cache journey preview images

2 files changed, 94 insertions, 7 deletions

diff --git a/fietsboek/data.py b/fietsboek/data.py
index d4bbb07..e288a03 100644
--- a/fietsboek/data.py
+++ b/fietsboek/data.py
@@ -42,6 +42,10 @@ def generate_filename(filename: Optional[str]) -> str:
     return str(uuid.uuid4())
 
 
+def _log_deletion_error(_, path, exc_info):
+    LOGGER.warning("Failed to remove %s", path, exc_info=exc_info)
+
+
 class DataManager:
     """Data manager.
 
@@ -61,6 +65,9 @@ class DataManager:
     def _user_data_dir(self, user_id):
         return self.data_dir / "users" / str(user_id)
 
+    def _journey_data_dir(self, journey_id):
+        return self.data_dir / "journeys" / str(journey_id)
+
     def maintenance_mode(self) -> Optional[str]:
         """Checks whether the maintenance mode is enabled.
 
@@ -103,6 +110,17 @@ class DataManager:
             path.mkdir(parents=True)
         return UserDataDir(user_id, path, txn=self.txn)
 
+    def initialize_journey(self, journey_id: int) -> "JourneyDataDir":
+        """Creates the data directory for a journey.
+
+        :raises FileExistsError: If the directory already exists.
+        :param journey_id: ID of the journey.
+        :return: The manager that can be used to manage this journey's data.
+        """
+        path = self._journey_data_dir(journey_id)
+        path.mkdir(parents=True)
+        return JourneyDataDir(journey_id, path)
+
     def purge(self, track_id: int):
         """Forcefully purges all data from the given track.
 
@@ -135,6 +153,18 @@ class DataManager:
             raise FileNotFoundError(f"The path {path} is not a directory") from None
         return UserDataDir(user_id, path, txn=self.txn)
 
+    def open_journey(self, journey_id: int) -> "JourneyDataDir":
+        """Open a journey's data directory.
+
+        :raises FileNotFoundError: If the journey directory does not exist.
+        :param journey_id: ID of the journey.
+        :return: The manager that can be used to manage this journey's data.
+        """
+        path = self._journey_data_dir(journey_id)
+        if not path.is_dir():
+            raise FileNotFoundError(f"The path {path} is not a directory") from None
+        return JourneyDataDir(journey_id, path)
+
     def size(self) -> int:
         """Returns the size of all data.
 
@@ -162,6 +192,16 @@ class DataManager:
         except FileNotFoundError:
             return []
 
+    def list_journeys(self) -> list[int]:
+        """Returns a list of all journeys.
+
+        :return: A list of all journey IDs.
+        """
+        try:
+            return [int(journey.name) for journey in self._journey_data_dir(".").iterdir()]
+        except FileNotFoundError:
+            return []
+
 
 class TrackDataDir:
     """Manager for a single track's data.
@@ -185,10 +225,6 @@ class TrackDataDir:
         """
         return FileLock(self.path / "lock")
 
-    @staticmethod
-    def _log_deletion_error(_, path, exc_info):
-        LOGGER.warning("Failed to remove %s", path, exc_info=exc_info)
-
     def purge(self):
         """Purge all data pertaining to the track.
 
@@ -199,7 +235,7 @@ class TrackDataDir:
             self.txn.purge(self.path)
         else:
             if self.path.is_dir():
-                shutil.rmtree(self.path, ignore_errors=False, onerror=self._log_deletion_error)
+                shutil.rmtree(self.path, ignore_errors=False, onerror=_log_deletion_error)
 
     def size(self) -> int:
         """Returns the size of the data that this track entails.
@@ -343,4 +379,39 @@ class UserDataDir:
         return self.path / "tilehunt.sqlite"
 
 
-__all__ = ["generate_filename", "DataManager", "TrackDataDir", "UserDataDir"]
+class JourneyDataDir:
+    """Manager for a single journey's data."""
+
+    def __init__(self, journey_id: int, path: Path):
+        self.journey_id = journey_id
+        self.path = path
+
+    def purge(self):
+        """Purge all data pertaining to the journey.
+
+        This function logs errors but raises no exception, as such it can
+        always be used to clean up after a track.
+        """
+        if self.path.is_dir():
+            shutil.rmtree(self.path, ignore_errors=False, onerror=_log_deletion_error)
+
+    def preview_path(self) -> Path:
+        """Gets the path to the "preview image".
+
+        :return: The path to the preview image.
+        """
+        return self.path / "preview.png"
+
+    def set_preview(self, data: bytes):
+        """Sets the preview image to the given data.
+
+        :param data: The data of the preview image.
+        """
+        self.preview_path().write_bytes(data)
+
+    def remove_preview(self):
+        """Deletes the preview image."""
+        self.preview_path().unlink()
+
+
+__all__ = ["generate_filename", "DataManager", "TrackDataDir", "UserDataDir", "JourneyDataDir"]
diff --git a/fietsboek/views/journey.py b/fietsboek/views/journey.py
index 60ed433..8621f4a 100644
--- a/fietsboek/views/journey.py
+++ b/fietsboek/views/journey.py
@@ -10,6 +10,7 @@ from sqlalchemy import select
 from sqlalchemy.orm import aliased
 
 from .. import trackmap, util
+from ..data import JourneyDataDir
 from ..models.journey import Journey, Visibility
 from ..models.track import Track, TrackWithMetadata
 from ..models import User
@@ -62,7 +63,14 @@ def journey_gpx(request: Request):
 
 @view_config(route_name="journey-map", http_cache=3600, permission="journey.view")
 def journey_map(request: Request):
-    journey = request.context
+    journey: Journey = request.context
+    journey_data: JourneyDataDir = request.data_manager.open_journey(journey.id)
+    preview_path = journey_data.preview_path()
+
+    if preview_path.exists():
+        response = Response(preview_path.read_bytes(), content_type="image/png")
+        response.md5_etag()
+        return response
 
     loader: ITileRequester = request.registry.getUtility(ITileRequester)
     layer = request.config.public_tile_layers()[0]
@@ -73,6 +81,10 @@ def journey_map(request: Request):
     track_image.save(imageio, "png")
     tile_data = imageio.getvalue()
 
+    if not preview_path.exists():
+        LOGGER.debug("Setting preview at %s", preview_path)
+        journey_data.set_preview(tile_data)
+
     response = Response(tile_data, content_type="image/png")
     response.md5_etag()
     return response
@@ -108,6 +120,8 @@ def do_journey_new(request: Request):
     track_ids = _extract_valid_tracks(request)
     journey.set_track_ids(track_ids)
 
+    request.data_manager.initialize_journey(journey.id)
+
     return HTTPFound(request.route_url("journey-details", journey_id=journey.id))
 
 
@@ -130,6 +144,7 @@ def journey_edit(request: Request):
 )
 def do_journey_edit(request: Request):
     journey: Journey = request.context
+    request.data_manager.open_journey(journey.id).remove_preview()
 
     journey.title = request.params.get("journeyTitle")
     journey.description = request.params.get("journeyDescription")
@@ -182,6 +197,7 @@ def _extract_valid_tracks(request: Request) -> list[int]:
 )
 def do_journey_delete(request: Request):
     journey: Journey = request.context
+    request.data_manager.open_journey(journey.id).purge()
     request.dbsession.delete(journey)
     request.session.flash(request.localizer.translate(_("journeys.deleted")))
     return HTTPFound(request.route_url("journey-list"))