Do PPB_FileIO Query and Read in the plugin process.

ppapi/proxy/file_io_resource.cc

 // 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 "ppapi/proxy/file_io_resource.h"
 
 #include "base/bind.h"
 #include "ipc/ipc_message.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/shared_impl/array_writer.h"
+#include "ppapi/shared_impl/file_type_conversion.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/proxy_lock.h"
 #include "ppapi/shared_impl/resource_tracker.h"
 #include "ppapi/thunk/enter.h"
 #include "ppapi/thunk/ppb_file_ref_api.h"
 
 using ppapi::thunk::EnterResourceNoLock;
 using ppapi::thunk::PPB_FileIO_API;
 using ppapi::thunk::PPB_FileRef_API;
 
 namespace {
 
 // An adapter to let Read() share the same implementation with ReadToArray().
 void* DummyGetDataBuffer(void* user_data, uint32_t count, uint32_t size) {
   return user_data;
 }
 
+// File thread task to close the file handle.
+void DoClose(base::PlatformFile file) {
+  base::ClosePlatformFile(file);
+}
+
 }  // namespace
 
 namespace ppapi {
 namespace proxy {
 
 FileIOResource::FileIOResource(Connection connection, PP_Instance instance)
-    : PluginResource(connection, instance) {
+    : PluginResource(connection, instance),
+      file_handle_(base::kInvalidPlatformFileValue),
+      file_system_type_(PP_FILESYSTEMTYPE_INVALID) {
   SendCreate(RENDERER, PpapiHostMsg_FileIO_Create());
 }
 
 FileIOResource::~FileIOResource() {
+  CloseFileHandle();
 }
 
 PPB_FileIO_API* FileIOResource::AsPPB_FileIO_API() {
   return this;
 }
 
 int32_t FileIOResource::Open(PP_Resource file_ref,
                              int32_t open_flags,
                              scoped_refptr<TrackedCallback> callback) {
   EnterResourceNoLock<PPB_FileRef_API> enter(file_ref, true);
   if (enter.failed())
     return PP_ERROR_BADRESOURCE;
 
+  PPB_FileRef_API* file_ref_api = enter.object();
+  PP_FileSystemType type = file_ref_api->GetFileSystemType();
+  if (type != PP_FILESYSTEMTYPE_LOCALPERSISTENT &&
+      type != PP_FILESYSTEMTYPE_LOCALTEMPORARY &&
+      type != PP_FILESYSTEMTYPE_EXTERNAL &&
+      type != PP_FILESYSTEMTYPE_ISOLATED) {
+    NOTREACHED();
+    return PP_ERROR_FAILED;
+  }
+  file_system_type_ = type;
+
   int32_t rv = state_manager_.CheckOperationState(
       FileIOStateManager::OPERATION_EXCLUSIVE, false);
   if (rv != PP_OK)
     return rv;
 
   Call<PpapiPluginMsg_FileIO_OpenReply>(RENDERER,
       PpapiHostMsg_FileIO_Open(
           enter.resource()->host_resource().host_resource(),
           open_flags),
       base::Bind(&FileIOResource::OnPluginMsgOpenFileComplete, this,
                  callback));
 
   state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
   return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t FileIOResource::Query(PP_FileInfo* info,
                               scoped_refptr<TrackedCallback> callback) {
   int32_t rv = state_manager_.CheckOperationState(
       FileIOStateManager::OPERATION_EXCLUSIVE, true);
   if (rv != PP_OK)
     return rv;
 
+  if (callback->is_blocking() &&
+      file_handle_ != base::kInvalidPlatformFileValue) {
+    state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
+    int32_t result = PP_ERROR_FAILED;
+    base::PlatformFileInfo file_info;
+    // Release the proxy lock while making a potentially blocking file call.
+    {
+      ProxyAutoUnlock unlock;
+      result = base::GetPlatformFileInfo(file_handle_, &file_info) ?
+          PP_OK : PP_ERROR_FAILED;
+    }
+    if ((result == PP_OK) && TrackedCallback::IsPending(callback)) {
+      ppapi::PlatformFileInfoToPepperFileInfo(file_info, file_system_type_,
+                                              info);
+    }
+
+    state_manager_.SetOperationFinished();
+    return result;
+  }
+
   Call<PpapiPluginMsg_FileIO_QueryReply>(RENDERER,
       PpapiHostMsg_FileIO_Query(),
       base::Bind(&FileIOResource::OnPluginMsgQueryComplete, this,
                  callback, info));
 
   state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
   return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t FileIOResource::Touch(PP_Time last_access_time,
@@ skipping 18 matching lines @@
                              int32_t bytes_to_read,
                              scoped_refptr<TrackedCallback> callback) {
   int32_t rv = state_manager_.CheckOperationState(
       FileIOStateManager::OPERATION_READ, true);
   if (rv != PP_OK)
     return rv;
 
   PP_ArrayOutput output_adapter;
   output_adapter.GetDataBuffer = &DummyGetDataBuffer;
   output_adapter.user_data = buffer;
-  state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_READ);
   return ReadValidated(offset, bytes_to_read, output_adapter, callback);
 }
 
 int32_t FileIOResource::ReadToArray(int64_t offset,
                                     int32_t max_read_length,
                                     PP_ArrayOutput* array_output,
                                     scoped_refptr<TrackedCallback> callback) {
   DCHECK(array_output);
   int32_t rv = state_manager_.CheckOperationState(
       FileIOStateManager::OPERATION_READ, true);
   if (rv != PP_OK)
     return rv;
 
-  state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_READ);
   return ReadValidated(offset, max_read_length, *array_output, callback);
 }
 
 int32_t FileIOResource::Write(int64_t offset,
                               const char* buffer,
                               int32_t bytes_to_write,
                               scoped_refptr<TrackedCallback> callback) {
   int32_t rv = state_manager_.CheckOperationState(
       FileIOStateManager::OPERATION_WRITE, true);
   if (rv != PP_OK)
@@ skipping 36 matching lines @@
   Call<PpapiPluginMsg_FileIO_GeneralReply>(RENDERER,
       PpapiHostMsg_FileIO_Flush(),
       base::Bind(&FileIOResource::OnPluginMsgGeneralComplete, this,
                  callback));
 
   state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
   return PP_OK_COMPLETIONPENDING;
 }
 
 void FileIOResource::Close() {
+  CloseFileHandle();
   Post(RENDERER, PpapiHostMsg_FileIO_Close());
 }
 
 int32_t FileIOResource::GetOSFileDescriptor() {
   int32_t file_descriptor;
   // Only available when running in process.
   SyncCall<PpapiPluginMsg_FileIO_GetOSFileDescriptorReply>(
       RENDERER, PpapiHostMsg_FileIO_GetOSFileDescriptor(), &file_descriptor);
   return file_descriptor;
 }
 
+int32_t FileIOResource::RequestOSFileHandle(
+    PP_FileHandle* handle,
+    scoped_refptr<TrackedCallback> callback) {
+  int32_t rv = state_manager_.CheckOperationState(
+      FileIOStateManager::OPERATION_EXCLUSIVE, true);
+  if (rv != PP_OK)
+    return rv;
+
+  Call<PpapiPluginMsg_FileIO_RequestOSFileHandleReply>(RENDERER,
+      PpapiHostMsg_FileIO_RequestOSFileHandle(),
+      base::Bind(&FileIOResource::OnPluginMsgRequestOSFileHandleComplete, this,
+                 callback, handle));
+
+  state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
+  return PP_OK_COMPLETIONPENDING;
+}
+
 int32_t FileIOResource::WillWrite(int64_t offset,
                                   int32_t bytes_to_write,
                                   scoped_refptr<TrackedCallback> callback) {
   Call<PpapiPluginMsg_FileIO_GeneralReply>(RENDERER,
       PpapiHostMsg_FileIO_WillWrite(offset, bytes_to_write),
-      base::Bind(&FileIOResource::OnPluginMsgGeneralComplete, this,
-                 callback));
+      base::Bind(&FileIOResource::OnPluginMsgGeneralComplete, this, callback));
+
   state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
   return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t FileIOResource::WillSetLength(int64_t length,
                                       scoped_refptr<TrackedCallback> callback) {
   Call<PpapiPluginMsg_FileIO_GeneralReply>(RENDERER,
       PpapiHostMsg_FileIO_WillSetLength(length),
-      base::Bind(&FileIOResource::OnPluginMsgGeneralComplete, this,
-                 callback));
+      base::Bind(&FileIOResource::OnPluginMsgGeneralComplete, this, callback));
+
   state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
   return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t FileIOResource::ReadValidated(int64_t offset,
                                       int32_t bytes_to_read,
                                       const PP_ArrayOutput& array_output,
                                       scoped_refptr<TrackedCallback> callback) {
+  state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_READ);
+
+  if (callback->is_blocking() &&
+      file_handle_ != base::kInvalidPlatformFileValue) {
+    int32_t result = PP_ERROR_FAILED;
+    if (bytes_to_read >= 0) {
+      // We can't read directly into the plugin's buffer since we don't know if
+      // we should write to it until after we re-acquire the lock.
+      scoped_ptr<char[]> buffer(new char[bytes_to_read]);

[dmichael (off chromium), 2013/08/08 17:44:44]

It would probably be better to do the allocation after you drop the lock, just
to minimize the time you're holding the lock.

[bbudge, 2013/08/08 18:44:31]

Done.

+      // Release the proxy lock while making a potentially blocking file call.
+      {
+        ProxyAutoUnlock unlock;
+        int32_t bytes_read = base::ReadPlatformFile(
+            file_handle_, offset, buffer.get(), bytes_to_read);
+        result = (bytes_read >= 0) ? bytes_read : PP_ERROR_FAILED;

[dmichael (off chromium), 2013/08/08 17:44:44]

I may be reading it wrong, but it looks in the host like 0 is a valid param for
bytes_to_read, and therefore a valid response. I think you might want
(bytes_read > 0)?

[bbudge, 2013/08/08 18:44:31]

That would cause a result of 0 to return PP_ERROR_FAILED. I switched this around
to hopefully make it clearer.

[dmichael (off chromium), 2013/08/08 19:51:38]

My bad, thanks

+      }
+      if ((result >= 0) && TrackedCallback::IsPending(callback)) {
+        ArrayWriter output;
+        output.set_pp_array_output(array_output);
+        if (output.is_valid())
+          output.StoreArray(buffer.get(), result);
+        else
+          result = PP_ERROR_FAILED;
+      }
+    }
+
+    state_manager_.SetOperationFinished();
+    return result;
+  }
+
   Call<PpapiPluginMsg_FileIO_ReadReply>(RENDERER,
       PpapiHostMsg_FileIO_Read(offset, bytes_to_read),
       base::Bind(&FileIOResource::OnPluginMsgReadComplete, this,
                  callback, array_output));
   return PP_OK_COMPLETIONPENDING;
 }
 
-int32_t FileIOResource::RequestOSFileHandle(
-    PP_FileHandle* handle,
-    scoped_refptr<TrackedCallback> callback) {
-  int32_t rv = state_manager_.CheckOperationState(
-      FileIOStateManager::OPERATION_EXCLUSIVE, true);
-  if (rv != PP_OK)
-    return rv;
+void FileIOResource::CloseFileHandle() {
+  if (file_handle_ != base::kInvalidPlatformFileValue) {
+    // Close our local fd on the file thread.
+    base::TaskRunner* file_task_runner =
+        PpapiGlobals::Get()->GetFileTaskRunner(pp_instance());
+    file_task_runner->PostTask(FROM_HERE,
+                               base::Bind(&DoClose, file_handle_));
 
-  Call<PpapiPluginMsg_FileIO_RequestOSFileHandleReply>(RENDERER,
-      PpapiHostMsg_FileIO_RequestOSFileHandle(),
-      base::Bind(&FileIOResource::OnPluginMsgRequestOSFileHandleComplete, this,
-                 callback, handle));
-
-  state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
-  return PP_OK_COMPLETIONPENDING;
+    file_handle_ = base::kInvalidPlatformFileValue;
+  }
 }
 
 void FileIOResource::OnPluginMsgGeneralComplete(
     scoped_refptr<TrackedCallback> callback,
     const ResourceMessageReplyParams& params) {
   DCHECK(state_manager_.get_pending_operation() ==
          FileIOStateManager::OPERATION_EXCLUSIVE ||
          state_manager_.get_pending_operation() ==
          FileIOStateManager::OPERATION_WRITE);
-  // End the operation now. The callback may perform another file operation.
+  // End this operation now, so the user's callback can execute another FileIO
+  // operation, assuming there are no other pending operations.
   state_manager_.SetOperationFinished();
   callback->Run(params.result());
 }
 
 void FileIOResource::OnPluginMsgOpenFileComplete(
     scoped_refptr<TrackedCallback> callback,
     const ResourceMessageReplyParams& params) {
   DCHECK(state_manager_.get_pending_operation() ==
          FileIOStateManager::OPERATION_EXCLUSIVE);
   if (params.result() == PP_OK)
     state_manager_.SetOpenSucceed();
-  // End the operation now. The callback may perform another file operation.
+
+  int32_t result = params.result();
+  IPC::PlatformFileForTransit transit_file;
+  if ((result == PP_OK) && params.TakeFileHandleAtIndex(0, &transit_file))
+    file_handle_ = IPC::PlatformFileForTransitToPlatformFile(transit_file);
+  // End this operation now, so the user's callback can execute another FileIO
+  // operation, assuming there are no other pending operations.
   state_manager_.SetOperationFinished();
-  callback->Run(params.result());
+  callback->Run(result);
 }
 
 void FileIOResource::OnPluginMsgQueryComplete(
     scoped_refptr<TrackedCallback> callback,
     PP_FileInfo* output_info,
     const ResourceMessageReplyParams& params,
     const PP_FileInfo& info) {
   DCHECK(state_manager_.get_pending_operation() ==
          FileIOStateManager::OPERATION_EXCLUSIVE);
   *output_info = info;
-  // End the operation now. The callback may perform another file operation.
+  // End this operation now, so the user's callback can execute another FileIO
+  // operation, assuming there are no other pending operations.
   state_manager_.SetOperationFinished();
   callback->Run(params.result());
 }
 
 void FileIOResource::OnPluginMsgReadComplete(
     scoped_refptr<TrackedCallback> callback,
     PP_ArrayOutput array_output,
     const ResourceMessageReplyParams& params,
     const std::string& data) {
   DCHECK(state_manager_.get_pending_operation() ==
          FileIOStateManager::OPERATION_READ);
 
   // The result code should contain the data size if it's positive.
   int32_t result = params.result();
   DCHECK((result < 0 && data.size() == 0) ||
          result == static_cast<int32_t>(data.size()));
 
   ArrayWriter output;
   output.set_pp_array_output(array_output);
   if (output.is_valid())
     output.StoreArray(data.data(), std::max(0, result));
   else
     result = PP_ERROR_FAILED;
 
-  // End the operation now. The callback may perform another file operation.
+  // End this operation now, so the user's callback can execute another FileIO
+  // operation, assuming there are no other pending operations.
   state_manager_.SetOperationFinished();
   callback->Run(result);
 }
 
 void FileIOResource::OnPluginMsgRequestOSFileHandleComplete(
     scoped_refptr<TrackedCallback> callback,
     PP_FileHandle* output_handle,
     const ResourceMessageReplyParams& params) {
   DCHECK(state_manager_.get_pending_operation() ==
          FileIOStateManager::OPERATION_EXCLUSIVE);
 
   if (!TrackedCallback::IsPending(callback)) {
     state_manager_.SetOperationFinished();
     return;
   }
 
   int32_t result = params.result();
   IPC::PlatformFileForTransit transit_file;
   if (!params.TakeFileHandleAtIndex(0, &transit_file))
     result = PP_ERROR_FAILED;
   *output_handle = IPC::PlatformFileForTransitToPlatformFile(transit_file);
 
-  // End the operation now. The callback may perform another file operation.
+  // End this operation now, so the user's callback can execute another FileIO
+  // operation, assuming there are no other pending operations.
   state_manager_.SetOperationFinished();
   callback->Run(result);
 }
 
 }  // namespace proxy
 }  // namespace ppapi