[Android] Fix handling of asset files loading.

chrome/browser/android/android_protocol_adapter.cc

Index: chrome/browser/android/android_protocol_adapter.cc
diff --git a/chrome/browser/android/android_protocol_adapter.cc b/chrome/browser/android/android_protocol_adapter.cc
index 3229ee49dd272ce40ef47b21fc2606290547ecd3..5bda3d2c382a4fcb84c0fd668effa8d49b3bf460 100644
--- a/chrome/browser/android/android_protocol_adapter.cc
+++ b/chrome/browser/android/android_protocol_adapter.cc
@@ -11,7 +11,9 @@
 #include "base/android/jni_string.h"
 #include "base/string_util.h"
 #include "chrome/browser/android/android_stream_reader_url_request_job.h"
+#include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/common/url_constants.h"

[joth, 2012/08/23 18:23:28]

prefer to be removing chrome/ deps from here rather than adding new ones. see
comment below.

[mnaganov (inactive), 2012/08/24 12:53:05]

Done.

+#include "content/public/browser/browser_thread.h"
 #include "googleurl/src/gurl.h"
 #include "jni/AndroidProtocolAdapter_jni.h"
 #include "net/base/io_buffer.h"
@@ -19,8 +21,9 @@
 #include "net/base/net_errors.h"
 #include "net/base/net_util.h"
 #include "net/http/http_util.h"
-#include "net/url_request/url_request_error_job.h"
-#include "net/url_request/url_request_file_job.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "net/url_request/url_request_job_factory.h"
 #include "net/url_request/url_request_job_manager.h"
 
 using base::android::AttachCurrentThread;
@@ -64,6 +67,22 @@ class AndroidStreamReaderURLRequestJobDelegateImpl
   virtual ~AndroidStreamReaderURLRequestJobDelegateImpl();
 };
 
+class AssetFileProtocolInterceptor :
+      public net::URLRequestJobFactory::Interceptor {
+ public:
+  AssetFileProtocolInterceptor();
+  virtual ~AssetFileProtocolInterceptor() OVERRIDE;
+  virtual net::URLRequestJob* MaybeIntercept(net::URLRequest* request) const OVERRIDE;
+  virtual net::URLRequestJob* MaybeInterceptRedirect(
+      const GURL& location,
+      net::URLRequest* request) const OVERRIDE;
+  virtual net::URLRequestJob* MaybeInterceptResponse(
+      net::URLRequest* request) const OVERRIDE;
+
+ private:
+  const std::string kAssetPrefix;
+  const std::string kResourcePrefix;
+};
 
 } // namespace
 
@@ -75,30 +94,21 @@ static bool InitJNIBindings(JNIEnv* env) {
 // static
 net::URLRequestJob* AndroidProtocolAdapter::Factory(
     net::URLRequest* request, const std::string& scheme) {
-  DCHECK(scheme == chrome::kFileScheme ||
-         scheme == chrome::kContentScheme);
-  JNIEnv* env = AttachCurrentThread();
-  DCHECK(env);
-  // If this is a file:// URL we cannot handle, fall back to the default
-  // handler.
-  const std::string& url = request->url().spec();
-  std::string assetPrefix = std::string(chrome::kFileScheme) + "://" +
-      chrome::kAndroidAssetPath;
-  std::string resourcePrefix = std::string(chrome::kFileScheme) + "://" +
-      chrome::kAndroidResourcePath;
-
-  if (scheme == chrome::kFileScheme &&
-      !StartsWithASCII(url, assetPrefix, /*case_sensitive=*/ true) &&
-      !StartsWithASCII(url, resourcePrefix,  /*case_sensitive=*/ true)) {
-    return net::URLRequestFileJob::Factory(request, scheme);
-  }
-
+  DCHECK(scheme == chrome::kContentScheme);
   return new AndroidStreamReaderURLRequestJob(
       request,
       scoped_ptr<AndroidStreamReaderURLRequestJob::Delegate>(
           new AndroidStreamReaderURLRequestJobDelegateImpl()));
 }
 
+static void AddFileSchemeInterceptorOnIOThread(
+    net::URLRequestContextGetter* context_getter) {
+  // The job factory takes ownership of the interceptor.
+  const_cast<net::URLRequestJobFactory*>(
+      context_getter->GetURLRequestContext()->job_factory())->AddInterceptor(
+          new AssetFileProtocolInterceptor());
+}
+
 // static
 bool AndroidProtocolAdapter::RegisterProtocols(JNIEnv* env) {
   DCHECK(env);
@@ -106,16 +116,25 @@ bool AndroidProtocolAdapter::RegisterProtocols(JNIEnv* env) {
   if (!InitJNIBindings(env))
     return false;

[joth, 2012/08/23 18:23:28]

out of scope for this CL, but this should never fail now -- could add a TODO to
remove it

[mnaganov (inactive), 2012/08/24 12:53:05]

Removed.

 
-  // Register content:// and file://. Note that even though a scheme is
+  // Register content://. Note that even though a scheme is
   // registered here, it cannot be used by child processes until access to it is
   // granted via ChildProcessSecurityPolicy::GrantScheme(). This is done in
   // RenderViewHost.
+  //
+  // TODO(mnaganov): Convert into a ProtocolHandler.
   net::URLRequestJobManager* job_manager =
       net::URLRequestJobManager::GetInstance();
   job_manager->RegisterProtocolFactory(chrome::kContentScheme,
       &AndroidProtocolAdapter::Factory);
-  job_manager->RegisterProtocolFactory(
-      chrome::kFileScheme, &AndroidProtocolAdapter::Factory);
+
+  // Register a file: scheme interceptor for application assets.
+  net::URLRequestContextGetter* context_getter =
+      ProfileManager::GetDefaultProfile()->GetRequestContext();

[joth, 2012/08/23 18:23:28]

could you have the context_getter passed in as a param? This will make it much
easier when we come to move this to android_webview. (as per
go/clank-webview-components)

[mnaganov (inactive), 2012/08/24 12:53:05]

Done.

+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO, FROM_HERE,
+      base::Bind(&AddFileSchemeInterceptorOnIOThread,
+                 base::Unretained(context_getter)));
+  // TODO(mnaganov): Add an interceptor for the incognito profile?
 
   return true;
 }
@@ -222,3 +241,42 @@ bool AndroidStreamReaderURLRequestJobDelegateImpl::GetCharset(
   // TODO: We should probably be getting this from the managed side.
   return false;
 }
+
+AssetFileProtocolInterceptor::AssetFileProtocolInterceptor() :
+    kAssetPrefix(std::string(chrome::kFileScheme) +
+                 std::string(content::kStandardSchemeSeparator) +
+                 chrome::kAndroidAssetPath),
+    kResourcePrefix(std::string(chrome::kFileScheme) +
+                    std::string(content::kStandardSchemeSeparator) +
+                    chrome::kAndroidResourcePath) {
+}
+
+AssetFileProtocolInterceptor::~AssetFileProtocolInterceptor() {
+}
+
+net::URLRequestJob* AssetFileProtocolInterceptor::MaybeIntercept(
+    net::URLRequest* request) const {
+  if (!request->url().SchemeIsFile()) return NULL;
+
+  const std::string& url = request->url().spec();
+  if (!StartsWithASCII(url, kAssetPrefix, /*case_sensitive=*/ true) &&
+      !StartsWithASCII(url, kResourcePrefix,  /*case_sensitive=*/ true)) {
+    return NULL;
+  }
+
+  return new AndroidStreamReaderURLRequestJob(
+      request,
+      scoped_ptr<AndroidStreamReaderURLRequestJob::Delegate>(
+          new AndroidStreamReaderURLRequestJobDelegateImpl()));
+}
+
+net::URLRequestJob* AssetFileProtocolInterceptor::MaybeInterceptRedirect(
+    const GURL& location,
+    net::URLRequest* request) const {
+  return NULL;
+}
+
+net::URLRequestJob* AssetFileProtocolInterceptor::MaybeInterceptResponse(
+    net::URLRequest* request) const {
+  return NULL;
+}