gecko-dev/dom/indexedDB/FileManagerBase.h

136 строки
3.7 KiB
C++

/* -*- 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 mozilla_dom_indexeddb_filemanagerbase_h__
#define mozilla_dom_indexeddb_filemanagerbase_h__
#include "mozilla/Attributes.h"
#include "mozilla/Mutex.h"
#include "mozilla/StaticMutex.h"
#include "nsTHashMap.h"
#include "nsHashKeys.h"
#include "nsISupportsImpl.h"
#include "FileInfoT.h"
#include "FlippedOnce.h"
namespace mozilla {
namespace dom {
namespace indexedDB {
template <typename FileManager>
class FileManagerBase {
public:
using FileInfo = FileInfoT<FileManager>;
using MutexType = StaticMutex;
using AutoLock = mozilla::detail::BaseAutoLock<MutexType&>;
[[nodiscard]] SafeRefPtr<FileInfo> GetFileInfo(int64_t aId) const {
return AcquireFileInfo([this, aId] { return mFileInfos.MaybeGet(aId); });
}
[[nodiscard]] SafeRefPtr<FileInfo> CreateFileInfo() {
return AcquireFileInfo([this] {
const int64_t id = ++mLastFileId;
auto fileInfo =
MakeNotNull<FileInfo*>(FileManagerGuard{},
SafeRefPtr{static_cast<FileManager*>(this),
AcquireStrongRefFromRawPtr{}},
id);
mFileInfos.InsertOrUpdate(id, fileInfo);
return Some(fileInfo);
});
}
void RemoveFileInfo(const int64_t aId, const AutoLock& aFileMutexLock) {
#ifdef DEBUG
aFileMutexLock.AssertOwns(FileManager::Mutex());
#endif
mFileInfos.Remove(aId);
}
nsresult Invalidate() {
AutoLock lock(FileManager::Mutex());
mInvalidated.Flip();
mFileInfos.RemoveIf([](const auto& iter) {
FileInfo* info = iter.Data();
MOZ_ASSERT(info);
return !info->LockedClearDBRefs(FileManagerGuard{});
});
return NS_OK;
}
bool Invalidated() const { return mInvalidated; }
class FileManagerGuard {
FileManagerGuard() = default;
};
private:
// Runs the given aFileInfoTableOp operation, which must return a FileInfo*,
// under the file manager lock, acquires a strong reference to the returned
// object under the lock, and returns the strong reference.
template <typename FileInfoTableOp>
[[nodiscard]] SafeRefPtr<FileInfo> 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<FileInfo> {
AutoLock 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:
bool AssertValid() const {
if (NS_WARN_IF(static_cast<const FileManager*>(this)->Invalidated())) {
MOZ_ASSERT(false);
return false;
}
return true;
}
#ifdef DEBUG
~FileManagerBase() { MOZ_ASSERT(mFileInfos.IsEmpty()); }
#else
~FileManagerBase() = default;
#endif
// Access to the following fields must be protected by
// FileManager::Mutex()
int64_t mLastFileId = 0;
nsTHashMap<nsUint64HashKey, NotNull<FileInfo*>> mFileInfos;
FlippedOnce<false> mInvalidated;
};
} // namespace indexedDB
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_indexeddb_filemanagerbase_h__