summaryrefslogtreecommitdiffstats
path: root/dom/indexedDB/FileInfoManager.h
blob: 75842aa53fc6ed9e08beecd3ba45f5d463ad992e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
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_