Componentize HistoryQuickProvider and its supporting cast

chrome/browser/autocomplete/in_memory_url_index.cc

Index: chrome/browser/autocomplete/in_memory_url_index.cc
diff --git a/chrome/browser/autocomplete/in_memory_url_index.cc b/chrome/browser/autocomplete/in_memory_url_index.cc
deleted file mode 100644
index bd0a33c19e3d58e91eaa5e57ae24d015e481d53e..0000000000000000000000000000000000000000
--- a/chrome/browser/autocomplete/in_memory_url_index.cc
+++ /dev/null
@@ -1,344 +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.
-
-#include "chrome/browser/autocomplete/in_memory_url_index.h"
-
-#include "base/files/file_util.h"
-#include "base/strings/utf_string_conversions.h"
-#include "base/trace_event/trace_event.h"
-#include "chrome/browser/autocomplete/url_index_private_data.h"
-#include "components/history/core/browser/history_service.h"
-#include "components/history/core/browser/url_database.h"
-
-using in_memory_url_index::InMemoryURLIndexCacheItem;
-
-// Initializes a whitelist of URL schemes.
-void InitializeSchemeWhitelist(
-    SchemeSet* whitelist,
-    const SchemeSet& client_schemes_to_whitelist) {
-  DCHECK(whitelist);
-  if (!whitelist->empty())
-    return;  // Nothing to do, already initialized.
-
-  whitelist->insert(client_schemes_to_whitelist.begin(),
-                    client_schemes_to_whitelist.end());
-
-  whitelist->insert(std::string(url::kAboutScheme));
-  whitelist->insert(std::string(url::kFileScheme));
-  whitelist->insert(std::string(url::kFtpScheme));
-  whitelist->insert(std::string(url::kHttpScheme));
-  whitelist->insert(std::string(url::kHttpsScheme));
-  whitelist->insert(std::string(url::kMailToScheme));
-}
-
-// Restore/SaveCacheObserver ---------------------------------------------------
-
-InMemoryURLIndex::RestoreCacheObserver::~RestoreCacheObserver() {
-}
-
-InMemoryURLIndex::SaveCacheObserver::~SaveCacheObserver() {
-}
-
-// RebuildPrivateDataFromHistoryDBTask -----------------------------------------
-
-InMemoryURLIndex::RebuildPrivateDataFromHistoryDBTask::
-    RebuildPrivateDataFromHistoryDBTask(
-        InMemoryURLIndex* index,
-        const std::string& languages,
-        const SchemeSet& scheme_whitelist)
-    : index_(index),
-      languages_(languages),
-      scheme_whitelist_(scheme_whitelist),
-      succeeded_(false) {
-}
-
-bool InMemoryURLIndex::RebuildPrivateDataFromHistoryDBTask::RunOnDBThread(
-    history::HistoryBackend* backend,
-    history::HistoryDatabase* db) {
-  data_ = URLIndexPrivateData::RebuildFromHistory(db, languages_,
-                                                  scheme_whitelist_);
-  succeeded_ = data_.get() && !data_->Empty();
-  if (!succeeded_ && data_.get())
-    data_->Clear();
-  return true;
-}
-
-void InMemoryURLIndex::RebuildPrivateDataFromHistoryDBTask::
-    DoneRunOnMainThread() {
-  index_->DoneRebuidingPrivateDataFromHistoryDB(succeeded_, data_);
-}
-
-InMemoryURLIndex::RebuildPrivateDataFromHistoryDBTask::
-    ~RebuildPrivateDataFromHistoryDBTask() {
-}
-
-// InMemoryURLIndex ------------------------------------------------------------
-
-InMemoryURLIndex::InMemoryURLIndex(
-    bookmarks::BookmarkModel* bookmark_model,
-    history::HistoryService* history_service,
-    base::SequencedWorkerPool* worker_pool,
-    const base::FilePath& history_dir,
-    const std::string& languages,
-    const SchemeSet& client_schemes_to_whitelist)
-    : bookmark_model_(bookmark_model),
-      history_service_(history_service),
-      history_dir_(history_dir),
-      languages_(languages),
-      private_data_(new URLIndexPrivateData),
-      restore_cache_observer_(NULL),
-      save_cache_observer_(NULL),
-      task_runner_(
-          worker_pool->GetSequencedTaskRunner(worker_pool->GetSequenceToken())),
-      shutdown_(false),
-      restored_(false),
-      needs_to_be_cached_(false),
-      listen_to_history_service_loaded_(false) {
-  InitializeSchemeWhitelist(&scheme_whitelist_, client_schemes_to_whitelist);
-  // TODO(mrossetti): Register for language change notifications.
-  if (history_service_)
-    history_service_->AddObserver(this);
-}
-
-InMemoryURLIndex::~InMemoryURLIndex() {
-  // If there was a history directory (which there won't be for some unit tests)
-  // then insure that the cache has already been saved.
-  DCHECK(history_dir_.empty() || !needs_to_be_cached_);
-  DCHECK(!history_service_);
-  DCHECK(shutdown_);
-}
-
-void InMemoryURLIndex::Init() {
-  PostRestoreFromCacheFileTask();
-}
-
-void InMemoryURLIndex::ClearPrivateData() {
-  private_data_->Clear();
-}
-
-bool InMemoryURLIndex::GetCacheFilePath(base::FilePath* file_path) {
-  if (history_dir_.empty())
-    return false;
-  *file_path = history_dir_.Append(FILE_PATH_LITERAL("History Provider Cache"));
-  return true;
-}
-
-// Querying --------------------------------------------------------------------
-
-ScoredHistoryMatches InMemoryURLIndex::HistoryItemsForTerms(
-    const base::string16& term_string,
-    size_t cursor_position,
-    size_t max_matches) {
-  return private_data_->HistoryItemsForTerms(
-      term_string, cursor_position, max_matches, languages_, bookmark_model_);
-}
-
-// Updating --------------------------------------------------------------------
-
-void InMemoryURLIndex::DeleteURL(const GURL& url) {
-  private_data_->DeleteURL(url);
-}
-
-void InMemoryURLIndex::OnURLVisited(history::HistoryService* history_service,
-                                    ui::PageTransition transition,
-                                    const history::URLRow& row,
-                                    const history::RedirectList& redirects,
-                                    base::Time visit_time) {
-  DCHECK_EQ(history_service_, history_service);
-  needs_to_be_cached_ |= private_data_->UpdateURL(history_service_,
-                                                  row,
-                                                  languages_,
-                                                  scheme_whitelist_,
-                                                  &private_data_tracker_);
-}
-
-void InMemoryURLIndex::OnURLsModified(history::HistoryService* history_service,
-                                      const history::URLRows& changed_urls) {
-  DCHECK_EQ(history_service_, history_service);
-  for (const auto& row : changed_urls) {
-    needs_to_be_cached_ |= private_data_->UpdateURL(history_service_,
-                                                    row,
-                                                    languages_,
-                                                    scheme_whitelist_,
-                                                    &private_data_tracker_);
-  }
-}
-
-void InMemoryURLIndex::OnURLsDeleted(history::HistoryService* history_service,
-                                     bool all_history,
-                                     bool expired,
-                                     const history::URLRows& deleted_rows,
-                                     const std::set<GURL>& favicon_urls) {
-  if (all_history) {
-    ClearPrivateData();
-    needs_to_be_cached_ = true;
-  } else {
-    for (const auto& row : deleted_rows)
-      needs_to_be_cached_ |= private_data_->DeleteURL(row.url());
-  }
-  // If we made changes, destroy the previous cache.  Otherwise, if we go
-  // through an unclean shutdown (and therefore fail to write a new cache file),
-  // when Chrome restarts and we restore from the previous cache, we'll end up
-  // searching over URLs that may be deleted.  This would be wrong, and
-  // surprising to the user who bothered to delete some URLs from his/her
-  // history.  In this situation, deleting the cache is a better solution than
-  // writing a new cache (after deleting the URLs from the in-memory structure)
-  // because deleting the cache forces it to be rebuilt from history upon
-  // startup.  If we instead write a new, updated cache then at the time of next
-  // startup (after an unclean shutdown) we will not rebuild the in-memory data
-  // structures from history but rather use the cache.  This solution is
-  // mediocre because this cache may not have the most-recently-visited URLs
-  // in it (URLs visited after user deleted some URLs from history), which
-  // would be odd and confusing.  It's better to force a rebuild.
-  base::FilePath path;
-  if (needs_to_be_cached_ && GetCacheFilePath(&path))
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(base::IgnoreResult(base::DeleteFile), path, false));
-}
-
-void InMemoryURLIndex::OnHistoryServiceLoaded(
-    history::HistoryService* history_service) {
-  if (listen_to_history_service_loaded_)
-    ScheduleRebuildFromHistory();
-  listen_to_history_service_loaded_ = false;
-}
-
-// Restoring from Cache --------------------------------------------------------
-
-void InMemoryURLIndex::PostRestoreFromCacheFileTask() {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  TRACE_EVENT0("browser", "InMemoryURLIndex::PostRestoreFromCacheFileTask");
-
-  base::FilePath path;
-  if (!GetCacheFilePath(&path) || shutdown_) {
-    restored_ = true;
-    if (restore_cache_observer_)
-      restore_cache_observer_->OnCacheRestoreFinished(false);
-    return;
-  }
-
-  base::PostTaskAndReplyWithResult(
-      task_runner_.get(),
-      FROM_HERE,
-      base::Bind(&URLIndexPrivateData::RestoreFromFile, path, languages_),
-      base::Bind(&InMemoryURLIndex::OnCacheLoadDone, AsWeakPtr()));
-}
-
-void InMemoryURLIndex::OnCacheLoadDone(
-    scoped_refptr<URLIndexPrivateData> private_data) {
-  if (private_data.get() && !private_data->Empty()) {
-    private_data_tracker_.TryCancelAll();
-    private_data_ = private_data;
-    restored_ = true;
-    if (restore_cache_observer_)
-      restore_cache_observer_->OnCacheRestoreFinished(true);
-  } else if (history_service_) {
-    // When unable to restore from the cache file delete the cache file, if
-    // it exists, and then rebuild from the history database if it's available,
-    // otherwise wait until the history database loaded and then rebuild.
-    base::FilePath path;
-    if (!GetCacheFilePath(&path) || shutdown_)
-      return;
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(base::IgnoreResult(base::DeleteFile), path, false));
-    if (history_service_->backend_loaded()) {
-      ScheduleRebuildFromHistory();
-    } else {
-      listen_to_history_service_loaded_ = true;
-    }
-  }
-}
-
-// Cleanup ---------------------------------------------------------------------
-
-void InMemoryURLIndex::Shutdown() {
-  if (history_service_) {
-    history_service_->RemoveObserver(this);
-    history_service_ = nullptr;
-  }
-  cache_reader_tracker_.TryCancelAll();
-  shutdown_ = true;
-  base::FilePath path;
-  if (!GetCacheFilePath(&path))
-    return;
-  private_data_tracker_.TryCancelAll();
-  task_runner_->PostTask(
-      FROM_HERE,
-      base::Bind(
-          base::IgnoreResult(
-              &URLIndexPrivateData::WritePrivateDataToCacheFileTask),
-          private_data_, path));
-  needs_to_be_cached_ = false;
-}
-
-// Restoring from the History DB -----------------------------------------------
-
-void InMemoryURLIndex::ScheduleRebuildFromHistory() {
-  DCHECK(history_service_);
-  history_service_->ScheduleDBTask(
-      scoped_ptr<history::HistoryDBTask>(
-          new InMemoryURLIndex::RebuildPrivateDataFromHistoryDBTask(
-              this, languages_, scheme_whitelist_)),
-      &cache_reader_tracker_);
-}
-
-void InMemoryURLIndex::DoneRebuidingPrivateDataFromHistoryDB(
-    bool succeeded,
-    scoped_refptr<URLIndexPrivateData> private_data) {
-  DCHECK(thread_checker_.CalledOnValidThread());
-  if (succeeded) {
-    private_data_tracker_.TryCancelAll();
-    private_data_ = private_data;
-    PostSaveToCacheFileTask();  // Cache the newly rebuilt index.
-  } else {
-    private_data_->Clear();  // Dump the old private data.
-    // There is no need to do anything with the cache file as it was deleted
-    // when the rebuild from the history operation was kicked off.
-  }
-  restored_ = true;
-  if (restore_cache_observer_)
-    restore_cache_observer_->OnCacheRestoreFinished(succeeded);
-}
-
-void InMemoryURLIndex::RebuildFromHistory(
-    history::HistoryDatabase* history_db) {
-  private_data_tracker_.TryCancelAll();
-  private_data_ = URLIndexPrivateData::RebuildFromHistory(history_db,
-                                                          languages_,
-                                                          scheme_whitelist_);
-}
-
-// Saving to Cache -------------------------------------------------------------
-
-void InMemoryURLIndex::PostSaveToCacheFileTask() {
-  base::FilePath path;
-  if (!GetCacheFilePath(&path))
-    return;
-  // If there is anything in our private data then make a copy of it and tell
-  // it to save itself to a file.
-  if (private_data_.get() && !private_data_->Empty()) {
-    // Note that ownership of the copy of our private data is passed to the
-    // completion closure below.
-    scoped_refptr<URLIndexPrivateData> private_data_copy =
-        private_data_->Duplicate();
-    base::PostTaskAndReplyWithResult(
-        task_runner_.get(),
-        FROM_HERE,
-        base::Bind(&URLIndexPrivateData::WritePrivateDataToCacheFileTask,
-                   private_data_copy, path),
-        base::Bind(&InMemoryURLIndex::OnCacheSaveDone, AsWeakPtr()));
-  } else {
-    // If there is no data in our index then delete any existing cache file.
-    task_runner_->PostTask(
-        FROM_HERE,
-        base::Bind(base::IgnoreResult(base::DeleteFile), path, false));
-  }
-}
-
-void InMemoryURLIndex::OnCacheSaveDone(bool succeeded) {
-  if (save_cache_observer_)
-    save_cache_observer_->OnCacheSaveFinished(succeeded);
-}