import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

toolkit/components/places/History.h

@@ -0,0 +1,224 @@
+/* -*- 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_places_History_h_
+#define mozilla_places_History_h_
+
+#include "mozilla/IHistory.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/Mutex.h"
+#include "mozIAsyncHistory.h"
+#include "nsIDownloadHistory.h"
+#include "Database.h"
+
+#include "mozilla/dom/Link.h"
+#include "nsTHashtable.h"
+#include "nsString.h"
+#include "nsURIHashKey.h"
+#include "nsTObserverArray.h"
+#include "nsDeque.h"
+#include "nsIMemoryReporter.h"
+#include "nsIObserver.h"
+#include "mozIStorageConnection.h"
+
+namespace mozilla {
+namespace places {
+
+struct VisitData;
+class ConcurrentStatementsHolder;
+
+#define NS_HISTORYSERVICE_CID \
+  {0x0937a705, 0x91a6, 0x417a, {0x82, 0x92, 0xb2, 0x2e, 0xb1, 0x0d, 0xa8, 0x6c}}
+
+// Initial size of mRecentlyVisitedURIs.
+#define RECENTLY_VISITED_URIS_SIZE 64
+// Microseconds after which a visit can be expired from mRecentlyVisitedURIs.
+// When an URI is reloaded we only take into account the first visit to it, and
+// ignore any subsequent visits, if they happen before this time has elapsed.
+// A commonly found case is to reload a page every 5 minutes, so we pick a time
+// larger than that.
+#define RECENTLY_VISITED_URIS_MAX_AGE 6 * 60 * PR_USEC_PER_SEC
+
+class History final : public IHistory
+                    , public nsIDownloadHistory
+                    , public mozIAsyncHistory
+                    , public nsIObserver
+                    , public nsIMemoryReporter
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_IHISTORY
+  NS_DECL_NSIDOWNLOADHISTORY
+  NS_DECL_MOZIASYNCHISTORY
+  NS_DECL_NSIOBSERVER
+  NS_DECL_NSIMEMORYREPORTER
+
+  History();
+
+  /**
+   * Obtains the statement to use to check if a URI is visited or not.
+   */
+  nsresult GetIsVisitedStatement(mozIStorageCompletionCallback* aCallback);
+
+  /**
+   * Adds an entry in moz_places with the data in aVisitData.
+   *
+   * @param aVisitData
+   *        The visit data to use to populate a new row in moz_places.
+   */
+  nsresult InsertPlace(VisitData& aVisitData);
+
+  /**
+   * Updates an entry in moz_places with the data in aVisitData.
+   *
+   * @param aVisitData
+   *        The visit data to use to update the existing row in moz_places.
+   */
+  nsresult UpdatePlace(const VisitData& aVisitData);
+
+  /**
+   * Loads information about the page into _place from moz_places.
+   *
+   * @param _place
+   *        The VisitData for the place we need to know information about.
+   * @param [out] _exists
+   *        Whether or the page was recorded in moz_places, false otherwise.
+   */
+  nsresult FetchPageInfo(VisitData& _place, bool* _exists);
+
+  /**
+   * Get the number of bytes of memory this History object is using,
+   * including sizeof(*this))
+   */
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
+
+  /**
+   * Obtains a pointer to this service.
+   */
+  static History* GetService();
+
+  /**
+   * Obtains a pointer that has had AddRef called on it.  Used by the service
+   * manager only.
+   */
+  static History* GetSingleton();
+
+  template<int N>
+  already_AddRefed<mozIStorageStatement>
+  GetStatement(const char (&aQuery)[N])
+  {
+    mozIStorageConnection* dbConn = GetDBConn();
+    NS_ENSURE_TRUE(dbConn, nullptr);
+    return mDB->GetStatement(aQuery);
+  }
+
+  already_AddRefed<mozIStorageStatement>
+  GetStatement(const nsACString& aQuery)
+  {
+    mozIStorageConnection* dbConn = GetDBConn();
+    NS_ENSURE_TRUE(dbConn, nullptr);
+    return mDB->GetStatement(aQuery);
+  }
+
+  bool IsShuttingDown() const {
+    return mShuttingDown;
+  }
+  Mutex& GetShutdownMutex() {
+    return mShutdownMutex;
+  }
+
+  /**
+   * Helper function to append a new URI to mRecentlyVisitedURIs. See
+   * mRecentlyVisitedURIs.
+   */
+  void AppendToRecentlyVisitedURIs(nsIURI* aURI);
+
+private:
+  virtual ~History();
+
+  void InitMemoryReporter();
+
+  /**
+   * Obtains a read-write database connection.
+   */
+  mozIStorageConnection* GetDBConn();
+
+  /**
+   * The database handle.  This is initialized lazily by the first call to
+   * GetDBConn(), so never use it directly, or, if you really need, always
+   * invoke GetDBConn() before.
+   */
+  RefPtr<mozilla::places::Database> mDB;
+
+  RefPtr<ConcurrentStatementsHolder> mConcurrentStatementsHolder;
+
+  /**
+   * Remove any memory references to tasks and do not take on any more.
+   */
+  void Shutdown();
+
+  static History* gService;
+
+  // Ensures new tasks aren't started on destruction.
+  bool mShuttingDown;
+  // This mutex guards mShuttingDown. Code running in other threads that might
+  // schedule tasks that use the database should grab it and check the value of
+  // mShuttingDown. If we are already shutting down, the code must gracefully
+  // avoid using the db. If we are not, the lock will prevent shutdown from
+  // starting in an unexpected moment.
+  Mutex mShutdownMutex;
+
+  typedef nsTObserverArray<mozilla::dom::Link* > ObserverArray;
+
+  class KeyClass : public nsURIHashKey
+  {
+  public:
+    explicit KeyClass(const nsIURI* aURI)
+    : nsURIHashKey(aURI)
+    {
+    }
+    KeyClass(const KeyClass& aOther)
+    : nsURIHashKey(aOther)
+    {
+      NS_NOTREACHED("Do not call me!");
+    }
+    size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+    {
+      return array.ShallowSizeOfExcludingThis(aMallocSizeOf);
+    }
+    ObserverArray array;
+  };
+
+  nsTHashtable<KeyClass> mObservers;
+
+  /**
+   * mRecentlyVisitedURIs remembers URIs which have been recently added to
+   * history, to avoid saving these locations repeatedly in a short period.
+   */
+  class RecentURIKey : public nsURIHashKey
+  {
+  public:
+    explicit RecentURIKey(const nsIURI* aURI) : nsURIHashKey(aURI)
+    {
+    }
+    RecentURIKey(const RecentURIKey& aOther) : nsURIHashKey(aOther)
+    {
+      NS_NOTREACHED("Do not call me!");
+    }
+    MOZ_INIT_OUTSIDE_CTOR PRTime time;
+  };
+  nsTHashtable<RecentURIKey> mRecentlyVisitedURIs;
+  /**
+   * Whether aURI has been visited "recently".
+   * See RECENTLY_VISITED_URIS_MAX_AGE.
+   */
+  bool IsRecentlyVisitedURI(nsIURI* aURI);
+};
+
+} // namespace places
+} // namespace mozilla
+
+#endif // mozilla_places_History_h_