node-manager: limit number of reguests to the registry during single …

…node lookup

avoids useless transactions for already registered nodes

lib/dcell.rb

@@ -65,7 +65,9 @@ def setup(options = {})
     # Returns actors from multiple nodes
     def find(actor)
       actors = Array.new
-      Directory.each do |node|
+      Directory.each do |id|
+        node = Directory[id]
+        next unless node
         next if node.id == DCell.id
         next unless node.actors.include? actor
         begin

lib/dcell/directory.rb

@@ -65,9 +65,7 @@ def find(id)
     # Iterates over all registered nodes
     def each
       DCell.registry.nodes.each do |id|
-        node = Directory[id]
-        next unless node
-        yield node
+        yield id
       end
     end
 

lib/dcell/node_manager.rb

@@ -5,14 +5,16 @@ class NodeCache
 
     class << self
       # Finds a node by its node ID and adds to the cache
-      def register(id, addr)
+      def register(id)
         return DCell.me if id == DCell.id
-        return nil unless addr
         loop do
           begin
             node = nil
             return @nodes.register(id) do
-              node = Node.new(id, addr) rescue nil
+              ninfo = Directory[id]
+              if ninfo and ninfo.alive? and ninfo.address
+                node = Node.new(id, ninfo.address) rescue nil
+              end
             end
           rescue ResourceManagerConflict => e
             # :nocov:
@@ -38,19 +40,16 @@ def delete(id)
   module NodeManager
     # Iterate across all available nodes
     def each
-      Directory.each do |node|
-        # skip dead nodes and nodes w/o an address, those might not be operational yet
-        next unless node.alive? and node.address
-        remote = NodeCache.register node.id, node.address
+      Directory.each do |id|
+        remote = NodeCache.register id
+        next unless remote
         yield remote
       end
     end
 
     # Find a node by its node ID
     def find(id)
-      node = Directory[id]
-      return nil unless node and node.alive? and node.address
-      NodeCache.register id, node.address
+      NodeCache.register id
     end
     alias_method :[], :find
   end

spec/dcell/directory_spec.rb

@@ -23,8 +23,8 @@
   it "presents all stored addresses" do
     DCell::Directory["foo"].address = "tcp://fooaddress"
     DCell::Directory["bar"].address = "tcp://baraddress"
-    DCell::Directory.map{|node| node.id}.should include("foo")
-    DCell::Directory.map{|node| node.id}.should include("bar")
+    DCell::Directory.to_a.should include("foo")
+    DCell::Directory.to_a.should include("bar")
   end
 
   it "clears node addresses" do