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// Copyright 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 "components/web_resource/web_resource_service.h"
#include "base/bind.h"
#include "base/location.h"
#include "base/memory/ptr_util.h"
#include "base/single_thread_task_runner.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/time/time.h"
#include "base/values.h"
#include "components/google/core/browser/google_util.h"
#include "components/prefs/pref_service.h"
#include "net/base/load_flags.h"
#include "net/url_request/url_fetcher.h"
#include "net/url_request/url_request_context_getter.h"
#include "net/url_request/url_request_status.h"
#include "url/gurl.h"
// No anonymous namespace, because const variables automatically get internal
// linkage.
const char kInvalidDataTypeError[] =
"Data from web resource server is missing or not valid JSON.";
const char kUnexpectedJSONFormatError[] =
"Data from web resource server does not have expected format.";
namespace web_resource {
WebResourceService::WebResourceService(
PrefService* prefs,
const GURL& web_resource_server,
const std::string& application_locale,
const char* last_update_time_pref_name,
int start_fetch_delay_ms,
int cache_update_delay_ms,
net::URLRequestContextGetter* request_context,
const char* disable_network_switch,
const ParseJSONCallback& parse_json_callback)
: prefs_(prefs),
resource_request_allowed_notifier_(prefs, disable_network_switch),
in_fetch_(false),
web_resource_server_(web_resource_server),
application_locale_(application_locale),
last_update_time_pref_name_(last_update_time_pref_name),
start_fetch_delay_ms_(start_fetch_delay_ms),
cache_update_delay_ms_(cache_update_delay_ms),
request_context_(request_context),
parse_json_callback_(parse_json_callback),
weak_ptr_factory_(this) {
resource_request_allowed_notifier_.Init(this);
DCHECK(prefs);
}
void WebResourceService::StartAfterDelay() {
// If resource requests are not allowed, we'll get a callback when they are.
if (resource_request_allowed_notifier_.ResourceRequestsAllowed())
OnResourceRequestsAllowed();
}
WebResourceService::~WebResourceService() {
}
void WebResourceService::OnURLFetchComplete(const net::URLFetcher* source) {
// Delete the URLFetcher when this function exits.
std::unique_ptr<net::URLFetcher> clean_up_fetcher(url_fetcher_.release());
if (source->GetStatus().is_success() && source->GetResponseCode() == 200) {
std::string data;
source->GetResponseAsString(&data);
// Calls EndFetch() on completion.
// Full JSON parsing might spawn a utility process (for security).
// To limit the the number of simultaneously active processes
// (on Android in particular) we short-cut the full parsing in the case of
// trivially "empty" JSONs.
if (data.empty() || data == "{}") {
OnUnpackFinished(base::MakeUnique<base::DictionaryValue>());
} else {
parse_json_callback_.Run(data,
base::Bind(&WebResourceService::OnUnpackFinished,
weak_ptr_factory_.GetWeakPtr()),
base::Bind(&WebResourceService::OnUnpackError,
weak_ptr_factory_.GetWeakPtr()));
}
} else {
// Don't parse data if attempt to download was unsuccessful.
// Stop loading new web resource data, and silently exit.
// We do not call parse_json_callback_, so we need to call EndFetch()
// ourselves.
EndFetch();
}
}
// Delay initial load of resource data into cache so as not to interfere
// with startup time.
void WebResourceService::ScheduleFetch(int64_t delay_ms) {
base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
FROM_HERE, base::Bind(&WebResourceService::StartFetch,
weak_ptr_factory_.GetWeakPtr()),
base::TimeDelta::FromMilliseconds(delay_ms));
}
// Initializes the fetching of data from the resource server. Data
// load calls OnURLFetchComplete.
void WebResourceService::StartFetch() {
// First, put our next cache load on the MessageLoop.
ScheduleFetch(cache_update_delay_ms_);
// Set cache update time in preferences.
prefs_->SetString(last_update_time_pref_name_,
base::DoubleToString(base::Time::Now().ToDoubleT()));
// If we are still fetching data, exit.
if (in_fetch_)
return;
in_fetch_ = true;
GURL web_resource_server =
application_locale_.empty()
? web_resource_server_
: google_util::AppendGoogleLocaleParam(web_resource_server_,
application_locale_);
DVLOG(1) << "WebResourceService StartFetch " << web_resource_server;
url_fetcher_ =
net::URLFetcher::Create(web_resource_server, net::URLFetcher::GET, this);
// Do not let url fetcher affect existing state in system context
// (by setting cookies, for example).
url_fetcher_->SetLoadFlags(net::LOAD_DISABLE_CACHE |
net::LOAD_DO_NOT_SEND_COOKIES |
net::LOAD_DO_NOT_SAVE_COOKIES);
url_fetcher_->SetRequestContext(request_context_.get());
url_fetcher_->Start();
}
void WebResourceService::EndFetch() {
in_fetch_ = false;
}
void WebResourceService::OnUnpackFinished(std::unique_ptr<base::Value> value) {
if (!value) {
// Page information not properly read, or corrupted.
OnUnpackError(kInvalidDataTypeError);
return;
}
const base::DictionaryValue* dict = nullptr;
if (!value->GetAsDictionary(&dict)) {
OnUnpackError(kUnexpectedJSONFormatError);
return;
}
Unpack(*dict);
EndFetch();
}
void WebResourceService::OnUnpackError(const std::string& error_message) {
LOG(ERROR) << error_message;
EndFetch();
}
void WebResourceService::OnResourceRequestsAllowed() {
int64_t delay = start_fetch_delay_ms_;
// Check whether we have ever put a value in the web resource cache;
// if so, pull it out and see if it's time to update again.
if (prefs_->HasPrefPath(last_update_time_pref_name_)) {
std::string last_update_pref =
prefs_->GetString(last_update_time_pref_name_);
if (!last_update_pref.empty()) {
double last_update_value;
base::StringToDouble(last_update_pref, &last_update_value);
int64_t ms_until_update =
cache_update_delay_ms_ -
static_cast<int64_t>(
(base::Time::Now() - base::Time::FromDoubleT(last_update_value))
.InMilliseconds());
// Wait at least |start_fetch_delay_ms_|.
if (ms_until_update > start_fetch_delay_ms_)
delay = ms_until_update;
}
}
// Start fetch and wait for UpdateResourceCache.
ScheduleFetch(delay);
}
} // namespace web_resource
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