From 2be0fde3d65c2dec7fb088de20736b9e81ada948 Mon Sep 17 00:00:00 2001 From: Sean Quah <8349537+squahtx@users.noreply.github.com> Date: Wed, 29 Sep 2021 10:24:37 +0100 Subject: [PATCH] Fix empty `url_cache_thumbnails/yyyy-mm-dd/` directories being left behind (#10924) --- changelog.d/10924.bugfix | 1 + synapse/rest/media/v1/preview_url_resource.py | 74 +++++++++++-------- tests/rest/media/v1/test_url_preview.py | 31 ++++++++ 3 files changed, 75 insertions(+), 31 deletions(-) create mode 100644 changelog.d/10924.bugfix diff --git a/changelog.d/10924.bugfix b/changelog.d/10924.bugfix new file mode 100644 index 000000000..c73a51e32 --- /dev/null +++ b/changelog.d/10924.bugfix @@ -0,0 +1 @@ +Fix a bug where empty `yyyy-mm-dd/` directories would be left behind in the media store's `url_cache_thumbnails/` directory. diff --git a/synapse/rest/media/v1/preview_url_resource.py b/synapse/rest/media/v1/preview_url_resource.py index 79a42b245..044f44a39 100644 --- a/synapse/rest/media/v1/preview_url_resource.py +++ b/synapse/rest/media/v1/preview_url_resource.py @@ -73,6 +73,7 @@ OG_TAG_VALUE_MAXLEN = 1000 ONE_HOUR = 60 * 60 * 1000 ONE_DAY = 24 * ONE_HOUR +IMAGE_CACHE_EXPIRY_MS = 2 * ONE_DAY @attr.s(slots=True, frozen=True, auto_attribs=True) @@ -496,6 +497,27 @@ class PreviewUrlResource(DirectServeJsonResource): logger.info("Still running DB updates; skipping expiry") return + def try_remove_parent_dirs(dirs: Iterable[str]) -> None: + """Attempt to remove the given chain of parent directories + + Args: + dirs: The list of directory paths to delete, with children appearing + before their parents. + """ + for dir in dirs: + try: + os.rmdir(dir) + except FileNotFoundError: + # Already deleted, continue with deleting the rest + pass + except OSError as e: + # Failed, skip deleting the rest of the parent dirs + if e.errno != errno.ENOTEMPTY: + logger.warning( + "Failed to remove media directory: %r: %s", dir, e + ) + break + # First we delete expired url cache entries media_ids = await self.store.get_expired_url_cache(now) @@ -504,20 +526,16 @@ class PreviewUrlResource(DirectServeJsonResource): fname = self.filepaths.url_cache_filepath(media_id) try: os.remove(fname) + except FileNotFoundError: + pass # If the path doesn't exist, meh except OSError as e: - # If the path doesn't exist, meh - if e.errno != errno.ENOENT: - logger.warning("Failed to remove media: %r: %s", media_id, e) - continue + logger.warning("Failed to remove media: %r: %s", media_id, e) + continue removed_media.append(media_id) - try: - dirs = self.filepaths.url_cache_filepath_dirs_to_delete(media_id) - for dir in dirs: - os.rmdir(dir) - except Exception: - pass + dirs = self.filepaths.url_cache_filepath_dirs_to_delete(media_id) + try_remove_parent_dirs(dirs) await self.store.delete_url_cache(removed_media) @@ -530,7 +548,7 @@ class PreviewUrlResource(DirectServeJsonResource): # These may be cached for a bit on the client (i.e., they # may have a room open with a preview url thing open). # So we wait a couple of days before deleting, just in case. - expire_before = now - 2 * ONE_DAY + expire_before = now - IMAGE_CACHE_EXPIRY_MS media_ids = await self.store.get_url_cache_media_before(expire_before) removed_media = [] @@ -538,36 +556,30 @@ class PreviewUrlResource(DirectServeJsonResource): fname = self.filepaths.url_cache_filepath(media_id) try: os.remove(fname) + except FileNotFoundError: + pass # If the path doesn't exist, meh except OSError as e: - # If the path doesn't exist, meh - if e.errno != errno.ENOENT: - logger.warning("Failed to remove media: %r: %s", media_id, e) - continue + logger.warning("Failed to remove media: %r: %s", media_id, e) + continue - try: - dirs = self.filepaths.url_cache_filepath_dirs_to_delete(media_id) - for dir in dirs: - os.rmdir(dir) - except Exception: - pass + dirs = self.filepaths.url_cache_filepath_dirs_to_delete(media_id) + try_remove_parent_dirs(dirs) thumbnail_dir = self.filepaths.url_cache_thumbnail_directory(media_id) try: shutil.rmtree(thumbnail_dir) + except FileNotFoundError: + pass # If the path doesn't exist, meh except OSError as e: - # If the path doesn't exist, meh - if e.errno != errno.ENOENT: - logger.warning("Failed to remove media: %r: %s", media_id, e) - continue + logger.warning("Failed to remove media: %r: %s", media_id, e) + continue removed_media.append(media_id) - try: - dirs = self.filepaths.url_cache_thumbnail_dirs_to_delete(media_id) - for dir in dirs: - os.rmdir(dir) - except Exception: - pass + dirs = self.filepaths.url_cache_thumbnail_dirs_to_delete(media_id) + # Note that one of the directories to be deleted has already been + # removed by the `rmtree` above. + try_remove_parent_dirs(dirs) await self.store.delete_url_cache_media(removed_media) diff --git a/tests/rest/media/v1/test_url_preview.py b/tests/rest/media/v1/test_url_preview.py index 4d09b5d07..ce43de780 100644 --- a/tests/rest/media/v1/test_url_preview.py +++ b/tests/rest/media/v1/test_url_preview.py @@ -21,11 +21,13 @@ from twisted.internet.error import DNSLookupError from twisted.test.proto_helpers import AccumulatingProtocol from synapse.config.oembed import OEmbedEndpointConfig +from synapse.rest.media.v1.preview_url_resource import IMAGE_CACHE_EXPIRY_MS from synapse.util.stringutils import parse_and_validate_mxc_uri from tests import unittest from tests.server import FakeTransport from tests.test_utils import SMALL_PNG +from tests.utils import MockClock try: import lxml @@ -851,3 +853,32 @@ class URLPreviewTests(unittest.HomeserverTestCase): 404, "URL cache thumbnail was unexpectedly retrieved from a storage provider", ) + + def test_cache_expiry(self): + """Test that URL cache files and thumbnails are cleaned up properly on expiry.""" + self.preview_url.clock = MockClock() + + _host, media_id = self._download_image() + + file_path = self.preview_url.filepaths.url_cache_filepath(media_id) + file_dirs = self.preview_url.filepaths.url_cache_filepath_dirs_to_delete( + media_id + ) + thumbnail_dir = self.preview_url.filepaths.url_cache_thumbnail_directory( + media_id + ) + thumbnail_dirs = self.preview_url.filepaths.url_cache_thumbnail_dirs_to_delete( + media_id + ) + + self.assertTrue(os.path.isfile(file_path)) + self.assertTrue(os.path.isdir(thumbnail_dir)) + + self.preview_url.clock.advance_time_msec(IMAGE_CACHE_EXPIRY_MS + 1) + self.get_success(self.preview_url._expire_url_cache_data()) + + for path in [file_path] + file_dirs + [thumbnail_dir] + thumbnail_dirs: + self.assertFalse( + os.path.exists(path), + f"{os.path.relpath(path, self.media_store_path)} was not deleted", + )