pylibcerebrum/pylibcerebrum.py

   1
   2 import serial
   3 import json
   4 import struct
   5 import pylzma
   6
   7 class Ganglion:
   8         # NOTE: the device config is *not* the stuff from the config "dev" section but
   9         #read from the device. It can also be found in that [devicename].config.json
  10         #file created by the code generator
  11         def __init__(self, device=None, baudrate=115200, config=None, ser=None):
  12                 #FIXME HACK to et the initialization go smooth despite the __*__ special functions and "config" not yet being set
  13                 self._config = None
  14                 if ser is None:
  15                         self._ser = serial.Serial(device, baudrate)
  16                         self._opened_ser = self._ser
  17                         self._config = self.read_config()
  18                 else:
  19                         self._config = config
  20                         self._ser = ser
  21
  22         def __del__(self):
  23                 self.close()
  24
  25         def close(self):
  26                 try:
  27                         self._opened_ser.close()
  28                 except AttributeError:
  29                         pass
  30
  31         def read_config(self):
  32                 self._ser.write(b'\\#\x00\x00\x00\x00')
  33                 (clen,) = struct.unpack(">H", self._ser.read(2))
  34                 cbytes = self._ser.read(clen)
  35                 self._ser.read(2) #read and ignore the not-yet-crc
  36                 return json.JSONDecoder().decode(str(pylzma.decompress(cbytes), "UTF-8"))
  37
  38         @property
  39         def members(self):
  40                 if "members" in self._config:
  41                         return list(self._config["members"].keys())
  42                 return []
  43
  44         @property
  45         def properties(self):
  46                 if "properties" in self._config:
  47                         return list(self._config["properties"].keys())
  48                 return []
  49
  50         @property
  51         def functions(self):
  52                 if "functions" in self._config:
  53                         return list(self._config["functions"].keys())
  54                 return []
  55
  56         def callfunc(self, fid, argsfmt, args, retfmt):
  57                 cmd = b'\\#' + struct.pack(">HH", fid, struct.calcsize(argsfmt)) + struct.pack(argsfmt, *args) + b'\x00\x00'
  58                 self._ser.write(cmd)
  59                 (clen,) = struct.unpack(">H", self._ser.read(2))
  60                 cbytes = self._ser.read(clen)
  61                 self._ser.read(2) #read and ignore the not-yet-crc
  62                 if clen is not struct.calcsize(retfmt):
  63                         #FIXME error handling
  64                         print("Length mismatch: {} != {}".format(clen, struct.calcsize(retfmt)))
  65                         return None
  66                 return struct.unpack(retfmt, cbytes)
  67
  68         def __dir__(self):
  69                 return self.members + self.properties + self.functions + list(self.__dict__.keys())
  70
  71         def __setattr__(self, name, value):
  72                 if name is not "_config":
  73                         if self._config and "properties" in self._config and name in self._config["properties"]:
  74                                 var = self._config["properties"][name]
  75                                 return self.callfunc(var["id"]+1, var["fmt"], value, "")
  76                 self.__dict__[name] = value
  77
  78         def __getattr__(self, name):
  79                 if not self._config:
  80                         raise AttributeError(name)
  81
  82                 if "members" in self._config and name in self._config["members"]:
  83                         return Ganglion(config=self._config["members"][name], ser=self._ser)
  84
  85                 if "properties" in self._config and name in self._config["properties"]:
  86                         var = self._config["properties"][name]
  87                         return self.callfunc(var["id"], "", None, var["fmt"])
  88
  89                 if "functions" in self._config and  name in self._config["functions"]:
  90                         fun = self._config["functions"][name]
  91                         def proxy_method(*args):
  92                                 return self.callfunc(fun["id"], fun.get("args", ""), args, fun.get("returns", ""))
  93                         return proxy_method
  94