Pepper: Stop using SRPC for irt_open_resource().

ppapi/nacl_irt/manifest_service.cc

 // Copyright 2014 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 "ppapi/nacl_irt/manifest_service.h"
 
 #include "base/message_loop/message_loop_proxy.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "ipc/ipc_sync_message_filter.h"
@@ skipping 66 matching lines @@
 
 void ManifestService::StartupInitializationComplete() {
   filter_->Send(new PpapiHostMsg_StartupInitializationComplete);
 }
 
 bool ManifestService::OpenResource(const char* file, int* fd) {
   // OpenResource will return INVALID SerializedHandle, if it is not supported.
   // Specifically, PNaCl doesn't support open resource.
   ppapi::proxy::SerializedHandle ipc_fd;
   if (!filter_->Send(new PpapiHostMsg_OpenResource(
-          std::string(kFilePrefix) + file, &ipc_fd)) ||
-      !ipc_fd.is_file()) {

[Mark Seaborn, 2014/08/07 04:46:23]

Is this change required to fix something?  Maybe comment this in commit message?

[teravest, 2014/08/07 18:47:02]

Removing this condition is required as part of this change. I've added a comment
in the code for readability at line 93.

OpenResource() has the following behavior:
Returns false if there was an IO error.
Returns true, but an fd of -1 if the file does not exist.
Returns true, with a a valid fd if the file was opened successfully.

Now that NaClIPCAdapter is being used to transmit this message, having an
"invalid" file that would resolve to -1 in ipc_fd.descriptor(). fd doesn't work.

It might be clearer to have ManifestService::OpenResource() return an enum and
only set "fd" on success-- I was a bit confused when I had to change how this
worked.

+          std::string(kFilePrefix) + file, &ipc_fd))) {
     LOG(ERROR) << "ManifestService::OpenResource failed:" << file;
     *fd = -1;
     return false;
   }
 
-  *fd = ipc_fd.descriptor().fd;
+  if (ipc_fd.is_file())
+    *fd = ipc_fd.descriptor().fd;

[Mark Seaborn, 2014/08/07 04:46:23]

Nit: I think multi-line ifs are meant to use {}s

[teravest, 2014/08/07 18:47:02]

The rule is that the if and else clauses must agree on whether they have braces.
I don't see any deviation from the Google style guide specified in the Chrome
style guide, and I've been encouraged to not use braces for single line if
statements.

http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml?showone=Condit...

+  else
+    *fd = -1;
   return true;
 }
 
 int IrtOpenResource(const char* file, int* fd) {
   // Remove leading '/' character.
   if (file[0] == '/')
     ++file;
 
   ManifestService* manifest_service = GetManifestService();
   if (manifest_service == NULL ||
       !manifest_service->OpenResource(file, fd)) {
     return NACL_ABI_EIO;
   }
-
   return (*fd == -1) ? NACL_ABI_ENOENT : 0;
 }
 
 }  // namespace ppapi