Create a URLRequestContextBuilder.

URLRequestContext has become quite complicated and difficult to instantiate
properly. Here I create a simplified URLRequestContext builder class to assist
in building it properly. I provide a few simple knobs and assume that people 
generally just want the defaults.

BUG=122779
TEST=none


Review URL: http://codereview.chromium.org/9999023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@132659 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 444 insertions, 1 deletions

diff --git a/net/ftp/ftp_network_layer.h b/net/ftp/ftp_network_layer.h
index d4bfe46..0c48f13 100644
--- a/net/ftp/ftp_network_layer.h
+++ b/net/ftp/ftp_network_layer.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 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.
 
@@ -6,6 +6,7 @@
 #define NET_FTP_FTP_NETWORK_LAYER_H_
 #pragma once
 
+#include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "net/base/net_export.h"
@@ -30,6 +31,7 @@ class NET_EXPORT FtpNetworkLayer : public FtpTransactionFactory {
  private:
   scoped_refptr<FtpNetworkSession> session_;
   bool suspended_;
+  DISALLOW_COPY_AND_ASSIGN(FtpNetworkLayer);
 };
 
 }  // namespace net
diff --git a/net/net.gyp b/net/net.gyp
index 8dacba7..cf23c45 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -713,6 +713,8 @@
         'url_request/url_request_about_job.h',
         'url_request/url_request_context.cc',
         'url_request/url_request_context.h',
+        'url_request/url_request_context_builder.cc',
+        'url_request/url_request_context_builder.h',
         'url_request/url_request_context_getter.cc',
         'url_request/url_request_context_getter.h',
         'url_request/url_request_context_storage.cc',
@@ -1234,6 +1236,7 @@
         'tools/dump_cache/url_utilities.cc',
         'tools/dump_cache/url_utilities_unittest.cc',
         'udp/udp_socket_unittest.cc',
+        'url_request/url_request_context_builder_unittest.cc',
         'url_request/url_request_job_factory_unittest.cc',
         'url_request/url_request_job_unittest.cc',
         'url_request/url_request_throttler_simulation_unittest.cc',
diff --git a/net/url_request/url_request_context_builder.cc b/net/url_request/url_request_context_builder.cc
new file mode 100644
index 0000000..7a38431
--- /dev/null
+++ b/net/url_request/url_request_context_builder.cc
@@ -0,0 +1,265 @@
+// Copyright (c) 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 "net/url_request/url_request_context_builder.h"
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/logging.h"
+#include "base/threading/thread.h"
+#include "net/base/cert_verifier.h"
+#include "net/base/host_resolver.h"
+#include "net/base/net_errors.h"
+#include "net/base/network_delegate.h"
+#include "net/base/ssl_config_service_defaults.h"
+#include "net/base/transport_security_state.h"
+#include "net/cookies/cookie_monster.h"
+#include "net/ftp/ftp_network_layer.h"
+#include "net/http/http_auth_handler_factory.h"
+#include "net/http/http_cache.h"
+#include "net/http/http_network_layer.h"
+#include "net/http/http_network_session.h"
+#include "net/http/http_server_properties_impl.h"
+#include "net/proxy/proxy_service.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_context_storage.h"
+
+namespace net {
+
+namespace {
+
+class BasicNetworkDelegate : public NetworkDelegate {
+ public:
+  BasicNetworkDelegate() {}
+  virtual ~BasicNetworkDelegate() {}
+
+ private:
+  virtual int OnBeforeURLRequest(URLRequest* request,
+                                 const CompletionCallback& callback,
+                                 GURL* new_url) OVERRIDE {
+    return OK;
+  }
+
+  virtual int OnBeforeSendHeaders(URLRequest* request,
+                                  const CompletionCallback& callback,
+                                  HttpRequestHeaders* headers) OVERRIDE {
+    return OK;
+  }
+
+  virtual void OnSendHeaders(URLRequest* request,
+                             const HttpRequestHeaders& headers) OVERRIDE {}
+
+  virtual int OnHeadersReceived(
+      URLRequest* request,
+      const CompletionCallback& callback,
+      HttpResponseHeaders* original_response_headers,
+      scoped_refptr<HttpResponseHeaders>* override_response_headers)
+      OVERRIDE {
+    return OK;
+  }
+
+  virtual void OnBeforeRedirect(URLRequest* request,
+                                const GURL& new_location) OVERRIDE {}
+
+  virtual void OnResponseStarted(URLRequest* request) OVERRIDE {}
+
+  virtual void OnRawBytesRead(const URLRequest& request,
+                              int bytes_read) OVERRIDE {}
+
+  virtual void OnCompleted(URLRequest* request, bool started) OVERRIDE {}
+
+  virtual void OnURLRequestDestroyed(URLRequest* request) OVERRIDE {}
+
+  virtual void OnPACScriptError(int line_number,
+                                const string16& error) OVERRIDE {}
+
+  virtual NetworkDelegate::AuthRequiredResponse OnAuthRequired(
+      URLRequest* request,
+      const AuthChallengeInfo& auth_info,
+      const AuthCallback& callback,
+      AuthCredentials* credentials) OVERRIDE {
+    return NetworkDelegate::AUTH_REQUIRED_RESPONSE_NO_ACTION;
+  }
+
+  virtual bool CanGetCookies(const URLRequest* request,
+                             const CookieList& cookie_list) OVERRIDE {
+    return true;
+  }
+
+  virtual bool CanSetCookie(const URLRequest* request,
+                            const std::string& cookie_line,
+                            CookieOptions* options) OVERRIDE {
+    return true;
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(BasicNetworkDelegate);
+};
+
+class BasicURLRequestContext : public URLRequestContext {
+ public:
+  BasicURLRequestContext()
+      : cache_thread_("Cache Thread"),
+        file_thread_("File Thread"),
+        ALLOW_THIS_IN_INITIALIZER_LIST(storage_(this)) {}
+
+  URLRequestContextStorage* storage() {
+    return &storage_;
+  }
+
+  void set_user_agent(const std::string& user_agent) {
+    user_agent_ = user_agent;
+  }
+
+  void StartCacheThread() {
+    cache_thread_.StartWithOptions(
+        base::Thread::Options(MessageLoop::TYPE_IO, 0));
+  }
+
+  scoped_refptr<base::MessageLoopProxy> cache_message_loop_proxy() {
+    DCHECK(cache_thread_.IsRunning());
+    return cache_thread_.message_loop_proxy();
+  }
+
+  void StartFileThread() {
+    file_thread_.StartWithOptions(
+        base::Thread::Options(MessageLoop::TYPE_DEFAULT, 0));
+  }
+
+  MessageLoop* file_message_loop() {
+    DCHECK(file_thread_.IsRunning());
+    return file_thread_.message_loop();
+  }
+
+  virtual const std::string& GetUserAgent(
+      const GURL& /* url */) const OVERRIDE {
+    return user_agent_;
+  }
+
+ protected:
+  virtual ~BasicURLRequestContext() {}
+
+ private:
+  std::string user_agent_;
+  base::Thread cache_thread_;
+  base::Thread file_thread_;
+  URLRequestContextStorage storage_;
+  DISALLOW_COPY_AND_ASSIGN(BasicURLRequestContext);
+};
+
+}  // namespace
+
+URLRequestContextBuilder::HostResolverParams::HostResolverParams()
+    : parallelism(HostResolver::kDefaultParallelism),
+      retry_attempts(HostResolver::kDefaultRetryAttempts) {}
+URLRequestContextBuilder::HostResolverParams::~HostResolverParams() {}
+
+URLRequestContextBuilder::HttpCacheParams::HttpCacheParams()
+    : type(DISK),
+      max_size(0),
+      path(FILE_PATH_LITERAL("Cache")) {}
+URLRequestContextBuilder::HttpCacheParams::~HttpCacheParams() {}
+
+URLRequestContextBuilder::URLRequestContextBuilder()
+    : ftp_enabled_(false),
+      http_cache_enabled_(true) {}
+URLRequestContextBuilder::~URLRequestContextBuilder() {}
+
+scoped_refptr<URLRequestContext> URLRequestContextBuilder::Build() {
+  BasicURLRequestContext* context = new BasicURLRequestContext;
+  URLRequestContextStorage* storage = context->storage();
+
+  context->set_user_agent(user_agent_);
+
+  BasicNetworkDelegate* network_delegate = new BasicNetworkDelegate;
+  storage->set_network_delegate(network_delegate);
+
+  net::HostResolver* host_resolver = net::CreateSystemHostResolver(
+      host_resolver_params_.parallelism,
+      host_resolver_params_.retry_attempts,
+      NULL /* no NetLog */);
+  storage->set_host_resolver(host_resolver);
+
+  if (ftp_enabled_) {
+    storage->set_ftp_transaction_factory(new FtpNetworkLayer(host_resolver));
+  }
+
+  context->StartFileThread();
+
+  storage->set_proxy_service(
+      ProxyService::CreateDirectWithNetLog(context->net_log()));
+
+  // TODO(willchan): Switch to using this code when
+  // ProxyService::CreateSystemProxyConfigService()'s signature doesn't suck.
+#if 0
+      ProxyService::CreateUsingSystemProxyResolver(
+          ProxyService::CreateSystemProxyConfigService(
+              MessageLoop::current(),
+              context->file_message_loop()),
+          4,  // TODO(willchan): Find a better constant somewhere.
+          context->net_log()));
+#endif
+  storage->set_ssl_config_service(new net::SSLConfigServiceDefaults);
+  storage->set_http_auth_handler_factory(
+      net::HttpAuthHandlerRegistryFactory::CreateDefault(host_resolver));
+  storage->set_cookie_store(new CookieMonster(NULL, NULL));
+  storage->set_transport_security_state(new net::TransportSecurityState(""));
+  storage->set_http_server_properties(new net::HttpServerPropertiesImpl);
+  storage->set_cert_verifier(CertVerifier::CreateDefault());
+
+  HttpTransactionFactory* http_transaction_factory = NULL;
+  if (http_cache_enabled_) {
+    HttpCache::BackendFactory* http_cache_backend = NULL;
+    if (http_cache_params_.type == HttpCacheParams::DISK) {
+      context->StartCacheThread();
+      http_cache_backend =
+          new HttpCache::DefaultBackend(DISK_CACHE,
+                                        http_cache_params_.path,
+                                        http_cache_params_.max_size,
+                                        context->cache_message_loop_proxy());
+    } else {
+      http_cache_backend =
+          HttpCache::DefaultBackend::InMemory(http_cache_params_.max_size);
+    }
+    http_transaction_factory = new HttpCache(
+        context->host_resolver(),
+        context->cert_verifier(),
+        context->server_bound_cert_service(),
+        context->transport_security_state(),
+        context->proxy_service(),
+        "",
+        context->ssl_config_service(),
+        context->http_auth_handler_factory(),
+        context->network_delegate(),
+        context->http_server_properties(),
+        context->net_log(),
+        http_cache_backend);
+  } else {
+    HttpNetworkSession::Params session_params;
+    session_params.host_resolver = context->host_resolver();
+    session_params.cert_verifier = context->cert_verifier();
+    session_params.transport_security_state =
+        context->transport_security_state();
+    session_params.proxy_service = context->proxy_service();
+    session_params.ssl_config_service = context->ssl_config_service();
+    session_params.http_auth_handler_factory =
+        context->http_auth_handler_factory();
+    session_params.network_delegate = context->network_delegate();
+    session_params.http_server_properties =
+        context->http_server_properties();
+    session_params.net_log = context->net_log();
+    scoped_refptr<net::HttpNetworkSession> network_session(
+        new net::HttpNetworkSession(session_params));
+
+    http_transaction_factory = new HttpNetworkLayer(network_session);
+  }
+  storage->set_http_transaction_factory(http_transaction_factory);
+
+  // TODO(willchan): Support sdch.
+
+  return context;
+}
+
+}  // namespace net
diff --git a/net/url_request/url_request_context_builder.h b/net/url_request/url_request_context_builder.h
new file mode 100644
index 0000000..ba7541d
--- /dev/null
+++ b/net/url_request/url_request_context_builder.h
@@ -0,0 +1,101 @@
+// Copyright (c) 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.
+
+// This class is useful for building a simple URLRequestContext. Most creators
+// of new URLRequestContexts should use this helper class to construct it. Call
+// any configuration params, and when done, invoke Build() to construct the
+// URLRequestContext. This URLRequestContext will own all its own storage.
+//
+// URLRequestContextBuilder and its associated params classes are initially
+// populated with "sane" default values. Read through the comments to figure out
+// what these are.
+
+#ifndef NET_URL_REQUEST_URL_REQUEST_CONTEXT_BUILDER_H_
+#define NET_URL_REQUEST_URL_REQUEST_CONTEXT_BUILDER_H_
+#pragma once
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/file_path.h"
+#include "base/memory/ref_counted.h"
+#include "net/base/net_export.h"
+
+namespace net {
+
+class URLRequestContext;
+
+class NET_EXPORT URLRequestContextBuilder {
+ public:
+  struct NET_EXPORT HostResolverParams {
+    HostResolverParams();
+    ~HostResolverParams();
+
+    // The limit on the number of parallel host resolutions.
+    size_t parallelism;
+
+    // When the host resolution is taking too long, we'll retry this many times,
+    // in a backing off manner.
+    size_t retry_attempts;
+  };
+
+  struct NET_EXPORT HttpCacheParams {
+    enum Type {
+      IN_MEMORY,
+      DISK,
+    };
+
+    HttpCacheParams();
+    ~HttpCacheParams();
+
+    // The type of HTTP cache. Default is DISK.
+    Type type;
+
+    // The max size of the cache in bytes. Default is algorithmically determined
+    // based off available disk space.
+    int max_size;
+
+    // The cache path (when type is DISK).
+    FilePath path;
+  };
+
+  URLRequestContextBuilder();
+  ~URLRequestContextBuilder();
+
+  // Call this function to specify a hard-coded User-Agent for all requests that
+  // don't have a User-Agent already set.
+  void set_user_agent(const std::string& user_agent) {
+    user_agent_ = user_agent;
+  }
+
+  // Allows for overriding the default HostResolver params.
+  void set_host_resolver_params(
+      const HostResolverParams& host_resolver_params) {
+    host_resolver_params_ = host_resolver_params;
+  }
+
+  // By default it's disabled.
+  void set_ftp_enabled(bool enable) {
+    ftp_enabled_ = enable;
+  }
+
+  // By default HttpCache is enabled with a default constructed HttpCacheParams.
+  void EnableHttpCache(const HttpCacheParams& params);
+  void DisableHttpCache();
+
+  scoped_refptr<URLRequestContext> Build();
+
+ private:
+  std::string user_agent_;
+  bool ftp_enabled_;
+  HostResolverParams host_resolver_params_;
+  bool http_cache_enabled_;
+  HttpCacheParams http_cache_params_;
+
+  DISALLOW_COPY_AND_ASSIGN(URLRequestContextBuilder);
+};
+
+}  // namespace net
+
+#endif  // NET_URL_REQUEST_URL_REQUEST_CONTEXT_BUILDER_H_
diff --git a/net/url_request/url_request_context_builder_unittest.cc b/net/url_request/url_request_context_builder_unittest.cc
new file mode 100644
index 0000000..039b15d
--- /dev/null
+++ b/net/url_request/url_request_context_builder_unittest.cc
@@ -0,0 +1,72 @@
+// Copyright (c) 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 "net/url_request/url_request_context_builder.h"
+
+#include "net/test/test_server.h"
+#include "net/url_request/url_request.h"
+#include "net/url_request/url_request_test_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/platform_test.h"
+
+namespace net {
+
+namespace {
+
+// A subclass of TestServer that uses a statically-configured hostname. This is
+// to work around mysterious failures in chrome_frame_net_tests. See:
+// http://crbug.com/114369
+class LocalHttpTestServer : public TestServer {
+ public:
+  explicit LocalHttpTestServer(const FilePath& document_root)
+      : TestServer(TestServer::TYPE_HTTP,
+                   ScopedCustomUrlRequestTestHttpHost::value(),
+                   document_root) {}
+  LocalHttpTestServer()
+      : TestServer(TestServer::TYPE_HTTP,
+                   ScopedCustomUrlRequestTestHttpHost::value(),
+                   FilePath()) {}
+};
+
+class URLRequestContextBuilderTest : public PlatformTest {
+ protected:
+  URLRequestContextBuilderTest()
+      : test_server_(
+          FilePath(FILE_PATH_LITERAL("net/data/url_request_unittest"))) {}
+
+  LocalHttpTestServer test_server_;
+  URLRequestContextBuilder builder_;
+};
+
+TEST_F(URLRequestContextBuilderTest, DefaultSettings) {
+  ASSERT_TRUE(test_server_.Start());
+
+  scoped_refptr<URLRequestContext> context = builder_.Build();
+  TestDelegate delegate;
+  URLRequest request(test_server_.GetURL("echoheader?Foo"), &delegate);
+  request.set_context(context);
+  request.set_method("GET");
+  request.SetExtraRequestHeaderByName("Foo", "Bar", false);
+  request.Start();
+  MessageLoop::current()->Run();
+  EXPECT_EQ("Bar", delegate.data_received());
+}
+
+TEST_F(URLRequestContextBuilderTest, UserAgent) {
+  ASSERT_TRUE(test_server_.Start());
+
+  builder_.set_user_agent("Bar");
+  scoped_refptr<URLRequestContext> context = builder_.Build();
+  TestDelegate delegate;
+  URLRequest request(test_server_.GetURL("echoheader?User-Agent"), &delegate);
+  request.set_context(context);
+  request.set_method("GET");
+  request.Start();
+  MessageLoop::current()->Run();
+  EXPECT_EQ("Bar", delegate.data_received());
+}
+
+}  // namespace
+
+}  // namespace net