Implementation of ProxyResolver that uses a Mojo service.

net/proxy/proxy_resolver_mojo.cc

+// Copyright 2015 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 "net/proxy/proxy_resolver_mojo.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/stl_util.h"
+#include "mojo/common/common_type_converters.h"
+#include "net/base/net_errors.h"
+#include "net/dns/mojo_host_resolver_impl.h"
+#include "net/proxy/mojo_proxy_resolver_factory.h"
+#include "net/proxy/mojo_proxy_type_converters.h"
+#include "net/proxy/proxy_info.h"
+#include "third_party/mojo/src/mojo/public/cpp/bindings/binding.h"
+#include "third_party/mojo/src/mojo/public/cpp/bindings/error_handler.h"
+
+namespace net {
+
+class ProxyResolverMojo::Job : public interfaces::ProxyResolverRequestClient,
+                               public mojo::ErrorHandler {
+ public:
+  Job(ProxyResolverMojo* resolver,
+      const GURL& url,
+      ProxyInfo* results,
+      const net::CompletionCallback& callback);
+  ~Job() override;
+
+  // Cancels the job and prevents the callback from being run.
+  void Cancel();
+
+ private:
+  // Overridden from mojo::ErrorHandler:
+  void OnConnectionError() override;
+
+  // Overridden from interfaces::ProxyResolverRequestClient:
+  void ReportResult(
+      int32_t error,
+      mojo::Array<interfaces::ProxyServerPtr> proxy_servers) override;
+
+  ProxyResolverMojo* resolver_;
+  const GURL url_;
+  ProxyInfo* results_;
+  net::CompletionCallback callback_;
+
+  base::ThreadChecker thread_checker_;
+  mojo::Binding<interfaces::ProxyResolverRequestClient> binding_;
+};
+
+ProxyResolverMojo::Job::Job(ProxyResolverMojo* resolver,
+                            const GURL& url,
+                            ProxyInfo* results,
+                            const net::CompletionCallback& callback)
+    : resolver_(resolver),
+      url_(url),
+      results_(results),
+      callback_(callback),
+      binding_(this) {
+  binding_.set_error_handler(this);
+
+  interfaces::ProxyResolverRequestClientPtr client_ptr;
+  binding_.Bind(mojo::GetProxy(&client_ptr));
+  resolver_->mojo_proxy_resolver_ptr_->GetProxyForUrl(mojo::String::From(url_),
+                                                      client_ptr.Pass());
+}
+
+ProxyResolverMojo::Job::~Job() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (!callback_.is_null())
+    callback_.Run(ERR_PAC_SCRIPT_TERMINATED);
+}
+
+void ProxyResolverMojo::Job::Cancel() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!callback_.is_null());
+  callback_.Reset();
+}
+
+void ProxyResolverMojo::Job::OnConnectionError() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DVLOG(1) << "ProxyResolverMojo::Job::OnConnectionError";
+  ReportResult(ERR_PAC_SCRIPT_FAILED,

[Sam McNally, 2015/03/02 02:43:05]

Why report ERR_PAC_SCRIPT_FAILED here? Shouldn't this only be reached if the
utility process crashes and this connection is detected as disconnected first?

[Anand Mistry (off Chromium), 2015/03/02 06:44:00]

Honestly, I've flip-flopped between the two and can't really decide. You're
right, this should only happen if the utility process crashes, taking down the
reply channel. On the other hand, this is only one request and relies on
particular semantic whereas the main service channel is for the entire service
and in no uncertain terms represents a disconnection from the Mojo service (and
hence process crash).

I've changed this back to TERMINATED since I have no strong opinion either way.

+               mojo::Array<interfaces::ProxyServerPtr>());
+}
+
+void ProxyResolverMojo::Job::ReportResult(
+    int32_t error,
+    mojo::Array<interfaces::ProxyServerPtr> proxy_servers) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DVLOG(1) << "ProxyResolverMojo::Job::ReportResult: " << error;
+
+  if (error == OK) {
+    *results_ = proxy_servers.To<ProxyInfo>();
+    DVLOG(1) << "Servers: " << results_->ToPacString();
+  }
+
+  callback_.Run(error);
+  callback_.Reset();
+  resolver_->RemoveJob(this);
+}
+
+ProxyResolverMojo::ProxyResolverMojo(
+    MojoProxyResolverFactory* mojo_proxy_resolver_factory,
+    HostResolver* host_resolver)
+    : ProxyResolver(true /* |expects_pac_bytes| */),
+      mojo_proxy_resolver_factory_(mojo_proxy_resolver_factory),
+      host_resolver_(host_resolver) {
+}
+
+ProxyResolverMojo::~ProxyResolverMojo() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // All pending requests should have been cancelled.
+  DCHECK(pending_jobs_.empty());
+  DCHECK(set_pac_script_callback_.IsCancelled());
+}
+
+void ProxyResolverMojo::CancelSetPacScript() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  set_pac_script_callback_.Cancel();
+}
+
+int ProxyResolverMojo::SetPacScript(
+    const scoped_refptr<ProxyResolverScriptData>& pac_script,
+    const net::CompletionCallback& callback) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(set_pac_script_callback_.IsCancelled());
+  DCHECK(!callback.is_null());
+  if (pac_script->type() != ProxyResolverScriptData::TYPE_SCRIPT_CONTENTS ||
+      pac_script->utf16().empty()) {
+    return ERR_PAC_SCRIPT_FAILED;
+  }
+
+  DVLOG(1) << "ProxyResolverMojo::SetPacScript: " << pac_script->utf16();
+  set_pac_script_callback_.Reset(
+      base::Bind(&ProxyResolverMojo::OnSetPacScriptDone, base::Unretained(this),
+                 pac_script, callback));
+
+  if (!mojo_proxy_resolver_ptr_)
+    SetUpServices();
+
+  mojo_proxy_resolver_ptr_->SetPacScript(
+      mojo::String::From(pac_script->utf16()),
+      set_pac_script_callback_.callback());
+
+  return ERR_IO_PENDING;
+}
+
+void ProxyResolverMojo::OnSetPacScriptDone(
+    const scoped_refptr<ProxyResolverScriptData>& pac_script,
+    const net::CompletionCallback& callback,
+    int32_t result) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(!set_pac_script_callback_.IsCancelled());
+  DVLOG(1) << "ProxyResolverMojo::OnSetPacScriptDone: " << result;
+
+  callback.Run(result);
+  set_pac_script_callback_.Cancel();
+}
+
+void ProxyResolverMojo::SetUpServices() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // A Mojo service implementation must outlive its binding.
+  mojo_host_resolver_binding_.reset();
+
+  interfaces::HostResolverPtr mojo_host_resolver_ptr;
+  mojo_host_resolver_.reset(new MojoHostResolverImpl(host_resolver_));
+  mojo_host_resolver_binding_.reset(new mojo::Binding<interfaces::HostResolver>(
+      mojo_host_resolver_.get(), mojo::GetProxy(&mojo_host_resolver_ptr)));
+  mojo_proxy_resolver_ptr_.reset();
+  mojo_proxy_resolver_factory_->Create(
+      mojo::GetProxy(&mojo_proxy_resolver_ptr_), mojo_host_resolver_ptr.Pass());
+  mojo_proxy_resolver_ptr_.set_error_handler(this);
+}
+
+void ProxyResolverMojo::CancelPendingRequests() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (!set_pac_script_callback_.IsCancelled()) {
+    set_pac_script_callback_.callback().Run(ERR_PAC_SCRIPT_TERMINATED);
+    set_pac_script_callback_.Cancel();
+  }
+
+  // Need to use this loop because deleting a Job will cause its callback to be
+  // run with a failure error code, which may cause other Jobs to be deleted.
+  while (!pending_jobs_.empty()) {
+    auto it = pending_jobs_.begin();
+    Job* job = *it;
+    pending_jobs_.erase(it);
+
+    delete job;
+  }
+}
+
+void ProxyResolverMojo::OnConnectionError() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DVLOG(1) << "ProxyResolverMojo::OnConnectionError";
+  CancelPendingRequests();
+
+  // Disconnect from the Mojo proxy resolver service. An attempt to reconnect
+  // will happen on the next request.

[Sam McNally, 2015/03/02 02:43:05]

next SetPacScript request.

[Anand Mistry (off Chromium), 2015/03/02 06:44:00]

Done.

+  mojo_proxy_resolver_ptr_.reset();
+}
+
+void ProxyResolverMojo::RemoveJob(Job* job) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  size_t num_erased = pending_jobs_.erase(job);
+  DCHECK(num_erased);
+  delete job;
+}
+
+int ProxyResolverMojo::GetProxyForURL(const GURL& url,
+                                      ProxyInfo* results,
+                                      const net::CompletionCallback& callback,
+                                      RequestHandle* request,
+                                      const BoundNetLog& net_log) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  // If the Mojo service is not connected, fail. The Mojo service is connected
+  // when the script is set, which must be done after construction and after a
+  // previous request returns ERR_PAC_SCRIPT_TERMINATED due to the Mojo process

[Sam McNally, 2015/03/02 02:43:05]

How about "proxy resolver process"?

[Anand Mistry (off Chromium), 2015/03/02 06:44:00]

Done.

+  // crashing.
+  if (!mojo_proxy_resolver_ptr_) {
+    DVLOG(1) << "ProxyResolverMojo::GetProxyForURL: Mojo not connected";
+    return ERR_PAC_SCRIPT_TERMINATED;
+  }
+
+  Job* job = new Job(this, url, results, callback);
+  bool inserted = pending_jobs_.insert(job).second;
+  DCHECK(inserted);
+  *request = job;
+
+  return ERR_IO_PENDING;
+}
+
+void ProxyResolverMojo::CancelRequest(RequestHandle request) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  Job* job = static_cast<Job*>(request);
+  DCHECK(job);
+  job->Cancel();
+  RemoveJob(job);
+}
+
+LoadState ProxyResolverMojo::GetLoadState(RequestHandle request) const {
+  // TODO(amistry): Implement real LoadState.
+  return LOAD_STATE_RESOLVING_PROXY_FOR_URL;
+}
+
+}  // namespace net