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diff --git a/dom/quota/CipherKeyManager.h b/dom/quota/CipherKeyManager.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef DOM_QUOTA_CIPHERKEYMANAGER_H_
+#define DOM_QUOTA_CIPHERKEYMANAGER_H_
+
+#include "mozilla/DataMutex.h"
+#include "mozilla/dom/FlippedOnce.h"
+#include "mozilla/dom/quota/QuotaCommon.h"
+#include "nsTHashMap.h"
+
+namespace mozilla::dom::quota {
+
+using mozilla::FlippedOnce;
+
+template <typename CipherStrategy>
+class CipherKeyManager {
+  // This helper class is used by quota clients to store/retrieve cipher
+  // keys in private browsing mode. All data in private mode must be encrypted
+  // using a cipher key and unique IV (Initialization Vector).
+
+  // This class uses hashmap (represented by mCipherKeys) to store cipher keys
+  // and is currently used by IndexedDB and Cache quota clients. At any given
+  // time, IndexedDB may contain multiple instances of this class where each is
+  // used to cipherkeys relevant to a particular database. Unlike IndexedDB,
+  // CacheAPI only  has one physical sqlite db  per origin, so all cipher keys
+  // corresponding to an origin in cacheAPI gets stored together in this
+  // hashmap.
+
+  // Bug1859558: It could be better if QuotaManager owns cipherKeys for
+  // all the quota clients and exposes, methods like
+  // GetOrCreateCipherManager(aOrigin, aDatabaseName, aClientType) for
+  // clients to access their respective cipherKeys scoped.
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CipherKeyManager)
+
+  using CipherKey = typename CipherStrategy::KeyType;
+
+ public:
+  explicit CipherKeyManager(const char* aName) : mCipherKeys(aName){};
+
+  Maybe<CipherKey> Get(const nsACString& aKeyId = "default"_ns) {
+    auto lockedCipherKeys = mCipherKeys.Lock();
+
+    MOZ_ASSERT(!mInvalidated);
+
+    return lockedCipherKeys->MaybeGet(aKeyId);
+  }
+
+  CipherKey Ensure(const nsACString& aKeyId = "default"_ns) {
+    auto lockedCipherKeys = mCipherKeys.Lock();
+
+    MOZ_ASSERT(!mInvalidated);
+
+    return lockedCipherKeys->LookupOrInsertWith(aKeyId, [] {
+      // Generate a new key if one corresponding to keyStoreId does not exist
+      // already.
+
+      QM_TRY_RETURN(CipherStrategy::GenerateKey(), [](const auto&) {
+        // Bug1800110 Propagate the error to the caller rather than asserting.
+        MOZ_RELEASE_ASSERT(false);
+
+        return CipherKey{};
+      });
+    });
+  }
+
+  bool Invalidated() {
+    auto lockedCipherKeys = mCipherKeys.Lock();
+
+    return mInvalidated;
+  }
+
+  // After calling this method, callers should not call any more methods on this
+  // class.
+  void Invalidate() {
+    auto lockedCipherKeys = mCipherKeys.Lock();
+
+    mInvalidated.Flip();
+
+    lockedCipherKeys->Clear();
+  }
+
+ private:
+  ~CipherKeyManager() = default;
+  // XXX Maybe we can avoid a mutex here by moving all accesses to the
+  // background thread.
+  DataMutex<nsTHashMap<nsCStringHashKey, CipherKey>> mCipherKeys;
+
+  FlippedOnce<false> mInvalidated;
+};
+
+}  // namespace mozilla::dom::quota
+
+#endif  // DOM_QUOTA_CIPHERKEYMANAGER_H_