commit a6e4f92f079e36ad86f84790e35e7d1d497c47bf
parent 5ee058cf7767b5e2ebae5558f99912d7d6d54596
Author: Jan Varga <Jan.Varga@gmail.com>
Date: Wed, 12 Nov 2025 08:07:02 +0000
Bug 1988590 - QM: Add prefs to control clearing of non-persisted zero-usage origins; r=asuth,dom-storage-reviewers,jari
Introducing two new prefs:
- dom.quotaManager.temporaryStorage.clearNonPersistedZeroUsageOrigins controls
whether non-persisted origins with zero quota-charged usage are cleared
during the final steps of temporary storage initialization.
- dom.quotaManager.temporaryStorage.maxOriginsToClearDuringCleanup controls the
maximum number of origins cleared in a single batch. Defaults to 50 on
Android and 150 on other platforms. Currently this is only applied when
clearing non-persisted zero-usage origins, but it is intended as a general
batch limit for future clearing strategies as well.
Testing: The new prefs and related code is exercised in a new test
(test_temporaryStorageCleanup.js) added in a follow-up patch for this bug.
Differential Revision: https://phabricator.services.mozilla.com/D266641
Diffstat:
1 file changed, 34 insertions(+), 0 deletions(-)
diff --git a/modules/libpref/init/StaticPrefList.yaml b/modules/libpref/init/StaticPrefList.yaml
@@ -4072,6 +4072,40 @@
mirror: always
do_not_use_directly: true
+# Should we clear non-persisted origins with zero usage during final steps of
+# temporary storage initialization?
+# When enabled, the QuotaManager will automatically clear non-persisted
+# origins that have zero quota-charged usage during final steps of temporary
+# storage initialization. This removes directories and files belonging to
+# origins that do not store any real data but still consume resources through
+# bookkeeping structures on disk. The feature helps reduce storage bloat and
+# improve initialization performance, especially on long-lived profiles with a
+# large number of unused origins.
+- name: dom.quotaManager.temporaryStorage.clearNonPersistedZeroUsageOrigins
+ type: RelaxedAtomicBool
+ value: false
+ mirror: always
+
+# Controls the maximum number of origins cleared in a single batch during
+# final steps of temporary storage initialization. The value defaults to 50 on
+# Android and 150 on other platforms. Smaller values can be useful for testing
+# and experimentation to exercise multi-batch clearing behavior without
+# requiring hundreds of origins. Larger values may reduce the number of
+# batches but can increase I/O spikes.
+#
+# Currently this pref is only applied when clearing non-persisted zero-usage
+# origins, but it is intended to serve as a general batch limit for other
+# clearing strategies that may be introduced in the future (for example, to
+# remove very old origins).
+- name: dom.quotaManager.temporaryStorage.maxOriginsToClearDuringCleanup
+ type: RelaxedAtomicUint32
+#if defined(MOZ_WIDGET_ANDROID)
+ value: 50
+#else
+ value: 150
+#endif
+ mirror: always
+
# A pref that is used to slow down origin operations for testing purposes.
- name: dom.quotaManager.originOperations.pauseOnIOThreadMs
type: RelaxedAtomicUint32
