rpc: new RPC implementation with pub/sub support

1 files changed, 102 insertions, 0 deletions

diff --git a/rpc/v2/doc.go b/rpc/v2/doc.go
new file mode 100644
index 000000000..e51494adb
--- /dev/null
+++ b/rpc/v2/doc.go
@@ -0,0 +1,102 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+/*
+Package rpc provides access to the exported methods of an object across a network
+or other I/O connection. After creating a server instance objects can be registered,
+making it visible from the outside. Exported methods that follow specific
+conventions can be called remotely. It also has support for the publish/subscribe
+pattern.
+
+Methods that satisfy the following criteria are made available for remote access:
+ - object must be exported
+ - method must be exported
+ - method returns 0, 1 (response or error) or 2 (response and error) values
+ - method argument(s) must be exported or builtin types
+ - method returned value(s) must be exported or builtin types
+
+An example method:
+ func (s *CalcService) Div(a, b int) (int, error)
+
+When the returned error isn't nil the returned integer is ignored and the error is
+send back to the client. Otherwise the returned integer is send back to the client.
+
+The server offers the ServeCodec method which accepts a ServerCodec instance. It will
+read requests from the codec, process the request and sends the response back to the
+client using the codec. The server can execute requests concurrently. Responses
+can be send back to the client out of order.
+
+An example server which uses the JSON codec:
+ type CalculatorService struct {}
+
+ func (s *CalculatorService) Add(a, b int) int {
+	return a + b
+ }
+
+ func (s *CalculatorService Div(a, b int) (int, error) {
+	if b == 0 {
+		return 0, errors.New("divide by zero")
+	}
+	return a/b, nil
+ }
+
+ calculator := new(CalculatorService)
+ server := NewServer()
+ server.RegisterName("calculator", calculator")
+
+ l, _ := net.ListenUnix("unix", &net.UnixAddr{Net: "unix", Name: "/tmp/calculator.sock"})
+ for {
+	c, _ := l.AcceptUnix()
+	codec := v2.NewJSONCodec(c)
+	go server.ServeCodec(codec)
+ }
+
+The package also supports the publish subscribe pattern through the use of subscriptions.
+A method that is considered eligible for notifications must satisfy the following criteria:
+ - object must be exported
+ - method must be exported
+ - method argument(s) must be exported or builtin types
+ - method must return the tuple Subscription, error
+
+
+An example method:
+ func (s *BlockChainService) Head() (Subscription, error) {
+ 	sub := s.bc.eventMux.Subscribe(ChainHeadEvent{})
+	return v2.NewSubscription(sub), nil
+ }
+
+This method will push all raised ChainHeadEvents to subscribed clients. If the client is only
+interested in every N'th block it is possible to add a criteria.
+
+ func (s *BlockChainService) HeadFiltered(nth uint64) (Subscription, error) {
+ 	sub := s.bc.eventMux.Subscribe(ChainHeadEvent{})
+
+	criteria := func(event interface{}) bool {
+		chainHeadEvent := event.(ChainHeadEvent)
+		if chainHeadEvent.Block.NumberU64() % nth == 0 {
+			return true
+		}
+		return false
+	}
+
+	return v2.NewSubscriptionFiltered(sub, criteria), nil
+ }
+
+Subscriptions are deleted when:
+ - the user sends an unsubscribe request
+ - the connection which was used to create the subscription is closed
+*/
+package v2