import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

storage/mozStorageService.h

@@ -0,0 +1,197 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
+ * 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 MOZSTORAGESERVICE_H
+#define MOZSTORAGESERVICE_H
+
+#include "nsCOMPtr.h"
+#include "nsICollation.h"
+#include "nsIFile.h"
+#include "nsIMemoryReporter.h"
+#include "nsIObserver.h"
+#include "nsTArray.h"
+#include "mozilla/Mutex.h"
+
+#include "mozIStorageService.h"
+
+class nsIMemoryReporter;
+class nsIXPConnect;
+struct sqlite3_vfs;
+
+namespace mozilla {
+namespace storage {
+
+class Connection;
+class Service : public mozIStorageService
+              , public nsIObserver
+              , public nsIMemoryReporter
+{
+public:
+  /**
+   * Initializes the service.  This must be called before any other function!
+   */
+  nsresult initialize();
+
+  /**
+   * Compares two strings using the Service's locale-aware collation.
+   *
+   * @param  aStr1
+   *         The string to be compared against aStr2.
+   * @param  aStr2
+   *         The string to be compared against aStr1.
+   * @param  aComparisonStrength
+   *         The sorting strength, one of the nsICollation constants.
+   * @return aStr1 - aStr2.  That is, if aStr1 < aStr2, returns a negative
+   *         number.  If aStr1 > aStr2, returns a positive number.  If
+   *         aStr1 == aStr2, returns 0.
+   */
+  int localeCompareStrings(const nsAString &aStr1,
+                           const nsAString &aStr2,
+                           int32_t aComparisonStrength);
+
+  static Service *getSingleton();
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_MOZISTORAGESERVICE
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSIMEMORYREPORTER
+
+  /**
+   * Obtains an already AddRefed pointer to XPConnect.  This is used by
+   * language helpers.
+   */
+  static already_AddRefed<nsIXPConnect> getXPConnect();
+
+  /**
+   * Obtains the cached data for the toolkit.storage.synchronous preference.
+   */
+  static int32_t getSynchronousPref();
+
+  /**
+   * Obtains the default page size for this platform. The default value is
+   * specified in the SQLite makefile (SQLITE_DEFAULT_PAGE_SIZE) but it may be
+   * overriden with the PREF_TS_PAGESIZE hidden preference.
+   */
+  static int32_t getDefaultPageSize()
+  {
+    return sDefaultPageSize;
+  }
+
+  /**
+   * Returns a boolean value indicating whether or not the given page size is
+   * valid (currently understood as a power of 2 between 512 and 65536).
+   */
+  static bool pageSizeIsValid(int32_t aPageSize)
+  {
+    return aPageSize == 512 || aPageSize == 1024 || aPageSize == 2048 ||
+           aPageSize == 4096 || aPageSize == 8192 || aPageSize == 16384 ||
+           aPageSize == 32768 || aPageSize == 65536;
+  }
+
+  /**
+   * Registers the connection with the storage service.  Connections are
+   * registered so they can be iterated over.
+   *
+   * @pre mRegistrationMutex is not held
+   *
+   * @param  aConnection
+   *         The connection to register.
+   */
+  void registerConnection(Connection *aConnection);
+
+  /**
+   * Unregisters the connection with the storage service.
+   *
+   * @pre mRegistrationMutex is not held
+   *
+   * @param  aConnection
+   *         The connection to unregister.
+   */
+  void unregisterConnection(Connection *aConnection);
+
+  /**
+   * Gets the list of open connections.  Note that you must test each
+   * connection with mozIStorageConnection::connectionReady before doing
+   * anything with it, and skip it if it's not ready.
+   *
+   * @pre mRegistrationMutex is not held
+   *
+   * @param  aConnections
+   *         An inout param;  it is cleared and the connections are appended to
+   *         it.
+   * @return The open connections.
+   */
+  void getConnections(nsTArray<RefPtr<Connection> >& aConnections);
+
+private:
+  Service();
+  virtual ~Service();
+
+  /**
+   * Used for 1) locking around calls when initializing connections so that we
+   * can ensure that the state of sqlite3_enable_shared_cache is sane and 2)
+   * synchronizing access to mLocaleCollation.
+   */
+  Mutex mMutex;
+  
+  sqlite3_vfs *mSqliteVFS;
+
+  /**
+   * Protects mConnections.
+   */
+  Mutex mRegistrationMutex;
+
+  /**
+   * The list of connections we have created.  Modifications to it are
+   * protected by |mRegistrationMutex|.
+   */
+  nsTArray<RefPtr<Connection> > mConnections;
+
+  /**
+   * Frees as much heap memory as possible from all of the known open
+   * connections.
+   */
+  void minimizeMemory();
+
+  /**
+   * Shuts down the storage service, freeing all of the acquired resources.
+   */
+  void shutdown();
+
+  /**
+   * Lazily creates and returns a collation created from the application's
+   * locale that all statements of all Connections of this Service may use.
+   * Since the collation's lifetime is that of the Service and no statement may
+   * execute outside the lifetime of the Service, this method returns a raw
+   * pointer.
+   */
+  nsICollation *getLocaleCollation();
+
+  /**
+   * Lazily created collation that all statements of all Connections of this
+   * Service may use.  The collation is created from the application's locale.
+   *
+   * @note Collation implementations are platform-dependent and in general not
+   *       thread-safe.  Access to this collation should be synchronized.
+   */
+  nsCOMPtr<nsICollation> mLocaleCollation;
+
+  nsCOMPtr<nsIFile> mProfileStorageFile;
+
+  nsCOMPtr<nsIMemoryReporter> mStorageSQLiteReporter;
+
+  static Service *gService;
+
+  static nsIXPConnect *sXPConnect;
+
+  static int32_t sSynchronousPref;
+  static int32_t sDefaultPageSize;
+};
+
+} // namespace storage
+} // namespace mozilla
+
+#endif /* MOZSTORAGESERVICE_H */