introduce subscription concept to simplify unsubscribing from events

csdr.py

@@ -137,7 +137,10 @@ class dsp(object):
                     "CSDR_FIXED_BUFSIZE=1 csdr psk31_varicode_decoder_u8_u8"
 
     def set_secondary_demodulator(self, what):
+        if self.get_secondary_demodulator() == what:
+            return
         self.secondary_demodulator = what
+        self.restart()
 
     def secondary_fft_block_size(self):
         return (self.samp_rate/self.decimation)/(self.fft_fps*2) #*2 is there because we do FFT on real signal here

owrx/config.py

@@ -2,25 +2,49 @@ import logging
 logger = logging.getLogger(__name__)
 
 
+class Subscription(object):
+    def __init__(self, subscriptee, subscriber):
+        self.subscriptee = subscriptee
+        self.subscriber = subscriber
+
+    def call(self, *args, **kwargs):
+        self.subscriber(*args, **kwargs)
+
+    def cancel(self):
+        self.subscriptee.unwire(self)
+
+
 class Property(object):
     def __init__(self, value = None):
         self.value = value
-        self.callbacks = []
+        self.subscribers = []
+
     def getValue(self):
         return self.value
+
     def setValue(self, value):
         if (self.value == value):
             return self
         self.value = value
-        for c in self.callbacks:
+        for c in self.subscribers:
             try:
-                c(self.value)
+                c.call(self.value)
             except Exception as e:
                 logger.exception(e)
         return self
+
     def wire(self, callback):
-        self.callbacks.append(callback)
+        sub = Subscription(self, callback)
-        if not self.value is None: callback(self.value)
+        self.subscribers.append(sub)
+        if not self.value is None: sub.call(self.value)
+        return sub
+
+    def unwire(self, sub):
+        try:
+            self.subscribers.remove(sub)
+        except ValueError:
+            # happens when already removed before
+            pass
         return self
 
 class PropertyManager(object):
@@ -36,7 +60,7 @@ class PropertyManager(object):
 
     def __init__(self, properties = None):
         self.properties = {}
-        self.callbacks = []
+        self.subscribers = []
         if properties is not None:
             for (name, prop) in properties.items():
                 self.add(name, prop)
@@ -44,9 +68,9 @@ class PropertyManager(object):
     def add(self, name, prop):
         self.properties[name] = prop
         def fireCallbacks(value):
-            for c in self.callbacks:
+            for c in self.subscribers:
                 try:
-                    c(name, value)
+                    c.call(name, value)
                 except Exception as e:
                     logger.exception(e)
         prop.wire(fireCallbacks)
@@ -78,11 +102,16 @@ class PropertyManager(object):
         return self.getProperty(name).getValue()
 
     def wire(self, callback):
-        self.callbacks.append(callback)
+        sub = Subscription(self, callback)
-        return self
+        self.subscribers.append(sub)
+        return sub
 
-    def unwire(self, callback):
+    def unwire(self, sub):
-        self.callbacks.remove(callback)
+        try:
+            self.subscribers.remove(sub)
+        except ValueError:
+            # happens when already removed before
+            pass
         return self
 
     def defaults(self, other_pm):

owrx/connection.py

@@ -19,7 +19,7 @@ class OpenWebRxClient(object):
 
         self.dsp = None
         self.sdr = None
-        self.configProps = None
+        self.configSub = None
 
         pm = PropertyManager.getSharedInstance()
 
@@ -39,11 +39,6 @@ class OpenWebRxClient(object):
 
         CpuUsageThread.getSharedInstance().add_client(self)
 
-    def sendConfig(self, key, value):
-        config = dict((key, self.configProps[key]) for key in OpenWebRxClient.config_keys)
-        # TODO mathematical properties? hmmmm
-        config["start_offset_freq"] = self.configProps["start_freq"] - self.configProps["center_freq"]
-        self.write_config(config)
     def setSdr(self, id = None):
         next = SdrService.getSource(id)
         if (next == self.sdr):
@@ -51,16 +46,23 @@ class OpenWebRxClient(object):
 
         self.stopDsp()
 
-        if self.configProps is not None:
+        if self.configSub is not None:
-            self.configProps.unwire(self.sendConfig)
+            self.configSub.cancel()
+            self.configSub = None
 
         self.sdr = next
 
         # send initial config
-        self.configProps = self.sdr.getProps().collect(*OpenWebRxClient.config_keys).defaults(PropertyManager.getSharedInstance())
+        configProps = self.sdr.getProps().collect(*OpenWebRxClient.config_keys).defaults(PropertyManager.getSharedInstance())
 
-        self.configProps.wire(self.sendConfig)
+        def sendConfig(key, value):
-        self.sendConfig(None, None)
+            config = dict((key, configProps[key]) for key in OpenWebRxClient.config_keys)
+            # TODO mathematical properties? hmmmm
+            config["start_offset_freq"] = configProps["start_freq"] - configProps["center_freq"]
+            self.write_config(config)
+
+        self.configSub = configProps.wire(sendConfig)
+        sendConfig(None, None)
 
         self.sdr.addSpectrumClient(self)
 
@@ -73,6 +75,9 @@ class OpenWebRxClient(object):
         self.stopDsp()
         CpuUsageThread.getSharedInstance().remove_client(self)
         ClientRegistry.getSharedInstance().removeClient(self)
+        if self.configSub is not None:
+            self.configSub.cancel()
+            self.configSub = None
         self.conn.close()
         logger.debug("connection closed")
 

owrx/source.py

@@ -261,10 +261,6 @@ class SpectrumThread(csdr.output):
         self.dsp = dsp = csdr.dsp(self)
         dsp.nc_port = self.sdrSource.getPort()
         dsp.set_demodulator("fft")
-        props.getProperty("samp_rate").wire(dsp.set_samp_rate)
-        props.getProperty("fft_size").wire(dsp.set_fft_size)
-        props.getProperty("fft_fps").wire(dsp.set_fft_fps)
-        props.getProperty("fft_compression").wire(dsp.set_fft_compression)
 
         def set_fft_averages(key, value):
             samp_rate = props["samp_rate"]
@@ -273,7 +269,15 @@ class SpectrumThread(csdr.output):
             fft_voverlap_factor = props["fft_voverlap_factor"]
 
             dsp.set_fft_averages(int(round(1.0 * samp_rate / fft_size / fft_fps / (1.0 - fft_voverlap_factor))) if fft_voverlap_factor>0 else 0)
+
+        self.subscriptions = [
+            props.getProperty("samp_rate").wire(dsp.set_samp_rate),
+            props.getProperty("fft_size").wire(dsp.set_fft_size),
+            props.getProperty("fft_fps").wire(dsp.set_fft_fps),
+            props.getProperty("fft_compression").wire(dsp.set_fft_compression),
             props.collect("samp_rate", "fft_size", "fft_fps", "fft_voverlap_factor").wire(set_fft_averages)
+        ]
+
         set_fft_averages(None, None)
 
         dsp.csdr_dynamic_bufsize = props["csdr_dynamic_bufsize"]
@@ -309,6 +313,9 @@ class SpectrumThread(csdr.output):
     def stop(self):
         self.dsp.stop()
         self.sdrSource.removeClient(self)
+        for c in self.subscriptions:
+            c.cancel()
+        self.subscriptions = []
 
     def onSdrAvailable(self):
         self.dsp.start()
@@ -326,43 +333,40 @@ class DspManager(csdr.output):
         ).defaults(PropertyManager.getSharedInstance())
 
         self.dsp = csdr.dsp(self)
-        #dsp_initialized=False
-        self.localProps.getProperty("audio_compression").wire(self.dsp.set_audio_compression)
-        self.localProps.getProperty("fft_compression").wire(self.dsp.set_fft_compression)
-        self.dsp.set_offset_freq(0)
-        self.dsp.set_bpf(-4000,4000)
-        self.localProps.getProperty("digimodes_fft_size").wire(self.dsp.set_secondary_fft_size)
-
         self.dsp.nc_port = self.sdrSource.getPort()
-        self.dsp.csdr_dynamic_bufsize = self.localProps["csdr_dynamic_bufsize"]
-        self.dsp.csdr_print_bufsizes = self.localProps["csdr_print_bufsizes"]
-        self.dsp.csdr_through = self.localProps["csdr_through"]
-
-        self.localProps.getProperty("samp_rate").wire(self.dsp.set_samp_rate)
-
-        self.localProps.getProperty("output_rate").wire(self.dsp.set_output_rate)
-        self.localProps.getProperty("offset_freq").wire(self.dsp.set_offset_freq)
-        self.localProps.getProperty("squelch_level").wire(self.dsp.set_squelch_level)
 
         def set_low_cut(cut):
             bpf = self.dsp.get_bpf()
             bpf[0] = cut
             self.dsp.set_bpf(*bpf)
-        self.localProps.getProperty("low_cut").wire(set_low_cut)
 
         def set_high_cut(cut):
             bpf = self.dsp.get_bpf()
             bpf[1] = cut
             self.dsp.set_bpf(*bpf)
-        self.localProps.getProperty("high_cut").wire(set_high_cut)
 
+        self.subscriptions = [
+            self.localProps.getProperty("audio_compression").wire(self.dsp.set_audio_compression),
+            self.localProps.getProperty("fft_compression").wire(self.dsp.set_fft_compression),
+            self.localProps.getProperty("digimodes_fft_size").wire(self.dsp.set_secondary_fft_size),
+            self.localProps.getProperty("samp_rate").wire(self.dsp.set_samp_rate),
+            self.localProps.getProperty("output_rate").wire(self.dsp.set_output_rate),
+            self.localProps.getProperty("offset_freq").wire(self.dsp.set_offset_freq),
+            self.localProps.getProperty("squelch_level").wire(self.dsp.set_squelch_level),
+            self.localProps.getProperty("low_cut").wire(set_low_cut),
+            self.localProps.getProperty("high_cut").wire(set_high_cut),
             self.localProps.getProperty("mod").wire(self.dsp.set_demodulator)
+        ]
+
+        self.dsp.set_offset_freq(0)
+        self.dsp.set_bpf(-4000,4000)
+        self.dsp.csdr_dynamic_bufsize = self.localProps["csdr_dynamic_bufsize"]
+        self.dsp.csdr_print_bufsizes = self.localProps["csdr_print_bufsizes"]
+        self.dsp.csdr_through = self.localProps["csdr_through"]
 
         if (self.localProps["digimodes_enable"]):
             def set_secondary_mod(mod):
                 if mod == False: mod = None
-                if self.dsp.get_secondary_demodulator() == mod: return
-                self.dsp.stop()
                 self.dsp.set_secondary_demodulator(mod)
                 if mod is not None:
                     self.handler.write_secondary_dsp_config({
@@ -370,11 +374,10 @@ class DspManager(csdr.output):
                         "if_samp_rate":self.dsp.if_samp_rate(),
                         "secondary_bw":self.dsp.secondary_bw()
                     })
-                self.dsp.start()
+            self.subscriptions += [
-
+                self.localProps.getProperty("secondary_mod").wire(set_secondary_mod),
-            self.localProps.getProperty("secondary_mod").wire(set_secondary_mod)
-
                 self.localProps.getProperty("secondary_offset_freq").wire(self.dsp.set_secondary_offset_freq)
+            ]
 
         self.sdrSource.addClient(self)
 
@@ -412,6 +415,9 @@ class DspManager(csdr.output):
     def stop(self):
         self.dsp.stop()
         self.sdrSource.removeClient(self)
+        for sub in self.subscriptions:
+            sub.cancel()
+        self.subscriptions = []
 
     def setProperty(self, prop, value):
         self.localProps.getProperty(prop).setValue(value)