lib/amqp/exceptions.rb in amqp-0.8.0.rc2 vs lib/amqp/exceptions.rb in amqp-0.8.0.rc3

@@ -1,18 +1,60 @@
 # encoding: utf-8
 
 module AMQP
-  # Raised whenever an illegal operation is attempted.
-  class Error < StandardError; end
+  # Base class for AMQP connection lifecycle exceptions.
+  # @api public
+  class Error < StandardError
+    # An exception in one of the underlying libraries that caused this
+    # exception to be re-thrown. May be nil.
+    attr_reader :cause
+  end
 
+
+  # All the exceptions below are new in 0.8.0. Previous versions
+  # used AMQP::Error for everything. We have to carry this baggage but
+  # there is a way out: simply subclass AMQP::Error and provide a backwards-compatible
+  # way of attaching root cause exception (like AMQ::Client::TCPConnectionFailed) instance
+  # to it.
+  #
+  # In other words: AMQP::Error is here to stay for a long time. MK.
+
+
+
+  # Raised when initial TCP connection to the broker fails.
+  # @api public
+  class TCPConnectionFailed < Error
+
+    #
+    # API
+    #
+
+    # @return [Hash] connection settings that were used
+    attr_reader :settings
+
+    def initialize(settings, cause = nil)
+      @settings = settings
+      @cause    = cause
+
+      super("Could not estabilish TCP connection to #{@settings[:host]}:#{@settings[:port]}")
+    end # TCPConnectionFailed
+  end
+
+
+  # Raised when queue (or exchange) declaration fails because another queue with the same
+  # name but different attributes already exists in the channel object cache.
+  # @api public
   class IncompatibleOptionsError < Error
     def initialize(name, opts_1, opts_2)
       super("There is already an instance called #{name} with options #{opts_1.inspect}, you can't define the same instance with different options (#{opts_2.inspect})!")
     end
   end # IncompatibleOptionsError
 
+  # Raised on attempt to use a channel that was previously closed
+  # (either due to channel-level exception or intentionally via AMQP::Channel#close).
+  # @api public
   class ChannelClosedError < Error
     def initialize(instance)
-      super("The channel #{instance.channel} was closed, you can't use it anymore!")
+      super("Channel with id = #{instance.channel} is closed, you can't use it anymore!")
     end
   end # ChannelClosedError
 end # AMQP