Enable Sdch in Cronet

components/cronet/android/test/native_test_server.cc

Index: components/cronet/android/test/native_test_server.cc
diff --git a/components/cronet/android/test/native_test_server.cc b/components/cronet/android/test/native_test_server.cc
index 97261645d361c60480eb00597df1b5e8b7c562b7..a1e118257576e98f901d6869ace93b757d334f61 100644
--- a/components/cronet/android/test/native_test_server.cc
+++ b/components/cronet/android/test/native_test_server.cc
@@ -4,14 +4,25 @@
 
 #include "native_test_server.h"
 
+#include <string>
+
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
+#include "base/android/path_utils.h"
 #include "base/bind.h"
 #include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/path_service.h"
+#include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "components/cronet/android/cronet_url_request_context_adapter.h"
+#include "components/cronet/android/url_request_context_adapter.h"
 #include "jni/NativeTestServer_jni.h"
+#include "net/dns/host_resolver_impl.h"
+#include "net/dns/mock_host_resolver.h"
 #include "net/http/http_status_code.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "net/test/embedded_test_server/http_request.h"
@@ -27,10 +38,54 @@ const char echo_header_path[] = "/echo_header";
 const char echo_all_headers_path[] = "/echo_all_headers";
 const char echo_method_path[] = "/echo_method";
 const char redirect_to_echo_body_path[] = "/redirect_to_echo_body";
+const char fake_sdch_domain[] = "fake.sdch.domain";
+// Path that advertises the dictionaries passed in query params if client
+// supports Sdch encoding. E.g. /sdch/index?q=LeQxM80O will make the server
+// responds with "Get-Dictionary: /sdch/dict/LeQxM80O".
+const char sdch_path[] = "/sdch/index";
+// Path that returns encoded response if client has the right dictionary.
+const char sdch_test_path[] = "/sdch/test";
+// Path where dictionaries are stored.
+const char sdch_dict_path[] = "/sdch/dict/";
 
 net::test_server::EmbeddedTestServer* g_test_server = nullptr;
 
-scoped_ptr<net::test_server::HttpResponse> UploadServerRequestHandler(
+class CustomHttpResponse : public net::test_server::HttpResponse {
+ public:
+  CustomHttpResponse(const std::string& headers, const std::string& contents)
+      : headers_(headers), contents_(contents) {}
+
+  std::string ToResponseString() const override {
+    return headers_ + "\r\n" + contents_;
+  }
+
+  void AddHeader(const std::string& key_value_pair) {
+    headers_.append(base::StringPrintf("%s\r\n", key_value_pair.c_str()));
+  }
+
+ private:
+  std::string headers_;
+  std::string contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(CustomHttpResponse);
+};
+
+scoped_ptr<CustomHttpResponse> ConstructResponseBasedOnFile(
+    const base::FilePath& file_path) {
+  std::string file_contents;
+  bool read_file = base::ReadFileToString(file_path, &file_contents);
+  DCHECK(read_file);
+  base::FilePath headers_path(
+      file_path.AddExtension(FILE_PATH_LITERAL("mock-http-headers")));
+  std::string headers_contents;
+  bool read_headers = base::ReadFileToString(headers_path, &headers_contents);
+  DCHECK(read_headers);
+  scoped_ptr<CustomHttpResponse> http_response(
+      new CustomHttpResponse(headers_contents, file_contents));
+  return http_response.Pass();
+}
+
+scoped_ptr<net::test_server::HttpResponse> NativeTestServerRequestHandler(
     const net::test_server::HttpRequest& request) {
   DCHECK(g_test_server);
   scoped_ptr<net::test_server::BasicHttpResponse> response(
@@ -77,6 +132,85 @@ scoped_ptr<net::test_server::HttpResponse> UploadServerRequestHandler(
   return scoped_ptr<net::test_server::BasicHttpResponse>();
 }
 
+scoped_ptr<net::test_server::HttpResponse> SdchRequestHandler(
+    const net::test_server::HttpRequest& request) {
+  DCHECK(g_test_server);
+  base::FilePath dir_path;
+  bool get_data_dir = base::android::GetDataDirectory(&dir_path);
+  DCHECK(get_data_dir);
+  dir_path = dir_path.Append(FILE_PATH_LITERAL("test"));
+
+  if (StartsWithASCII(request.relative_url, sdch_path, true)) {
+    base::FilePath file_path = dir_path.Append("sdch/index");
+    scoped_ptr<CustomHttpResponse> response =
+        ConstructResponseBasedOnFile(file_path).Pass();
+    // Check for query params to see which dictionaries to advertise.

[mef, 2015/04/28 20:37:11]

Need comment on what query params are used to define which dictionaries to
advertise.

[xunjieli, 2015/04/29 02:05:09]

Done.

+    GURL url = g_test_server->GetURL(request.relative_url);
+    base::StringPairs pairs;
+    if (!base::SplitStringIntoKeyValuePairs(url.query(), '=', '&', &pairs)) {

[mef, 2015/04/28 20:37:11]

Suggest: using GetValueForKeyInQuery()

[xunjieli, 2015/04/29 02:05:09]

Done. Was thinking we should support multiple dictionaries. Since the
functionality isn't exercised, I will use GetValueForKeyInQuery.

+      DCHECK(false) << "parsing query params failed";
+    }
+    auto it = request.headers.find("Accept-Encoding");

[mef, 2015/04/28 20:37:10]

'it' is a bit generic, suggest calling it 'accept_encoding_header'.

[xunjieli, 2015/04/29 02:05:09]

Done.

+    if (it != request.headers.end()) {
+      if (it->second.find("sdch") != std::string::npos) {
+        std::string get_dictionary_header = "";
+        for (base::StringPairs::const_iterator it = pairs.begin();

[mef, 2015/04/28 20:37:11]

This 'it' masks upper level 'it', which makes it confusing. 
Can you give 'it' more descriptive name?

[xunjieli, 2015/04/29 02:05:09]

Done.

+             it != pairs.end(); ++it) {

[mef, 2015/04/28 20:37:10]

Could we use range-based for loop here?
Why do we need a loop? To support multiple dictionaries?
Maybe populate a vector<string> and use base::JoinString()?

[xunjieli, 2015/04/29 02:05:09]

Done. Was thinking of supporting multiple dictionaries. However, since that
isn't used, I will just remove the loop. We can add the functionality later when
we need it. Less code is always better :)

+          get_dictionary_header += sdch_dict_path + it->second + ", ";
+        }
+        if (!get_dictionary_header.empty()) {
+          // Remove trailing comma and space.
+          get_dictionary_header =
+              get_dictionary_header.substr(0, get_dictionary_header.size() - 2);
+          response->AddHeader("Get-Dictionary: " + get_dictionary_header);
+        }
+      }
+    }
+    return response.Pass();
+  }
+
+  if (StartsWithASCII(request.relative_url, sdch_test_path, true)) {
+    auto it = request.headers.find("Avail-Dictionary");

[mef, 2015/04/28 20:37:10]

more descriptive name than 'it'?

[xunjieli, 2015/04/29 02:05:09]

Done.

+    if (it != request.headers.end()) {
+      base::FilePath file_path =
+          dir_path.Append("sdch/" + it->second + "_encoded");
+      return ConstructResponseBasedOnFile(file_path).Pass();
+    }
+    scoped_ptr<net::test_server::BasicHttpResponse> response(
+        new net::test_server::BasicHttpResponse());
+    response->set_content_type("text/plain");
+    response->set_content("Sdch is not used.\n");

[mef, 2015/04/28 20:37:10]

maybe construct response based on another file with predefined suffix?

[xunjieli, 2015/04/29 02:05:09]

Hmm.. but we just want to make sure here that sdch encoding isn't used. Reading
from file seems like a stretch for that purpose, not mention we will have 2
additional files to install at runtime. There are examples like this in this
file (response->set_content("Request has no body. :(")), so I'd prefer to keep
it like this, unless you have a strong feeling. 

[mef, 2015/04/29 15:37:29]

sg, thanks!

+    return response.Pass();
+  }
+
+  // Unhandled requests result in the Embedded test server sending a 404.
+  return scoped_ptr<net::test_server::BasicHttpResponse>();
+}
+
+void RegisterHostResolverProcHelper(
+    net::URLRequestContext* url_request_context) {
+  net::HostResolverImpl* resolver =
+      static_cast<net::HostResolverImpl*>(url_request_context->host_resolver());
+  scoped_refptr<net::RuleBasedHostResolverProc> proc =
+      new net::RuleBasedHostResolverProc(NULL);
+  proc->AddRule(fake_sdch_domain, "127.0.0.1");
+  resolver->set_proc_params_for_test(
+      net::HostResolverImpl::ProcTaskParams(proc.get(), 1u));
+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_NativeTestServer_onHostResolverProcRegistered(env);
+}
+
+void RegisterHostResolverProcOnNetworkThread(
+    CronetURLRequestContextAdapter* context_adapter) {
+  RegisterHostResolverProcHelper(context_adapter->GetURLRequestContext());
+}
+
+// TODO(xunjieli): Delete this once legacy API is removed.
+void RegisterHostResolverProcOnNetworkThreadLegacyAPI(
+    URLRequestContextAdapter* context_adapter) {
+  RegisterHostResolverProcHelper(context_adapter->GetURLRequestContext());
+}
+
 }  // namespace
 
 jboolean StartNativeTestServer(JNIEnv* env,
@@ -87,15 +221,36 @@ jboolean StartNativeTestServer(JNIEnv* env,
     return false;
   g_test_server = new net::test_server::EmbeddedTestServer();
   g_test_server->RegisterRequestHandler(
-      base::Bind(&UploadServerRequestHandler));
-  // Add a second handler for paths that UploadServerRequestHandler does not
-  // handle.
+      base::Bind(&NativeTestServerRequestHandler));
+  g_test_server->RegisterRequestHandler(base::Bind(&SdchRequestHandler));
   base::FilePath test_files_root(
       base::android::ConvertJavaStringToUTF8(env, jtest_files_root));
+
+  // Add a third handler for paths that NativeTestServerRequestHandler does not
+  // handle.
   g_test_server->ServeFilesFromDirectory(test_files_root);
   return g_test_server->InitializeAndWaitUntilReady();
 }
 
+void RegisterHostResolverProc(JNIEnv* env,
+                              jclass jcaller,
+                              jlong jadapter,
+                              jboolean jlegacy_api) {
+  if (jlegacy_api == JNI_TRUE) {
+    URLRequestContextAdapter* context_adapter =
+        reinterpret_cast<URLRequestContextAdapter*>(jadapter);
+    context_adapter->PostTaskToNetworkThread(
+        FROM_HERE, base::Bind(&RegisterHostResolverProcOnNetworkThreadLegacyAPI,
+                              base::Unretained(context_adapter)));
+  } else {
+    CronetURLRequestContextAdapter* context_adapter =
+        reinterpret_cast<CronetURLRequestContextAdapter*>(jadapter);
+    context_adapter->PostTaskToNetworkThread(
+        FROM_HERE, base::Bind(&RegisterHostResolverProcOnNetworkThread,
+                              base::Unretained(context_adapter)));
+  }
+}
+
 void ShutdownNativeTestServer(JNIEnv* env, jclass jcaller) {
   if (!g_test_server)
     return;
@@ -144,6 +299,13 @@ jstring GetFileURL(JNIEnv* env, jclass jcaller, jstring jfile_path) {
   return base::android::ConvertUTF8ToJavaString(env, url.spec()).Release();
 }
 
+jstring GetSdchURL(JNIEnv* env, jclass jcaller) {
+  DCHECK(g_test_server);
+  std::string url(base::StringPrintf("http://%s:%d", fake_sdch_domain,
+                                     g_test_server->port()));
+  return base::android::ConvertUTF8ToJavaString(env, url).Release();
+}
+
 bool RegisterNativeTestServer(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }