    return nil if timeout and total_timeout >= timeout

    if current_timeout <= 0.0001
      # Always try the base timeout next
      current_timeout = SELECT_BASE_TIMEOUT
      total_timeout = SELECT_BASE_TIMEOUT
    else
      # Then start doubling the timeout
      current_timeout = current_timeout * 2

      # Until it is bigger than our max timeout
      if current_timeout >= SELECT_MAX_TIMEOUT
        if timeout
          # Block for the remaining requested timeout
          current_timeout = timeout - total_timeout
          total_timeout = timeout
        else
          # Or block forever
          current_timeout = nil
        end
      else
        # Or it is bigger than the given timeout
        if timeout and current_timeout >= timeout
          # Block for the remaining requested timeout
          current_timeout = timeout - total_timeout
          total_timeout = timeout
        else
          # Up our total time in select
          total_timeout += current_timeout
        end
        if timeout and total_timeout > timeout
          # Block for the remaining requested timeout
          current_timeout = timeout - total_timeout
          total_timeout = timeout
        end
      end
      return nil if current_timeout and current_timeout < 0
    end
  end # while true
end

.fast_write_select(write_sockets, timeout) ⇒ Object 



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# File 'lib/cosmos/core_ext/io.rb', line 72

def self.fast_write_select(write_sockets, timeout)
  return fast_select(nil, write_sockets, nil, timeout)
end