Add support to ProxyService for downloading a PAC script on behalf of the Pro...

net/proxy/proxy_service_unittest.cc

Index: net/proxy/proxy_service_unittest.cc
===================================================================
--- net/proxy/proxy_service_unittest.cc	(revision 10072)
+++ net/proxy/proxy_service_unittest.cc	(working copy)
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/compiler_specific.h"
 #include "googleurl/src/gurl.h"
 #include "net/base/net_errors.h"
 #include "net/proxy/proxy_service.h"
@@ -27,7 +28,8 @@
 
 class MockProxyResolver : public net::ProxyResolver {
  public:
-  MockProxyResolver() : fail_get_proxy_for_url(false) {
+  MockProxyResolver() : net::ProxyResolver(true),
+                        fail_get_proxy_for_url(false) {
   }
 
   virtual int GetProxyForURL(const GURL& query_url,
@@ -80,8 +82,272 @@
   scoped_refptr<net::SyncProxyServiceHelper> sync_proxy_service_;
 };
 
+// ResultFuture is a handle to get at the result from
+// ProxyService::ResolveProxyForURL() that ran on another thread.
+class ResultFuture : public base::RefCountedThreadSafe<ResultFuture> {
+ public:
+  // |service| is the ProxyService to issue requests on, and |io_message_loop|
+  // is the message loop where ProxyService lives.
+  ResultFuture(MessageLoop* io_message_loop,
+               net::ProxyService* service)
+       : io_message_loop_(io_message_loop),
+         service_(service),
+         request_(NULL),
+         ALLOW_THIS_IN_INITIALIZER_LIST(
+             callback_(this, &ResultFuture::OnCompletion)),
+         completion_(true, false),
+         cancelled_(false, false),
+         started_(false, false),
+         did_complete_(false) {
+  }
+
+  // Block until the request has completed, then return the result.
+  int GetResultCode() {
+    DCHECK(MessageLoop::current() != io_message_loop_);
+    WaitUntilCompleted();
+    return result_code_;
+  }
+
+  // Block until the request has completed, then return the result.
+  const net::ProxyInfo& GetProxyInfo() {
+    DCHECK(MessageLoop::current() != io_message_loop_);
+    WaitUntilCompleted();
+    return proxy_info_;
+  }
+
+  // Cancel this request (wait until the cancel has been issued before
+  // returning).
+  void Cancel() {
+    DCHECK(MessageLoop::current() != io_message_loop_);
+    io_message_loop_->PostTask(FROM_HERE, NewRunnableMethod(
+        this, &ResultFuture::DoCancel));
+    cancelled_.Wait();
+  }
+
+  // Return true if the request has already completed.
+  bool IsCompleted() {
+    DCHECK(MessageLoop::current() != io_message_loop_);
+    return did_complete_;
+  }
+
+  // Wait until the ProxyService completes this request.
+  void WaitUntilCompleted() {
+    DCHECK(MessageLoop::current() != io_message_loop_);
+    completion_.Wait();
+    DCHECK(did_complete_);
+  }
+
+ private:
+  friend class ProxyServiceWithFutures;
+
+  // Start the request. Return once ProxyService::GetProxyForURL() returns.
+  void StartResolve(const GURL& url) {
+    DCHECK(MessageLoop::current() != io_message_loop_);
+    io_message_loop_->PostTask(FROM_HERE, NewRunnableMethod(
+        this, &ResultFuture::DoStartResolve, url));
+    started_.Wait();
+  }
+
+  // Called on |io_message_loop_|.
+  void DoStartResolve(const GURL& url) {
+    DCHECK(MessageLoop::current() == io_message_loop_);
+    int rv = service_->ResolveProxy(url, &proxy_info_, &callback_, &request_);
+    if (rv != net::ERR_IO_PENDING) {
+      // Completed synchronously.
+      OnCompletion(rv);
+    }
+    started_.Signal();
+  }
+
+  // Called on |io_message_loop_|.
+  void DoCancel() {
+    DCHECK(MessageLoop::current() == io_message_loop_);
+    if (!did_complete_)
+      service_->CancelPacRequest(request_);
+    cancelled_.Signal();
+  }
+
+  // Called on |io_message_loop_|.
+  void OnCompletion(int result) {
+    DCHECK(MessageLoop::current() == io_message_loop_);
+    DCHECK(!did_complete_);
+    did_complete_ = true;
+    result_code_ = result;
+    request_ = NULL;
+    completion_.Signal();
+  }
+
+  // The message loop where the ProxyService lives.
+  MessageLoop* io_message_loop_;
+
+  // The proxy service that started this request.
+  net::ProxyService* service_;
+
+  // The in-progress request.
+  net::ProxyService::PacRequest* request_;
+
+  net::CompletionCallbackImpl<ResultFuture> callback_;
+  base::WaitableEvent completion_;
+  base::WaitableEvent cancelled_;
+  base::WaitableEvent started_;
+  bool did_complete_;
+
+  // Results from the request.
+  int result_code_;
+  net::ProxyInfo proxy_info_;
+};
+
+// Wraps a ProxyService running on its own IO thread.
+class ProxyServiceWithFutures {
+ public:
+  ProxyServiceWithFutures(net::ProxyConfigService* config_service,
+                          net::ProxyResolver* resolver)
+      : io_thread_("IO_Thread"),
+        service_(config_service, resolver) {
+    base::Thread::Options options;
+    options.message_loop_type = MessageLoop::TYPE_IO;
+    io_thread_.StartWithOptions(options);
+  }
+
+  // Start the request on |io_thread_|, and return a handle that can be
+  // used to access the results. The caller is responsible for freeing
+  // the ResultFuture.
+  void ResolveProxy(scoped_refptr<ResultFuture>* result, const GURL& url) {
+    (*result) = new ResultFuture(io_thread_.message_loop(), &service_);
+    (*result)->StartResolve(url);
+  }
+
+  void SetProxyScriptFetcher(net::ProxyScriptFetcher* proxy_script_fetcher) {
+    service_.SetProxyScriptFetcher(proxy_script_fetcher);
+  }
+
+ private:
+  base::Thread io_thread_;
+  net::ProxyService service_;
+};
+
+// A ProxyResolver which can be set to block upon reaching GetProxyForURL.
+class BlockableProxyResolver : public net::ProxyResolver {
+ public:
+  BlockableProxyResolver() : net::ProxyResolver(true),
+                             should_block_(false),
+                             unblocked_(true, true),
+      blocked_(true, false) {
+  }
+
+  void Block() {
+    should_block_ = true;
+    unblocked_.Reset();
+  }
+
+  void Unblock() {
+    should_block_ = false;
+    blocked_.Reset();
+    unblocked_.Signal();
+  }
+
+  void WaitUntilBlocked() {
+    blocked_.Wait();
+  }
+
+  // net::ProxyResolver implementation:
+  virtual int GetProxyForURL(const GURL& query_url,
+                             const GURL& pac_url,
+                             net::ProxyInfo* results) {
+    if (should_block_) {
+      blocked_.Signal();
+      unblocked_.Wait();
+    }
+
+    results->UseNamedProxy(query_url.host());
+    return net::OK;
+  }
+
+ private:
+  bool should_block_;
+  base::WaitableEvent unblocked_;
+  base::WaitableEvent blocked_;
+};
+
+// A mock ProxyResolverWithoutFetch which concatenates the query's host with
+// the last download PAC contents.  This way the result describes what the last
+// downloaded PAC script's contents were, in addition to the query url itself.
+class MockProxyResolverWithoutFetch : public net::ProxyResolver {
+ public:
+  MockProxyResolverWithoutFetch() : net::ProxyResolver(false),
+                                    last_pac_contents_("NONE") {}
+
+  // net::ProxyResolver implementation:
+  virtual int GetProxyForURL(const GURL& query_url,
+                             const GURL& pac_url,
+                             net::ProxyInfo* results) {
+    results->UseNamedProxy(last_pac_contents_ + "." + query_url.host());
+    return net::OK;
+  }
+
+  virtual void SetPacScript(const std::string& bytes) {
+    last_pac_contents_ = bytes;
+  }
+
+ private:
+  std::string last_pac_contents_;
+};
+
 }  // namespace
 
+// A mock ProxyScriptFetcher. No result will be returned to the fetch client
+// until we call NotifyFetchCompletion() to set the results.
+class MockProxyScriptFetcher : public net::ProxyScriptFetcher {
+ public:
+  MockProxyScriptFetcher() : pending_request_loop_(NULL),
+      pending_request_callback_(NULL), pending_request_bytes_(NULL) {}
+
+  // net::ProxyScriptFetcher implementation.
+  virtual void Fetch(const GURL& url, std::string* bytes,
+                     net::CompletionCallback* callback) {
+    DCHECK(!HasPendingRequest());
+
+    // Save the caller's information, and have them wait.
+    pending_request_loop_ = MessageLoop::current();
+    pending_request_url_ = url;
+    pending_request_callback_ = callback;
+    pending_request_bytes_ = bytes;
+  }
+
+  void NotifyFetchCompletion(int result, const std::string& bytes) {
+    DCHECK(HasPendingRequest());
+    pending_request_loop_->PostTask(FROM_HERE, NewRunnableMethod(
+        this, &MockProxyScriptFetcher::DoNotifyFetchCompletion, result, bytes));
+  }
+
+  virtual void Cancel() {}
+
+ private:
+  // Runs on |pending_request_loop_|.
+  void DoNotifyFetchCompletion(int result, const std::string& bytes) {
+    DCHECK(HasPendingRequest());
+    *pending_request_bytes_ = bytes;
+    pending_request_callback_->Run(result);
+  }
+
+  bool HasPendingRequest() const {
+    return pending_request_loop_ != NULL;
+  }
+
+  MessageLoop* pending_request_loop_;
+  GURL pending_request_url_;
+  net::CompletionCallback* pending_request_callback_;
+  std::string* pending_request_bytes_;
+};
+
+// Template specialization so MockProxyScriptFetcher does not have to be refcounted.
+template<>
+void RunnableMethodTraits<MockProxyScriptFetcher>::RetainCallee(
+    MockProxyScriptFetcher* remover) {}
+template<>
+void RunnableMethodTraits<MockProxyScriptFetcher>::ReleaseCallee(
+    MockProxyScriptFetcher* remover) {}
+
 // Test parsing from a PAC string.
 TEST(ProxyListTest, SetFromPacString) {
   const struct {
@@ -419,7 +685,7 @@
   config.proxy_rules = "foopy1:8080;foopy2:9090";
   config.auto_detect = false;
   config.proxy_bypass_local_names = true;
-  
+
   SyncProxyService service(new MockProxyConfigService(config),
                            new MockProxyResolver());
   GURL url("http://www.google.com/");
@@ -537,3 +803,186 @@
   EXPECT_EQ("foopy1:8080", info4.proxy_server().ToURI());
 }
 
+// Test cancellation of a queued request.
+TEST(ProxyServiceTest, CancelQueuedRequest) {
+  MockProxyConfigService* config_service =
+      new MockProxyConfigService("http://foopy/proxy.pac");
+
+  BlockableProxyResolver* resolver = new BlockableProxyResolver;
+
+  ProxyServiceWithFutures service(config_service, resolver);
+
+  // Cause requests to pile up, by having them block in the PAC thread.
+  resolver->Block();
+
+  // Start 3 requests.
+  scoped_refptr<ResultFuture> result1;
+  service.ResolveProxy(&result1, GURL("http://request1"));
+
+  scoped_refptr<ResultFuture> result2;
+  service.ResolveProxy(&result2, GURL("http://request2"));
+
+  scoped_refptr<ResultFuture> result3;
+  service.ResolveProxy(&result3, GURL("http://request3"));
+
+  // Wait until the first request has become blocked in the PAC thread.
+  resolver->WaitUntilBlocked();
+
+  // Cancel the second request
+  result2->Cancel();
+
+  // Unblock the PAC thread.
+  resolver->Unblock();
+
+  // Wait for the final request to complete.
+  result3->WaitUntilCompleted();
+
+  // Verify that requests ran as expected.
+
+  EXPECT_TRUE(result1->IsCompleted());
+  EXPECT_EQ(net::OK, result1->GetResultCode());
+  EXPECT_EQ("request1:80", result1->GetProxyInfo().proxy_server().ToURI());
+
+  EXPECT_FALSE(result2->IsCompleted());  // Cancelled.
+
+  EXPECT_TRUE(result3->IsCompleted());
+  EXPECT_EQ(net::OK, result3->GetResultCode());
+  EXPECT_EQ("request3:80", result3->GetProxyInfo().proxy_server().ToURI());
+}
+
+// Test cancellation of an in-progress request.
+TEST(ProxyServiceTest, CancelInprogressRequest) {
+  MockProxyConfigService* config_service =
+      new MockProxyConfigService("http://foopy/proxy.pac");
+
+  BlockableProxyResolver* resolver = new BlockableProxyResolver;
+
+  ProxyServiceWithFutures service(config_service, resolver);
+
+  // Cause requests to pile up, by having them block in the PAC thread.
+  resolver->Block();
+
+  // Start 3 requests.
+  scoped_refptr<ResultFuture> result1;
+  service.ResolveProxy(&result1, GURL("http://request1"));
+
+  scoped_refptr<ResultFuture> result2;
+  service.ResolveProxy(&result2, GURL("http://request2"));
+
+  scoped_refptr<ResultFuture> result3;
+  service.ResolveProxy(&result3, GURL("http://request3"));
+
+  // Wait until the first request has become blocked in the PAC thread.
+  resolver->WaitUntilBlocked();
+
+  // Cancel the first request
+  result1->Cancel();
+
+  // Unblock the PAC thread.
+  resolver->Unblock();
+
+  // Wait for the final request to complete.
+  result3->WaitUntilCompleted();
+
+  // Verify that requests ran as expected.
+
+  EXPECT_FALSE(result1->IsCompleted());  // Cancelled.
+
+  EXPECT_TRUE(result2->IsCompleted());
+  EXPECT_EQ(net::OK, result2->GetResultCode());
+  EXPECT_EQ("request2:80", result2->GetProxyInfo().proxy_server().ToURI());
+
+  EXPECT_TRUE(result3->IsCompleted());
+  EXPECT_EQ(net::OK, result3->GetResultCode());
+  EXPECT_EQ("request3:80", result3->GetProxyInfo().proxy_server().ToURI());
+}
+
+// Test the initial PAC download for ProxyResolverWithoutFetch.
+TEST(ProxyServiceTest, InitialPACScriptDownload) {
+  MockProxyConfigService* config_service =
+      new MockProxyConfigService("http://foopy/proxy.pac");
+
+  MockProxyResolverWithoutFetch* resolver = new MockProxyResolverWithoutFetch;
+
+  ProxyServiceWithFutures service(config_service, resolver);
+
+  MockProxyScriptFetcher* fetcher = new MockProxyScriptFetcher;
+  service.SetProxyScriptFetcher(fetcher);
+
+  // Start 3 requests.
+  scoped_refptr<ResultFuture> result1;
+  service.ResolveProxy(&result1, GURL("http://request1"));
+
+  scoped_refptr<ResultFuture> result2;
+  service.ResolveProxy(&result2, GURL("http://request2"));
+
+  scoped_refptr<ResultFuture> result3;
+  service.ResolveProxy(&result3, GURL("http://request3"));
+
+  // At this point the ProxyService should be waiting for the
+  // ProxyScriptFetcher to invoke its completion callback, notifying it of
+  // PAC script download completion.
+  fetcher->NotifyFetchCompletion(net::OK, "pac-v1");
+
+  // Complete all the requests.
+  result3->WaitUntilCompleted();
+
+  EXPECT_TRUE(result1->IsCompleted());
+  EXPECT_EQ(net::OK, result1->GetResultCode());
+  EXPECT_EQ("pac-v1.request1:80",
+            result1->GetProxyInfo().proxy_server().ToURI());
+
+  EXPECT_TRUE(result2->IsCompleted());
+  EXPECT_EQ(net::OK, result2->GetResultCode());
+  EXPECT_EQ("pac-v1.request2:80",
+            result2->GetProxyInfo().proxy_server().ToURI());
+
+  EXPECT_TRUE(result3->IsCompleted());
+  EXPECT_EQ(net::OK, result3->GetResultCode());
+  EXPECT_EQ("pac-v1.request3:80",
+            result3->GetProxyInfo().proxy_server().ToURI());
+}
+
+// Test cancellation of a request, while the PAC script is being fetched.
+TEST(ProxyServiceTest, CancelWhilePACFetching) {
+  MockProxyConfigService* config_service =
+      new MockProxyConfigService("http://foopy/proxy.pac");
+
+  MockProxyResolverWithoutFetch* resolver = new MockProxyResolverWithoutFetch;
+
+  ProxyServiceWithFutures service(config_service, resolver);
+
+  MockProxyScriptFetcher* fetcher = new MockProxyScriptFetcher;
+  service.SetProxyScriptFetcher(fetcher);
+
+  // Start 3 requests.
+  scoped_refptr<ResultFuture> result1;
+  service.ResolveProxy(&result1, GURL("http://request1"));
+
+  scoped_refptr<ResultFuture> result2;
+  service.ResolveProxy(&result2, GURL("http://request2"));
+
+  scoped_refptr<ResultFuture> result3;
+  service.ResolveProxy(&result3, GURL("http://request3"));
+
+  // Cancel the first 2 requests.
+  result1->Cancel();
+  result2->Cancel();
+
+  // At this point the ProxyService should be waiting for the
+  // ProxyScriptFetcher to invoke its completion callback, notifying it of
+  // PAC script download completion.
+  fetcher->NotifyFetchCompletion(net::OK, "pac-v1");
+
+  // Complete all the requests.
+  result3->WaitUntilCompleted();
+
+  EXPECT_FALSE(result1->IsCompleted());  // Cancelled.
+  EXPECT_FALSE(result2->IsCompleted());  // Cancelled.
+
+  EXPECT_TRUE(result3->IsCompleted());
+  EXPECT_EQ(net::OK, result3->GetResultCode());
+  EXPECT_EQ("pac-v1.request3:80",
+            result3->GetProxyInfo().proxy_server().ToURI());
+}
+