Module: Lich::Common::Buffer

Defined in:
lib/common/buffer.rb

Constant Summary collapse

DOWNSTREAM_STRIPPED = 
1
DOWNSTREAM_RAW = 
2
DOWNSTREAM_MOD = 
4
UPSTREAM = 
8
UPSTREAM_MOD = 
16
SCRIPT_OUTPUT = 
32
@@index = 
Hash.new
@@streams = 
Hash.new
@@mutex = 
Mutex.new
@@offset = 
0
@@buffer = 
Array.new
@@max_size = 
3000

Class Method Summary collapse

Class Method Details

.cleanup ⇒ self

Note:

This method will remove entries for threads that are no longer running.

Cleans up the index and streams for threads that are no longer active.

Examples:

Buffer.cleanup

Returns:

  • (self) —

    the Buffer instance



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# File 'lib/common/buffer.rb', line 181

def Buffer.cleanup
  @@index.delete_if { |k, _v| not Thread.list.any? { |t| t.object_id == k } }
  @@streams.delete_if { |k, _v| not Thread.list.any? { |t| t.object_id == k } }
  return self
end

.clear ⇒ Array<Object>

Clears the buffer for the current thread and returns all lines that match the current stream.

Examples:

lines = Buffer.clear

Returns:

  • (Array<Object>) —

    an array of lines that match the current stream



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# File 'lib/common/buffer.rb', line 100

def Buffer.clear
  thread_id = Thread.current.object_id
  if @@index[thread_id].nil?
    @@mutex.synchronize {
      @@index[thread_id] = (@@offset + @@buffer.length)
      @@streams[thread_id] ||= DOWNSTREAM_STRIPPED
    }
  end
  lines = Array.new
  loop {
    if (@@index[thread_id] - @@offset) >= @@buffer.length
      return lines
    end

    line = nil
    @@mutex.synchronize {
      if @@index[thread_id] < @@offset
        @@index[thread_id] = @@offset
      end
      line = @@buffer[@@index[thread_id] - @@offset]
    }
    @@index[thread_id] += 1
    lines.push(line) if ((line.stream & @@streams[thread_id]) != 0)
  }
  return lines
end

.gets ⇒ Object

Note:

This method will block if no line is available until one becomes available.

Retrieves the next line from the buffer, blocking until a line is available.

Examples:

line = Buffer.gets

Returns:

  • (Object) —

    the next line from the buffer



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# File 'lib/common/buffer.rb', line 27

def Buffer.gets
  thread_id = Thread.current.object_id
  if @@index[thread_id].nil?
    @@mutex.synchronize {
      @@index[thread_id] = (@@offset + @@buffer.length)
      @@streams[thread_id] ||= DOWNSTREAM_STRIPPED
    }
  end
  line = nil
  loop {
    if (@@index[thread_id] - @@offset) >= @@buffer.length
      sleep 0.05 while ((@@index[thread_id] - @@offset) >= @@buffer.length)
    end
    @@mutex.synchronize {
      if @@index[thread_id] < @@offset
        @@index[thread_id] = @@offset
      end
      line = @@buffer[@@index[thread_id] - @@offset]
    }
    @@index[thread_id] += 1
    break if ((line.stream & @@streams[thread_id]) != 0)
  }
  return line
end

.gets? ⇒ Object?

Retrieves the next line from the buffer if available, otherwise returns nil.

Examples:

line = Buffer.gets?

Returns:

  • (Object, nil) —

    the next line from the buffer or nil if no line is available



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# File 'lib/common/buffer.rb', line 57

def Buffer.gets?
  thread_id = Thread.current.object_id
  if @@index[thread_id].nil?
    @@mutex.synchronize {
      @@index[thread_id] = (@@offset + @@buffer.length)
      @@streams[thread_id] ||= DOWNSTREAM_STRIPPED
    }
  end
  line = nil
  loop {
    if (@@index[thread_id] - @@offset) >= @@buffer.length
      return nil
    end

    @@mutex.synchronize {
      if @@index[thread_id] < @@offset
        @@index[thread_id] = @@offset
      end
      line = @@buffer[@@index[thread_id] - @@offset]
    }
    @@index[thread_id] += 1
    break if ((line.stream & @@streams[thread_id]) != 0)
  }
  return line
end

.rewind ⇒ self

Resets the index for the current thread to the beginning of the buffer.

Examples:

Buffer.rewind

Returns:

  • (self) —

    the Buffer instance



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# File 'lib/common/buffer.rb', line 88

def Buffer.rewind
  thread_id = Thread.current.object_id
  @@index[thread_id] = @@offset
  @@streams[thread_id] ||= DOWNSTREAM_STRIPPED
  return self
end

.streams ⇒ Integer

Note:

This method is subject to rubocop error Lint/HashCompareByIdentity.

Retrieves the current stream identifier for the calling thread.

Examples:

current_stream = Buffer.streams

Returns:

  • (Integer) —

    the current stream identifier



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# File 'lib/common/buffer.rb', line 156

def Buffer.streams
  @@streams[Thread.current.object_id]
end

.streams=(val) ⇒ nil

Sets the stream identifier for the calling thread.

Examples:

Buffer.streams = new_stream_id

Parameters:

  • val (Integer) —

    the new stream identifier

Returns:

  • (nil) —

    if the value is invalid

Raises:

  • (StandardError) —

    if the value is not an Integer or if it does not represent a valid stream



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# File 'lib/common/buffer.rb', line 167

def Buffer.streams=(val)
  if (val.class != Integer) or ((val & 63) == 0)
    respond "--- Lich: error: invalid streams value\n\t#{$!.caller[0..2].join("\n\t")}"
    return nil
  end
  @@streams[Thread.current.object_id] = val
end

.update(line, stream = nil) ⇒ self

Updates the buffer with a new line and an optional stream identifier.

Examples:

Buffer.update(new_line, stream_id)

Parameters:

  • line (Object) —

    the line to be added to the buffer

  • stream (Integer, nil) (defaults to: nil) —

    the stream identifier for the line (default: nil)

Returns:

  • (self) —

    the Buffer instance



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# File 'lib/common/buffer.rb', line 134

def Buffer.update(line, stream = nil)
  @@mutex.synchronize {
    frozen_line = line.dup
    unless stream.nil?
      frozen_line.stream = stream
    end
    frozen_line.freeze
    @@buffer.push(frozen_line)
    while (@@buffer.length > @@max_size)
      @@buffer.shift
      @@offset += 1
    end
  }
  return self
end