summaryrefslogtreecommitdiff
path: root/src/modules/stdio.lua
blob: 539cbcb7fc4facd36551069d503839c6ff4192c2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
--
--  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/>.
--

-- stdio module class
local stdio = {}
stdio.properties = { type=defines.INOUT_MODULE, name="stdio", max_instances=1 }

-- create new instance of stdio module class
function stdio:new(config, runtype)
   local inst = {}
   inst.class = self
   inst.config = config
   inst.config.runtype = runtype
   if(config.name == nil or config.name == "") then
      inst.name = self.properties.name
   else
      inst.name = config.name
   end

   local in_handle = {}
   in_handle.fd = 0
   rawio.setnonblock(in_handle.fd)
   in_handle.client_instance = nil
   in_handle.in_buffer = ""
   function in_handle:read()
      -- TODO: which size should we request??
      local buffer, err = rawio.read(0, 100)
      if(buffer == nil) then
         log.printf(log.ERROR, inst.name .. ": connection error: %s", err)
         return defines.KILL_MODULE_CLASS
      end

      self.in_buffer = self.in_buffer .. buffer
      if(inst.config.runtype == defines.IN_MODULE) then
         self.in_buffer = command_table:dispatch(self.in_buffer, self.client_instance)
      else
         self.in_buffer = response_table:dispatch(self.in_buffer)
      end

      return defines.OK
   end
   function in_handle:write() end

   local out_handle = {}
   out_handle.fd = 1
   rawio.setnonblock(out_handle.fd)
   out_handle.client_instance = nil
   out_handle.out_buffer = ""
   function out_handle:read() end
   function out_handle:write()
      local len, err = rawio.write(1, self.out_buffer)
      if(len == nil) then
         log.printf(log.ERROR, inst.name .. ": connection error: %s", err)
         ret = defines.KILL_MODULE_CLASS
      else
         self.out_buffer = string.sub(self.out_buffer, len+1)
      end
      if(inst.config.runtype == defines.OUT_MODULE and self.out_buffer == "") then
         command_queue:command_sent()
      end
      return defines.OK
   end

   local client = {}
   client.module_instance = inst
   client.name = inst.name .. "#0"
   function client:process_response(response)
      out_handle.out_buffer = out_handle.out_buffer .. response
   end
   function client:process_timeout() end
   function client:get_read_handles()
      return { in_handle }
   end
   function client:get_write_handles()
      if(out_handle.out_buffer ~= "") then
         return { out_handle }
      else
         return {}
      end
   end
   function client:cleanup() end
   in_handle.client_instance = client
   out_handle.client_instance = client

   function inst:cleanup()
      client_list:unregister_by_module(self)
   end
   function inst:get_read_handles()
      return {}
   end
   function inst:get_write_handles()
      return {}
   end
   function inst:start_command(command)
      out_handle.out_buffer = command
   end
   setmetatable(inst, {})
   getmetatable(inst).__gc = function() inst:cleanup() end

   client_list:register(client)
   return inst
end

return stdio