Class: Dalli::Ring
- Inherits:
-
Object
- Object
- Dalli::Ring
- Defined in:
- lib/dalli/ring.rb
Defined Under Namespace
Classes: Entry
Constant Summary collapse
- POINTS_PER_SERVER =
this is the default in libmemcached
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Instance Attribute Summary collapse
-
#continuum ⇒ Object
Returns the value of attribute continuum.
-
#servers ⇒ Object
Returns the value of attribute servers.
Instance Method Summary collapse
-
#initialize(servers) ⇒ Ring
constructor
A new instance of Ring.
- #lock ⇒ Object
- #server_for_key(key) ⇒ Object
- #threadsafe! ⇒ Object
Constructor Details
#initialize(servers) ⇒ Ring
Returns a new instance of Ring.
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# File 'lib/dalli/ring.rb', line 10 def initialize(servers) @servers = servers if servers.size > 1 total_weight = servers.inject(0) { |memo, srv| memo + srv.weight } continuum = [] servers.each do |server| entry_count_for(server, servers.size, total_weight).times do |idx| hash = Digest::SHA1.hexdigest("#{server.hostname}:#{server.port}:#{idx}") value = Integer("0x#{hash[0..7]}") continuum << Dalli::Ring::Entry.new(value, server) end end continuum.sort { |a, b| a.value <=> b.value } @continuum = continuum end end |
Instance Attribute Details
#continuum ⇒ Object
Returns the value of attribute continuum.
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# File 'lib/dalli/ring.rb', line 8 def continuum @continuum end |
#servers ⇒ Object
Returns the value of attribute servers.
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# File 'lib/dalli/ring.rb', line 8 def servers @servers end |
Instance Method Details
#lock ⇒ Object
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# File 'lib/dalli/ring.rb', line 48 def lock @servers.each { |s| s.lock! } begin return yield ensure @servers.each { |s| s.unlock! } end end |
#server_for_key(key) ⇒ Object
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# File 'lib/dalli/ring.rb', line 27 def server_for_key(key) return @servers.first unless @continuum hkey = hash_for(key) 20.times do |try| entryidx = self.class.binary_search(@continuum, hkey) server = @continuum[entryidx].server return server if server.alive? hkey = hash_for("#{try}#{key}") end raise Dalli::NetworkError, "No servers available" end |
#threadsafe! ⇒ Object
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# File 'lib/dalli/ring.rb', line 42 def threadsafe! @servers.each do |s| s.extend(Dalli::Threadsafe) end end |