DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (5350524bb654)

VCS Links

Line Code
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331
/* 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_places_Database_h_
#define mozilla_places_Database_h_

#include "MainThreadUtils.h"
#include "nsWeakReference.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIObserver.h"
#include "nsIAsyncShutdown.h"
#include "mozilla/storage.h"
#include "mozilla/storage/StatementCache.h"
#include "mozilla/Attributes.h"
#include "nsIEventTarget.h"
#include "Shutdown.h"

// This is the schema version. Update it at any schema change and add a
// corresponding migrateVxx method below.
#define DATABASE_SCHEMA_VERSION 35

// Fired after Places inited.
#define TOPIC_PLACES_INIT_COMPLETE "places-init-complete"
// Fired when initialization fails due to a locked database.
#define TOPIC_DATABASE_LOCKED "places-database-locked"
// This topic is received when the profile is about to be lost.  Places does
// initial shutdown work and notifies TOPIC_PLACES_SHUTDOWN to all listeners.
// Any shutdown work that requires the Places APIs should happen here.
#define TOPIC_PROFILE_CHANGE_TEARDOWN "profile-change-teardown"
// Fired when Places is shutting down.  Any code should stop accessing Places
// APIs after this notification.  If you need to listen for Places shutdown
// you should only use this notification, next ones are intended only for
// internal Places use.
#define TOPIC_PLACES_SHUTDOWN "places-shutdown"
// For Internal use only.  Fired when connection is about to be closed, only
// cleanup tasks should run at this stage, nothing should be added to the
// database, nor APIs should be called.
#define TOPIC_PLACES_WILL_CLOSE_CONNECTION "places-will-close-connection"
// Fired when the connection has gone, nothing will work from now on.
#define TOPIC_PLACES_CONNECTION_CLOSED "places-connection-closed"

// Simulate profile-before-change. This topic may only be used by
// calling `observe` directly on the database. Used for testing only.
#define TOPIC_SIMULATE_PLACES_SHUTDOWN "test-simulate-places-shutdown"

class nsIRunnable;

namespace mozilla {
namespace places {

enum JournalMode {
  // Default SQLite journal mode.
  JOURNAL_DELETE = 0
  // Can reduce fsyncs on Linux when journal is deleted (See bug 460315).
  // We fallback to this mode when WAL is unavailable.
, JOURNAL_TRUNCATE
  // Unsafe in case of crashes on database swap or low memory.
, JOURNAL_MEMORY
  // Can reduce number of fsyncs.  We try to use this mode by default.
, JOURNAL_WAL
};

class ClientsShutdownBlocker;
class ConnectionShutdownBlocker;

class Database final : public nsIObserver
                     , public nsSupportsWeakReference
{
  typedef mozilla::storage::StatementCache<mozIStorageStatement> StatementCache;
  typedef mozilla::storage::StatementCache<mozIStorageAsyncStatement> AsyncStatementCache;

public:
  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSIOBSERVER

  Database();

  /**
   * Initializes the database connection and the schema.
   * In case of corruption the database is copied to a backup file and replaced.
   */
  nsresult Init();

  /**
   * The AsyncShutdown client used by clients of this API to be informed of shutdown.
   */
  already_AddRefed<nsIAsyncShutdownClient> GetClientsShutdown();

  /**
   * Getter to use when instantiating the class.
   *
   * @return Singleton instance of this class.
   */
  static already_AddRefed<Database> GetDatabase();

  /**
   * Returns last known database status.
   *
   * @return one of the nsINavHistoryService::DATABASE_STATUS_* constants.
   */
  uint16_t GetDatabaseStatus() const
  {
    return mDatabaseStatus;
  }

  /**
   * Returns a pointer to the storage connection.
   *
   * @return The connection handle.
   */
  mozIStorageConnection* MainConn() const
  {
    return mMainConn;
  }

  /**
   * Dispatches a runnable to the connection async thread, to be serialized
   * with async statements.
   *
   * @param aEvent
   *        The runnable to be dispatched.
   */
  void DispatchToAsyncThread(nsIRunnable* aEvent) const
  {
    if (mClosed) {
      return;
    }
    nsCOMPtr<nsIEventTarget> target = do_GetInterface(mMainConn);
    if (target) {
      (void)target->Dispatch(aEvent, NS_DISPATCH_NORMAL);
    }
  }

  //////////////////////////////////////////////////////////////////////////////
  //// Statements Getters.

  /**
   * Gets a cached synchronous statement.
   *
   * @param aQuery
   *        SQL query literal.
   * @return The cached statement.
   * @note Always null check the result.
   * @note Always use a scoper to reset the statement.
   */
  template<int N>
  already_AddRefed<mozIStorageStatement>
  GetStatement(const char (&aQuery)[N]) const
  {
    nsDependentCString query(aQuery, N - 1);
    return GetStatement(query);
  }

  /**
   * Gets a cached synchronous statement.
   *
   * @param aQuery
   *        nsCString of SQL query.
   * @return The cached statement.
   * @note Always null check the result.
   * @note Always use a scoper to reset the statement.
   */
  already_AddRefed<mozIStorageStatement>  GetStatement(const nsACString& aQuery) const;

  /**
   * Gets a cached asynchronous statement.
   *
   * @param aQuery
   *        SQL query literal.
   * @return The cached statement.
   * @note Always null check the result.
   * @note AsyncStatements are automatically reset on execution.
   */
  template<int N>
  already_AddRefed<mozIStorageAsyncStatement>
  GetAsyncStatement(const char (&aQuery)[N]) const
  {
    nsDependentCString query(aQuery, N - 1);
    return GetAsyncStatement(query);
  }

  /**
   * Gets a cached asynchronous statement.
   *
   * @param aQuery
   *        nsCString of SQL query.
   * @return The cached statement.
   * @note Always null check the result.
   * @note AsyncStatements are automatically reset on execution.
   */
  already_AddRefed<mozIStorageAsyncStatement> GetAsyncStatement(const nsACString& aQuery) const;

  uint32_t MaxUrlLength();

protected:
  /**
   * Finalizes the cached statements and closes the database connection.
   * A TOPIC_PLACES_CONNECTION_CLOSED notification is fired when done.
   */
  void Shutdown();

  bool IsShutdownStarted() const;

  /**
   * Initializes the database file.  If the database does not exist or is
   * corrupt, a new one is created.  In case of corruption it also creates a
   * backup copy of the database.
   *
   * @param aStorage
   *        mozStorage service instance.
   * @param aNewDatabaseCreated
   *        whether a new database file has been created.
   */
  nsresult InitDatabaseFile(nsCOMPtr<mozIStorageService>& aStorage,
                            bool* aNewDatabaseCreated);

  /**
   * Creates a database backup and replaces the original file with a new
   * one.
   *
   * @param aStorage
   *        mozStorage service instance.
   */
  nsresult BackupAndReplaceDatabaseFile(nsCOMPtr<mozIStorageService>& aStorage);

  /**
   * Initializes the database.  This performs any necessary migrations for the
   * database.  All migration is done inside a transaction that is rolled back
   * if any error occurs.
   * @param aDatabaseMigrated
   *        Whether a schema upgrade happened.
   */
  nsresult InitSchema(bool* aDatabaseMigrated);

  /**
   * Creates bookmark roots in a new DB.
   */
  nsresult CreateBookmarkRoots();

  /**
   * Initializes additionale SQLite functions, defined in SQLFunctions.h
   */
  nsresult InitFunctions();

  /**
   * Initializes temp entities, like triggers, tables, views...
   */
  nsresult InitTempEntities();

  /**
   * Helpers used by schema upgrades.
   */
  nsresult MigrateV13Up();
  nsresult MigrateV15Up();
  nsresult MigrateV17Up();
  nsresult MigrateV18Up();
  nsresult MigrateV19Up();
  nsresult MigrateV20Up();
  nsresult MigrateV21Up();
  nsresult MigrateV22Up();
  nsresult MigrateV23Up();
  nsresult MigrateV24Up();
  nsresult MigrateV25Up();
  nsresult MigrateV26Up();
  nsresult MigrateV27Up();
  nsresult MigrateV28Up();
  nsresult MigrateV30Up();
  nsresult MigrateV31Up();
  nsresult MigrateV32Up();
  nsresult MigrateV33Up();
  nsresult MigrateV34Up();
  nsresult MigrateV35Up();

  nsresult UpdateBookmarkRootTitles();

  friend class ConnectionShutdownBlocker;

  int64_t CreateMobileRoot();
  nsresult GetItemsWithAnno(const nsACString& aAnnoName, int32_t aItemType,
                            nsTArray<int64_t>& aItemIds);
  nsresult DeleteBookmarkItem(int32_t aItemId);

private:
  ~Database();

  /**
   * Singleton getter, invoked by class instantiation.
   */
  static already_AddRefed<Database> GetSingleton();

  static Database* gDatabase;

  nsCOMPtr<mozIStorageConnection> mMainConn;

  mutable StatementCache mMainThreadStatements;
  mutable AsyncStatementCache mMainThreadAsyncStatements;
  mutable StatementCache mAsyncThreadStatements;

  int32_t mDBPageSize;
  uint16_t mDatabaseStatus;
  bool mClosed;

  /**
   * Phases for shutting down the Database.
   * See Shutdown.h for further details about the shutdown procedure.
   */
  already_AddRefed<nsIAsyncShutdownClient> GetProfileChangeTeardownPhase();
  already_AddRefed<nsIAsyncShutdownClient> GetProfileBeforeChangePhase();

  /**
   * Blockers in charge of waiting for the Places clients and then shutting
   * down the mozStorage connection.
   * See Shutdown.h for further details about the shutdown procedure.
   *
   * Cycles with these are broken in `Shutdown()`.
   */
  RefPtr<ClientsShutdownBlocker> mClientsShutdown;
  RefPtr<ConnectionShutdownBlocker> mConnectionShutdown;

  // Maximum length of a stored url.
  // For performance reasons we don't store very long urls in history, since
  // they are slower to search through and cause abnormal database growth,
  // affecting the awesomebar fetch time.
  uint32_t mMaxUrlLength;
};

} // namespace places
} // namespace mozilla

#endif // mozilla_places_Database_h_