Refactoring, moving and renaming the NetworkActionPredictor.

chrome/browser/autocomplete/network_action_predictor.cc

Index: chrome/browser/autocomplete/network_action_predictor.cc
diff --git a/chrome/browser/autocomplete/network_action_predictor.cc b/chrome/browser/autocomplete/network_action_predictor.cc
deleted file mode 100644
index 7afc9f82eb941dbc614baa07436d45ee7751d5a5..0000000000000000000000000000000000000000
--- a/chrome/browser/autocomplete/network_action_predictor.cc
+++ /dev/null
@@ -1,512 +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/network_action_predictor.h"
-
-#include <math.h>
-
-#include <vector>
-
-#include "base/bind.h"
-#include "base/i18n/case_conversion.h"
-#include "base/metrics/histogram.h"
-#include "base/string_util.h"
-#include "base/stringprintf.h"
-#include "base/utf_string_conversions.h"
-#include "chrome/browser/autocomplete/autocomplete.h"
-#include "chrome/browser/autocomplete/autocomplete_match.h"
-#include "chrome/browser/autocomplete/network_action_predictor_database.h"
-#include "chrome/browser/history/history.h"
-#include "chrome/browser/history/history_notifications.h"
-#include "chrome/browser/history/in_memory_database.h"
-#include "chrome/browser/prerender/prerender_field_trial.h"
-#include "chrome/browser/prerender/prerender_manager.h"
-#include "chrome/browser/prerender/prerender_manager_factory.h"
-#include "chrome/browser/profiles/profile.h"
-#include "chrome/common/chrome_notification_types.h"
-#include "chrome/common/guid.h"
-#include "content/public/browser/browser_thread.h"
-#include "content/public/browser/notification_details.h"
-#include "content/public/browser/notification_service.h"
-#include "content/public/browser/notification_source.h"
-
-namespace {
-
-const float kConfidenceCutoff[] = {
-  0.8f,
-  0.5f
-};
-
-const size_t kMinimumUserTextLength = 1;
-const int kMinimumNumberOfHits = 3;
-
-COMPILE_ASSERT(arraysize(kConfidenceCutoff) ==
-               NetworkActionPredictor::LAST_PREDICT_ACTION,
-               ConfidenceCutoff_count_mismatch);
-
-enum DatabaseAction {
-  DATABASE_ACTION_ADD,
-  DATABASE_ACTION_UPDATE,
-  DATABASE_ACTION_DELETE_SOME,
-  DATABASE_ACTION_DELETE_ALL,
-  DATABASE_ACTION_COUNT
-};
-
-bool IsAutocompleteMatchSearchType(const AutocompleteMatch& match) {
-  switch (match.type) {
-    // Matches using the user's default search engine.
-    case AutocompleteMatch::SEARCH_WHAT_YOU_TYPED:
-    case AutocompleteMatch::SEARCH_HISTORY:
-    case AutocompleteMatch::SEARCH_SUGGEST:
-    // A match that uses a non-default search engine (e.g. for tab-to-search).
-    case AutocompleteMatch::SEARCH_OTHER_ENGINE:
-      return true;
-
-    default:
-      return false;
-  }
-}
-
-}
-
-const int NetworkActionPredictor::kMaximumDaysToKeepEntry = 14;
-
-double NetworkActionPredictor::hit_weight_ = 1.0;
-
-NetworkActionPredictor::NetworkActionPredictor(Profile* profile)
-    : profile_(profile),
-      db_(new NetworkActionPredictorDatabase(profile)),
-      initialized_(false) {
-  content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::Initialize, db_));
-
-  // Request the in-memory database from the history to force it to load so it's
-  // available as soon as possible.
-  HistoryService* history_service =
-      profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
-  if (history_service)
-    history_service->InMemoryDatabase();
-
-  // Create local caches using the database as loaded. We will garbage collect
-  // rows from the caches and the database once the history service is
-  // available.
-  std::vector<NetworkActionPredictorDatabase::Row>* rows =
-      new std::vector<NetworkActionPredictorDatabase::Row>();
-  content::BrowserThread::PostTaskAndReply(
-      content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::GetAllRows, db_, rows),
-      base::Bind(&NetworkActionPredictor::CreateCaches, AsWeakPtr(),
-                 base::Owned(rows)));
-
-}
-
-NetworkActionPredictor::~NetworkActionPredictor() {
-}
-
-void NetworkActionPredictor::RegisterTransitionalMatches(
-    const string16& user_text,
-    const AutocompleteResult& result) {
-  if (user_text.length() < kMinimumUserTextLength)
-    return;
-  const string16 lower_user_text(base::i18n::ToLower(user_text));
-
-  // Merge this in to an existing match if we already saw |user_text|
-  std::vector<TransitionalMatch>::iterator match_it =
-      std::find(transitional_matches_.begin(), transitional_matches_.end(),
-                lower_user_text);
-
-  if (match_it == transitional_matches_.end()) {
-    TransitionalMatch transitional_match;
-    transitional_match.user_text = lower_user_text;
-    match_it = transitional_matches_.insert(transitional_matches_.end(),
-                                            transitional_match);
-  }
-
-  for (AutocompleteResult::const_iterator it = result.begin();
-       it != result.end(); ++it) {
-    if (std::find(match_it->urls.begin(), match_it->urls.end(),
-                  it->destination_url) == match_it->urls.end()) {
-      match_it->urls.push_back(it->destination_url);
-    }
-  }
-}
-
-void NetworkActionPredictor::ClearTransitionalMatches() {
-  transitional_matches_.clear();
-}
-
-// Given a match, return a recommended action.
-NetworkActionPredictor::Action NetworkActionPredictor::RecommendAction(
-    const string16& user_text,
-    const AutocompleteMatch& match) const {
-  bool is_in_db = false;
-  const double confidence = CalculateConfidence(user_text, match, &is_in_db);
-  DCHECK(confidence >= 0.0 && confidence <= 1.0);
-
-  UMA_HISTOGRAM_BOOLEAN("NetworkActionPredictor.MatchIsInDb", is_in_db);
-
-  if (is_in_db) {
-    // Multiple enties with the same URL are fine as the confidence may be
-    // different.
-    tracked_urls_.push_back(std::make_pair(match.destination_url, confidence));
-    UMA_HISTOGRAM_COUNTS_100("NetworkActionPredictor.Confidence",
-                             confidence * 100);
-  }
-
-  // Map the confidence to an action.
-  Action action = ACTION_NONE;
-  for (int i = 0; i < LAST_PREDICT_ACTION; ++i) {
-    if (confidence >= kConfidenceCutoff[i]) {
-      action = static_cast<Action>(i);
-      break;
-    }
-  }
-
-  // Downgrade prerender to preconnect if this is a search match or if omnibox
-  // prerendering is disabled. There are cases when Instant will not handle a
-  // search suggestion and in those cases it would be good to prerender the
-  // search results, however search engines have not been set up to correctly
-  // handle being prerendered and until they are we should avoid it.
-  // http://crbug.com/117495
-  if (action == ACTION_PRERENDER &&
-      (IsAutocompleteMatchSearchType(match) ||
-       !prerender::IsOmniboxEnabled(profile_))) {
-    action = ACTION_PRECONNECT;
-  }
-
-  return action;
-}
-
-// Return true if the suggestion type warrants a TCP/IP preconnection.
-// i.e., it is now quite likely that the user will select the related domain.
-// static
-bool NetworkActionPredictor::IsPreconnectable(const AutocompleteMatch& match) {
-  return IsAutocompleteMatchSearchType(match);
-}
-
-void NetworkActionPredictor::Shutdown() {
-  db_->OnPredictorDestroyed();
-}
-
-void NetworkActionPredictor::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  switch (type) {
-    case chrome::NOTIFICATION_HISTORY_URLS_DELETED: {
-      DCHECK(initialized_);
-      const content::Details<const history::URLsDeletedDetails>
-          urls_deleted_details =
-              content::Details<const history::URLsDeletedDetails>(details);
-      if (urls_deleted_details->all_history)
-        DeleteAllRows();
-      else
-        DeleteRowsWithURLs(urls_deleted_details->urls);
-      break;
-    }
-
-    // This notification does not catch all instances of the user navigating
-    // from the Omnibox, but it does catch the cases where the dropdown is open
-    // and those are the events we're most interested in.
-    case chrome::NOTIFICATION_OMNIBOX_OPENED_URL: {
-      DCHECK(initialized_);
-
-      // TODO(dominich): This doesn't need to be synchronous. Investigate
-      // posting it as a task to be run later.
-      OnOmniboxOpenedUrl(*content::Details<AutocompleteLog>(details).ptr());
-      break;
-    }
-
-    case chrome::NOTIFICATION_HISTORY_LOADED: {
-      DCHECK(!initialized_);
-      TryDeleteOldEntries(content::Details<HistoryService>(details).ptr());
-
-      notification_registrar_.Remove(this,
-                                     chrome::NOTIFICATION_HISTORY_LOADED,
-                                     content::Source<Profile>(profile_));
-      break;
-    }
-
-    default:
-      NOTREACHED() << "Unexpected notification observed.";
-      break;
-  }
-}
-
-void NetworkActionPredictor::OnOmniboxOpenedUrl(const AutocompleteLog& log) {
-  if (log.text.length() < kMinimumUserTextLength)
-    return;
-
-  const AutocompleteMatch& match = log.result.match_at(log.selected_index);
-
-  UMA_HISTOGRAM_BOOLEAN(
-      StringPrintf("Prerender.OmniboxNavigationsCouldPrerender_%.1f%s",
-                   get_hit_weight(),
-                   prerender::PrerenderManager::GetModeString()).c_str(),
-      prerender::IsOmniboxEnabled(profile_));
-
-  const GURL& opened_url = match.destination_url;
-
-  // If the Omnibox triggered a prerender but the URL doesn't match the one the
-  // user is navigating to, cancel the prerender.
-  prerender::PrerenderManager* prerender_manager =
-      prerender::PrerenderManagerFactory::GetForProfile(profile_);
-  // |prerender_manager| can be NULL in incognito mode or if prerendering is
-  // otherwise disabled.
-  if (prerender_manager && !prerender_manager->IsPrerendering(opened_url))
-    prerender_manager->CancelOmniboxPrerenders();
-
-  const string16 lower_user_text(base::i18n::ToLower(log.text));
-
-  BeginTransaction();
-  // Traverse transitional matches for those that have a user_text that is a
-  // prefix of |lower_user_text|.
-  for (std::vector<TransitionalMatch>::const_iterator it =
-       transitional_matches_.begin(); it != transitional_matches_.end();
-       ++it) {
-    if (!StartsWith(lower_user_text, it->user_text, true))
-      continue;
-
-    // Add entries to the database for those matches.
-    for (std::vector<GURL>::const_iterator url_it = it->urls.begin();
-         url_it != it->urls.end(); ++url_it) {
-      DCHECK(it->user_text.length() >= kMinimumUserTextLength);
-      const DBCacheKey key = { it->user_text, *url_it };
-      const bool is_hit = (*url_it == opened_url);
-
-      NetworkActionPredictorDatabase::Row row;
-      row.user_text = key.user_text;
-      row.url = key.url;
-
-      DBCacheMap::iterator it = db_cache_.find(key);
-      if (it == db_cache_.end()) {
-        row.id = guid::GenerateGUID();
-        row.number_of_hits = is_hit ? 1 : 0;
-        row.number_of_misses = is_hit ? 0 : 1;
-
-        AddRow(key, row);
-      } else {
-        DCHECK(db_id_cache_.find(key) != db_id_cache_.end());
-        row.id = db_id_cache_.find(key)->second;
-        row.number_of_hits = it->second.number_of_hits + (is_hit ? 1 : 0);
-        row.number_of_misses = it->second.number_of_misses + (is_hit ? 0 : 1);
-
-        UpdateRow(it, row);
-      }
-    }
-  }
-  CommitTransaction();
-
-  ClearTransitionalMatches();
-
-  // Check against tracked urls and log accuracy for the confidence we
-  // predicted.
-  for (std::vector<std::pair<GURL, double> >::const_iterator it =
-       tracked_urls_.begin(); it != tracked_urls_.end();
-       ++it) {
-    if (opened_url == it->first) {
-      UMA_HISTOGRAM_COUNTS_100("NetworkActionPredictor.AccurateCount",
-                               it->second * 100);
-    }
-  }
-  tracked_urls_.clear();
-}
-
-void NetworkActionPredictor::DeleteOldIdsFromCaches(
-    history::URLDatabase* url_db,
-    std::vector<NetworkActionPredictorDatabase::Row::Id>* id_list) {
-  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  DCHECK(url_db);
-  DCHECK(id_list);
-  id_list->clear();
-  for (DBCacheMap::iterator it = db_cache_.begin(); it != db_cache_.end();) {
-    history::URLRow url_row;
-
-    if ((url_db->GetRowForURL(it->first.url, &url_row) == 0) ||
-        ((base::Time::Now() - url_row.last_visit()).InDays() >
-         kMaximumDaysToKeepEntry)) {
-      const DBIdCacheMap::iterator id_it = db_id_cache_.find(it->first);
-      DCHECK(id_it != db_id_cache_.end());
-      id_list->push_back(id_it->second);
-      db_id_cache_.erase(id_it);
-      db_cache_.erase(it++);
-    } else {
-      ++it;
-    }
-  }
-}
-
-void NetworkActionPredictor::DeleteOldEntries(history::URLDatabase* url_db) {
-  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  DCHECK(!initialized_);
-
-  std::vector<NetworkActionPredictorDatabase::Row::Id> ids_to_delete;
-  DeleteOldIdsFromCaches(url_db, &ids_to_delete);
-
-  content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::DeleteRows, db_,
-                 ids_to_delete));
-
-  // Register for notifications and set the |initialized_| flag.
-  notification_registrar_.Add(this, chrome::NOTIFICATION_OMNIBOX_OPENED_URL,
-                              content::Source<Profile>(profile_));
-  notification_registrar_.Add(this, chrome::NOTIFICATION_HISTORY_URLS_DELETED,
-                              content::Source<Profile>(profile_));
-  initialized_ = true;
-}
-
-void NetworkActionPredictor::CreateCaches(
-    std::vector<NetworkActionPredictorDatabase::Row>* rows) {
-  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-  DCHECK(!initialized_);
-  DCHECK(db_cache_.empty());
-  DCHECK(db_id_cache_.empty());
-
-  for (std::vector<NetworkActionPredictorDatabase::Row>::const_iterator it =
-       rows->begin(); it != rows->end(); ++it) {
-    const DBCacheKey key = { it->user_text, it->url };
-    const DBCacheValue value = { it->number_of_hits, it->number_of_misses };
-    db_cache_[key] = value;
-    db_id_cache_[key] = it->id;
-  }
-
-  // If the history service is ready, delete any old or invalid entries.
-  HistoryService* history_service =
-      profile_->GetHistoryService(Profile::EXPLICIT_ACCESS);
-  if (!TryDeleteOldEntries(history_service)) {
-    // Wait for the notification that the history service is ready and the URL
-    // DB is loaded.
-    notification_registrar_.Add(this, chrome::NOTIFICATION_HISTORY_LOADED,
-                                content::Source<Profile>(profile_));
-  }
-}
-
-bool NetworkActionPredictor::TryDeleteOldEntries(HistoryService* service) {
-  if (!service)
-    return false;
-
-  history::URLDatabase* url_db = service->InMemoryDatabase();
-  if (!url_db)
-    return false;
-
-  DeleteOldEntries(url_db);
-  return true;
-}
-
-double NetworkActionPredictor::CalculateConfidence(
-    const string16& user_text,
-    const AutocompleteMatch& match,
-    bool* is_in_db) const {
-  const DBCacheKey key = { user_text, match.destination_url };
-
-  *is_in_db = false;
-  if (user_text.length() < kMinimumUserTextLength)
-    return 0.0;
-
-  const DBCacheMap::const_iterator iter = db_cache_.find(key);
-  if (iter == db_cache_.end())
-    return 0.0;
-
-  *is_in_db = true;
-  return CalculateConfidenceForDbEntry(iter);
-}
-
-double NetworkActionPredictor::CalculateConfidenceForDbEntry(
-    DBCacheMap::const_iterator iter) const {
-  const DBCacheValue& value = iter->second;
-  if (value.number_of_hits < kMinimumNumberOfHits)
-    return 0.0;
-
-  const double number_of_hits = value.number_of_hits * hit_weight_;
-  return number_of_hits / (number_of_hits + value.number_of_misses);
-}
-
-void NetworkActionPredictor::AddRow(
-    const DBCacheKey& key,
-    const NetworkActionPredictorDatabase::Row& row) {
-  if (!initialized_)
-    return;
-
-  DBCacheValue value = { row.number_of_hits, row.number_of_misses };
-  db_cache_[key] = value;
-  db_id_cache_[key] = row.id;
-  content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::AddRow, db_, row));
-
-  UMA_HISTOGRAM_ENUMERATION("NetworkActionPredictor.DatabaseAction",
-                            DATABASE_ACTION_ADD, DATABASE_ACTION_COUNT);
-}
-
-void NetworkActionPredictor::UpdateRow(
-    DBCacheMap::iterator it,
-    const NetworkActionPredictorDatabase::Row& row) {
-  if (!initialized_)
-    return;
-
-  DCHECK(it != db_cache_.end());
-  it->second.number_of_hits = row.number_of_hits;
-  it->second.number_of_misses = row.number_of_misses;
-  content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::UpdateRow, db_, row));
-  UMA_HISTOGRAM_ENUMERATION("NetworkActionPredictor.DatabaseAction",
-                            DATABASE_ACTION_UPDATE, DATABASE_ACTION_COUNT);
-}
-
-void NetworkActionPredictor::DeleteAllRows() {
-  if (!initialized_)
-    return;
-
-  db_cache_.clear();
-  db_id_cache_.clear();
-  content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::DeleteAllRows, db_));
-  UMA_HISTOGRAM_ENUMERATION("NetworkActionPredictor.DatabaseAction",
-                            DATABASE_ACTION_DELETE_ALL, DATABASE_ACTION_COUNT);
-}
-
-void NetworkActionPredictor::DeleteRowsWithURLs(const std::set<GURL>& urls) {
-  if (!initialized_)
-    return;
-
-  std::vector<NetworkActionPredictorDatabase::Row::Id> id_list;
-
-  for (DBCacheMap::iterator it = db_cache_.begin(); it != db_cache_.end();) {
-    if (urls.find(it->first.url) != urls.end()) {
-      const DBIdCacheMap::iterator id_it = db_id_cache_.find(it->first);
-      DCHECK(id_it != db_id_cache_.end());
-      id_list.push_back(id_it->second);
-      db_id_cache_.erase(id_it);
-      db_cache_.erase(it++);
-    } else {
-      ++it;
-    }
-  }
-
-  content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::DeleteRows, db_, id_list));
-  UMA_HISTOGRAM_ENUMERATION("NetworkActionPredictor.DatabaseAction",
-                            DATABASE_ACTION_DELETE_SOME, DATABASE_ACTION_COUNT);
-}
-
-void NetworkActionPredictor::BeginTransaction() {
-  if (!initialized_)
-    return;
-
-  content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::BeginTransaction, db_));
-}
-
-void NetworkActionPredictor::CommitTransaction() {
-  if (!initialized_)
-    return;
-
-  content::BrowserThread::PostTask(content::BrowserThread::DB, FROM_HERE,
-      base::Bind(&NetworkActionPredictorDatabase::CommitTransaction, db_));
-}
-
-NetworkActionPredictor::TransitionalMatch::TransitionalMatch() {
-}
-
-NetworkActionPredictor::TransitionalMatch::~TransitionalMatch() {
-}