redict/client-libraries/ruby/lib/server.rb
2009-05-26 18:10:50 +02:00

132 lines
3.4 KiB
Ruby

begin
# Timeout code is courtesy of Ruby memcache-client
# http://github.com/mperham/memcache-client/tree
# Try to use the SystemTimer gem instead of Ruby's timeout library
# when running on something that looks like Ruby 1.8.x. See:
# http://ph7spot.com/articles/system_timer
# We don't want to bother trying to load SystemTimer on jruby and
# ruby 1.9+.
if defined?(JRUBY_VERSION) || (RUBY_VERSION >= '1.9')
require 'timeout'
RedisTimer = Timeout
else
require 'system_timer'
RedisTimer = SystemTimer
end
rescue LoadError => e
puts "[redis-rb] Could not load SystemTimer gem, falling back to Ruby's slower/unsafe timeout library: #{e.message}"
require 'timeout'
RedisTimer = Timeout
end
##
# This class represents a redis server instance.
class Server
##
# The host the redis server is running on.
attr_reader :host
##
# The port the redis server is listening on.
attr_reader :port
##
# 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, timeout = 10)
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
@status = 'NOT CONNECTED'
@timeout = timeout
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 socket_alive?
close
# Attempt to connect if not already connected.
begin
@sock = connect_to(@host, @port, @timeout)
@sock.setsockopt Socket::IPPROTO_TCP, Socket::TCP_NODELAY, 1
@status = 'CONNECTED'
rescue Errno::EPIPE, Errno::ECONNREFUSED => e
puts "Socket died... : #{e}\n" if $debug
retry
rescue SocketError, SystemCallError, IOError => err
puts "Unable to open socket: #{err.class.name}, #{err.message}" if $debug
end
@sock
end
def connect_to(host, port, timeout=nil)
socket = TCPSocket.new(host, port)
socket.set_encoding(Encoding::BINARY) if socket.respond_to?(:set_encoding)
if timeout
socket.instance_eval <<-EOR
alias :blocking_readline :readline
def readline(*args)
RedisTimer.timeout(#{timeout}) do
self.blocking_readline(*args)
end
end
alias :blocking_read :read
def read(*args)
RedisTimer.timeout(#{timeout}) do
self.blocking_read(*args)
end
end
alias :blocking_write :write
def write(*args)
RedisTimer.timeout(#{timeout}) do
self.blocking_write(*args)
end
end
EOR
end
socket
end
# Close the connection to the redis server targeted by this
# object.
def close
@sock.close if !@sock.nil? && !@sock.closed?
@sock = nil
@status = "NOT CONNECTED"
end
private
def socket_alive?
#BTM - TODO - FileStat is borked under JRuby
unless defined?(JRUBY_VERSION)
!@sock.nil? && !@sock.closed? && @sock.stat.readable?
else
!@sock.nil? && !@sock.closed?
end
end
end