Don't use filesystem APIs to manipulate URLs

Following #1743, this removes the remaining uses of the filesystem APIs
`os.path` and `pathlib` (which are platform-dependent and contain methods for
local filesystem manipulation) to process URLs.

The `zarr_checksum` package still has this confusion in its `ZarrArchiveFile`
class, but attempts to refactor some of that code failed due to other issues
with it. So, the `ZarrArchiveFile.path` field is just cast to a `str` when
interfacing with local application code.

dandiapi/analytics/tasks/__init__.py

@@ -1,6 +1,5 @@
 from collections import Counter
 from collections.abc import Generator
-from pathlib import Path
 
 from celery.app import shared_task
 from celery.utils.log import get_task_logger
@@ -70,7 +69,7 @@ def process_s3_log_file_task(bucket: LogBucket, s3_log_key: str) -> None:
 
     # short circuit if the log file has already been processed. note that this doesn't guarantee
     # exactly once processing, that's what the unique constraint on ProcessedS3Log is for.
-    if ProcessedS3Log.objects.filter(name=Path(s3_log_key).name, embargoed=embargoed).exists():
+    if ProcessedS3Log.objects.filter(name=s3_log_key.split('/')[-1], embargoed=embargoed).exists():
         return
 
     s3 = get_boto_client(get_storage() if not embargoed else get_embargo_storage())
@@ -86,7 +85,7 @@ def process_s3_log_file_task(bucket: LogBucket, s3_log_key: str) -> None:
 
     with transaction.atomic():
         try:
-            log = ProcessedS3Log(name=Path(s3_log_key).name, embargoed=embargoed)
+            log = ProcessedS3Log(name=s3_log_key.split('/')[-1], embargoed=embargoed)
             # disable constraint validation checking so duplicate errors can be detected and
             # ignored. the rest of the full_clean errors should still be raised.
             log.full_clean(validate_constraints=False)

dandiapi/api/tests/test_asset.py

@@ -1,5 +1,4 @@
 import json
-import os.path
 from uuid import uuid4
 
 from django.conf import settings
@@ -1349,7 +1348,7 @@ def test_asset_download(api_client, storage, version, asset):
     download = requests.get(download_url, timeout=5)
     cd_header = download.headers.get('Content-Disposition')
 
-    assert cd_header == f'attachment; filename="{os.path.basename(asset.path)}"'
+    assert cd_header == f'attachment; filename="{asset.path.split("/")[-1]}"'
 
     with asset.blob.blob.file.open('rb') as reader:
         assert download.content == reader.read()
@@ -1395,7 +1394,7 @@ def test_asset_download_embargo(
     download = requests.get(download_url, timeout=5)
     cd_header = download.headers.get('Content-Disposition')
 
-    assert cd_header == f'attachment; filename="{os.path.basename(asset.path)}"'
+    assert cd_header == f'attachment; filename="{asset.path.split("/")[-1]}"'
 
     with asset.embargoed_blob.blob.file.open('rb') as reader:
         assert download.content == reader.read()
@@ -1430,7 +1429,7 @@ def test_asset_direct_download(api_client, storage, version, asset):
     download = requests.get(download_url, timeout=5)
     cd_header = download.headers.get('Content-Disposition')
 
-    assert cd_header == f'attachment; filename="{os.path.basename(asset.path)}"'
+    assert cd_header == f'attachment; filename="{asset.path.split("/")[-1]}"'
 
     with asset.blob.blob.file.open('rb') as reader:
         assert download.content == reader.read()
@@ -1462,7 +1461,7 @@ def test_asset_direct_download_head(api_client, storage, version, asset):
     download = requests.get(download_url, timeout=5)
     cd_header = download.headers.get('Content-Disposition')
 
-    assert cd_header == f'attachment; filename="{os.path.basename(asset.path)}"'
+    assert cd_header == f'attachment; filename="{asset.path.split("/")[-1]}"'
 
     with asset.blob.blob.file.open('rb') as reader:
         assert download.content == reader.read()

dandiapi/api/tests/test_upload.py

@@ -1,4 +1,3 @@
-import os
 import uuid
 
 from django.core.files.base import ContentFile
@@ -536,7 +535,7 @@ def test_upload_validate_wrong_size(api_client, user, upload):
     api_client.force_authenticate(user=user)
 
     wrong_content = b'not 100 bytes'
-    upload.blob.save(os.path.basename(upload.blob.name), ContentFile(wrong_content))
+    upload.blob.save(upload.blob.name.split('/')[-1], ContentFile(wrong_content))
 
     resp = api_client.post(f'/api/uploads/{upload.upload_id}/validate/')
     assert resp.status_code == 400

dandiapi/api/views/asset.py

@@ -22,8 +22,6 @@
     # This should only be used for type interrogation, never instantiation
     MinioStorage = type('FakeMinioStorage', (), {})
 
-import os.path
-
 from django.conf import settings
 from django.db import transaction
 from django.db.models import QuerySet
@@ -143,7 +141,7 @@ def download(self, request, *args, **kwargs):
         serializer.is_valid(raise_exception=True)
         content_disposition = serializer.validated_data['content_disposition']
         content_type = asset.metadata.get('encodingFormat', 'application/octet-stream')
-        asset_basename = os.path.basename(asset.path)
+        asset_basename = asset.path.split('/')[-1]
 
         if content_disposition == 'attachment':
             return HttpResponseRedirect(

dandiapi/zarr/models.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import logging
-from pathlib import Path
 from urllib.parse import urlparse, urlunparse
 from uuid import uuid4
 
@@ -100,7 +99,7 @@ class ZarrArchive(BaseZarrArchive):
     storage = get_storage()
     dandiset = models.ForeignKey(Dandiset, related_name='zarr_archives', on_delete=models.CASCADE)
 
-    def s3_path(self, zarr_path: str | Path):
+    def s3_path(self, zarr_path: str) -> str:
         """Generate a full S3 object path from a path in this zarr_archive."""
         return f'{settings.DANDI_DANDISETS_BUCKET_PREFIX}{settings.DANDI_ZARR_PREFIX_NAME}/{self.zarr_id}/{zarr_path}'  # noqa: E501
 
@@ -111,6 +110,6 @@ class EmbargoedZarrArchive(BaseZarrArchive):
         Dandiset, related_name='embargoed_zarr_archives', on_delete=models.CASCADE
     )
 
-    def s3_path(self, zarr_path: str | Path):
+    def s3_path(self, zarr_path: str) -> str:
         """Generate a full S3 object path from a path in this zarr_archive."""
         return f'{settings.DANDI_DANDISETS_EMBARGO_BUCKET_PREFIX}{settings.DANDI_ZARR_PREFIX_NAME}/{self.dandiset.identifier}/{self.zarr_id}/{zarr_path}'  # noqa: E501

dandiapi/zarr/tests/test_zarr.py

@@ -235,7 +235,7 @@ def test_zarr_rest_delete_file(
         f'/api/zarr/{zarr_archive.zarr_id}/files/', [{'path': str(zarr_file.path)}]
     )
     assert resp.status_code == 204
-    assert not zarr_archive.storage.exists(zarr_archive.s3_path(zarr_file.path))
+    assert not zarr_archive.storage.exists(zarr_archive.s3_path(str(zarr_file.path)))
 
     # Assert zarr is back in pending state
     zarr_archive.refresh_from_db()
@@ -334,7 +334,7 @@ def test_zarr_rest_delete_multiple_files(
 
     # Assert not found
     for file in zarr_files:
-        assert not zarr_archive.storage.exists(zarr_archive.s3_path(file))
+        assert not zarr_archive.storage.exists(zarr_archive.s3_path(str(file.path)))
 
     ingest_zarr_archive(zarr_archive.zarr_id)
     zarr_archive.refresh_from_db()
@@ -367,7 +367,7 @@ def test_zarr_rest_delete_missing_file(
     assert resp.json() == [
         f'File test-prefix/test-zarr/{zarr_archive.zarr_id}/does/not/exist does not exist.'
     ]
-    assert zarr_archive.storage.exists(zarr_archive.s3_path(zarr_file.path))
+    assert zarr_archive.storage.exists(zarr_archive.s3_path(str(zarr_file.path)))
 
     # Ingest
     zarr_archive.status = ZarrArchiveStatus.UPLOADED

dandiapi/zarr/views/__init__.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import logging
-from pathlib import Path
 
 from django.db import IntegrityError, transaction
 from django.db.models.query import QuerySet
@@ -193,17 +192,16 @@ def files(self, request, zarr_id: str):
         serializer.is_valid(raise_exception=True)
 
         # The root path for this zarr in s3
-        base_path = Path(zarr_archive.s3_path(''))
+        base_path = zarr_archive.s3_path('')
 
         # Retrieve and join query params
         limit = serializer.validated_data['limit']
         download = serializer.validated_data['download']
 
         raw_prefix = serializer.validated_data['prefix']
-        full_prefix = str(base_path / raw_prefix)
+        full_prefix = base_path + raw_prefix
 
-        _after = serializer.validated_data['after']
-        after = str(base_path / _after) if _after else ''
+        after = base_path + serializer.validated_data["after"]
 
         # Handle head request redirects
         if request.method == 'HEAD':
@@ -229,7 +227,7 @@ def files(self, request, zarr_id: str):
         # Map/filter listing
         results = [
             {
-                'Key': str(Path(obj['Key']).relative_to(base_path)),
+                'Key': obj['Key'].removeprefix(base_path),
                 'LastModified': obj['LastModified'],
                 'ETag': obj['ETag'].strip('"'),
                 'Size': obj['Size'],