From 44cbc874165fd585f5f0374c9a5a2afc0ad10a24 Mon Sep 17 00:00:00 2001
From: Joel Collins <j.collins@bath.ac.uk>
Date: Fri, 3 Jul 2020 15:05:53 +0100
Subject: [PATCH] Re-synchronised capture IO

---
 openflexure_microscope/captures/capture.py | 50 ++++++++--------------
 1 file changed, 17 insertions(+), 33 deletions(-)

diff --git a/openflexure_microscope/captures/capture.py b/openflexure_microscope/captures/capture.py
index 57db09d5..00777442 100644
--- a/openflexure_microscope/captures/capture.py
+++ b/openflexure_microscope/captures/capture.py
@@ -10,9 +10,6 @@ from PIL import Image
 import dateutil.parser
 import atexit
 
-from gevent.fileobject import FileObjectThread
-import gevent
-
 from collections import OrderedDict
 
 from openflexure_microscope.camera import piexif
@@ -129,10 +126,6 @@ class CaptureObject(object):
         """Create a new StreamObject, to manage capture data."""
         # Stream for buffering capture data
         self.stream = io.BytesIO()
-        # Event to notify when the stream has finished writing to disk
-        self.file_ready = gevent.event.Event()
-        # Access lock for the disk file
-        self.lock = gevent.lock.BoundedSemaphore()
 
         # Store a nice ID
         self.id = uuid.uuid4()  #: str: Unique capture ID
@@ -160,19 +153,12 @@ class CaptureObject(object):
     def write(self, s):
         self.stream.write(s)
 
-    def _stream_to_file(self):
-        with self.lock:
-            logging.info(f"Writing to disk {self.file}")
-            with FileObjectThread(open(self.file, "wb"), 'wb')  as outfile:
-                outfile.write(self.stream.getbuffer())
-            self.stream.close()
-            self.file_ready.set()
-            logging.info(f"Finished writing to disk {self.file}")
-
     def flush(self):
-        logging.debug(f"Flushing {self.file}")
-        gevent.spawn(self._stream_to_file)
-        logging.debug(f"Returning flushing {self.file}")
+        logging.info(f"Writing to disk {self.file}")
+        with open(self.file, "wb")  as outfile:
+            outfile.write(self.stream.getbuffer())
+        self.stream.close()
+        logging.info(f"Finished writing to disk {self.file}")
 
     def open(self, mode):
         return open(self.file, mode)
@@ -275,20 +261,18 @@ class CaptureObject(object):
         global EXIF_FORMATS
 
         if self.format.upper() in EXIF_FORMATS and self.exists:
-            self.file_ready.wait()
-            with self.lock:
-                logging.debug("Writing exif data to capture file")
-                # Extract current Exif data
-                exif_dict = piexif.load(self.file)
-                # Serialize metadata
-                metadata_string = json.dumps(self.metadata, cls=JSONEncoder)
-                logging.debug(f"Saving metadata string to file: {metadata_string}")
-                # Insert metadata into exif_dict
-                exif_dict["Exif"][piexif.ExifIFD.UserComment] = metadata_string.encode()
-                # Convert new exif dict to exif bytes
-                exif_bytes = piexif.dump(exif_dict)
-                # Insert exif into file
-                piexif.insert(exif_bytes, self.file)
+            logging.debug("Writing exif data to capture file")
+            # Extract current Exif data
+            exif_dict = piexif.load(self.file)
+            # Serialize metadata
+            metadata_string = json.dumps(self.metadata, cls=JSONEncoder)
+            logging.debug(f"Saving metadata string to file: {metadata_string}")
+            # Insert metadata into exif_dict
+            exif_dict["Exif"][piexif.ExifIFD.UserComment] = metadata_string.encode()
+            # Convert new exif dict to exif bytes
+            exif_bytes = piexif.dump(exif_dict)
+            # Insert exif into file
+            piexif.insert(exif_bytes, self.file)
             logging.info(f"Finished saving metadata to {self.file}")
 
     @property