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
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.
# File rinda/tuplespace.rb, line 26 def initialize(ary, sec=nil) @cancel = false @expires = nil @tuple = make_tuple(ary) @renewer = nil renew(sec) end
Public Instance Methods
Retrieves key
from the tuple.
# File rinda/tuplespace.rb, line 110 def [](key) @tuple[key] end
A TupleEntry
is dead when it is canceled or expired.
# File rinda/tuplespace.rb, line 44 def alive? !canceled? && !expired? end
Marks this TupleEntry
as canceled.
# File rinda/tuplespace.rb, line 37 def cancel @cancel = true end
Returns the canceled status.
# File rinda/tuplespace.rb, line 57 def canceled?; @cancel; end
Has this tuple expired? (true/false).
A tuple has expired when its expiry timer based on the sec
argument to initialize runs out.
# File 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
Fetches key
from the tuple.
# File rinda/tuplespace.rb, line 117 def fetch(key) @tuple.fetch(key) 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)
# File 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
Creates a Rinda::Tuple
for ary
.
# File rinda/tuplespace.rb, line 131 def make_tuple(ary) Rinda::Tuple.new(ary) 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.
# File rinda/tuplespace.rb, line 84 def renew(sec_or_renewer) sec, @renewer = get_renewer(sec_or_renewer) @expires = make_expires(sec) end
The size of the tuple.
# File rinda/tuplespace.rb, line 124 def size @tuple.size end
Return the object which makes up the tuple itself: the Array or Hash.
# File rinda/tuplespace.rb, line 52 def value; @tuple.value; end
Private Instance Methods
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.
# File 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