module DRb::DRbProtocol
Module managing the underlying network protocol(s) used by drb.
By default, drb uses the DRbTCPSocket
protocol. Other protocols can be defined. A protocol must define the following class methods:
[open(uri, config)] Open a client connection to the server at +uri+, using configuration +config+. Return a protocol instance for this connection. [open_server(uri, config)] Open a server listening at +uri+, using configuration +config+. Return a protocol instance for this listener. [uri_option(uri, config)] Take a URI, possibly containing an option component (e.g. a trailing '?param=val'), and return a [uri, option] tuple.
All of these methods should raise a DRbBadScheme
error if the URI does not identify the protocol they support (e.g. “druby:” for the standard Ruby protocol). This is how the DRbProtocol
module, given a URI, determines which protocol implementation serves that protocol.
The protocol instance returned by open_server
must have the following methods:
- accept
-
Accept a new connection to the server. Returns a protocol instance capable of communicating with the client.
- close
-
Close the server connection.
- uri
-
Get the URI for this server.
The protocol instance returned by open
must have the following methods:
- send_request (ref, msg_id, arg, b)
-
Send a request to
ref
with the given message id and arguments. This is most easily implemented by calling DRbMessage.send_request, providing a stream that sits on top of the current protocol. - recv_reply
-
Receive a reply from the server and return it as a [success-boolean, reply-value] pair. This is most easily implemented by calling DRb.recv_reply, providing a stream that sits on top of the current protocol.
- alive?
-
Is this connection still alive?
- close
-
Close this connection.
The protocol instance returned by open_server()
.accept() must have the following methods:
- recv_request
-
Receive a request from the client and return a [object, message, args, block] tuple. This is most easily implemented by calling DRbMessage.recv_request, providing a stream that sits on top of the current protocol.
- send_reply(succ, result)
-
Send a reply to the client. This is most easily implemented by calling DRbMessage.send_reply, providing a stream that sits on top of the current protocol.
- close
-
Close this connection.
A new protocol is registered with the DRbProtocol
module using the add_protocol
method.
For examples of other protocols, see DRbUNIXSocket
in drb/unix.rb, and HTTP0 in sample/http0.rb and sample/http0serv.rb in the full drb distribution.
Public Class Methods
Add a new protocol to the DRbProtocol
module.
# File drb/drb.rb, line 724 def add_protocol(prot) @protocol.push(prot) end
Open a client connection to uri
with the configuration config
.
The DRbProtocol
module asks each registered protocol in turn to try to open the URI. Each protocol signals that it does not handle that URI by raising a DRbBadScheme
error. If no protocol recognises the URI, then a DRbBadURI
error is raised. If a protocol accepts the URI, but an error occurs in opening it, a DRbConnError
is raised.
# File drb/drb.rb, line 736 def open(uri, config, first=true) @protocol.each do |prot| begin return prot.open(uri, config) rescue DRbBadScheme rescue DRbConnError raise($!) rescue raise(DRbConnError, "#{uri} - #{$!.inspect}") end end if first && (config[:auto_load] != false) auto_load(uri) return open(uri, config, false) end raise DRbBadURI, 'can\'t parse uri:' + uri end
Open a server listening for connections at uri
with configuration config
.
The DRbProtocol
module asks each registered protocol in turn to try to open a server at the URI. Each protocol signals that it does not handle that URI by raising a DRbBadScheme
error. If no protocol recognises the URI, then a DRbBadURI
error is raised. If a protocol accepts the URI, but an error occurs in opening it, the underlying error is passed on to the caller.
# File drb/drb.rb, line 764 def open_server(uri, config, first=true) @protocol.each do |prot| begin return prot.open_server(uri, config) rescue DRbBadScheme end end if first && (config[:auto_load] != false) auto_load(uri) return open_server(uri, config, false) end raise DRbBadURI, 'can\'t parse uri:' + uri end
Parse uri
into a [uri, option] pair.
The DRbProtocol
module asks each registered protocol in turn to try to parse the URI. Each protocol signals that it does not handle that URI by raising a DRbBadScheme
error. If no protocol recognises the URI, then a DRbBadURI
error is raised.
# File drb/drb.rb, line 785 def uri_option(uri, config, first=true) @protocol.each do |prot| begin uri, opt = prot.uri_option(uri, config) # opt = nil if opt == '' return uri, opt rescue DRbBadScheme end end if first && (config[:auto_load] != false) auto_load(uri) return uri_option(uri, config, false) end raise DRbBadURI, 'can\'t parse uri:' + uri end
Private Instance Methods
Add a new protocol to the DRbProtocol
module.
# File drb/drb.rb, line 724 def add_protocol(prot) @protocol.push(prot) end
Open a client connection to uri
with the configuration config
.
The DRbProtocol
module asks each registered protocol in turn to try to open the URI. Each protocol signals that it does not handle that URI by raising a DRbBadScheme
error. If no protocol recognises the URI, then a DRbBadURI
error is raised. If a protocol accepts the URI, but an error occurs in opening it, a DRbConnError
is raised.
# File drb/drb.rb, line 736 def open(uri, config, first=true) @protocol.each do |prot| begin return prot.open(uri, config) rescue DRbBadScheme rescue DRbConnError raise($!) rescue raise(DRbConnError, "#{uri} - #{$!.inspect}") end end if first && (config[:auto_load] != false) auto_load(uri) return open(uri, config, false) end raise DRbBadURI, 'can\'t parse uri:' + uri end
Open a server listening for connections at uri
with configuration config
.
The DRbProtocol
module asks each registered protocol in turn to try to open a server at the URI. Each protocol signals that it does not handle that URI by raising a DRbBadScheme
error. If no protocol recognises the URI, then a DRbBadURI
error is raised. If a protocol accepts the URI, but an error occurs in opening it, the underlying error is passed on to the caller.
# File drb/drb.rb, line 764 def open_server(uri, config, first=true) @protocol.each do |prot| begin return prot.open_server(uri, config) rescue DRbBadScheme end end if first && (config[:auto_load] != false) auto_load(uri) return open_server(uri, config, false) end raise DRbBadURI, 'can\'t parse uri:' + uri end
Parse uri
into a [uri, option] pair.
The DRbProtocol
module asks each registered protocol in turn to try to parse the URI. Each protocol signals that it does not handle that URI by raising a DRbBadScheme
error. If no protocol recognises the URI, then a DRbBadURI
error is raised.
# File drb/drb.rb, line 785 def uri_option(uri, config, first=true) @protocol.each do |prot| begin uri, opt = prot.uri_option(uri, config) # opt = nil if opt == '' return uri, opt rescue DRbBadScheme end end if first && (config[:auto_load] != false) auto_load(uri) return uri_option(uri, config, false) end raise DRbBadURI, 'can\'t parse uri:' + uri end