Dynamically refresh pref-configured proxies.

chrome/browser/net/pref_proxy_config_service.cc

+// Copyright (c) 2010 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/net/pref_proxy_config_service.h"
+
+#include "chrome/browser/browser_thread.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/prefs/pref_set_observer.h"
+#include "chrome/common/notification_details.h"
+#include "chrome/common/notification_source.h"
+#include "chrome/common/notification_type.h"
+#include "chrome/common/pref_names.h"
+
+PrefProxyConfigTracker::PrefProxyConfigTracker(PrefService* pref_service)
+    : pref_service_(pref_service) {
+  valid_ = ReadPrefConfig(&pref_config_);
+  proxy_prefs_observer_.reset(
+      PrefSetObserver::CreateProxyPrefSetObserver(pref_service_, this));
+}
+
+PrefProxyConfigTracker::~PrefProxyConfigTracker() {
+  DCHECK(pref_service_ == NULL);
+}
+
+bool PrefProxyConfigTracker::GetProxyConfig(net::ProxyConfig* config) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (valid_)
+    *config = pref_config_;
+  return valid_;
+}
+
+void PrefProxyConfigTracker::DetachFromPrefService() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  // Stop notifications.
+  proxy_prefs_observer_.reset();
+  pref_service_ = NULL;
+}
+
+void PrefProxyConfigTracker::AddObserver(
+    PrefProxyConfigTracker::ObserverInterface* observer) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  observers_.AddObserver(observer);
+}
+
+void PrefProxyConfigTracker::RemoveObserver(
+    PrefProxyConfigTracker::ObserverInterface* observer) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  observers_.RemoveObserver(observer);
+}
+
+void PrefProxyConfigTracker::Observe(NotificationType type,
+                                     const NotificationSource& source,
+                                     const NotificationDetails& details) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (type == NotificationType::PREF_CHANGED &&
+      Source<PrefService>(source).ptr() == pref_service_) {
+    net::ProxyConfig new_config;
+    bool valid = ReadPrefConfig(&new_config);
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        NewRunnableMethod(this,
+                          &PrefProxyConfigTracker::InstallProxyConfig,
+                          new_config, valid));
+  } else {
+    NOTREACHED() << "Unexpected notification of type " << type.value;
+  }
+}
+
+void PrefProxyConfigTracker::InstallProxyConfig(const net::ProxyConfig& config,
+                                                bool valid) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (valid_ != valid || !pref_config_.Equals(config)) {

[eroman, 2010/11/30 02:58:54]

This is a little weird in the case where (!valid_ && !valid). 

It probably doesn't make sense to compare pref_config_ to config in this case
(since by definition it "isn't valid").

It looks like it is still correct because config is reset to net::ProxyConfig()
by ReadPrefConfig in this case, but that isn't immediately obvious.

[battre (please use the other), 2010/12/02 18:06:12]

Done.

+    valid_ = valid;
+    if (valid_)
+      pref_config_ = config;
+    FOR_EACH_OBSERVER(ObserverInterface, observers_,
+                      OnPrefProxyConfigChanged());
+  }
+}
+
+bool PrefProxyConfigTracker::ReadPrefConfig(net::ProxyConfig* config) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+
+  // Clear the configuration.
+  *config = net::ProxyConfig();
+
+  // Scan for all "enable" type proxy switches.
+  static const char* proxy_prefs[] = {
+    prefs::kProxyPacUrl,
+    prefs::kProxyServer,
+    prefs::kProxyBypassList,
+    prefs::kProxyAutoDetect
+  };
+
+  // Check whether the preference system holds a valid proxy configuration. Note
+  // that preferences coming from a lower-priority source than the user settings
+  // are ignored. That's because chrome treats the system settings as the
+  // default values, which should apply if there's no explicit value forced by
+  // policy or the user.
+  bool found_enable_proxy_pref = false;
+  for (size_t i = 0; i < arraysize(proxy_prefs); i++) {
+    const PrefService::Preference* pref =
+        pref_service_->FindPreference(proxy_prefs[i]);
+    DCHECK(pref);
+    if (pref && (!pref->IsUserModifiable() || pref->HasUserSetting())) {
+      found_enable_proxy_pref = true;
+      break;
+    }
+  }
+
+  if (!found_enable_proxy_pref &&
+      !pref_service_->GetBoolean(prefs::kNoProxyServer)) {
+    return false;
+  }
+
+  if (pref_service_->GetBoolean(prefs::kNoProxyServer)) {
+    // Ignore all the other proxy config preferences if the use of a proxy
+    // has been explicitly disabled.
+    return true;
+  }
+
+  if (pref_service_->HasPrefPath(prefs::kProxyServer)) {
+    std::string proxy_server = pref_service_->GetString(prefs::kProxyServer);
+    config->proxy_rules().ParseFromString(proxy_server);
+  }
+
+  if (pref_service_->HasPrefPath(prefs::kProxyPacUrl)) {
+    std::string proxy_pac = pref_service_->GetString(prefs::kProxyPacUrl);
+    config->set_pac_url(GURL(proxy_pac));
+  }
+
+  config->set_auto_detect(pref_service_->GetBoolean(prefs::kProxyAutoDetect));
+
+  if (pref_service_->HasPrefPath(prefs::kProxyBypassList)) {
+    std::string proxy_bypass =
+        pref_service_->GetString(prefs::kProxyBypassList);
+    config->proxy_rules().bypass_rules.ParseFromString(proxy_bypass);
+  }
+
+  return true;
+}
+
+PrefProxyConfigService::PrefProxyConfigService(
+    PrefProxyConfigTracker* tracker,
+    net::ProxyConfigService* base_service)
+    : base_service_(base_service),
+      pref_config_tracker_(tracker),
+      registered_observers_(false) {
+}
+
+PrefProxyConfigService::~PrefProxyConfigService() {
+  if (registered_observers_) {
+    base_service_->RemoveObserver(this);
+    pref_config_tracker_->RemoveObserver(this);
+  }
+}
+
+void PrefProxyConfigService::AddObserver(
+    net::ProxyConfigService::Observer* observer) {
+  RegisterObservers();
+  observers_.AddObserver(observer);
+}
+
+void PrefProxyConfigService::RemoveObserver(
+    net::ProxyConfigService::Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+bool PrefProxyConfigService::GetLatestProxyConfig(net::ProxyConfig* config) {
+  RegisterObservers();
+  const net::ProxyConfig pref_config;
+  if (pref_config_tracker_->GetProxyConfig(config))
+    return true;
+
+  return base_service_->GetLatestProxyConfig(config);
+}
+
+void PrefProxyConfigService::OnLazyPoll() {
+  base_service_->OnLazyPoll();
+}
+
+void PrefProxyConfigService::OnProxyConfigChanged(
+    const net::ProxyConfig& config) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  // Check whether there is a proxy configuration defined by preferences. In
+  // this case that proxy configuration takes precedence and the change event
+  // from the delegate proxy service can be disregarded.
+  net::ProxyConfig pref_config;
+  if (!pref_config_tracker_->GetProxyConfig(&pref_config)) {
+    FOR_EACH_OBSERVER(net::ProxyConfigService::Observer, observers_,
+                      OnProxyConfigChanged(config));
+  }
+}
+
+void PrefProxyConfigService::OnPrefProxyConfigChanged() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  // Evaluate the proxy configuration. If GetLatestProxyConfig returns false,
+  // we are using the system proxy service, but it doesn't have a valid
+  // configuration yet. Once it is ready, OnProxyConfigChanged() will be called
+  // and broadcast the proxy configuration.
+  // Note: If a switch between a preference proxy configuration and the system
+  // proxy configuration occurs an unnecessary notification might get send if
+  // the two configurations agree. This case should be rare however, so we don't
+  // handle that case specially.
+  net::ProxyConfig new_config;
+  if (GetLatestProxyConfig(&new_config)) {
+    FOR_EACH_OBSERVER(net::ProxyConfigService::Observer, observers_,
+                      OnProxyConfigChanged(new_config));
+  }
+}
+
+void PrefProxyConfigService::RegisterObservers() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (!registered_observers_) {
+    base_service_->AddObserver(this);
+    pref_config_tracker_->AddObserver(this);
+    registered_observers_ = true;
+  }
+}