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/plugin_globals.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;
 }
 
+typedef base::Callback<void(base::PlatformFileError,
+                            const base::PlatformFileInfo&)> QueryCallback;
+
+// Reads from a file. This should only be called on the file thread.
+void DoQuery(base::PlatformFile file,
+             const QueryCallback& callback) {
+  base::PlatformFileError error = base::PLATFORM_FILE_OK;
+  base::PlatformFileInfo file_info;
+  if (!GetPlatformFileInfo(file, &file_info))
+    error = base::PLATFORM_FILE_ERROR_FAILED;
+
+  // Detect whether this plugin is running out-of-process. If so, we can invoke
+  // the callback directly. If we are running in-process, we must post a task
+  // since there is no proxy lock and any resource access would be unsafe.
+  // TODO(bbudge) Remove this when in-process support is eliminated.
+  if (ppapi::PpapiGlobals::Get()->GetProxyLock()) {
+    callback.Run(error, file_info);
+  } else {
+    ppapi::PpapiGlobals::Get()->GetMainThreadMessageLoop()->PostTask(
+        FROM_HERE,
+        Bind(callback, error, file_info));
+  }
+}
+
+typedef base::Callback<void(base::PlatformFileError,
+                            const char* /* data */,
+                            int /* bytes read */)> ReadCallback;
+
+// Reads file info. This should only be called on the file thread.
+void DoRead(base::PlatformFile file,
+            int64 offset,
+            int bytes_to_read,
+            const ReadCallback& callback) {
+  scoped_ptr<char[]> buffer(new char[bytes_to_read]);
+  int bytes_read =
+      base::ReadPlatformFile(file, offset, buffer.get(), bytes_to_read);
+  base::PlatformFileError error = (bytes_read < 0) ?
+      base::PLATFORM_FILE_ERROR_FAILED : base::PLATFORM_FILE_OK;
+
+  // Detect whether this plugin is running out-of-process. See note in DoQuery.
+  if (ppapi::PpapiGlobals::Get()->GetProxyLock()) {
+    callback.Run(error, buffer.get(), bytes_read);

[bbudge, 2013/08/06 20:58:05]

David: is it safe to pass the buffer this way? callback will wake the original
thread, so will this go out of scope during the copying?

+  } else {
+    // We can't use base::Passed to transfer buffer since scoped_ptr arguments
+    // aren't supported by RunWhileLocked. Transfer ownership to the callback.
+    ppapi::PpapiGlobals::Get()->GetMainThreadMessageLoop()->PostTask(
+        FROM_HERE,
+        Bind(callback, error, base::Owned(buffer.release()), bytes_read));
+  }
+}
+
+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_(PP_kInvalidFileHandle),
+      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;
 
-  Call<PpapiPluginMsg_FileIO_QueryReply>(RENDERER,
-      PpapiHostMsg_FileIO_Query(),
-      base::Bind(&FileIOResource::OnPluginMsgQueryComplete, this,
-                 callback, info));
+  if (file_handle_ == base::kInvalidPlatformFileValue)
+    return PP_ERROR_FAILED;
+
+  PpapiGlobals::Get()->GetFileTaskRunner(pp_instance())->PostTask(
+      FROM_HERE,
+      Bind(&DoQuery, file_handle_,
+           RunWhileLocked(base::Bind(&FileIOResource::OnQueryComplete, this,
+                                     callback, info))));
 
   state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
   return PP_OK_COMPLETIONPENDING;
 }
 
 int32_t FileIOResource::Touch(PP_Time last_access_time,
                               PP_Time last_modified_time,
                               scoped_refptr<TrackedCallback> callback) {
   int32_t rv = state_manager_.CheckOperationState(
       FileIOStateManager::OPERATION_EXCLUSIVE, true);
@@ skipping 14 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));
+
   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));
+
   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) {
-  Call<PpapiPluginMsg_FileIO_ReadReply>(RENDERER,
-      PpapiHostMsg_FileIO_Read(offset, bytes_to_read),
-      base::Bind(&FileIOResource::OnPluginMsgReadComplete, this,
-                 callback, array_output));
+  if (file_handle_ == base::kInvalidPlatformFileValue)
+    return PP_ERROR_FAILED;
+  if (bytes_to_read < 0)
+    return PP_ERROR_FAILED;
+
+  PpapiGlobals::Get()->GetFileTaskRunner(pp_instance())->PostTask(
+      FROM_HERE,
+      Bind(&DoRead, file_handle_, offset, bytes_to_read,
+           RunWhileLocked(base::Bind(&FileIOResource::OnReadComplete, this,
+                                     callback, array_output))));
+
+  state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_READ);
   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) {
+    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));
+    file_handle_ = base::kInvalidPlatformFileValue;
+  }
+}
 
-  state_manager_.SetPendingOperation(FileIOStateManager::OPERATION_EXCLUSIVE);
-  return PP_OK_COMPLETIONPENDING;
+void FileIOResource::OnQueryComplete(
+    scoped_refptr<TrackedCallback> callback,
+    PP_FileInfo* output_info,
+    base::PlatformFileError error_code,
+    const base::PlatformFileInfo& file_info) {
+  DCHECK(state_manager_.get_pending_operation() ==
+         FileIOStateManager::OPERATION_EXCLUSIVE);
+
+  if (!TrackedCallback::IsPending(callback)) {
+    state_manager_.SetOperationFinished();
+    return;
+  }
+
+  int32_t result = ::ppapi::PlatformFileErrorToPepperError(error_code);
+  if (result == PP_OK) {
+    ppapi::PlatformFileInfoToPepperFileInfo(file_info, file_system_type_,
+                                            output_info);
+  }
+
+  // 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::OnReadComplete(
+    scoped_refptr<TrackedCallback> callback,
+    PP_ArrayOutput array_output,
+    base::PlatformFileError error_code,
+    const char* data, int bytes_read) {
+  DCHECK(state_manager_.get_pending_operation() ==
+         FileIOStateManager::OPERATION_READ);
+
+  if (!TrackedCallback::IsPending(callback)) {
+    state_manager_.SetOperationFinished();
+    return;
+  }
+
+  int32_t result = ::ppapi::PlatformFileErrorToPepperError(error_code);
+  if (result == PP_OK) {
+    result = std::max(0, bytes_read);
+    ArrayWriter output;
+    output.set_pp_array_output(array_output);
+    if (output.is_valid())
+      output.StoreArray(data, result);
+    else
+      result = PP_ERROR_FAILED;
+  }
+
+  // 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::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))
+    result = PP_ERROR_FAILED;
+  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());
 }
 
-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.
-  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.
-  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