feat: delete datalayer's files on delete

Until now, uMap was not deleting files on delete, which can increase
file storage a lot after some time.

The files are not deleted, but moved to a "purgatory" folder, from
where they can be deleted after some time.

docs/config/settings.md

@@ -282,6 +282,12 @@ How many total maps to return in the search.
 
 How many maps to show in the user "my maps" page.
 
+#### UMAP_PURGATORY_ROOT
+
+Path where files are moved when a datalayer is deleted. They will stay there until
+`umap purge_purgatory` is run. May be useful in case a user deletes by mistake
+a datalayer, or even a map.
+
 #### UMAP_SEARCH_CONFIGURATION
 
 Use it if you take control over the search configuration.

umap/management/commands/purge_purgatory.py

@@ -0,0 +1,28 @@
+import time
+from pathlib import Path
+
+from django.conf import settings
+from django.core.management.base import BaseCommand
+
+
+class Command(BaseCommand):
+    help = "Remove old files from purgatory. Eg.: umap purge_purgatory --days 7"
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            "--days",
+            help="Number of days to consider files for removal",
+            default=30,
+            type=int,
+        )
+
+    def handle(self, *args, **options):
+        days = options["days"]
+        root = Path(settings.UMAP_PURGATORY_ROOT)
+        threshold = time.time() - days * 86400
+        for path in root.iterdir():
+            stats = path.stat()
+            filestamp = stats.st_mtime
+            if filestamp < threshold:
+                path.unlink()
+                print(f"Removed old file {path}")

umap/models.py

@@ -3,6 +3,7 @@ import operator
 import os
 import time
 import uuid
+from pathlib import Path
 
 from django.conf import settings
 from django.contrib.auth.models import User
@@ -255,6 +256,13 @@ class Map(NamedModel):
         )
         return map_settings
 
+    def delete(self, **kwargs):
+        # Explicitely call datalayers.delete, so we can deal with removing files
+        # (the cascade delete would not call the model delete method)
+        for datalayer in self.datalayer_set.all():
+            datalayer.delete()
+        return super().delete(**kwargs)
+
     def generate_umapjson(self, request):
         umapjson = self.settings
         umapjson["type"] = "umap"
@@ -462,7 +470,9 @@ class DataLayer(NamedModel):
 
     def save(self, force_insert=False, force_update=False, **kwargs):
         is_new = not bool(self.pk)
-        super(DataLayer, self).save(force_insert, force_update, **kwargs)
+        super(DataLayer, self).save(
+            force_insert=force_insert, force_update=force_update, **kwargs
+        )
 
         if is_new:
             force_insert, force_update = False, True
@@ -471,10 +481,25 @@ class DataLayer(NamedModel):
             new_name = self.geojson.storage.save(filename, self.geojson)
             self.geojson.storage.delete(old_name)
             self.geojson.name = new_name
-            super(DataLayer, self).save(force_insert, force_update, **kwargs)
+            super(DataLayer, self).save(
+                force_insert=force_insert, force_update=force_update, **kwargs
+            )
         self.purge_gzip()
         self.purge_old_versions()
 
+    def delete(self, **kwargs):
+        self.purge_gzip()
+        self.to_purgatory()
+        return super().delete(**kwargs)
+
+    def to_purgatory(self):
+        dest = Path(settings.UMAP_PURGATORY_ROOT)
+        dest.mkdir(parents=True, exist_ok=True)
+        src = Path(self.geojson.storage.location) / self.storage_root()
+        for version in self.versions:
+            name = version["name"]
+            (src / name).rename(dest / f"{self.map.pk}_{name}")
+
     def upload_to(self):
         root = self.storage_root()
         name = "%s_%s.geojson" % (self.pk, int(time.time() * 1000))

umap/settings/base.py

@@ -267,6 +267,7 @@ UMAP_DEFAULT_FEATURES_HAVE_OWNERS = False
 UMAP_HOME_FEED = "latest"
 UMAP_IMPORTERS = {}
 UMAP_HOST_INFOS = {}
+UMAP_PURGATORY_ROOT = "/tmp/umappurgatory"
 
 UMAP_READONLY = env("UMAP_READONLY", default=False)
 UMAP_GZIP = True

umap/tests/test_datalayer.py

@@ -1,3 +1,4 @@
+import tempfile
 from pathlib import Path
 
 import pytest
@@ -269,3 +270,26 @@ def test_anonymous_can_edit_in_inherit_mode_and_map_in_public_mode(
     map.save()
     fake_request.user = AnonymousUser()
     assert datalayer.can_edit(fake_request)
+
+
+def test_should_remove_all_versions_on_delete(map, settings):
+    settings.UMAP_PURGATORY_ROOT = tempfile.mkdtemp()
+    datalayer = DataLayerFactory(uuid="0f1161c0-c07f-4ba4-86c5-8d8981d8a813", old_id=17)
+    root = Path(datalayer.storage_root())
+    before = len(datalayer.geojson.storage.listdir(root)[1])
+    other = "123456_1440918637.geojson"
+    files = [
+        f"{datalayer.pk}_1440924889.geojson",
+        f"{datalayer.pk}_1440923687.geojson",
+        f"{datalayer.pk}_1440918637.geojson",
+        f"{datalayer.old_id}_1440918537.geojson",
+        other,
+    ]
+    for path in files:
+        datalayer.geojson.storage.save(root / path, ContentFile("{}"))
+        datalayer.geojson.storage.save(root / f"{path}.gz", ContentFile("{}"))
+    assert len(datalayer.geojson.storage.listdir(root)[1]) == 10 + before
+    datalayer.delete()
+    found = datalayer.geojson.storage.listdir(root)[1]
+    assert found == [other, f"{other}.gz"]
+    assert len(list(Path(settings.UMAP_PURGATORY_ROOT).iterdir())) == 4 + before

umap/tests/test_purge_purgatory.py

@@ -0,0 +1,25 @@
+import os
+import tempfile
+from pathlib import Path
+
+from django.core.management import call_command
+
+
+def test_purge_purgatory(settings):
+    settings.UMAP_PURGATORY_ROOT = tempfile.mkdtemp()
+    root = Path(settings.UMAP_PURGATORY_ROOT)
+    old = root / "old.json"
+    old.write_text("{}")
+    stat = old.stat()
+    os.utime(old, times=(stat.st_mtime - 31 * 86400, stat.st_mtime - 31 * 86400))
+    recent = root / "recent.json"
+    recent.write_text("{}")
+    stat = recent.stat()
+    os.utime(recent, times=(stat.st_mtime - 8 * 86400, stat.st_mtime - 8 * 86400))
+    now = root / "now.json"
+    now.write_text("{}")
+    assert {f.name for f in root.iterdir()} == {"old.json", "recent.json", "now.json"}
+    call_command("purge_purgatory")
+    assert {f.name for f in root.iterdir()} == {"recent.json", "now.json"}
+    call_command("purge_purgatory", "--days=7")
+    assert {f.name for f in root.iterdir()} == {"now.json"}