summaryrefslogtreecommitdiffstats
path: root/dom/quota/CachingDatabaseConnection.h
blob: 355baf52931cc37081c8f4a05eba2bddcbae9a53 (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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
/* -*- 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_CACHINGDATABASECONNECTION_H_
#define DOM_QUOTA_CACHINGDATABASECONNECTION_H_

#include "mozilla/dom/quota/Config.h"

#include "mozStorageHelper.h"
#include "nsCOMPtr.h"
#include "nscore.h"
#include "nsHashKeys.h"
#include "nsInterfaceHashtable.h"
#include "nsString.h"
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/InitializedOnce.h"
#include "mozilla/NotNull.h"
#include "mozilla/dom/quota/QuotaCommon.h"
#include "mozilla/dom/quota/ResultExtensions.h"
#include "mozilla/dom/quota/ScopedLogExtraInfo.h"

namespace mozilla::dom::quota {

class CachingDatabaseConnection {
 public:
  class CachedStatement;

  // A stack-only RAII wrapper that resets its borrowed statement when the
  // wrapper goes out of scope. Note it's intentionally not declared MOZ_RAII,
  // because it actually is used as a temporary in simple cases like
  // `stmt.Borrow()->Execute()`. It also automatically exposes the current query
  // to ScopedLogExtraInfo as "query" in builds where this mechanism is active.
  class MOZ_STACK_CLASS BorrowedStatement : mozStorageStatementScoper {
   public:
    mozIStorageStatement& operator*() const;

    MOZ_NONNULL_RETURN mozIStorageStatement* operator->() const
        MOZ_NO_ADDREF_RELEASE_ON_RETURN;

    BorrowedStatement(BorrowedStatement&& aOther) = default;

    // No funny business allowed.
    BorrowedStatement& operator=(BorrowedStatement&&) = delete;
    BorrowedStatement(const BorrowedStatement&) = delete;
    BorrowedStatement& operator=(const BorrowedStatement&) = delete;

   private:
    friend class CachedStatement;

#ifdef QM_SCOPED_LOG_EXTRA_INFO_ENABLED
    BorrowedStatement(NotNull<mozIStorageStatement*> aStatement,
                      const nsACString& aQuery)
        : mozStorageStatementScoper(aStatement),
          mExtraInfo{ScopedLogExtraInfo::kTagQuery, aQuery} {}

    ScopedLogExtraInfo mExtraInfo;
#else
    MOZ_IMPLICIT BorrowedStatement(NotNull<mozIStorageStatement*> aStatement)
        : mozStorageStatementScoper(aStatement) {}
#endif
  };

  class LazyStatement;

  void AssertIsOnConnectionThread() const {
#ifdef MOZ_THREAD_SAFETY_OWNERSHIP_CHECKS_SUPPORTED
    mOwningThread->AssertOwnership("CachingDatabaseConnection not thread-safe");
#endif
  }

  bool HasStorageConnection() const {
    return static_cast<bool>(mStorageConnection);
  }

  mozIStorageConnection& MutableStorageConnection() const {
    AssertIsOnConnectionThread();
    MOZ_ASSERT(mStorageConnection);

    return **mStorageConnection;
  }

  Result<CachedStatement, nsresult> GetCachedStatement(
      const nsACString& aQuery);

  Result<BorrowedStatement, nsresult> BorrowCachedStatement(
      const nsACString& aQuery);

  template <typename BindFunctor>
  nsresult ExecuteCachedStatement(const nsACString& aQuery,
                                  BindFunctor&& aBindFunctor) {
    QM_TRY_INSPECT(const auto& stmt, BorrowCachedStatement(aQuery));
    QM_TRY(std::forward<BindFunctor>(aBindFunctor)(*stmt));
    QM_TRY(MOZ_TO_RESULT(stmt->Execute()));

    return NS_OK;
  }

  nsresult ExecuteCachedStatement(const nsACString& aQuery);

  template <typename BindFunctor>
  Result<Maybe<BorrowedStatement>, nsresult>
  BorrowAndExecuteSingleStepStatement(const nsACString& aQuery,
                                      BindFunctor&& aBindFunctor);

#ifdef DEBUG
  ~CachingDatabaseConnection() {
    MOZ_ASSERT(!mStorageConnection);
    MOZ_ASSERT(!mCachedStatements.Count());
  }
#endif

 protected:
  explicit CachingDatabaseConnection(
      MovingNotNull<nsCOMPtr<mozIStorageConnection>> aStorageConnection);

  CachingDatabaseConnection() = default;

  void LazyInit(
      MovingNotNull<nsCOMPtr<mozIStorageConnection>> aStorageConnection);

  void Close();

 private:
#ifdef MOZ_THREAD_SAFETY_OWNERSHIP_CHECKS_SUPPORTED
  LazyInitializedOnce<const nsAutoOwningThread> mOwningThread;
#endif

  LazyInitializedOnceEarlyDestructible<
      const NotNull<nsCOMPtr<mozIStorageConnection>>>
      mStorageConnection;
  nsInterfaceHashtable<nsCStringHashKey, mozIStorageStatement>
      mCachedStatements;
};

class CachingDatabaseConnection::CachedStatement final {
  friend class CachingDatabaseConnection;

  nsCOMPtr<mozIStorageStatement> mStatement;

#ifdef QM_SCOPED_LOG_EXTRA_INFO_ENABLED
  nsCString mQuery;
#endif

#ifdef DEBUG
  CachingDatabaseConnection* mDEBUGConnection;
#endif

 public:
#if defined(DEBUG) || defined(NS_BUILD_REFCNT_LOGGING)
  CachedStatement();
  ~CachedStatement();
#else
  CachedStatement() = default;
#endif

  void AssertIsOnConnectionThread() const;

  explicit operator bool() const;

  BorrowedStatement Borrow() const;

 private:
  // Only called by CachingDatabaseConnection.
  CachedStatement(CachingDatabaseConnection* aConnection,
                  nsCOMPtr<mozIStorageStatement> aStatement,
                  const nsACString& aQuery);

 public:
#if defined(NS_BUILD_REFCNT_LOGGING)
  CachedStatement(CachedStatement&& aOther)
      : mStatement(std::move(aOther.mStatement))
#  ifdef QM_SCOPED_LOG_EXTRA_INFO_ENABLED
        ,
        mQuery(std::move(aOther.mQuery))
#  endif
#  ifdef DEBUG
        ,
        mDEBUGConnection(aOther.mDEBUGConnection)
#  endif
  {
    MOZ_COUNT_CTOR(CachingDatabaseConnection::CachedStatement);
  }
#else
  CachedStatement(CachedStatement&&) = default;
#endif

  CachedStatement& operator=(CachedStatement&&) = default;

  // No funny business allowed.
  CachedStatement(const CachedStatement&) = delete;
  CachedStatement& operator=(const CachedStatement&) = delete;
};

class CachingDatabaseConnection::LazyStatement final {
 public:
  LazyStatement(CachingDatabaseConnection& aConnection,
                const nsACString& aQueryString)
      : mConnection{aConnection}, mQueryString{aQueryString} {}

  Result<CachingDatabaseConnection::BorrowedStatement, nsresult> Borrow();

  template <typename BindFunctor>
  Result<Maybe<CachingDatabaseConnection::BorrowedStatement>, nsresult>
  BorrowAndExecuteSingleStep(BindFunctor&& aBindFunctor) {
    QM_TRY_UNWRAP(auto borrowedStatement, Borrow());

    QM_TRY(std::forward<BindFunctor>(aBindFunctor)(*borrowedStatement));

    QM_TRY_INSPECT(
        const bool& hasResult,
        MOZ_TO_RESULT_INVOKE_MEMBER(&*borrowedStatement, ExecuteStep));

    return hasResult ? Some(std::move(borrowedStatement)) : Nothing{};
  }

 private:
  Result<Ok, nsresult> Initialize();

  CachingDatabaseConnection& mConnection;
  const nsCString mQueryString;
  CachingDatabaseConnection::CachedStatement mCachedStatement;
};

template <typename BindFunctor>
Result<Maybe<CachingDatabaseConnection::BorrowedStatement>, nsresult>
CachingDatabaseConnection::BorrowAndExecuteSingleStepStatement(
    const nsACString& aQuery, BindFunctor&& aBindFunctor) {
  return LazyStatement{*this, aQuery}.BorrowAndExecuteSingleStep(
      std::forward<BindFunctor>(aBindFunctor));
}

}  // namespace mozilla::dom::quota

#endif  // DOM_QUOTA_CACHINGDATABASECONNECTION_H_