1 files changed, 140 insertions, 0 deletions
diff --git a/dom/indexedDB/FileInfoManager.h b/dom/indexedDB/FileInfoManager.h
new file mode 100644
index 0000000000..75842aa53f
--- /dev/null
+++ b/dom/indexedDB/FileInfoManager.h
@@ -0,0 +1,140 @@
+/* -*- 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_INDEXEDDB_FILEINFOMANAGER_H_
+#define DOM_INDEXEDDB_FILEINFOMANAGER_H_
+
+#include "mozilla/Attributes.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/StaticMutex.h"
+#include "nsTHashMap.h"
+#include "nsHashKeys.h"
+#include "nsISupportsImpl.h"
+#include "FileInfo.h"
+#include "FlippedOnce.h"
+
+namespace mozilla::dom::indexedDB {
+
+class FileInfoManagerBase {
+ public:
+  bool Invalidated() const { return mInvalidated; }
+
+ protected:
+  bool AssertValid() const {
+    if (NS_WARN_IF(Invalidated())) {
+      MOZ_ASSERT(false);
+      return false;
+    }
+
+    return true;
+  }
+
+  void Invalidate() { mInvalidated.Flip(); }
+
+ private:
+  FlippedOnce<false> mInvalidated;
+};
+
+template <typename FileManager>
+class FileInfoManager : public FileInfoManagerBase {
+ public:
+  using FileInfoType = FileInfo<FileManager>;
+  using MutexType = StaticMutex;
+  using AutoLockType = mozilla::detail::BaseAutoLock<MutexType&>;
+
+  [[nodiscard]] SafeRefPtr<FileInfoType> GetFileInfo(int64_t aId) const {
+    return AcquireFileInfo([this, aId] { return mFileInfos.MaybeGet(aId); });
+  }
+
+  [[nodiscard]] SafeRefPtr<FileInfoType> CreateFileInfo() {
+    return AcquireFileInfo([this] {
+      const int64_t id = ++mLastFileId;
+
+      auto fileInfo =
+          MakeNotNull<FileInfoType*>(FileInfoManagerGuard{},
+                                     SafeRefPtr{static_cast<FileManager*>(this),
+                                                AcquireStrongRefFromRawPtr{}},
+                                     id);
+
+      mFileInfos.InsertOrUpdate(id, fileInfo);
+      return Some(fileInfo);
+    });
+  }
+
+  void RemoveFileInfo(const int64_t aId, const AutoLockType& aFileMutexLock) {
+#ifdef DEBUG
+    aFileMutexLock.AssertOwns(FileManager::Mutex());
+#endif
+    mFileInfos.Remove(aId);
+  }
+
+  // After calling this method, callers should not call any more methods on this
+  // class.
+  virtual nsresult Invalidate() {
+    AutoLockType lock(FileManager::Mutex());
+
+    FileInfoManagerBase::Invalidate();
+
+    mFileInfos.RemoveIf([](const auto& iter) {
+      FileInfoType* info = iter.Data();
+      MOZ_ASSERT(info);
+
+      return !info->LockedClearDBRefs(FileInfoManagerGuard{});
+    });
+
+    return NS_OK;
+  }
+
+  struct FileInfoManagerGuard {
+    FileInfoManagerGuard() = default;
+  };
+
+ private:
+  // Runs the given aFileInfoTableOp operation, which must return a FileInfo*,
+  // under the FileManager lock, acquires a strong reference to the returned
+  // object under the lock, and returns the strong reference.
+  template <typename FileInfoTableOp>
+  [[nodiscard]] SafeRefPtr<FileInfoType> AcquireFileInfo(
+      const FileInfoTableOp& aFileInfoTableOp) const {
+    if (!AssertValid()) {
+      // In release, the assertions are disabled.
+      return nullptr;
+    }
+
+    // We cannot simply change this to SafeRefPtr<FileInfo>, because
+    // FileInfo::AddRef also acquires the FileManager::Mutex.
+    auto fileInfo = [&aFileInfoTableOp]() -> RefPtr<FileInfoType> {
+      AutoLockType lock(FileManager::Mutex());
+
+      const auto maybeFileInfo = aFileInfoTableOp();
+      if (maybeFileInfo) {
+        const auto& fileInfo = maybeFileInfo.ref();
+        fileInfo->LockedAddRef();
+        return dont_AddRef(fileInfo.get());
+      }
+
+      return {};
+    }();
+
+    return SafeRefPtr{std::move(fileInfo)};
+  }
+
+ protected:
+#ifdef DEBUG
+  ~FileInfoManager() { MOZ_ASSERT(mFileInfos.IsEmpty()); }
+#else
+  ~FileInfoManager() = default;
+#endif
+
+  // Access to the following fields must be protected by
+  // FileManager::Mutex()
+  int64_t mLastFileId = 0;
+  nsTHashMap<nsUint64HashKey, NotNull<FileInfoType*>> mFileInfos;
+};
+
+}  // namespace mozilla::dom::indexedDB
+
+#endif  // DOM_INDEXEDDB_FILEINFOMANAGER_H_