strix

commit 12deb2d438d3f9b5c6a0c75d426acc1578f66e1e
parent 09a491f14469033a0e74e2644d5111a8207e7bd7
Author: Brian C. Lane <bcl@brianlane.com>
Date:   Sat, 26 Feb 2022 09:12:26 -0800

Add .details.json cache to events

There's no reason to keep re-calculating the thumbnail, video url, etc.
after the first time so this adds storage of the info in a json file
named .details.json for faster loading.

If there is an error reading the file it will be recreated.

If a parameter effecting the data (eg. thumbnail offset) is changed the
cache can be 'cleared' by deleting all the .details.json files.

This also changes the event limit value to return all events if the
limit is set to 0.

Diffstat:
M
src/strix/events.py
 | 
18
++++++++++++++++--

1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/src/strix/events.py b/src/strix/events.py
@@ -16,6 +16,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 from datetime import datetime
 from glob import glob
+import json
 import os
 
 import structlog
@@ -42,6 +43,15 @@ def image_to_dt(event_date: str, image: str) -> datetime:
 
 def event_details(log: structlog.BoundLogger, event_path: str) -> Dict:
 #    log.info("event_details", path=event_path)
+
+    # Have the details already been created? If so read it and return.
+    try:
+        if os.path.exists(event_path+"/.details.json"):
+            with open(event_path+"/.details.json") as f:
+                return json.load(f)
+    except json.decoder.JSONDecodeError:
+        log.warn("Error reading .details.json from %s", event_path)
+
     (camera_name, event_date, event_time) = event_path.rsplit("/", 3)[-3:]
 
     # Grab the camera, date, and time and build the URL path
@@ -84,7 +94,7 @@ def event_details(log: structlog.BoundLogger, event_path: str) -> Dict:
 #    log.debug("event_details", thumbnail=thumbnail, start_time=str(start_time), end_time=str(end_time),
 #              video=video, debug_video=debug_video, saved=is_saved)
 
-    return {
+    details = {
         "start":        str(start_time),
         "end":          str(end_time),
         "video":        video[0],
@@ -93,6 +103,10 @@ def event_details(log: structlog.BoundLogger, event_path: str) -> Dict:
         "images":       [],
         "saved":        is_saved
     }
+    with open(event_path+"/.details.json", "w") as f:
+        json.dump(details, f)
+    return details
+
 
 def camera_events(log: structlog.BoundLogger, base_dir: str, camera: str,
                   start: datetime, end: datetime, offset: int, limit: int) -> List[Dict]:
@@ -114,7 +128,7 @@ def camera_events(log: structlog.BoundLogger, base_dir: str, camera: str,
         events.insert(0, event_details(log, event_path))
 
         added += 1
-        if added >= limit:
+        if limit > 0 and added >= limit:
             break
 
     return events