BEC free consumer

tomcat_bec/devices/gigafrost/pco_consumer.py

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+# -*- coding: utf-8 -*-
+"""
+Standard DAQ preview image stream module
+
+Created on Thu Jun 27 17:28:43 2024
+
+@author: mohacsi_i
+"""
+from time import sleep, time
+import threading
+import zmq
+import json
+
+ZMQ_TOPIC_FILTER = b""
+
+
+
+class PcoTestConsumer:
+    """Detector wrapper class around the StdDaq preview image stream.
+
+    This was meant to provide live image stream directly from the StdDAQ.
+    Note that the preview stream must be already throtled in order to cope
+    with the incoming data and the python class might throttle it further.
+
+    You can add a preview widget to the dock by:
+    cam_widget = gui.add_dock('cam_dock1').add_widget('BECFigure').image('daq_stream1')
+    """
+
+    # Subscriptions for plotting image
+    _shutdown_event = threading.Event()
+    _monitor_mutex = threading.Lock()
+    _monitor_thread = None
+
+    # Status attributes
+    _url = None
+    _image = None
+    _frame = None
+    _socket = None
+
+    def __init__(self, url: str = "tcp://129.129.95.38:20000") -> None:
+        super().__init__()
+        self._url = url
+
+    def connect(self):
+        """Connect to te StDAQs PUB-SUB streaming interface"""
+        # Socket to talk to server
+        context = zmq.Context()
+        self._socket = context.socket(zmq.PULL)
+        try:
+            self._socket.connect(self.url)
+        except ConnectionRefusedError:
+            sleep(1)
+            self._socket.connect(self.url)
+
+    def disconnect(self):
+        """Disconnect"""
+        try:
+            if self._socket is not None:
+                self._socket.disconnect(self.url)
+        except zmq.ZMQError:
+            pass
+        finally:
+            self._socket = None
+
+    @property
+    def url(self):
+        return self._url
+
+    @property
+    def image(self):
+        return self._image
+
+    @property
+    def frame(self):
+        return self._frame
+
+    # pylint: disable=protected-access
+    def start(self):
+        """Start listening for preview data stream"""
+        if self._monitor_mutex.locked():
+            raise RuntimeError("Only one consumer permitted")
+
+        self.connect()
+        self._mon = threading.Thread(target=self.poll, daemon=True)
+        self._mon.start()
+
+    def stop(self):
+        """Stop a running preview"""
+        self._shutdown_event.set()
+        if self._mon is not None:
+            self._stop_polling = True
+            # Might hang on recv_multipart
+            self._mon.join(timeout=1)
+            # So also disconnect the socket
+            self.disconnect()
+        self._shutdown_event.clear()
+
+    def poll(self):
+        """Collect streamed updates"""
+        try:
+            t_last = time()
+            print("Starting monitor")
+            with self._monitor_mutex:
+                while not self._shutdown_event.is_set():
+                    try:
+                        # pylint: disable=no-member
+                        r = self._socket.recv_multipart(flags=zmq.NOBLOCK)
+
+                        # Length and throtling checks
+                        t_curr = time()
+                        t_elapsed = t_curr - t_last
+                        if t_elapsed < self.parent.throttle.get():
+                            continue
+                        # # Unpack the Array V1 reply to metadata and array data
+                        meta, data = r
+
+                        # Update image and update subscribers
+                        header = json.loads(meta)
+                        self.header = header
+                        # if header["type"] == "uint16":
+                        #     image = np.frombuffer(data, dtype=np.uint16)
+                        # if image.size != np.prod(header['shape']):
+                        #     err = f"Unexpected array size of {image.size} for header: {header}"
+                        #     raise ValueError(err)
+                        # image = image.reshape(header['shape'])
+
+                        # # Update image and update subscribers
+                        # self._frame = header['frame']
+                        # self._image = image
+                        t_last = t_curr
+                        # print(
+                        #    f"[{self.name}] Updated frame {header['frame']}\t"
+                        #    f"Shape: {header['shape']}\tMean: {np.mean(image):.3f}"
+                        #    )
+                    except ValueError:
+                        # Happens when ZMQ partially delivers the multipart message
+                        pass
+                    except zmq.error.Again:
+                        # Happens when receive queue is empty
+                        sleep(0.1)
+        except Exception as ex:
+            print(f"{str(ex)}")
+            raise
+        finally:
+            try:
+                self._socket.disconnect(self.url)
+            except RuntimeError:
+                pass
+            self._monitor_thread = None
+            print(f"Detaching monitor")
+
+
+# Automatically connect to MicroSAXS testbench if directly invoked
+if __name__ == "__main__":
+    daq = PcoTestConsumer(url="tcp://10.4.0.82:8080")
+    daq.start()
+    sleep(500)
+    daq.stop()