class Rinda::TupleEntry

A TupleEntry is a Tuple (i.e. a possible entry in some Tuplespace) together with expiry and cancellation data.

Attributes

Public Class Methods

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 26
def initialize(ary, sec=nil)
  @cancel = false
  @expires = nil
  @tuple = make_tuple(ary)
  @renewer = nil
  renew(sec)
end

Creates a TupleEntry based on ary with an optional renewer or expiry time sec.

A renewer must implement the renew method which returns a Numeric, nil, or true to indicate when the tuple has expired.

Public Instance Methods

[] (key)

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 110
def [](key)
  @tuple[key]
end

Retrieves key from the tuple.

alive? ()

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 44
def alive?
  !canceled? && !expired?
end

A TupleEntry is dead when it is canceled or expired.

cancel ()

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 37
def cancel
  @cancel = true
end

Marks this TupleEntry as canceled.

canceled? ()

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 57
def canceled?; @cancel; end

Returns the canceled status.

expired? ()

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 65
def expired?
  return true unless @expires
  return false if @expires > Time.now
  return true if @renewer.nil?
  renew(@renewer)
  return true unless @expires
  return @expires < Time.now
end

Has this tuple expired? (true/false).

A tuple has expired when its expiry timer based on the sec argument to initialize runs out.

fetch (key)

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 117
def fetch(key)
  @tuple.fetch(key)
end

Fetches key from the tuple.

make_expires (sec=nil)

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 96
def make_expires(sec=nil)
  case sec
  when Numeric
    Time.now + sec
  when true
    Time.at(1)
  when nil
    Time.at(2**31-1)
  end
end

Returns an expiry Time based on sec which can be one of:

Numeric: sec seconds into the future
true: the expiry time is the start of 1970 (i.e. expired)
nil: it is Tue Jan 19 03:14:07 GMT Standard Time 2038 (i.e. when UNIX clocks will die)

make_tuple (ary)

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 131
def make_tuple(ary)
  Rinda::Tuple.new(ary)
end

Creates a Rinda::Tuple for ary.

renew (sec_or_renewer)

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 84
def renew(sec_or_renewer)
  sec, @renewer = get_renewer(sec_or_renewer)
  @expires = make_expires(sec)
end

Reset the expiry time according to sec_or_renewer.

nil: it is set to expire in the far future.
true: it has expired.
Numeric: it will expire in that many seconds.

Otherwise the argument refers to some kind of renewer object which will reset its expiry time.

size ()

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 124
def size
  @tuple.size
end

The size of the tuple.

value ()

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 52
def value; @tuple.value; end

Return the object which makes up the tuple itself: the Array or Hash.

Private Instance Methods

get_renewer (it)

Source

# File bundled-src/rinda-0.2.0/lib/rinda/tuplespace.rb, line 144
def get_renewer(it)
  case it
  when Numeric, true, nil
    return it, nil
  else
    begin
      return it.renew, it
    rescue Exception
      return it, nil
    end
  end
end

Returns a valid argument to make_expires and the renewer or nil.

Given true, nil, or Numeric, returns that value and nil (no actual renewer). Otherwise it returns an expiry value from calling it.renew and the renewer.