|  | // Copyright (c) 2011 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/prerender/prerender_history.h" | 
|  |  | 
|  | #include <memory> | 
|  | #include <utility> | 
|  |  | 
|  | #include "base/logging.h" | 
|  | #include "base/strings/string_number_conversions.h" | 
|  | #include "base/values.h" | 
|  |  | 
|  | namespace prerender { | 
|  |  | 
|  | PrerenderHistory::PrerenderHistory(size_t max_items) | 
|  | : max_items_(max_items) { | 
|  | DCHECK(max_items > 0); | 
|  | } | 
|  |  | 
|  | PrerenderHistory::~PrerenderHistory() { | 
|  | DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); | 
|  | } | 
|  |  | 
|  | void PrerenderHistory::AddEntry(const Entry& entry) { | 
|  | DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_); | 
|  | while (entries_.size() >= max_items_) | 
|  | entries_.pop_front(); | 
|  | entries_.push_back(entry); | 
|  | } | 
|  |  | 
|  | void PrerenderHistory::Clear() { | 
|  | entries_.clear(); | 
|  | } | 
|  |  | 
|  | std::unique_ptr<base::Value> PrerenderHistory::CopyEntriesAsValue() const { | 
|  | auto return_list = std::make_unique<base::ListValue>(); | 
|  | // Javascript needs times in terms of milliseconds since Jan 1, 1970. | 
|  | base::Time epoch_start = base::Time::UnixEpoch(); | 
|  | for (auto it = entries_.rbegin(); it != entries_.rend(); ++it) { | 
|  | const Entry& entry = *it; | 
|  | auto entry_dict = std::make_unique<base::DictionaryValue>(); | 
|  | entry_dict->SetString("url", entry.url.spec()); | 
|  | entry_dict->SetString("final_status", | 
|  | NameFromFinalStatus(entry.final_status)); | 
|  | entry_dict->SetString("origin", NameFromOrigin(entry.origin)); | 
|  | // Use a string to prevent overflow, as Values don't support 64-bit | 
|  | // integers. | 
|  | entry_dict->SetString( | 
|  | "end_time", | 
|  | base::Int64ToString((entry.end_time - epoch_start).InMilliseconds())); | 
|  | return_list->Append(std::move(entry_dict)); | 
|  | } | 
|  | return std::move(return_list); | 
|  | } | 
|  |  | 
|  | }  // namespace prerender |