Class: Async::IO::Stream

Inherits:
Object
  • Object
show all
Defined in:
lib/async/io/stream.rb

Constant Summary collapse

BLOCK_SIZE =

The default block size for IO buffers. BLOCK_SIZE = ENV.fetch(‘BLOCK_SIZE’, 1024*16).to_i

1024*8

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io, block_size: BLOCK_SIZE, sync: true) ⇒ Stream

Returns a new instance of Stream.



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# File 'lib/async/io/stream.rb', line 31

def initialize(io, block_size: BLOCK_SIZE, sync: true)
  @io = io
  @eof = false
  
  # We don't want Ruby to do any IO buffering.
  @io.sync = sync
  
  @block_size = block_size
  
  @read_buffer = BinaryString.new
  @write_buffer = BinaryString.new
end

Instance Attribute Details

#block_size ⇒ Object (readonly)

Returns the value of attribute block_size.



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# File 'lib/async/io/stream.rb', line 45

def block_size
  @block_size
end

#io ⇒ Object (readonly)

Returns the value of attribute io.



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# File 'lib/async/io/stream.rb', line 44

def io
  @io
end

Instance Method Details

#<<(string) ⇒ Object

Writes ‘string` to the stream and returns self.



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# File 'lib/async/io/stream.rb', line 113

def <<(string)
  write(string)
  
  return self
end

#close ⇒ Object

Closes the stream and flushes any unwritten data.



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# File 'lib/async/io/stream.rb', line 150

def close
  return if @io.closed?
  
  begin
    flush
  rescue
    # We really can't do anything here unless we want #close to raise exceptions.
    Async.logger.error(self) {$!}
  ensure
    @io.close
  end
end

#closed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/async/io/stream.rb', line 145

def closed?
  @io.closed?
end

#connected? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/async/io/stream.rb', line 141

def connected?
  @io.connected?
end

#eof! ⇒ Object

Raises:

  • (EOFError) 


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# File 'lib/async/io/stream.rb', line 172

def eof!
  @read_buffer.clear
  @eof = true
  
  raise EOFError
end

#eof? ⇒ Boolean Also known as: eof

Returns true if the stream is at file which means there is no more data to be read.

Returns:

  • (Boolean) 


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# File 'lib/async/io/stream.rb', line 164

def eof?
  fill_read_buffer if !@eof && @read_buffer.empty?
  
  return @eof && @read_buffer.empty?
end

#flush ⇒ Object

Flushes buffered data to the stream.



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# File 'lib/async/io/stream.rb', line 120

def flush
  unless @write_buffer.empty?
    syswrite(@write_buffer)
    @write_buffer.clear
  end
end

#gets(separator = $/) ⇒ Object 



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# File 'lib/async/io/stream.rb', line 127

def gets(separator = $/)
  flush
  
  read_until(separator)
end

#peek ⇒ Object 



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# File 'lib/async/io/stream.rb', line 87

def peek
  until yield(@read_buffer) || @eof
    fill_read_buffer
  end
end

#puts(*args, separator: $/) ⇒ Object 



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# File 'lib/async/io/stream.rb', line 133

def puts(*args, separator: $/)
  args.each do |arg|
    @write_buffer << arg << separator
  end
  
  flush
end

#read(size = nil) ⇒ Object

Reads ‘size` bytes from the stream. If size is not specified, read until end of file.



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# File 'lib/async/io/stream.rb', line 48

def read(size = nil)
  return '' if size == 0
  
  if size
    fill_read_buffer until @eof or @read_buffer.size >= size
  else
    fill_read_buffer until @eof
  end
  
  return consume_read_buffer(size)
end

#read_partial(size = nil) ⇒ Object

Read at most ‘size` bytes from the stream. Will avoid reading from the underlying stream if possible.



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# File 'lib/async/io/stream.rb', line 61

def read_partial(size = nil)
  return '' if size == 0
  
  if @read_buffer.empty? and !@eof
    fill_read_buffer
  end
  
  return consume_read_buffer(size)
end

#read_until(pattern, offset = 0) ⇒ String

Efficiently read data from the stream until encountering pattern.

Parameters:

  • pattern (String) —

    The pattern to match.

Returns:

  • (String) —

    The contents of the stream up until the pattern, which is consumed but not returned.



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# File 'lib/async/io/stream.rb', line 74

def read_until(pattern, offset = 0)
  until index = @read_buffer.index(pattern, offset)
    offset = @read_buffer.size
    
    return unless fill_read_buffer
  end
  
  matched = @read_buffer.slice!(0, index)
  @read_buffer.slice!(0, pattern.bytesize)
  
  return matched
end

#write(string) ⇒ Object

Writes ‘string` to the buffer. When the buffer is full or #sync is true the buffer is flushed to the underlying `io`.

Parameters:

  • string —

    the string to write to the buffer.

Returns:

  • the number of bytes appended to the buffer.



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# File 'lib/async/io/stream.rb', line 97

def write(string)
  if @write_buffer.empty? and string.bytesize >= @block_size
    syswrite(string)
  else
    @write_buffer << string
    
    if @write_buffer.size >= @block_size
      syswrite(@write_buffer)
      @write_buffer.clear
    end
  end
  
  return string.bytesize
end