app_list: Search result launch history and boost.

chrome/browser/ui/app_list/search/history_data.cc

+// Copyright 2013 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/ui/app_list/search/history_data.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "base/bind.h"
+#include "chrome/browser/ui/app_list/search/history_data_observer.h"
+#include "chrome/browser/ui/app_list/search/history_data_store.h"
+
+namespace app_list {
+
+namespace {
+
+// A struct used to sort query entries by time.
+struct EntrySortData {
+  EntrySortData() : query(NULL), update_time(NULL) {}
+  EntrySortData(const std::string* query,
+                const base::Time* update_time)
+      : query(query),
+        update_time(update_time) {
+  }
+
+  const std::string* query;
+  const base::Time* update_time;
+};
+
+bool EntrySortByTimeAscending(const EntrySortData& entry1,
+                              const EntrySortData& entry2) {
+  return *entry1.update_time < *entry2.update_time;
+}
+
+}  // namespace
+
+HistoryData::Data::Data() {}
+HistoryData::Data::~Data() {}
+
+HistoryData::HistoryData(HistoryDataStore* store,
+                         size_t max_primary,
+                         size_t max_secondary)
+    : store_(store),
+      max_primary_(max_primary),
+      max_secondary_(max_secondary) {
+  store_->Load(base::Bind(&HistoryData::OnStoreLoaded, AsWeakPtr()));
+}
+
+HistoryData::~HistoryData() {}
+
+void HistoryData::Add(const std::string& query, const std::string& result_id) {
+  Associations::iterator assoc_it = associations_.find(query);
+
+  // Creates a primary association if query is seen for the first time.
+  if (assoc_it == associations_.end()) {
+    Data& data = associations_[query];
+    data.primary = result_id;
+    data.update_time = base::Time::Now();
+
+    store_->SetPrimary(query, result_id);
+    store_->SetUpdateTime(query, data.update_time);
+
+    TrimEntries();
+    return;
+  }
+
+  Data& data = assoc_it->second;
+  data.update_time = base::Time::Now();
+  store_->SetUpdateTime(query, data.update_time);
+
+  SecondaryDeque& secondary = data.secondary;
+  if (!secondary.empty() && secondary.back() == result_id) {
+    // Nothing to do if the last secondary is the current primary.
+    if (data.primary == result_id)
+      return;
+
+    // If |result_id| is the last (the most recent) secondary and it's not the
+    // current primary, promote it and demote the primary.
+    secondary.pop_back();
+    secondary.push_back(data.primary);
+    data.primary = result_id;
+
+    store_->SetPrimary(query, result_id);
+    store_->SetSecondary(query, secondary);
+    return;
+  }
+
+  // Otherwise, append to secondary list.
+  SecondaryDeque::iterator secondary_it =
+      std::find(secondary.begin(), secondary.end(), result_id);
+  if (secondary_it != secondary.end())
+    secondary.erase(secondary_it);
+
+  secondary.push_back(result_id);
+  if (secondary.size() > max_secondary_)
+    secondary.pop_front();
+  store_->SetSecondary(query, secondary);
+}
+
+scoped_ptr<KnownResults> HistoryData::GetKnownResults(
+    const std::string& query) const {
+  scoped_ptr<KnownResults> results(new KnownResults);
+  for (Associations::const_iterator assoc_it =
+           associations_.lower_bound(query);
+       assoc_it != associations_.end();
+       ++assoc_it) {
+    // Break out of the loop if |query| is no longer a prefix.
+    if (assoc_it->first.size() < query.size() ||
+        strncmp(assoc_it->first.c_str(),
+                query.c_str(),
+                query.length()) != 0) {
+      break;
+    }
+
+    const bool perfect = assoc_it->first == query;
+    // Primary match should always be returned.
+    (*results)[assoc_it->second.primary] =
+        perfect ? PERFECT_PRIMARY : PREFIX_PRIMARY;
+
+    const KnownResultType secondary_type =
+        perfect ? PERFECT_SECONDARY : PREFIX_SECONDARY;
+    const HistoryData::SecondaryDeque& secondary = assoc_it->second.secondary;
+    for (HistoryData::SecondaryDeque::const_iterator secondary_it =
+             secondary.begin();
+         secondary_it != secondary.end();
+         ++secondary_it) {
+      const std::string& secondary_result_id = (*secondary_it);
+
+      // Secondary match only gets added if there there is no primary match.
+      if (results->find(secondary_result_id) != results->end())
+        continue;
+      (*results)[secondary_result_id] = secondary_type;
+    }
+  }
+
+  return results.Pass();
+}
+
+void HistoryData::AddObserver(HistoryDataObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void HistoryData::RemoveObserver(HistoryDataObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void HistoryData::OnStoreLoaded(scoped_ptr<Associations> loaded_data) {
+  if (loaded_data)
+    loaded_data->swap(associations_);
+
+  FOR_EACH_OBSERVER(HistoryDataObserver, observers_,
+                    OnHistoryDataLoadedFromStore());
+}
+
+void HistoryData::TrimEntries() {
+  if (associations_.size() <= max_primary_)
+    return;
+
+  std::vector<EntrySortData> entries;
+  for (Associations::const_iterator it = associations_.begin();
+       it != associations_.end(); ++it) {
+    entries.push_back(EntrySortData(&it->first, &it->second.update_time));
+  }
+
+  const size_t entries_to_remove = associations_.size() - max_primary_;
+  std::partial_sort(entries.begin(),
+                    entries.begin() + entries_to_remove,
+                    entries.end(),
+                    &EntrySortByTimeAscending);
+
+  for (size_t i = 0; i < entries_to_remove; ++i) {
+    const std::string& query = *entries[i].query;
+    store_->Delete(query);
+    associations_.erase(query);
+  }
+}
+
+}  // namespace app_list