Implement utility-side proxy resolver Mojo service.

net/proxy/mojo_proxy_resolver_impl.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/mojo_proxy_resolver_impl.h"
+
+#include "base/stl_util.h"
+#include "mojo/common/common_type_converters.h"
+#include "net/base/net_errors.h"
+#include "net/base/net_log.h"
+#include "net/proxy/mojo_type_converters.h"
+#include "net/proxy/proxy_info.h"
+#include "net/proxy/proxy_resolver.h"
+#include "net/proxy/proxy_resolver_script_data.h"
+
+namespace net {
+
+class MojoProxyResolverImpl::Job : public mojo::ErrorHandler {
+ public:
+  Job(interfaces::ProxyResolverRequestClientPtr client,
+      MojoProxyResolverImpl* resolver,
+      const GURL& url);
+  ~Job() override;
+
+  void Start();
+
+ private:
+  // mojo::ErrorHandler override.
+  void OnConnectionError() override;

[eroman, 2015/02/12 19:00:42]

Is this also how requests are cancelled from the browser side? (seen as a
connection error by utility side)

[Sam McNally, 2015/02/13 00:03:19]

Yes. Added a comment to make it more obvious.

+
+  void GetProxyDone(int32_t error);

[eroman, 2015/02/12 19:00:41]

Same comment as on Anand's CL:
  In the network stack network errors are "int", so code interfacing it should
be specifying "int" and not "int32".

In practice int32 == int for Chrome builds, however let's try to match the net
signatures. (Even better net should have a typedef for NetError, but that is a
separate issue).

[Sam McNally, 2015/02/13 00:03:19]

Done.

+
+  MojoProxyResolverImpl* resolver_;
+
+  interfaces::ProxyResolverRequestClientPtr client_;
+  ProxyInfo result_;
+  GURL url_;
+  net::ProxyResolver::RequestHandle request_handle_;
+
+  DISALLOW_COPY_AND_ASSIGN(Job);
+};
+
+MojoProxyResolverImpl::MojoProxyResolverImpl(
+    scoped_ptr<net::ProxyResolver> resolver)
+    : resolver_(resolver.Pass()) {
+  DCHECK(resolver_->expects_pac_bytes());
+}
+
+MojoProxyResolverImpl::~MojoProxyResolverImpl() {
+  if (!set_pac_script_callback_.is_null()) {
+    resolver_->CancelSetPacScript();
+    set_pac_script_callback_.Run(ERR_ABORTED);

[eroman, 2015/02/12 19:00:42]

Why is the callback run in this case?

Typically in cancellation paths we do not run callbacks, especially deletion, as
it can make things hard to reason about.

[Sam McNally, 2015/02/13 00:03:19]

It was to avoid leaving the client with a hanging callback. Hoever, on further
thought, either the client disconnected, in which case it doesn't care, or we're
disconnecting, in which case the client will find out when it gets an
OnConnectionError call. Removed it.

+  }
+  STLDeleteElements(&resolve_jobs_);
+}
+
+void MojoProxyResolverImpl::SetPacScript(
+    const mojo::String& data,
+    const mojo::Callback<void(int32_t)>& callback) {
+  DVLOG(1) << "SetPacScript(" << data << ")";
+  DCHECK(set_pac_script_callback_.is_null());
+  set_pac_script_callback_ = callback;
+  int result = resolver_->SetPacScript(
+      ProxyResolverScriptData::FromUTF8(data),
+      base::Bind(&MojoProxyResolverImpl::SetPacScriptDone,
+                 base::Unretained(this)));
+  if (result != ERR_IO_PENDING)
+    SetPacScriptDone(result);
+}
+
+void MojoProxyResolverImpl::GetProxyForUrl(
+    const mojo::String& url,
+    interfaces::ProxyResolverRequestClientPtr client) {
+  DVLOG(1) << "GetProxyForUrl(" << url << ")";
+  Job* job = new Job(client.Pass(), this, url.To<GURL>());
+  bool inserted = resolve_jobs_.insert(job).second;
+  DCHECK(inserted);
+  job->Start();
+}
+
+void MojoProxyResolverImpl::DeleteJob(Job* job) {
+  size_t num_erased = resolve_jobs_.erase(job);
+  DCHECK(num_erased);
+  delete job;
+}
+
+void MojoProxyResolverImpl::SetPacScriptDone(int result) {
+  DVLOG(1) << "SetPacScript finished with error " << result;
+  DCHECK(!set_pac_script_callback_.is_null());
+  set_pac_script_callback_.Run(result);
+  set_pac_script_callback_.reset();
+}
+
+MojoProxyResolverImpl::Job::Job(
+    interfaces::ProxyResolverRequestClientPtr client,
+    MojoProxyResolverImpl* resolver,
+    const GURL& url)
+    : resolver_(resolver),
+      client_(client.Pass()),
+      url_(url),
+      request_handle_(nullptr) {
+}
+
+MojoProxyResolverImpl::Job::~Job() {
+  if (request_handle_)
+    resolver_->resolver_->CancelRequest(request_handle_);
+}
+
+void MojoProxyResolverImpl::Job::Start() {
+  int result = resolver_->resolver_->GetProxyForURL(
+      url_, &result_, base::Bind(&Job::GetProxyDone, base::Unretained(this)),
+      &request_handle_, BoundNetLog());
+  if (result != ERR_IO_PENDING) {
+    GetProxyDone(result);
+    return;
+  }
+  client_.set_error_handler(this);

[eroman, 2015/02/12 19:00:42]

Is it intentional that the error handler is only set in the async completion
case?

I believe so, but just want to verify.

[Sam McNally, 2015/02/13 00:03:19]

Yes, there's no need to set it in the sync case.

+}
+
+void MojoProxyResolverImpl::Job::GetProxyDone(int32_t error) {

[eroman, 2015/02/12 19:00:42]

int

[Sam McNally, 2015/02/13 00:03:19]

Done.

+  request_handle_ = nullptr;
+  DVLOG(1) << "GetProxyForUrl(" << url_ << ") finished with error " << error
+           << ". " << result_.proxy_list().size() << " Proxies returned:";
+  for (const auto& proxy : result_.proxy_list().GetAll()) {
+    DVLOG(1) << proxy.ToURI();
+  }
+  mojo::Array<interfaces::ProxyServerPtr> result;
+  if (error == OK)

[eroman, 2015/02/12 19:00:41]

Use curly braces around this if statement (more than 1 line).

[Sam McNally, 2015/02/13 00:03:19]

Done.

+    result = mojo::Array<interfaces::ProxyServerPtr>::From(
+        result_.proxy_list().GetAll());
+  client_->ReportResult(error, result.Pass());
+  resolver_->DeleteJob(this);
+}
+
+void MojoProxyResolverImpl::Job::OnConnectionError() {
+  resolver_->DeleteJob(this);
+}
+
+}  // namespace net