[fsp] Extract common code to FileSystemProvidedInternalFunction.

chrome/browser/chromeos/extensions/file_system_provider/provider_function.cc

+// Copyright 2013 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 "chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h"
+
+#include "chrome/browser/chromeos/file_system_provider/provided_file_system_interface.h"
+#include "chrome/browser/chromeos/file_system_provider/request_manager.h"
+#include "chrome/browser/chromeos/file_system_provider/request_value.h"
+#include "chrome/browser/chromeos/file_system_provider/service.h"
+#include "chrome/common/extensions/api/file_system_provider_internal.h"
+
+using chromeos::file_system_provider::ProvidedFileSystemInterface;
+using chromeos::file_system_provider::RequestManager;
+using chromeos::file_system_provider::RequestValue;
+using chromeos::file_system_provider::Service;
+
+namespace extensions {
+
+const char kNotFoundErrorName[] = "NotFoundError";
+const char kSecurityErrorName[] = "SecurityError";
+
+const char kEmptyNameErrorMessage[] = "Empty display name is not allowed.";
+const char kMountFailedErrorMessage[] = "Mounting the file system failed.";
+const char kUnmountFailedErrorMessage[] = "Unmounting the file system failed.";
+const char kResponseFailedErrorMessage[] =
+    "Sending a response for the request failed.";
+
+base::DictionaryValue* CreateError(const std::string& name,
+                                   const std::string& message) {
+  base::DictionaryValue* error = new base::DictionaryValue();
+  error->SetString("name", name);
+  error->SetString("message", message);
+  return error;
+}
+
+base::File::Error ProviderErrorToFileError(
+    api::file_system_provider::ProviderError error) {
+  switch (error) {
+    case api::file_system_provider::PROVIDER_ERROR_OK:
+      return base::File::FILE_OK;
+    case api::file_system_provider::PROVIDER_ERROR_FAILED:
+      return base::File::FILE_ERROR_FAILED;
+    case api::file_system_provider::PROVIDER_ERROR_IN_USE:
+      return base::File::FILE_ERROR_IN_USE;
+    case api::file_system_provider::PROVIDER_ERROR_EXISTS:
+      return base::File::FILE_ERROR_EXISTS;
+    case api::file_system_provider::PROVIDER_ERROR_NOT_FOUND:
+      return base::File::FILE_ERROR_NOT_FOUND;
+    case api::file_system_provider::PROVIDER_ERROR_ACCESS_DENIED:
+      return base::File::FILE_ERROR_ACCESS_DENIED;
+    case api::file_system_provider::PROVIDER_ERROR_TOO_MANY_OPENED:
+      return base::File::FILE_ERROR_TOO_MANY_OPENED;
+    case api::file_system_provider::PROVIDER_ERROR_NO_MEMORY:
+      return base::File::FILE_ERROR_NO_MEMORY;
+    case api::file_system_provider::PROVIDER_ERROR_NO_SPACE:
+      return base::File::FILE_ERROR_NO_SPACE;
+    case api::file_system_provider::PROVIDER_ERROR_NOT_A_DIRECTORY:
+      return base::File::FILE_ERROR_NOT_A_DIRECTORY;
+    case api::file_system_provider::PROVIDER_ERROR_INVALID_OPERATION:
+      return base::File::FILE_ERROR_INVALID_OPERATION;
+    case api::file_system_provider::PROVIDER_ERROR_SECURITY:
+      return base::File::FILE_ERROR_SECURITY;
+    case api::file_system_provider::PROVIDER_ERROR_ABORT:
+      return base::File::FILE_ERROR_ABORT;
+    case api::file_system_provider::PROVIDER_ERROR_NOT_A_FILE:
+      return base::File::FILE_ERROR_NOT_A_FILE;
+    case api::file_system_provider::PROVIDER_ERROR_NOT_EMPTY:
+      return base::File::FILE_ERROR_NOT_EMPTY;
+    case api::file_system_provider::PROVIDER_ERROR_INVALID_URL:
+      return base::File::FILE_ERROR_INVALID_URL;
+    case api::file_system_provider::PROVIDER_ERROR_IO:
+      return base::File::FILE_ERROR_IO;
+    case api::file_system_provider::PROVIDER_ERROR_NONE:
+      NOTREACHED();
+  }
+  return base::File::FILE_ERROR_FAILED;
+}
+
+FileSystemProviderInternalFunction::FileSystemProviderInternalFunction()
+    : request_id_(0), request_manager_(NULL) {
+}
+
+void FileSystemProviderInternalFunction::RejectRequest(
+    base::File::Error error) {
+  if (!request_manager_->RejectRequest(request_id_, error))
+    SetErrorResponse(kSecurityErrorName, kResponseFailedErrorMessage);
+}
+
+void FileSystemProviderInternalFunction::FulfillRequest(
+    scoped_ptr<RequestValue> value,
+    bool has_next) {
+  if (!request_manager_->FulfillRequest(request_id_, value.Pass(), has_next))
+    SetErrorResponse(kSecurityErrorName, kResponseFailedErrorMessage);
+}
+
+bool FileSystemProviderInternalFunction::RunImpl() {
+  DCHECK(args_);
+  if (!Parse())
+    return true;
+
+  SendResponse(RunSync());

[hashimoto, 2014/05/02 05:56:18]

Seems RunSync always returns true.
Isn't it necessary to call SendResponse with false to run the error callback
given by the caller JS code on error cases?

[mtomasz, 2014/05/02 06:29:16]

It returns false if the request is malformed (EXTENSION_FUNCTION_VALIDATE
macro).

Basically, this is confusing. In case of a single callback, returning false is
used to return an error via chrome.runtime.lastError. However, in File System
Provider API we have two-callback architecture: onSuccess and onError, like in
fileapi methods. So, DOMError is used instead of chrome.runtime.lastError.

This is the same way it works for fileapi functions.
Eg. for webkitRequestLocalFileSystemURL a DOMError is returned via the error
callback, and chrome.runtime.lastError *is not* set.

+  return true;
+}
+
+bool FileSystemProviderInternalFunction::Parse() {
+  int file_system_id;
+
+  if (!args_->GetInteger(0, &file_system_id) ||
+      !args_->GetInteger(1, &request_id_)) {
+    bad_message_ = true;
+    SendResponse(false);
+    return false;
+  }
+
+  Service* service = Service::Get(GetProfile());
+  if (!service) {
+    SendResponse(false);
+    return false;
+  }
+
+  ProvidedFileSystemInterface* file_system =
+      service->GetProvidedFileSystem(extension_id(), file_system_id);
+  if (!file_system) {
+    SetErrorResponse(kNotFoundErrorName, kResponseFailedErrorMessage);
+    SendResponse(true);

[hashimoto, 2014/05/02 05:56:18]

Why true is passed to SendResponse here?
It seems an error case to me.

[mtomasz, 2014/05/02 06:29:16]

As above. DOMError vs. chrome.runtime.lastError problem.

+    return false;
+  }
+
+  request_manager_ = file_system->GetRequestManager();
+  return true;
+}
+
+void FileSystemProviderInternalFunction::SetErrorResponse(
+    const std::string& name,
+    const std::string& message) {
+  base::ListValue* result = new base::ListValue();
+  result->Append(CreateError(kNotFoundErrorName, kResponseFailedErrorMessage));

[hashimoto, 2014/05/02 05:56:18]

name and message are unused?

[mtomasz, 2014/05/02 06:29:16]

Done.

+  SetResult(result);
+}
+
+}  // namespace extensions