Ruby client library updated. Important changes in this new version!

client-libraries/ruby/lib/better_timeout.rb

@@ -163,6 +163,9 @@ end
 # Another name for Timeout::Error, defined for backwards compatibility with
 # earlier versions of timeout.rb.
 
+class Object
+  remove_const(:TimeoutError) if const_defined?(:TimeoutError)
+end
 TimeoutError = Timeout::Error # :nodoc:
 
 if __FILE__ == $0

client-libraries/ruby/lib/dist_redis.rb

@@ -24,7 +24,7 @@ class DistRedis
   end
   
   def method_missing(sym, *args, &blk)
-    if redis = node_for_key(args.first)
+    if redis = node_for_key(args.first.to_s)
       redis.send sym, *args, &blk
     else
       super
@@ -94,11 +94,11 @@ r = DistRedis.new 'localhost:6379', 'localhost:6380', 'localhost:6381', 'localho
   r.push_tail 'listor', 'foo4'
   r.push_tail 'listor', 'foo5'
   
-  p r.pop_tail 'listor'
-  p r.pop_tail 'listor'
-  p r.pop_tail 'listor'
-  p r.pop_tail 'listor'
-  p r.pop_tail 'listor'
+  p r.pop_tail('listor')
+  p r.pop_tail('listor')
+  p r.pop_tail('listor')
+  p r.pop_tail('listor')
+  p r.pop_tail('listor')
   
   puts "key distribution:"
   

client-libraries/ruby/lib/hash_ring.rb

@@ -1,10 +1,15 @@
-require 'digest/md5'
+require 'zlib'
+
 class HashRing
+
+  POINTS_PER_SERVER = 160 # this is the default in libmemcached
+
   attr_reader :ring, :sorted_keys, :replicas, :nodes
+
   # nodes is a list of objects that have a proper to_s representation.
   # replicas indicates how many virtual points should be used pr. node,
   # replicas are required to improve the distribution.
-  def initialize(nodes=[], replicas=3)
+  def initialize(nodes=[], replicas=POINTS_PER_SERVER)
     @replicas = replicas
     @ring = {}
     @nodes = []
@@ -18,7 +23,7 @@ class HashRing
   def add_node(node)
     @nodes << node
     @replicas.times do |i|
-      key = gen_key("#{node}:#{i}")
+      key = Zlib.crc32("#{node}:#{i}")
       @ring[key] = node
       @sorted_keys << key
     end
@@ -27,7 +32,7 @@ class HashRing
   
   def remove_node(node)
     @replicas.times do |i|
-      key = gen_key("#{node}:#{count}")
+      key = Zlib.crc32("#{node}:#{count}")
       @ring.delete(key)
       @sorted_keys.reject! {|k| k == key}
     end
@@ -40,15 +45,9 @@ class HashRing
   
   def get_node_pos(key)
     return [nil,nil] if @ring.size == 0
-    key = gen_key(key)
-    nodes = @sorted_keys
-    nodes.size.times do |i|
-      node = nodes[i]
-      if key <= node
-        return [@ring[node], i]
-      end
-    end
-    [@ring[nodes[0]], 0]
+    crc = Zlib.crc32(key)
+    idx = HashRing.binary_search(@sorted_keys, crc)
+    return [@ring[@sorted_keys[idx]], idx]
   end
   
   def iter_nodes(key)
@@ -59,11 +58,66 @@ class HashRing
     end  
   end
   
-  def gen_key(key)
-    key = Digest::MD5.hexdigest(key)
-    ((key[3] << 24) | (key[2] << 16) | (key[1] << 8) | key[0])
+  class << self
+
+    # gem install RubyInline to use this code
+    # Native extension to perform the binary search within the hashring.
+    # There's a pure ruby version below so this is purely optional
+    # for performance.  In testing 20k gets and sets, the native
+    # binary search shaved about 12% off the runtime (9sec -> 8sec).
+    begin
+      require 'inline'
+      inline do |builder|
+        builder.c <<-EOM
+        int binary_search(VALUE ary, unsigned int r) {
+            int upper = RARRAY_LEN(ary) - 1;
+            int lower = 0;
+            int idx = 0;
+
+            while (lower <= upper) {
+                idx = (lower + upper) / 2;
+
+                VALUE continuumValue = RARRAY_PTR(ary)[idx];
+                unsigned int l = NUM2UINT(continuumValue);
+                if (l == r) {
+                    return idx;
+                }
+                else if (l > r) {
+                    upper = idx - 1;
+                }
+                else {
+                    lower = idx + 1;
+                }
+            }
+            return upper;
+        }
+        EOM
+      end
+    rescue Exception => e
+      # Find the closest index in HashRing with value <= the given value
+      def binary_search(ary, value, &block)
+        upper = ary.size - 1
+        lower = 0
+        idx = 0
+
+        while(lower <= upper) do
+          idx = (lower + upper) / 2
+          comp = ary[idx] <=> value
+
+          if comp == 0
+            return idx
+          elsif comp > 0
+            upper = idx - 1
+          else
+            lower = idx + 1
+          end
+        end
+        return upper
+      end
+
+    end
   end
-  
+
 end
 
 # ring = HashRing.new ['server1', 'server2', 'server3']

client-libraries/ruby/lib/server.rb

@@ -0,0 +1,131 @@
+##
+# This class represents a redis server instance.
+
+class Server
+
+  ##
+  # The amount of time to wait before attempting to re-establish a
+  # connection with a server that is marked dead.
+
+  RETRY_DELAY = 30.0
+
+  ##
+  # The host the redis server is running on.
+
+  attr_reader :host
+
+  ##
+  # The port the redis server is listening on.
+
+  attr_reader :port
+  
+  ##
+  #
+  
+  attr_reader :replica
+
+  ##
+  # The time of next retry if the connection is dead.
+
+  attr_reader :retry
+
+  ##
+  # A text status string describing the state of the server.
+
+  attr_reader :status
+
+  ##
+  # Create a new Redis::Server object for the redis instance
+  # listening on the given host and port.
+
+  def initialize(host, port = DEFAULT_PORT)
+    raise ArgumentError, "No host specified" if host.nil? or host.empty?
+    raise ArgumentError, "No port specified" if port.nil? or port.to_i.zero?
+
+    @host   = host
+    @port   = port.to_i
+
+    @sock   = nil
+    @retry  = nil
+    @status = 'NOT CONNECTED'
+    @timeout = 1
+  end
+
+  ##
+  # Return a string representation of the server object.
+  def inspect
+    "<Redis::Server: %s:%d (%s)>" % [@host, @port, @status]
+  end
+
+  ##
+  # Try to connect to the redis server targeted by this object.
+  # Returns the connected socket object on success or nil on failure.
+
+  def socket
+    return @sock if @sock and not @sock.closed?
+
+    @sock = nil
+
+    # If the host was dead, don't retry for a while.
+    return if @retry and @retry > Time.now
+
+    # Attempt to connect if not already connected.
+    begin
+      @sock = connect_to(@host, @port, @timeout)
+      @sock.setsockopt Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1
+      @retry  = nil
+      @status = 'CONNECTED'
+    rescue Errno::EPIPE, Errno::ECONNREFUSED => e
+      puts "Socket died... socket: #{@sock.inspect}\n" if $debug
+      @sock.close
+      retry
+    rescue SocketError, SystemCallError, IOError => err
+      puts "Unable to open socket: #{err.class.name}, #{err.message}" if $debug
+      mark_dead err
+    end
+
+    return @sock
+  end
+
+  def connect_to(host, port, timeout=nil)
+    addrs = Socket.getaddrinfo('localhost', nil)
+    addr = addrs.detect { |ad| ad[0] == 'AF_INET' }
+    sock = Socket.new(Socket::AF_INET, Socket::SOCK_STREAM, 0)
+    #addr = Socket.getaddrinfo(host, nil)
+    #sock = Socket.new(Socket.const_get(addr[0][0]), Socket::SOCK_STREAM, 0)
+
+    if timeout
+      secs = Integer(timeout)
+      usecs = Integer((timeout - secs) * 1_000_000)
+      optval = [secs, usecs].pack("l_2")
+      sock.setsockopt Socket::SOL_SOCKET, Socket::SO_RCVTIMEO, optval
+      sock.setsockopt Socket::SOL_SOCKET, Socket::SO_SNDTIMEO, optval
+    end
+    sock.connect(Socket.pack_sockaddr_in('6379', addr[3]))
+    sock
+  end
+
+  ##
+  # Close the connection to the redis server targeted by this
+  # object.  The server is not considered dead.
+
+  def close
+    @sock.close if @sock && !@sock.closed?
+    @sock   = nil
+    @retry  = nil
+    @status = "NOT CONNECTED"
+  end
+
+  ##
+  # Mark the server as dead and close its socket.
+  def mark_dead(error)
+    @sock.close if @sock && !@sock.closed?
+    @sock   = nil
+    @retry  = Time.now #+ RETRY_DELAY
+
+    reason = "#{error.class.name}: #{error.message}"
+    @status = sprintf "%s:%s DEAD (%s), will retry at %s", @host, @port, reason, @retry
+    puts @status
+  end
+
+end