new camera worker functional in standalone mode

phytopi/camera/camera.py

@@ -1,48 +1,62 @@
 import io
 import os
 import sys
+import stat
 import subprocess
 import signal
 
+from enum import Enum
 from phytopi import db, models, app
 
+# map commands
+camera_cmds = {
+    'start_timelapse': 'tl 1',
+    'stop_timelapse': 'tl 0',
+}
+
+class CameraStatus(Enum):
+    STOPPED = 0
+    IDLE = 1
+    TIMELAPSE = 2
+    VIDEO = 3
+
 class CameraWorker(object):
-    def __init__(self, pidfile='/tmp/raspimjpeg.pid', executable='/usr/local/bin/raspimjpeg', fifo='/dev/shm/mjpeg/mjpeg_fifo', app=None):
+    def __init__(self, pidfile='/tmp/raspimjpeg.pid', executable='/usr/local/bin/raspimjpeg', fifo='/dev/shm/mjpeg/FIFO', app=None):
         self.pidfile = pidfile
         self.executable = executable
         self.fifo = fifo
         self.proc = None
         self.pid = None
         self.app = app
+        self.status = CameraStatus.STOPPED
     
     def start(self):
-        # create FIFO if not existent
-        if not os.path.isfile(self.fifo):
+        # create FIFO
         os.mkfifo(self.fifo)
 
         # check if process is already running
         if os.path.isfile(self.pidfile):
-            with open(self.pidfile) as fh:
+            with open(self.pidfile, 'r') as fh:
                 self.pid = int(fh.read())
 
         # if not, spawn new process and create pid file
-        self.proc = subprocess.Popen(self.executable, stdout=subprocess.PIPE)
+        self.proc = subprocess.Popen([self.executable])
         self.pid = self.proc.pid
-        with open(self.pidfile) as fh:
-            fh.write(self.pid)
+        with open(self.pidfile, 'w') as fh:
+            fh.write(str(self.pid))
+        self.status = CameraStatus.IDLE
 
     def stop(self):
-        # if process was spawned by this instance, killing is easy
-        if self.proc:
-            self.proc.kill()
-        else:
-            # otherwise send SIGTERM to pid
-            os.kill(self.pid, signal.SIGTERM)
+        os.killpg(os.getpgid(self.pid), signal.SIGTERM)
         os.unlink(self.fifo)
+        os.unlink(self.pidfile)
+        self.status = CameraStatus.STOPPED
 
     def send_cmd(self, cmd):
+        if cmd in camera_cmds:
             with open(self.fifo, 'w') as fh:
                 fh.write(cmd)
-
-    def read_output(self):
-        return self.proc.stdout.readlines()
+            if cmd == camera_cmds['start_timelapse']:
+                self.status = CameraStatus.TIMELAPSE
+            if cmd == camera_cmds['stop_timelapse']:
+                self.status = CameraStatus.IDLE