Merge branch 'master' of git@github.com:rails/rails

Conflicts:
	activesupport/CHANGELOG

3 files changed, 244 insertions, 223 deletions

diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index a74c645981..46081d11fb 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -2,6 +2,8 @@
 
 * Add Benchmark.ms convenience method to benchmark realtime in milliseconds.  [Jeremy Kemper]
 
+* Updated included memcache-client to the 1.5.0.5 version which includes fixes from fiveruns and 37signals to deal with failover and timeouts #1535 [Joshua Sierles]
+
 * Multibyte: add multibyte-safe Chars#ord rather than falling back to String#ord.  #1483 [Jason Cheow]
 
 * I18n support for Array#to_sentence. Introduces support.array.words_connector, .two_words_connector, and .last_word_connector translation keys.  #1397 [Akira Matsuda]
diff --git a/activesupport/lib/active_support/vendor.rb b/activesupport/lib/active_support/vendor.rb
index 463610722c..4525bba559 100644
--- a/activesupport/lib/active_support/vendor.rb
+++ b/activesupport/lib/active_support/vendor.rb
@@ -9,9 +9,9 @@ end
 require 'builder'
 
 begin
-  gem 'memcache-client', '~> 1.5.1'
+  gem 'memcache-client', '~> 1.5.0.5'
 rescue Gem::LoadError
-  $:.unshift "#{File.dirname(__FILE__)}/vendor/memcache-client-1.5.1"
+  $:.unshift "#{File.dirname(__FILE__)}/vendor/memcache-client-1.5.0.5"
 end
 
 begin
diff --git a/activesupport/lib/active_support/vendor/memcache-client-1.5.1/memcache.rb b/activesupport/lib/active_support/vendor/memcache-client-1.5.0.5/memcache.rb
index 99c9af0398..e90ddf3359 100644
--- a/activesupport/lib/active_support/vendor/memcache-client-1.5.1/memcache.rb
+++ b/activesupport/lib/active_support/vendor/memcache-client-1.5.0.5/memcache.rb
@@ -26,36 +26,13 @@
 # OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 # EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+$TESTING = defined?($TESTING) && $TESTING
 
 require 'socket'
 require 'thread'
 require 'timeout'
 require 'rubygems'
-
-class String
-
-  ##
-  # Uses the ITU-T polynomial in the CRC32 algorithm.
-
-  def crc32_ITU_T
-    n = length
-    r = 0xFFFFFFFF
-
-    n.times do |i|
-      r ^= self[i]
-      8.times do
-        if (r & 1) != 0 then
-          r = (r>>1) ^ 0xEDB88320
-        else
-          r >>= 1
-        end
-      end
-    end
-
-    r ^ 0xFFFFFFFF
-  end
-
-end
+require 'zlib'
 
 ##
 # A Ruby client library for memcached.
@@ -69,7 +46,7 @@ class MemCache
   ##
   # The version of MemCache you are using.
 
-  VERSION = '1.5.0'
+  VERSION = '1.5.0.5'
 
   ##
   # Default options for the cache object.
@@ -78,6 +55,7 @@ class MemCache
     :namespace   => nil,
     :readonly    => false,
     :multithread => false,
+    :failover    => true
   }
 
   ##
@@ -113,6 +91,10 @@ class MemCache
   attr_reader :servers
 
   ##
+  # Whether this client should failover reads and writes to another server
+
+  attr_accessor :failover
+  ##
   # Accepts a list of +servers+ and a list of +opts+.  +servers+ may be
   # omitted.  See +servers=+ for acceptable server list arguments.
   #
@@ -148,6 +130,7 @@ class MemCache
     @namespace   = opts[:namespace]
     @readonly    = opts[:readonly]
     @multithread = opts[:multithread]
+    @failover      = opts[:failover]
     @mutex       = Mutex.new if @multithread
     @buckets     = []
     self.servers = servers
@@ -182,7 +165,7 @@ class MemCache
 
   def servers=(servers)
     # Create the server objects.
-    @servers = servers.collect do |server|
+    @servers = Array(servers).collect do |server|
       case server
       when String
         host, port, weight = server.split ':', 3
@@ -212,15 +195,12 @@ class MemCache
   # 0.  +key+ can not be decremented below 0.
 
   def decr(key, amount = 1)
-    server, cache_key = request_setup key
-
-    if @multithread then
-      threadsafe_cache_decr server, cache_key, amount
-    else
+    raise MemCacheError, "Update of readonly cache" if @readonly
+    with_server(key) do |server, cache_key|
       cache_decr server, cache_key, amount
     end
-  rescue TypeError, SocketError, SystemCallError, IOError => err
-    handle_error server, err
+  rescue TypeError => err
+    handle_error nil, err
   end
 
   ##
@@ -228,21 +208,14 @@ class MemCache
   # unmarshalled.
 
   def get(key, raw = false)
-    server, cache_key = request_setup key
-
-    value = if @multithread then
-              threadsafe_cache_get server, cache_key
-            else
-              cache_get server, cache_key
-            end
-
-    return nil if value.nil?
-
-    value = Marshal.load value unless raw
-
-    return value
-  rescue TypeError, SocketError, SystemCallError, IOError => err
-    handle_error server, err
+    with_server(key) do |server, cache_key|
+      value = cache_get server, cache_key
+      return nil if value.nil?
+      value = Marshal.load value unless raw
+      return value
+    end
+  rescue TypeError => err
+    handle_error nil, err
   end
 
   ##
@@ -280,36 +253,29 @@ class MemCache
 
     server_keys.each do |server, keys_for_server|
       keys_for_server = keys_for_server.join ' '
-      values = if @multithread then
-                 threadsafe_cache_get_multi server, keys_for_server
-               else
-                 cache_get_multi server, keys_for_server
-               end
+      values = cache_get_multi server, keys_for_server
       values.each do |key, value|
         results[cache_keys[key]] = Marshal.load value
       end
     end
 
     return results
-  rescue TypeError, SocketError, SystemCallError, IOError => err
-    handle_error server, err
+  rescue TypeError, IndexError => err
+    handle_error nil, err
   end
 
   ##
-  # Increments the value for +key+ by +amount+ and retruns the new value.
+  # Increments the value for +key+ by +amount+ and returns the new value.
   # +key+ must already exist.  If +key+ is not an integer, it is assumed to be
   # 0.
 
   def incr(key, amount = 1)
-    server, cache_key = request_setup key
-
-    if @multithread then
-      threadsafe_cache_incr server, cache_key, amount
-    else
+    raise MemCacheError, "Update of readonly cache" if @readonly
+    with_server(key) do |server, cache_key|
       cache_incr server, cache_key, amount
     end
-  rescue TypeError, SocketError, SystemCallError, IOError => err
-    handle_error server, err
+  rescue TypeError => err
+    handle_error nil, err
   end
 
   ##
@@ -321,23 +287,23 @@ class MemCache
 
   def set(key, value, expiry = 0, raw = false)
     raise MemCacheError, "Update of readonly cache" if @readonly
-    server, cache_key = request_setup key
-    socket = server.socket
+    with_server(key) do |server, cache_key|
 
-    value = Marshal.dump value unless raw
-    command = "set #{cache_key} 0 #{expiry} #{value.size}\r\n#{value}\r\n"
+      value = Marshal.dump value unless raw
+      command = "set #{cache_key} 0 #{expiry} #{value.to_s.size}\r\n#{value}\r\n"
 
-    begin
-      @mutex.lock if @multithread
-      socket.write command
-      result = socket.gets
-      raise_on_error_response! result
-      result
-    rescue SocketError, SystemCallError, IOError => err
-      server.close
-      raise MemCacheError, err.message
-    ensure
-      @mutex.unlock if @multithread
+      with_socket_management(server) do |socket|
+        socket.write command
+        result = socket.gets
+        raise_on_error_response! result
+
+        if result.nil?
+          server.close
+          raise MemCacheError, "lost connection to #{server.host}:#{server.port}"
+        end
+
+        result
+      end
     end
   end
 
@@ -351,23 +317,16 @@ class MemCache
 
   def add(key, value, expiry = 0, raw = false)
     raise MemCacheError, "Update of readonly cache" if @readonly
-    server, cache_key = request_setup key
-    socket = server.socket
-
-    value = Marshal.dump value unless raw
-    command = "add #{cache_key} 0 #{expiry} #{value.size}\r\n#{value}\r\n"
-
-    begin
-      @mutex.lock if @multithread
-      socket.write command
-      result = socket.gets
-      raise_on_error_response! result
-      result
-    rescue SocketError, SystemCallError, IOError => err
-      server.close
-      raise MemCacheError, err.message
-    ensure
-      @mutex.unlock if @multithread
+    with_server(key) do |server, cache_key|
+      value = Marshal.dump value unless raw
+      command = "add #{cache_key} 0 #{expiry} #{value.size}\r\n#{value}\r\n"
+
+      with_socket_management(server) do |socket|
+        socket.write command
+        result = socket.gets
+        raise_on_error_response! result
+        result
+      end
     end
   end
 
@@ -375,26 +334,15 @@ class MemCache
   # Removes +key+ from the cache in +expiry+ seconds.
 
   def delete(key, expiry = 0)
-    @mutex.lock if @multithread
-
-    raise MemCacheError, "No active servers" unless active?
-    cache_key = make_cache_key key
-    server = get_server_for_key cache_key
-
-    sock = server.socket
-    raise MemCacheError, "No connection to server" if sock.nil?
-
-    begin
-      sock.write "delete #{cache_key} #{expiry}\r\n"
-      result = sock.gets
-      raise_on_error_response! result
-      result
-    rescue SocketError, SystemCallError, IOError => err
-      server.close
-      raise MemCacheError, err.message
+    raise MemCacheError, "Update of readonly cache" if @readonly
+    with_server(key) do |server, cache_key|
+      with_socket_management(server) do |socket|
+        socket.write "delete #{cache_key} #{expiry}\r\n"
+        result = socket.gets
+        raise_on_error_response! result
+        result
+      end
     end
-  ensure
-    @mutex.unlock if @multithread
   end
 
   ##
@@ -403,21 +351,19 @@ class MemCache
   def flush_all
     raise MemCacheError, 'No active servers' unless active?
     raise MemCacheError, "Update of readonly cache" if @readonly
+
     begin
       @mutex.lock if @multithread
       @servers.each do |server|
-        begin
-          sock = server.socket
-          raise MemCacheError, "No connection to server" if sock.nil?
-          sock.write "flush_all\r\n"
-          result = sock.gets
+        with_socket_management(server) do |socket|
+          socket.write "flush_all\r\n"
+          result = socket.gets
           raise_on_error_response! result
           result
-        rescue SocketError, SystemCallError, IOError => err
-          server.close
-          raise MemCacheError, err.message
         end
       end
+    rescue IndexError => err
+      handle_error nil, err
     ensure
       @mutex.unlock if @multithread
     end
@@ -469,14 +415,13 @@ class MemCache
     server_stats = {}
 
     @servers.each do |server|
-      sock = server.socket
-      raise MemCacheError, "No connection to server" if sock.nil?
+      next unless server.alive?
 
-      value = nil
-      begin
-        sock.write "stats\r\n"
+      with_socket_management(server) do |socket|
+        value = nil
+        socket.write "stats\r\n"
         stats = {}
-        while line = sock.gets do
+        while line = socket.gets do
           raise_on_error_response! line
           break if line == "END\r\n"
           if line =~ /\ASTAT ([\w]+) ([\w\.\:]+)/ then
@@ -498,12 +443,10 @@ class MemCache
           end
         end
         server_stats["#{server.host}:#{server.port}"] = stats
-      rescue SocketError, SystemCallError, IOError => err
-        server.close
-        raise MemCacheError, err.message
       end
     end
 
+    raise MemCacheError, "No active servers" if server_stats.empty?
     server_stats
   end
 
@@ -520,7 +463,7 @@ class MemCache
     set key, value
   end
 
-  protected
+  protected unless $TESTING
 
   ##
   # Create a key for the cache, incorporating the namespace qualifier if
@@ -537,7 +480,7 @@ class MemCache
   ##
   # Pick a server to handle the request based on a hash of the key.
 
-  def get_server_for_key(key)
+  def get_server_for_key(key, options = {})
     raise ArgumentError, "illegal character in key #{key.inspect}" if
       key =~ /\s/
     raise ArgumentError, "key too long #{key.inspect}" if key.length > 250
@@ -545,13 +488,17 @@ class MemCache
     return @servers.first if @servers.length == 1
 
     hkey = hash_for key
-
-    20.times do |try|
-      server = @buckets[hkey % @buckets.nitems]
-      return server if server.alive?
-      hkey += hash_for "#{try}#{key}"
+    
+    if @failover
+      20.times do |try|
+        server = @buckets[hkey % @buckets.compact.size]
+        return server if server.alive?
+        hkey += hash_for "#{try}#{key}"
+      end
+    else
+      return @buckets[hkey % @buckets.compact.size]
     end
-
+    
     raise MemCacheError, "No servers available"
   end
 
@@ -560,7 +507,7 @@ class MemCache
   # sketchy for down servers).
 
   def hash_for(key)
-    (key.crc32_ITU_T >> 16) & 0x7fff
+    (Zlib.crc32(key) >> 16) & 0x7fff
   end
 
   ##
@@ -568,12 +515,13 @@ class MemCache
   # found.
 
   def cache_decr(server, cache_key, amount)
-    socket = server.socket
-    socket.write "decr #{cache_key} #{amount}\r\n"
-    text = socket.gets
-    raise_on_error_response! text
-    return nil if text == "NOT_FOUND\r\n"
-    return text.to_i
+    with_socket_management(server) do |socket|
+      socket.write "decr #{cache_key} #{amount}\r\n"
+      text = socket.gets
+      raise_on_error_response! text
+      return nil if text == "NOT_FOUND\r\n"
+      return text.to_i
+    end
   end
 
   ##
@@ -581,52 +529,54 @@ class MemCache
   # miss.
 
   def cache_get(server, cache_key)
-    socket = server.socket
-    socket.write "get #{cache_key}\r\n"
-    keyline = socket.gets # "VALUE <key> <flags> <bytes>\r\n"
+    with_socket_management(server) do |socket|
+      socket.write "get #{cache_key}\r\n"
+      keyline = socket.gets # "VALUE <key> <flags> <bytes>\r\n"
 
-    if keyline.nil? then
-      server.close
-      raise MemCacheError, "lost connection to #{server.host}:#{server.port}"
-    end
+      if keyline.nil? then
+        server.close
+        raise MemCacheError, "lost connection to #{server.host}:#{server.port}"
+      end
 
-    raise_on_error_response! keyline
-    return nil if keyline == "END\r\n"
+      raise_on_error_response! keyline
+      return nil if keyline == "END\r\n"
 
-    unless keyline =~ /(\d+)\r/ then
-      server.close
-      raise MemCacheError, "unexpected response #{keyline.inspect}"
+      unless keyline =~ /(\d+)\r/ then
+        server.close
+        raise MemCacheError, "unexpected response #{keyline.inspect}"
+      end
+      value = socket.read $1.to_i
+      socket.read 2 # "\r\n"
+      socket.gets   # "END\r\n"
+      return value
     end
-    value = socket.read $1.to_i
-    socket.read 2 # "\r\n"
-    socket.gets   # "END\r\n"
-    return value
   end
 
   ##
   # Fetches +cache_keys+ from +server+ using a multi-get.
 
   def cache_get_multi(server, cache_keys)
-    values = {}
-    socket = server.socket
-    socket.write "get #{cache_keys}\r\n"
+    with_socket_management(server) do |socket|
+      values = {}
+      socket.write "get #{cache_keys}\r\n"
 
-    while keyline = socket.gets do
-      return values if keyline == "END\r\n"
-      raise_on_error_response! keyline
+      while keyline = socket.gets do
+        return values if keyline == "END\r\n"
+        raise_on_error_response! keyline
 
-      unless keyline =~ /\AVALUE (.+) (.+) (.+)/ then
-        server.close
-        raise MemCacheError, "unexpected response #{keyline.inspect}"
+        unless keyline =~ /\AVALUE (.+) (.+) (.+)/ then
+          server.close
+          raise MemCacheError, "unexpected response #{keyline.inspect}"
+        end
+
+        key, data_length = $1, $3
+        values[$1] = socket.read data_length.to_i
+        socket.read(2) # "\r\n"
       end
 
-      key, data_length = $1, $3
-      values[$1] = socket.read data_length.to_i
-      socket.read(2) # "\r\n"
+      server.close
+      raise MemCacheError, "lost connection to #{server.host}:#{server.port}" # TODO: retry here too
     end
-
-    server.close
-    raise MemCacheError, "lost connection to #{server.host}:#{server.port}"
   end
 
   ##
@@ -634,18 +584,76 @@ class MemCache
   # found.
 
   def cache_incr(server, cache_key, amount)
-    socket = server.socket
-    socket.write "incr #{cache_key} #{amount}\r\n"
-    text = socket.gets
-    raise_on_error_response! text
-    return nil if text == "NOT_FOUND\r\n"
-    return text.to_i
+    with_socket_management(server) do |socket|
+      socket.write "incr #{cache_key} #{amount}\r\n"
+      text = socket.gets
+      raise_on_error_response! text
+      return nil if text == "NOT_FOUND\r\n"
+      return text.to_i
+    end
+  end
+
+  ##
+  # Gets or creates a socket connected to the given server, and yields it
+  # to the block, wrapped in a mutex synchronization if @multithread is true.
+  #
+  # If a socket error (SocketError, SystemCallError, IOError) or protocol error
+  # (MemCacheError) is raised by the block, closes the socket, attempts to
+  # connect again, and retries the block (once).  If an error is again raised,
+  # reraises it as MemCacheError.
+  #
+  # If unable to connect to the server (or if in the reconnect wait period),
+  # raises MemCacheError.  Note that the socket connect code marks a server
+  # dead for a timeout period, so retrying does not apply to connection attempt
+  # failures (but does still apply to unexpectedly lost connections etc.).
+
+  def with_socket_management(server, &block)
+    @mutex.lock if @multithread
+    retried = false
+    
+    begin
+      socket = server.socket
+
+      # Raise an IndexError to show this server is out of whack. If were inside
+      # a with_server block, we'll catch it and attempt to restart the operation.
+      
+      raise IndexError, "No connection to server (#{server.status})" if socket.nil?
+      
+      block.call(socket)
+      
+    rescue SocketError => err
+      server.mark_dead(err.message)
+      handle_error(server, err)
+
+    rescue MemCacheError, SocketError, SystemCallError, IOError => err
+      handle_error(server, err) if retried || socket.nil?
+      retried = true
+      retry
+    end
+  ensure
+    @mutex.unlock if @multithread
+  end
+
+  def with_server(key)
+    retried = false
+    begin
+      server, cache_key = request_setup(key)
+      yield server, cache_key
+    rescue IndexError => e
+      if !retried && @servers.size > 1
+        puts "Connection to server #{server.inspect} DIED! Retrying operation..."
+        retried = true
+        retry
+      end
+      handle_error(nil, e)
+    end
   end
 
   ##
   # Handles +error+ from +server+.
 
   def handle_error(server, error)
+    raise error if error.is_a?(MemCacheError)
     server.close if server
     new_error = MemCacheError.new error.message
     new_error.set_backtrace error.backtrace
@@ -660,45 +668,15 @@ class MemCache
     raise MemCacheError, 'No active servers' unless active?
     cache_key = make_cache_key key
     server = get_server_for_key cache_key
-    raise MemCacheError, 'No connection to server' if server.socket.nil?
     return server, cache_key
   end
 
-  def threadsafe_cache_decr(server, cache_key, amount) # :nodoc:
-    @mutex.lock
-    cache_decr server, cache_key, amount
-  ensure
-    @mutex.unlock
-  end
-
-  def threadsafe_cache_get(server, cache_key) # :nodoc:
-    @mutex.lock
-    cache_get server, cache_key
-  ensure
-    @mutex.unlock
-  end
-
-  def threadsafe_cache_get_multi(socket, cache_keys) # :nodoc:
-    @mutex.lock
-    cache_get_multi socket, cache_keys
-  ensure
-    @mutex.unlock
-  end
-
-  def threadsafe_cache_incr(server, cache_key, amount) # :nodoc:
-    @mutex.lock
-    cache_incr server, cache_key, amount
-  ensure
-    @mutex.unlock
-  end
-
   def raise_on_error_response!(response)
-    if response =~ /\A(?:CLIENT_|SERVER_)?ERROR (.*)/
+    if response =~ /\A(?:CLIENT_|SERVER_)?ERROR(.*)/
       raise MemCacheError, $1.strip
     end
   end
 
-
   ##
   # This class represents a memcached server instance.
 
@@ -712,6 +690,13 @@ class MemCache
     CONNECT_TIMEOUT = 0.25
 
     ##
+    # The amount of time to wait for a response from a memcached server.
+    # If a response isn't received within this time limit,
+    # the server will be marked as down.
+
+    SOCKET_TIMEOUT = 0.5
+
+    ##
     # The amount of time to wait before attempting to re-establish a
     # connection with a server that is marked dead.
 
@@ -795,9 +780,9 @@ class MemCache
 
       # Attempt to connect if not already connected.
       begin
-        @sock = timeout CONNECT_TIMEOUT do
-          TCPSocket.new @host, @port
-        end
+
+        @sock = TCPTimeoutSocket.new @host, @port
+
         if Socket.constants.include? 'TCP_NODELAY' then
           @sock.setsockopt Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1
         end
@@ -826,8 +811,6 @@ class MemCache
       @mutex.unlock if @multithread
     end
 
-    private
-
     ##
     # Mark the server as dead and close its socket.
 
@@ -836,8 +819,9 @@ class MemCache
       @sock   = nil
       @retry  = Time.now + RETRY_DELAY
 
-      @status = sprintf "DEAD: %s, will retry at %s", reason, @retry
+      @status = sprintf "%s:%s DEAD: %s, will retry at %s", @host, @port, reason, @retry
     end
+
   end
 
   ##
@@ -847,3 +831,38 @@ class MemCache
 
 end
 
+# TCPSocket facade class which implements timeouts.
+class TCPTimeoutSocket
+  def initialize(*args)
+    Timeout::timeout(MemCache::Server::CONNECT_TIMEOUT, SocketError) do
+      @sock = TCPSocket.new(*args)
+      @len = MemCache::Server::SOCKET_TIMEOUT.to_f || 0.5
+    end
+  end
+  
+  def write(*args)
+    Timeout::timeout(@len, SocketError) do
+      @sock.write(*args)
+    end
+  end
+  
+  def gets(*args)
+    Timeout::timeout(@len, SocketError) do
+      @sock.gets(*args)
+    end
+  end
+  
+  def read(*args)
+    Timeout::timeout(@len, SocketError) do
+      @sock.read(*args)
+    end
+  end
+  
+  def _socket
+    @sock
+  end
+  
+  def method_missing(meth, *args)
+    @sock.__send__(meth, *args)
+  end
+end
\ No newline at end of file