GSoC: Add RPC client

libs/rpcc/Makefile

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+include ../../build/config.mk
+include ../../build/module.mk

libs/rpcc/luasrc/rpcc.lua

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+--[[
+LuCIRPCc
+(c) 2009 Steven Barth <steven@midlink.org>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+$Id$
+]]--
+
+local util = require "luci.util"
+local json = require "luci.json"
+local ltn12 = require "luci.ltn12"
+local nixio = require "nixio", require "nixio.util"
+
+local tostring, assert, setmetatable = tostring, assert, setmetatable
+local error = error
+
+--- LuCI RPC Client.
+-- @cstyle instance
+module "luci.rpcc"
+
+RQLIMIT = 32 * nixio.const.buffersize
+
+--- Create a new JSON-RPC stream client.
+-- @class function
+-- @param fd File descriptor
+-- @param v1 Use protocol version 1.0
+-- @return RPC Client
+Client = util.class()
+
+function Client.__init__(self, fd, v1)
+	self.fd = fd
+	self.uniqueid = tostring(self):match("0x([a-f0-9]+)")
+	self.msgid = 1
+	self.v1 = v1
+end
+
+--- Request an RP call and get the response.
+-- @param method Remote method
+-- @param params Parameters
+-- @param notification Notification only?
+-- @return response 
+function Client.request(self, method, params, notification)
+	local oldchunk = self.decoder and self.decoder.chunk
+	self.decoder = json.ActiveDecoder(self.fd:blocksource(nil, RQLIMIT))
+	self.decoder.chunk = oldchunk
+	
+	local reqid = self.msgid .. self.uniqueid
+	local reqdata = json.Encoder({
+		id = (not notification) and (self.msgid .. self.uniqueid) or nil,
+		jsonrpc = (not self.v1) and "2.0" or nil,
+		method = method,
+		params = params
+	})
+	ltn12.pump.all(reqdata:source(), self.fd:sink())
+	if not notification then
+		self.msgid = self.msgid + 1
+		local response = self.decoder:get()
+		assert(response.id == reqid, "Invalid response id")
+		if response.error then
+			error(response.error.message or response.error)
+		end
+		return response.result
+	end
+end
+
+--- Create a transparent RPC proxy.
+-- @param prefix Method prefix
+-- @return RPC Proxy object
+function Client.proxy(self, prefix)
+	prefix = prefix or ""
+	return setmetatable({}, {
+		__call = function(proxy, ...)
+			return self:request(prefix, {...})
+		end,
+		__index = function(proxy, name)
+			return self:proxy(prefix .. name .. ".")
+		end
+	})
+end

libs/rpcc/luasrc/rpcc/ruci.lua

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+--[[
+LuCIRPCc
+(c) 2009 Steven Barth <steven@midlink.org>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+$Id$
+]]--
+
+local util = require "luci.util"
+local rawget, setmetatable = rawget, setmetatable
+local ipairs = ipairs
+
+--- Transparent UCI over RPC client.
+-- @cstyle instance
+module "luci.rpcc.ruci"
+
+
+local Proxy = util.class()
+
+--- Create a new UCI over RPC proxy.
+-- @param rpccl RPC client
+-- @return Network transparent UCI module 
+function factory(rpccl)
+	return {
+		cursor = function(...)
+			return Proxy(rpccl, rpccl:request("ruci.cursor", {...}))
+		end,
+		cursor_state = function(...)
+			return Proxy(rpccl, rpccl:request("ruci.cursor_state", {...}))
+		end
+	}
+end
+
+function Proxy.__init__(self, rpccl, objid)
+	self.__rpccl = rpccl
+	self.__objid = objid
+
+	setmetatable(self, {
+		__index = function(self, key)
+			return rawget(self, key) or Proxy[key] or function(self, ...)
+				local argv = {self.__objid, ...}
+				return self.__rpccl:request("ruci."..key, argv)
+			end
+		end
+	})
+end
+
+function Proxy.foreach(self, config, section, callback)
+	local sections = self.__rpccl:request("ruci.foreach", {self.__objid, config, section})
+	if sections then
+		for _, s in ipairs(sections) do
+			callback(s)
+		end
+		return true
+	else
+		return false
+	end
+end