Class: Async::IO::Stream

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

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io, block_size: 1024*8, sync: true) ⇒ Stream

Returns a new instance of Stream.



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# File 'lib/async/io/stream.rb', line 27

def initialize(io, block_size: 1024*8, 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

#io ⇒ Object (readonly)

Returns the value of attribute io.



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# File 'lib/async/io/stream.rb', line 40

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 68

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 95

def close
  flush rescue nil
  
  @io.close
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 102

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 75

def flush
  syswrite(@write_buffer)
  @write_buffer.clear
end

#gets(separator = $/) ⇒ Object 



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# File 'lib/async/io/stream.rb', line 80

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

#peek ⇒ Object 



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# File 'lib/async/io/stream.rb', line 132

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 86

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 43

def read(size = nil)
  return "" if size == 0
  
  until @eof || (size && size <= @read_buffer.size)
    fill_read_buffer
  end

  return consume_read_buffer(size)
end

#read_until(pattern) ⇒ 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 113

def read_until(pattern)
  index = @read_buffer.index(pattern)
  
  until index
    offset = @read_buffer.size

    fill_read_buffer
    
    return if @eof

    index = @read_buffer.index(pattern, offset)
  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 57

def write(string)
  @write_buffer << string
  
  if @write_buffer.size > @block_size
    flush
  end
  
  return string.bytesize
end