implemented dispatch-table

added example dispatch-table table...
using dispatcher in stdio and exec module


git-svn-id: https://svn.spreadspace.org/gcsd/trunk@58 ac14a137-c7f1-4531-abe0-07747231d213

6 files changed, 100 insertions, 7 deletions

diff --git a/examples/simple_dispatcher.lua b/examples/simple_dispatcher.lua
new file mode 100644
index 0000000..5a931e3
--- /dev/null
+++ b/examples/simple_dispatcher.lua
@@ -0,0 +1,6 @@
+return {
+   ["%w+%s*"] = function(match)
+		   local cmd = string.match("(%w+)%s*", match)
+		   command_queue:enqueue_command(cmd)
+		end
+}
\ No newline at end of file
diff --git a/src/Makefile b/src/Makefile
index 603b3d2..358fb85 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -56,6 +56,7 @@ C_SRCS := $(C_OBJS:%.o=%.c)
 LUA_SRCS := client_list.lua \
             module_list.lua \
             command_queue.lua \
+            dispatch_table.lua \
             main_loop.lua
 
 LUA_BYTECODE := $(EXECUTABLE).lc
diff --git a/src/dispatch_table.lua b/src/dispatch_table.lua
new file mode 100644
index 0000000..912394a
--- /dev/null
+++ b/src/dispatch_table.lua
@@ -0,0 +1,79 @@
+--
+--  gcsd
+--
+--  gcsd the generic command sequencer daemon can be used to serialize 
+--  commands sent over various paralell communication channels to a
+--  single command output. It can be seen as a multiplexer for any
+--  kind of communication between a single resource and various clients
+--  which want to submit commands to it or query information from it.
+--  gcsd is written in C and Lua. The goal is to provide an easy to 
+--  understand high level API based on Lua which can be used to
+--  implement the business logic of the so formed multiplexer daemon.
+--  
+--
+--  Copyright (C) 2009-2010 Markus Grueneis <gimpf@spreadspace.org>
+--                          Christian Pointner <equinox@spreadspace.org>
+--
+--  This file is part of gcsd.
+--
+--  gcsd is free software: you can redistribute it and/or modify
+--  it under the terms of the GNU General Public License as published by
+--  the Free Software Foundation, either version 3 of the License, or
+--  any later version.
+--
+--  gcsd 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 General Public License for more details.
+--
+--  You should have received a copy of the GNU General Public License
+--  along with gcsd. If not, see <http://www.gnu.org/licenses/>.
+--
+
+dispatch_table = {}
+dispatch_table.regex_to_handler = {
+   -- TODO basic mode
+}
+
+function dispatch_table:load_handler_table_file(filename)
+   local defines = require('defines')
+   if (type(filename) ~= "nil") then
+      if (type(filename) ~= "string") then
+	 log.printf(log.ERROR, "filename must be of type 'string' and denote a valid path")
+	 return defines.KILL_DAEMON
+      end
+      local chunk = loadfile(filename)
+      if (not chunk) then
+	 log.printf(log.ERROR, "failed to load lua-file '%s'", filename)
+	 return defines.KILL_DAEMON
+      end
+      self:register_handler_table(chunk())
+      log.printf(log.NOTICE, "loaded dispatch table from file %s", filename)
+   end
+   return defines.OK
+end
+
+function dispatch_table:register_handler_table(handler_table)
+   if (type(handler_table) ~= "table") then
+      error("handler_table must be of type 'table'")
+   end
+   self.regex_to_handler = handler_table
+end
+
+function dispatch_table:dispatch(command_buffer)
+   local init = 1
+   repeat
+      local had_match = false
+      for regex, handler in pairs(self.regex_to_handler) do
+	 local match = string.match(command_buffer, "^" .. regex, init)
+	 if match then
+	    handler(match)
+	    had_match = true
+	    init = init + string.len(match)
+	    break
+	 end
+      end
+   until (not had_match)
+   
+   return string.sub(command_buffer, init + 1)
+end
diff --git a/src/main_loop.lua b/src/main_loop.lua
index 2a34477..42cc74c 100644
--- a/src/main_loop.lua
+++ b/src/main_loop.lua
@@ -74,11 +74,16 @@ function main_loop(opt)
    log.printf(log.NOTICE, "main_loop started")
    local sig = signal.init()
 
-   local return_value = module_list:init(opt)
-   if(return_value == defines.KILL_DAEMON) then
+   local return_value = dispatch_table:load_handler_table_file(opt.lua_code)
+   if (return_value == defines.KILL_DAEMON) then
       return_value = -1
    else
-      return_value = 0
+      return_value = module_list:init(opt)
+      if(return_value == defines.KILL_DAEMON) then
+	 return_value = -1
+      else
+	 return_value = 0
+      end
    end
 
    while return_value == 0 do
diff --git a/src/modules/exec.lua b/src/modules/exec.lua
index 14a8856..09a6335 100644
--- a/src/modules/exec.lua
+++ b/src/modules/exec.lua
@@ -83,9 +83,10 @@ function exec:new(config)
          return defines.KILL_MODULE_CLASS
       end
 
-      -- TODO: support read until matched command
       self.in_buffer = self.in_buffer .. buffer
-      -- TODO: dispatch table et al
+      self.in_buffer = dispatch_table:dispatch(self.in_buffer)
+
+      -- TODO: part of expected response handling
       command_queue:command_completed()
 
       return defines.OK
diff --git a/src/modules/stdio.lua b/src/modules/stdio.lua
index e31aa89..4069a87 100644
--- a/src/modules/stdio.lua
+++ b/src/modules/stdio.lua
@@ -61,9 +61,10 @@ function stdio:new(config)
          return defines.KILL_MODULE_CLASS
       end
 
-      -- TODO: support read until matched command
       self.in_buffer = self.in_buffer .. buffer
-      -- TODO: dispatch table et al
+      self.in_buffer = dispatch_table:dispatch(self.in_buffer)
+
+      -- TODO: part of expected response handling
       command_queue:command_completed()
 
       return defines.OK