Revert 130190 - Move InMemoryURLIndex Caching Operations to FILE Thread

Reading and writing of the InMemoryURLIndex (IMUI) cache is now peformed on the FILE thread and, when required, rebuilding of the index is performed on the history thread. Reading and rebuilding of the index from the cache file or history database are now performed as atomic operations rather than by restoring/rebuilding in-place, i.e. a new private data object is created and populated then swapped in for the live private data object.

BUG=83659
TEST=Unit tests updated/enhanced.

Previously reviewed: https://chromiumcodereview.appspot.com/9030031 (This change identical to 9030031.)
Review URL: https://chromiumcodereview.appspot.com/9703124

TBR=mrossetti@chromium.org
Review URL: https://chromiumcodereview.appspot.com/9969071

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@130206 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 0 insertions, 299 deletions

diff --git a/chrome/browser/history/in_memory_url_index.h b/chrome/browser/history/in_memory_url_index.h
index 7ee9abf..e69de29 100644
--- a/chrome/browser/history/in_memory_url_index.h
+++ b/chrome/browser/history/in_memory_url_index.h
@@ -1,299 +0,0 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef CHROME_BROWSER_HISTORY_IN_MEMORY_URL_INDEX_H_
-#define CHROME_BROWSER_HISTORY_IN_MEMORY_URL_INDEX_H_
-#pragma once
-
-#include <functional>
-#include <map>
-#include <set>
-#include <string>
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/file_path.h"
-#include "base/gtest_prod_util.h"
-#include "base/memory/ref_counted.h"
-#include "base/memory/weak_ptr.h"
-#include "base/string16.h"
-#include "chrome/browser/autocomplete/autocomplete_match.h"
-#include "chrome/browser/autocomplete/history_provider_util.h"
-#include "chrome/browser/cancelable_request.h"
-#include "chrome/browser/history/history.h"
-#include "chrome/browser/history/history_types.h"
-#include "chrome/browser/history/in_memory_url_index_types.h"
-#include "content/public/browser/notification_observer.h"
-#include "content/public/browser/notification_registrar.h"
-#include "sql/connection.h"
-
-class HistoryQuickProviderTest;
-class Profile;
-
-namespace base {
-class Time;
-}
-
-namespace in_memory_url_index {
-class InMemoryURLIndexCacheItem;
-}
-
-namespace history {
-
-namespace imui = in_memory_url_index;
-
-class HistoryDatabase;
-class URLIndexPrivateData;
-struct URLVisitedDetails;
-struct URLsModifiedDetails;
-struct URLsDeletedDetails;
-
-// A RefCountedThreadSafe class that manages a bool used for passing around
-// success when saving the persistent data for the InMemoryURLIndex in a cache.
-class RefCountedBool : public base::RefCountedThreadSafe<RefCountedBool> {
- public:
-  explicit RefCountedBool(bool value) : value_(value) {}
-
-  bool value() const { return value_; }
-  void set_value(bool value) { value_ = value; }
-
- private:
-  friend class base::RefCountedThreadSafe<RefCountedBool>;
-  virtual ~RefCountedBool();
-
-  bool value_;
-
-  DISALLOW_COPY_AND_ASSIGN(RefCountedBool);
-};
-
-// The URL history source.
-// Holds portions of the URL database in memory in an indexed form.  Used to
-// quickly look up matching URLs for a given query string.  Used by
-// the HistoryURLProvider for inline autocomplete and to provide URL
-// matches to the omnibox.
-//
-// Note about multi-byte codepoints and the data structures in the
-// InMemoryURLIndex class: One will quickly notice that no effort is made to
-// insure that multi-byte character boundaries are detected when indexing the
-// words and characters in the URL history database except when converting
-// URL strings to lowercase. Multi-byte-edness makes no difference when
-// indexing or when searching the index as the final filtering of results
-// is dependent on the comparison of a string of bytes, not individual
-// characters. While the lookup of those bytes during a search in the
-// |char_word_map_| could serve up words in which the individual char16
-// occurs as a portion of a composite character the next filtering step
-// will eliminate such words except in the case where a single character
-// is being searched on and which character occurs as the second char16 of a
-// multi-char16 instance.
-class InMemoryURLIndex : public content::NotificationObserver,
-                         public base::SupportsWeakPtr<InMemoryURLIndex> {
- public:
-  // Defines an abstract class which is notified upon completion of restoring
-  // the index's private data either by reading from the cache file or by
-  // rebuilding from the history database.
-  class RestoreCacheObserver {
-   public:
-    virtual ~RestoreCacheObserver();
-
-    // Callback that lets the observer know that the restore operation has
-    // completed. |succeeded| indicates if the restore was successful. This is
-    // called on the UI thread.
-    virtual void OnCacheRestoreFinished(bool succeeded) = 0;
-  };
-
-  // Defines an abstract class which is notified upon completion of saving
-  // the index's private data to the cache file.
-  class SaveCacheObserver {
-   public:
-    virtual ~SaveCacheObserver();
-
-    // Callback that lets the observer know that the save succeeded.
-    // This is called on the UI thread.
-    virtual void OnCacheSaveFinished(bool succeeded) = 0;
-  };
-
-  // |profile|, which may be NULL during unit testing, is used to register for
-  // history changes. |history_dir| is a path to the directory containing the
-  // history database within the profile wherein the cache and transaction
-  // journals will be stored. |languages| gives a list of language encodings by
-  // which URLs and omnibox searches are broken down into words and characters.
-  InMemoryURLIndex(Profile* profile,
-                   const FilePath& history_dir,
-                   const std::string& languages);
-  virtual ~InMemoryURLIndex();
-
-  // Opens and prepares the index of historical URL visits. If the index private
-  // data cannot be restored from its cache file then it is rebuilt from the
-  // history database.
-  void Init();
-
-  // Signals that any outstanding initialization should be canceled and
-  // flushes the cache to disk.
-  void ShutDown();
-
-  // Scans the history index and returns a vector with all scored, matching
-  // history items. This entry point simply forwards the call on to the
-  // URLIndexPrivateData class. For a complete description of this function
-  // refer to that class.
-  ScoredHistoryMatches HistoryItemsForTerms(const string16& term_string);
-
-  // Sets the optional observers for completion of restoral and saving of the
-  // index's private data.
-  void set_restore_cache_observer(
-      RestoreCacheObserver* restore_cache_observer) {
-    restore_cache_observer_ = restore_cache_observer;
-  }
-  void set_save_cache_observer(SaveCacheObserver* save_cache_observer) {
-    save_cache_observer_ = save_cache_observer;
-  }
-
- private:
-  friend class ::HistoryQuickProviderTest;
-  friend class InMemoryURLIndexTest;
-  friend class InMemoryURLIndexCacheTest;
-  FRIEND_TEST_ALL_PREFIXES(LimitedInMemoryURLIndexTest, Initialization);
-
-  // Creating one of me without a history path is not allowed (tests excepted).
-  InMemoryURLIndex();
-
-  // HistoryDBTask used to rebuild our private data from the history database.
-  class RebuildPrivateDataFromHistoryDBTask : public HistoryDBTask {
-   public:
-    explicit RebuildPrivateDataFromHistoryDBTask(
-        InMemoryURLIndex* index,
-        const std::string& languages,
-        const std::set<std::string>& scheme_whitelist);
-    virtual ~RebuildPrivateDataFromHistoryDBTask();
-
-    virtual bool RunOnDBThread(HistoryBackend* backend,
-                               history::HistoryDatabase* db) OVERRIDE;
-    virtual void DoneRunOnMainThread() OVERRIDE;
-
-   private:
-    InMemoryURLIndex* index_;  // Call back to this index at completion.
-    std::string languages_;  // Languages for word-breaking.
-    std::set<std::string> scheme_whitelist_;  // Schemes to be indexed.
-    bool succeeded_;  // Indicates if the rebuild was successful.
-    scoped_refptr<URLIndexPrivateData> data_;  // The rebuilt private data.
-
-    DISALLOW_COPY_AND_ASSIGN(RebuildPrivateDataFromHistoryDBTask);
-  };
-
-  // Initializes all index data members in preparation for restoring the index
-  // from the cache or a complete rebuild from the history database.
-  void ClearPrivateData();
-
-  // Constructs a file path for the cache file within the same directory where
-  // the history database is kept and saves that path to |file_path|. Returns
-  // true if |file_path| can be successfully constructed. (This function
-  // provided as a hook for unit testing.)
-  bool GetCacheFilePath(FilePath* file_path);
-
-  // Restores the index's private data from the cache file stored in the
-  // profile directory.
-  void PostRestoreFromCacheFileTask();
-
-  // Schedules a history task to rebuild our private data from the history
-  // database.
-  void ScheduleRebuildFromHistory();
-
-  // Callback used by RebuildPrivateDataFromHistoryDBTask to signal completion
-  // or rebuilding our private data from the history database. |succeeded|
-  // will be true if the rebuild was successful. |data| will point to a new
-  // instanceof the private data just rebuilt.
-  void DoneRebuidingPrivateDataFromHistoryDB(
-      bool succeeded,
-      scoped_refptr<URLIndexPrivateData> private_data);
-
-  // Rebuilds the history index from the history database in |history_db|.
-  // Used for unit testing only.
-  void RebuildFromHistory(HistoryDatabase* history_db);
-
-  // Determines if the private data was successfully reloaded from the cache
-  // file or if the private data must be rebuilt from the history database.
-  // |private_data_ptr|'s data will be NULL if the cache file load failed. If
-  // successful, sets the private data and notifies any
-  // |restore_cache_observer_|. Otherwise, kicks off a rebuild from the history
-  // database.
-  void OnCacheLoadDone(
-    scoped_refptr<URLIndexPrivateData> private_data_ptr);
-
-  // Callback function that sets the private data from the just-restored-from-
-  // file |private_data|. Notifies any |restore_cache_observer_| that the
-  // restore has succeeded.
-  void OnCacheRestored(URLIndexPrivateData* private_data);
-
-  // Posts a task to cache the index private data and write the cache file to
-  // the profile directory.
-  void PostSaveToCacheFileTask();
-
-  // Saves private_data_ to the given |path|. Runs on the UI thread.
-  // Provided for unit testing so that a test cache file can be used.
-  void DoSaveToCacheFile(const FilePath& path);
-
-  // Notifies the observer, if any, of the success of the private data caching.
-  // |succeeded| is true on a successful save.
-  void OnCacheSaveDone(scoped_refptr<RefCountedBool> succeeded);
-
-  // Handles notifications of history changes.
-  virtual void Observe(int notification_type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
-
-  // Notification handlers.
-  void OnURLVisited(const URLVisitedDetails* details);
-  void OnURLsModified(const URLsModifiedDetails* details);
-  void OnURLsDeleted(const URLsDeletedDetails* details);
-
-  // Sets the directory wherein the cache file will be maintained.
-  // For unit test usage only.
-  void set_history_dir(const FilePath& dir_path) { history_dir_ = dir_path; }
-
-  // Returns a pointer to our private data. For unit testing only.
-  URLIndexPrivateData* private_data() { return private_data_.get(); }
-
-  // Returns the set of whitelisted schemes. For unit testing only.
-  const std::set<std::string>& scheme_whitelist() { return scheme_whitelist_; }
-
-  // The profile, may be null when testing.
-  Profile* profile_;
-
-  // Directory where cache file resides. This is, except when unit testing,
-  // the same directory in which the profile's history database is found. It
-  // should never be empty.
-  FilePath history_dir_;
-
-  // Languages used during the word-breaking process during indexing.
-  std::string languages_;
-
-  // Only URLs with a whitelisted scheme are indexed.
-  std::set<std::string> scheme_whitelist_;
-
-  // The index's durable private data.
-  scoped_refptr<URLIndexPrivateData> private_data_;
-
-  // Observers to notify upon restoral or save of the private data cache.
-  RestoreCacheObserver* restore_cache_observer_;
-  SaveCacheObserver* save_cache_observer_;
-
-  CancelableRequestConsumer cache_reader_consumer_;
-  content::NotificationRegistrar registrar_;
-
-  // Set to true once the shutdown process has begun.
-  bool shutdown_;
-
-  // Set to true when changes to the index have been made and the index needs
-  // to be cached. Set to false when the index has been cached. Used as a
-  // temporary safety check to insure that the cache is saved before the
-  // index has been destructed.
-  // TODO(mrossetti): Eliminate once the transition to SQLite has been done.
-  // http://crbug.com/83659
-  bool needs_to_be_cached_;
-
-  DISALLOW_COPY_AND_ASSIGN(InMemoryURLIndex);
-};
-
-}  // namespace history
-
-#endif  // CHROME_BROWSER_HISTORY_IN_MEMORY_URL_INDEX_H_