A TupleEntry is a Tuple (i.e. a possible entry in some Tuplespace) together with expiry and cancellation data.
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 lib/rinda/tuplespace.rb, line 25 def initialize(ary, sec=nil) @cancel = false @expires = nil @tuple = make_tuple(ary) @renewer = nil renew(sec) end
Retrieves key
from the tuple.
# File lib/rinda/tuplespace.rb, line 109 def [](key) @tuple[key] end
A TupleEntry is dead when it is canceled or expired.
# File lib/rinda/tuplespace.rb, line 43 def alive? !canceled? && !expired? end
Marks this TupleEntry as canceled.
# File lib/rinda/tuplespace.rb, line 36 def cancel @cancel = true end
Returns the canceled status.
# File lib/rinda/tuplespace.rb, line 56 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 lib/rinda/tuplespace.rb, line 64 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 lib/rinda/tuplespace.rb, line 116 def fetch(key) @tuple.fetch(key) end
Returns an expiry Time based on sec
which can be one of:
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 lib/rinda/tuplespace.rb, line 95 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 lib/rinda/tuplespace.rb, line 130 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.
it will expire in that many seconds.
Otherwise the argument refers to some kind of renewer object which will reset its expiry time.
# File lib/rinda/tuplespace.rb, line 83 def renew(sec_or_renewer) sec, @renewer = get_renewer(sec_or_renewer) @expires = make_expires(sec) end
The size of the tuple.
# File lib/rinda/tuplespace.rb, line 123 def size @tuple.size end
Return the object which makes up the tuple itself: the Array or Hash.
# File lib/rinda/tuplespace.rb, line 51 def value; @tuple.value; 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.
# File lib/rinda/tuplespace.rb, line 143 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
Ruby Core © 1993–2017 Yukihiro Matsumoto
Licensed under the Ruby License.
Ruby Standard Library © contributors
Licensed under their own licenses.