Fix and allow streamable server cameras (#143)

* Allow server cameras to be streamable by removing precaution checks

* Unify interface, naming between get_microscope/camera(_class)

* Remove unused _init_attr_dict/get_attrs from microscope client/server

* Do not force server-side attributes to be callable, use them first: these 3 lines took ~3h

* EAFP: Allow camera to call functions whether they are registered or not

* EAFP: Allow camera to call unregistered functions - fixes server cameras

* Remove unnecessary print debug statement

* Add **streamable** description to `config.md` documentation

Author: Baharis

docs/config.md

@@ -230,6 +230,9 @@ This file holds the specifications of the camera. This file is must be located t
 **camera_rotation_vs_stage_xy**
 : In radians, give here the rotation of the position of the rotation axis with respect to the horizontal. Used for diffraction only. Corresponds to the rotation axis in RED and PETS, for example: `-2.24`. You can find the rotation axis for your setup using the script `edtools.find_rotation_axis` available from [here](https://github.com/instamatic-dev/edtools#find_rotation_axispy).
 
+**streamable**
+: Boolean value. If present, overwrites the default behavior as implemented in each camera interface class to force the camera to stream (if `True`) or prevent it from streaming (if `False`) all collected data live directly to the GUI.
+
 **stretch_amplitude**
 : Use `instamatic.stretch_correction` to characterize the lens distortion. The numbers here are used to calculate the XCORR/YCORR maps. The amplitude is the percentage difference between the maximum and minimum eigenvectors of the ellipsoid, i.e. if the amplitude is `2.43`, eig(max)/eig(min) = 1.0243. You can use the program `instamatic.stretch_correction` available [here](https://github.com/instamatic-dev/instamatic/blob/main/docs/programs.md#instamaticstretch_correction) on some powder patterns to define these numbers.
 

src/instamatic/camera/__init__.py

@@ -1,4 +1,4 @@
 from __future__ import annotations
 
-from .camera import Camera
+from .camera import get_camera, get_camera_class
 from .videostream import VideoStream

src/instamatic/camera/camera.py

@@ -2,18 +2,20 @@
 
 import logging
 from pathlib import Path
+from typing import Optional
 
 from instamatic import config
+from instamatic.camera.camera_base import CameraBase
 
 logger = logging.getLogger(__name__)
 
-__all__ = ['Camera']
+__all__ = ['get_camera', 'get_camera_class']
 
 default_cam_interface = config.camera.interface
 
 
-def get_cam(interface: str = None):
-    """Grabs the camera object defined by `interface`"""
+def get_camera_class(interface: str) -> type[CameraBase]:
+    """Grabs the camera class with the specific `interface`"""
 
     simulate = config.settings.simulate
 
@@ -39,10 +41,24 @@ def get_cam(interface: str = None):
     return cam
 
 
-def Camera(name: str = None, as_stream: bool = False, use_server: bool = False):
+def get_camera(
+    name: Optional[str] = None,
+    as_stream: bool = False,
+    use_server: bool = False,
+) -> CameraBase:
     """Initialize the camera identified by the 'name' parameter if `as_stream`
     is True, it will return a VideoStream object if `as_stream` is False, it
-    will return the raw Camera object."""
+    will return the raw Camera object.
+
+    name: Optional[str]
+        Specify which camera to use, must be implemented in `instamatic.camera`
+    as_stream: bool
+        If True (default False), allow streaming this camera image live.
+    use_server: bool
+        Connect to camera server running on the host/port defined in the config
+
+    returns: Camera interface class instance
+    """
 
     if name is None:
         name = config.camera.name
@@ -56,9 +72,8 @@ def Camera(name: str = None, as_stream: bool = False, use_server: bool = False):
         from instamatic.camera.camera_client import CamClient
 
         cam = CamClient(name=name, interface=interface)
-        as_stream = False  # precaution
     else:
-        cam_cls = get_cam(interface)
+        cam_cls = get_camera_class(interface)
 
         if interface in ('timepix', 'pytimepix'):
             tpx_config = (
@@ -221,7 +236,7 @@ def main_entry():
 
 if __name__ == '__main__':
     # main_entry()
-    cam = Camera(use_server=True)
+    cam = get_camera(use_server=True)
     arr = cam.get_image(exposure=0.1)
     print(arr)
     print(arr.shape)

src/instamatic/camera/camera_client.py

@@ -55,7 +55,6 @@ def __init__(
         self.name = name
         self.interface = interface
         self._bufsize = BUFSIZE
-        self.streamable = False  # overrides cam settings
         self.verbose = False
 
         try:
@@ -83,6 +82,7 @@ def __init__(
         self.buffers: Dict[str, np.ndarray] = {}
         self.shms = {}
 
+        self._attr_dct: dict = {}
         self._init_dict()
         self._init_attr_dict()
 
@@ -104,14 +104,14 @@ def connect(self):
 
     def __getattr__(self, attr_name):
         if attr_name in self._dct:
+            if attr_name in object.__getattribute__(self, '_attr_dct'):
+                return self._eval_dct({'attr_name': attr_name})
             wrapped = self._dct[attr_name]
         elif attr_name in self._attr_dct:
             dct = {'attr_name': attr_name}
             return self._eval_dct(dct)
         else:
-            raise AttributeError(
-                f'`{self.__class__.__name__}` object has no attribute `{attr_name}`'
-            )
+            wrapped = None  # AFAIK can't wrap with None, can cause odd errors
 
         @wraps(wrapped)
         def wrapper(*args, **kwargs):
@@ -156,9 +156,9 @@ def _eval_dct(self, dct):
     def _init_dict(self):
         """Get list of functions and their doc strings from the uninitialized
         class."""
-        from instamatic.camera.camera import get_cam
+        from instamatic.camera.camera import get_camera_class
 
-        cam = get_cam(self.interface)
+        cam = get_camera_class(self.interface)
 
         self._dct = {
             key: value for key, value in cam.__dict__.items() if not key.startswith('_')

src/instamatic/camera/videostream.py

@@ -10,7 +10,7 @@
 
 import numpy as np
 
-from instamatic.camera import Camera
+from instamatic.camera import get_camera
 from instamatic.camera.camera_base import CameraBase
 from instamatic.image_utils import autoscale
 
@@ -115,15 +115,15 @@ def from_any(
         cls: Type[VideoStream_T], cam: Union[CameraBase, str] = 'simulate'
     ) -> VideoStream_T:
         """Create a subclass based on passed cam or cam-str stream-ability."""
-        cam: CameraBase = Camera(name=cam) if isinstance(cam, str) else cam
+        cam: CameraBase = get_camera(name=cam) if isinstance(cam, str) else cam
         if cls is VideoStream:
             return (LiveVideoStream if cam.streamable else FakeVideoStream)(cam)
         return cls(cam)
 
     def __init__(self, cam: Union[CameraBase, str] = 'simulate') -> None:
         threading.Thread.__init__(self)
 
-        self.cam: CameraBase = Camera(name=cam) if isinstance(cam, str) else cam
+        self.cam: CameraBase = get_camera(name=cam) if isinstance(cam, str) else cam
         self.lock = threading.Lock()
 
         self.default_exposure = self.cam.default_exposure

src/instamatic/config/autoconfig.py

@@ -125,12 +125,12 @@ def main():
         cam_connect = False
         cam_name = None
 
-    from instamatic.camera.camera import get_cam
+    from instamatic.camera.camera import get_camera_class
     from instamatic.controller import TEMController
     from instamatic.microscope import get_microscope_class
 
     if cam_connect:
-        cam = get_cam(cam_name)() if cam_name else None
+        cam = get_camera_class(cam_name)() if cam_name else None
     else:
         cam = None
 

src/instamatic/controller.py

@@ -9,7 +9,7 @@
 import yaml
 
 from instamatic import config
-from instamatic.camera import Camera
+from instamatic.camera import get_camera
 from instamatic.camera.camera_base import CameraBase
 from instamatic.exceptions import TEMControllerError
 from instamatic.formats import write_tiff
@@ -61,7 +61,7 @@ def initialize(
 
         print(f'Camera    : {cam_name}{cam_tag}')
 
-        cam = Camera(cam_name, as_stream=stream, use_server=use_cam_server)
+        cam = get_camera(cam_name, as_stream=stream, use_server=use_cam_server)
     else:
         cam = None
 

src/instamatic/microscope/client.py

@@ -125,10 +125,6 @@ def _init_dict(self) -> None:
         }
         self._dct['get_attrs'] = None
 
-    def _init_attr_dict(self):
-        """Get list of attrs and their types."""
-        self._attr_dct = self.get_attrs()
-
     def __dir__(self) -> list:
         return list(self._dct.keys())
 

src/instamatic/microscope/microscope.py

@@ -10,7 +10,7 @@
 __all__ = ['get_microscope', 'get_microscope_class']
 
 
-def get_microscope_class(interface: str) -> 'type[MicroscopeBase]':
+def get_microscope_class(interface: str) -> type[MicroscopeBase]:
     """Grab tem class with the specific 'interface'."""
     simulate = config.settings.simulate
 
@@ -42,7 +42,7 @@ def get_microscope(name: Optional[str] = None, use_server: bool = False) -> Micr
     use_server: bool
         Connect to microscope server running on the host/port defined in the config file
 
-    returns: TEM interface class
+    returns: TEM interface class instance
     """
     if name is None:
         interface = default_tem_interface

src/instamatic/server/cam_server.py

@@ -11,7 +11,7 @@
 import numpy as np
 
 from instamatic import config
-from instamatic.camera import Camera
+from instamatic.camera import get_camera
 from instamatic.utils import high_precision_timers
 
 from .serializer import dumper, loader
@@ -81,7 +81,7 @@ def copy_data_to_shared_buffer(self, arr):
 
     def run(self):
         """Start server thread."""
-        self.cam = Camera(name=self._name, use_server=False)
+        self.cam = get_camera(name=self._name, use_server=False)
         self.cam.get_attrs = self.get_attrs
 
         print(f'Initialized camera: {self.cam.interface}')