Make Directory.list pull-based, making it possible to pause, resume and cancel directory listing.

runtime/bin/directory.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/directory.h"
 
 #include "bin/dartutils.h"
 #include "bin/thread.h"
 #include "include/dart_api.h"
 #include "platform/assert.h"
@@ skipping 132 matching lines @@
   // Create the list to hold the directory listing here, and pass it to the
   // SyncDirectoryListing object, which adds elements to it.
   Dart_Handle follow_links = Dart_GetNativeArgument(args, 2);
   // Create the list to hold the directory listing here, and pass it to the
   // SyncDirectoryListing object, which adds elements to it.
   Dart_Handle results =
       Dart_New(DartUtils::GetDartClass(DartUtils::kCoreLibURL, "List"),
                Dart_Null(),
                0,
                NULL);
-  SyncDirectoryListing sync_listing(results);
-  Directory::List(DartUtils::GetStringValue(path),
-                  DartUtils::GetBooleanValue(recursive),
-                  DartUtils::GetBooleanValue(follow_links),
-                  &sync_listing);
+  SyncDirectoryListing sync_listing(results,
+                                    DartUtils::GetStringValue(path),
+                                    DartUtils::GetBooleanValue(recursive),
+                                    DartUtils::GetBooleanValue(follow_links));
+  Directory::List(&sync_listing);
   Dart_SetReturnValue(args, results);
   Dart_ExitScope();
 }
 
 
 static CObject* DirectoryCreateRequest(const CObjectArray& request) {
   if (request.Length() == 2 && request[1]->IsString()) {
     CObjectString path(request[1]);
     if (Directory::Create(path.CString())) {
       return CObject::True();
@@ skipping 46 matching lines @@
       free(result);
       return temp_dir;
     } else {
       return CObject::NewOSError();
     }
   }
   return CObject::IllegalArgumentError();
 }
 
 
-static CObject* DirectoryListRequest(const CObjectArray& request,
-                                     Dart_Port response_port) {
+static CObject* DirectoryListStartRequest(const CObjectArray& request) {
   if (request.Length() == 4 &&
       request[1]->IsString() &&
       request[2]->IsBool() &&
       request[3]->IsBool()) {
-    AsyncDirectoryListing* dir_listing =
-        new AsyncDirectoryListing(response_port);
     CObjectString path(request[1]);
     CObjectBool recursive(request[2]);
     CObjectBool follow_links(request[3]);
-    bool completed = Directory::List(
-        path.CString(), recursive.Value(), follow_links.Value(), dir_listing);
-    delete dir_listing;
-    CObjectArray* response = new CObjectArray(CObject::NewArray(2));
-    response->SetAt(
-        0,
-        new CObjectInt32(CObject::NewInt32(AsyncDirectoryListing::kListDone)));
-    response->SetAt(1, CObject::Bool(completed));
+    AsyncDirectoryListing* dir_listing =
+        new AsyncDirectoryListing(path.CString(),
+                                  recursive.Value(),
+                                  follow_links.Value());
+    return new CObjectIntptr(CObject::NewIntptr(
+        reinterpret_cast<intptr_t>(dir_listing)));
+  }
+  // Respond with an illegal argument list error message.
+  CObjectArray* response = new CObjectArray(CObject::NewArray(3));
+  response->SetAt(0, new CObjectInt32(
+      CObject::NewInt32(AsyncDirectoryListing::kListError)));
+  response->SetAt(1, CObject::Null());
+  response->SetAt(2, CObject::IllegalArgumentError());
+  return response;
+}
+
+
+static CObject* DirectoryListNextRequest(const CObjectArray& request) {
+  if (request.Length() == 2 &&
+      request[1]->IsIntptr()) {
+    CObjectIntptr ptr(request[1]);
+    AsyncDirectoryListing* dir_listing =
+        reinterpret_cast<AsyncDirectoryListing*>(ptr.Value());
+    const int kArraySize = 128;
+    CObjectArray* response = new CObjectArray(CObject::NewArray(kArraySize));
+    dir_listing->set_array(response, kArraySize);
+    Directory::List(dir_listing);

[Søren Gjesse, 2013/06/12 12:52:41]

You should just set the length of the response array instead of filling in
null's.

[Anders Johnsen, 2013/06/13 08:38:24]

Done.

+    for (intptr_t i = dir_listing->index(); i < kArraySize; i++) {
+      response->SetAt(i, CObject::Null());
+    }
     return response;
   }
   // Respond with an illegal argument list error message.
   CObjectArray* response = new CObjectArray(CObject::NewArray(3));
   response->SetAt(0, new CObjectInt32(
       CObject::NewInt32(AsyncDirectoryListing::kListError)));
   response->SetAt(1, CObject::Null());
   response->SetAt(2, CObject::IllegalArgumentError());
-  Dart_PostCObject(response_port, response->AsApiCObject());
-
-  response = new CObjectArray(CObject::NewArray(2));
-  response->SetAt(
-      0, new CObjectInt32(CObject::NewInt32(AsyncDirectoryListing::kListDone)));
-  response->SetAt(1, CObject::False());
   return response;
 }
 
+
+static CObject* DirectoryListStopRequest(const CObjectArray& request) {
+  if (request.Length() == 2 && request[1]->IsIntptr()) {
+    CObjectIntptr ptr(request[1]);
+    AsyncDirectoryListing* dir_listing =
+        reinterpret_cast<AsyncDirectoryListing*>(ptr.Value());
+    delete dir_listing;
+    return new CObjectBool(CObject::Bool(true));
+  }
+  // Respond with an illegal argument list error message.
+  CObjectArray* response = new CObjectArray(CObject::NewArray(3));
+  response->SetAt(0, new CObjectInt32(
+      CObject::NewInt32(AsyncDirectoryListing::kListError)));
+  response->SetAt(1, CObject::Null());
+  response->SetAt(2, CObject::IllegalArgumentError());
+  return response;
+}
+
 
 static CObject* DirectoryRenameRequest(const CObjectArray& request,
                                        Dart_Port response_port) {
   if (request.Length() == 3 &&
       request[1]->IsString() &&
       request[2]->IsString()) {
     CObjectString path(request[1]);
     CObjectString new_path(request[2]);
     bool completed = Directory::Rename(path.CString(), new_path.CString());
     if (completed) return CObject::True();
@@ skipping 17 matching lines @@
           break;
         case Directory::kDeleteRequest:
           response = DirectoryDeleteRequest(request);
           break;
         case Directory::kExistsRequest:
           response = DirectoryExistsRequest(request);
           break;
         case Directory::kCreateTempRequest:
           response = DirectoryCreateTempRequest(request);
           break;
-        case Directory::kListRequest:
-          response = DirectoryListRequest(request, reply_port_id);
+        case Directory::kListStartRequest:
+          response = DirectoryListStartRequest(request);
+          break;
+        case Directory::kListNextRequest:
+          response = DirectoryListNextRequest(request);
+          break;
+        case Directory::kListStopRequest:
+          response = DirectoryListStopRequest(request);
           break;
         case Directory::kRenameRequest:
           response = DirectoryRenameRequest(request, reply_port_id);
           break;
         default:
           UNREACHABLE();
       }
     }
   }
 
@@ skipping 12 matching lines @@
   Dart_Port service_port = Directory::GetServicePort();
   if (service_port != ILLEGAL_PORT) {
     // Return a send port for the service port.
     Dart_Handle send_port = Dart_NewSendPort(service_port);
     Dart_SetReturnValue(args, send_port);
   }
   Dart_ExitScope();
 }
 
 
-CObjectArray* AsyncDirectoryListing::NewResponse(Response type, char* arg) {
+bool AsyncDirectoryListing::NewResponse(Response type, char* arg) {

[Søren Gjesse, 2013/06/12 12:52:41]

This is no longer a single new response, but part off the response to next. How
about just using the response array for both type (even index) and name (odd
index) to avoid allocating all these two element arrays?

[Anders Johnsen, 2013/06/13 08:38:24]

Done.

   CObjectArray* response = new CObjectArray(CObject::NewArray(2));
   response->SetAt(0, new CObjectInt32(CObject::NewInt32(type)));
-  response->SetAt(1, new CObjectString(CObject::NewString(arg)));
-  return response;
+  if (arg != NULL) {
+    response->SetAt(1, new CObjectString(CObject::NewString(arg)));
+  } else {
+    response->SetAt(1, CObject::Null());
+  }
+  array_->SetAt(index_++, response);
+  return index_ < length_;
 }
 
 
 bool AsyncDirectoryListing::HandleDirectory(char* dir_name) {
-  CObjectArray* response = NewResponse(kListDirectory, dir_name);
-  return Dart_PostCObject(response_port_, response->AsApiCObject());
+  return NewResponse(kListDirectory, dir_name);
 }
 
 
 bool AsyncDirectoryListing::HandleFile(char* file_name) {
-  CObjectArray* response = NewResponse(kListFile, file_name);
-  return Dart_PostCObject(response_port_, response->AsApiCObject());
+  return NewResponse(kListFile, file_name);
 }
 
 
 bool AsyncDirectoryListing::HandleLink(char* link_name) {
-  CObjectArray* response = NewResponse(kListLink, link_name);
-  return Dart_PostCObject(response_port_, response->AsApiCObject());
+  return NewResponse(kListLink, link_name);
+}
+
+void AsyncDirectoryListing::HandleDone() {
+  NewResponse(kListDone, NULL);
 }
 
 
 bool AsyncDirectoryListing::HandleError(const char* dir_name) {
   CObject* err = CObject::NewOSError();
   CObjectArray* response = new CObjectArray(CObject::NewArray(3));
   response->SetAt(0, new CObjectInt32(CObject::NewInt32(kListError)));
   response->SetAt(1, new CObjectString(CObject::NewString(dir_name)));
   response->SetAt(2, err);
-  return Dart_PostCObject(response_port_, response->AsApiCObject());
+  array_->SetAt(index_++, response);
+  return index_ < length_;
 }
 
 bool SyncDirectoryListing::HandleDirectory(char* dir_name) {
   Dart_Handle dir_name_dart = DartUtils::NewString(dir_name);
   Dart_Handle dir =
       Dart_New(directory_class_, Dart_Null(), 1, &dir_name_dart);
   Dart_Invoke(results_, add_string_, 1, &dir);
   return true;
 }
 
@@ skipping 22 matching lines @@
   Dart_ThrowException(Dart_New(
       DartUtils::GetDartClass(DartUtils::kIOLibURL, "DirectoryException"),
       Dart_Null(),
       3,
       args));
   return true;
 }
 
 }  // namespace bin
 }  // namespace dart