cmd, node, rpc: readd inproc RPC client, expose via node

1 files changed, 111 insertions, 0 deletions

diff --git a/rpc/inproc.go b/rpc/inproc.go
new file mode 100644
index 000000000..e138ba2c3
--- /dev/null
+++ b/rpc/inproc.go
@@ -0,0 +1,111 @@
+// Copyright 2016 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
+
+import "encoding/json"
+
+// NewInProcRPCClient creates an in-process buffer stream attachment to a given
+// RPC server.
+func NewInProcRPCClient(handler *Server) Client {
+	buffer := &inprocBuffer{
+		requests:  make(chan []byte, 16),
+		responses: make(chan []byte, 16),
+	}
+	client := &inProcClient{
+		server: handler,
+		buffer: buffer,
+	}
+	go handler.ServeCodec(NewJSONCodec(client.buffer))
+	return client
+}
+
+// inProcClient is an in-process buffer stream attached to an RPC server.
+type inProcClient struct {
+	server *Server
+	buffer *inprocBuffer
+}
+
+// Close tears down the request channel of the in-proc client.
+func (c *inProcClient) Close() {
+	c.buffer.Close()
+}
+
+// Send marshals a message into a json format and injects in into the client
+// request channel.
+func (c *inProcClient) Send(msg interface{}) error {
+	d, err := json.Marshal(msg)
+	if err != nil {
+		return err
+	}
+	c.buffer.requests <- d
+	return nil
+}
+
+// Recv reads a message from the response channel and tries to parse it into the
+// given msg interface.
+func (c *inProcClient) Recv(msg interface{}) error {
+	data := <-c.buffer.responses
+	return json.Unmarshal(data, &msg)
+}
+
+// Returns the collection of modules the RPC server offers.
+func (c *inProcClient) SupportedModules() (map[string]string, error) {
+	return SupportedModules(c)
+}
+
+// inprocBuffer represents the connection between the RPC server and console
+type inprocBuffer struct {
+	readBuf   []byte      // store remaining request bytes after a partial read
+	requests  chan []byte // list with raw serialized requests
+	responses chan []byte // list with raw serialized responses
+}
+
+// Read will read the next request in json format.
+func (b *inprocBuffer) Read(p []byte) (int, error) {
+	// last read didn't read entire request, return remaining bytes
+	if len(b.readBuf) > 0 {
+		n := copy(p, b.readBuf)
+		if n < len(b.readBuf) {
+			b.readBuf = b.readBuf[:n]
+		} else {
+			b.readBuf = b.readBuf[:0]
+		}
+		return n, nil
+	}
+	// read next request
+	req := <-b.requests
+	n := copy(p, req)
+	if n < len(req) {
+		// inprocBuffer too small, store remaining chunk for next read
+		b.readBuf = req[n:]
+	}
+	return n, nil
+}
+
+// Write sends the given buffer to the backend.
+func (b *inprocBuffer) Write(p []byte) (n int, err error) {
+	b.responses <- p
+	return len(p), nil
+}
+
+// Close cleans up obtained resources.
+func (b *inprocBuffer) Close() error {
+	close(b.requests)
+	close(b.responses)
+
+	return nil
+}