Implement Pepper proxy for PPB_DirectoryReader

ppapi/proxy/directory_reader_resource.cc

Index: ppapi/proxy/directory_reader_resource.cc
diff --git a/ppapi/proxy/directory_reader_resource.cc b/ppapi/proxy/directory_reader_resource.cc
new file mode 100644
index 0000000000000000000000000000000000000000..7bdfa75ce28906d2de48f21cbe114de77df8cecb
--- /dev/null
+++ b/ppapi/proxy/directory_reader_resource.cc
@@ -0,0 +1,104 @@
+// Copyright (c) 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 "ppapi/proxy/directory_reader_resource.h"
+
+#include "base/bind.h"
+#include "ipc/ipc_message.h"
+#include "ppapi/c/pp_errors.h"
+#include "ppapi/proxy/dispatch_reply_message.h"
+#include "ppapi/proxy/plugin_globals.h"
+#include "ppapi/proxy/ppapi_messages.h"
+#include "ppapi/proxy/ppb_file_ref_proxy.h"
+#include "ppapi/shared_impl/ppapi_globals.h"
+#include "ppapi/shared_impl/resource.h"
+#include "ppapi/shared_impl/resource_tracker.h"
+#include "ppapi/thunk/enter.h"
+#include "ppapi/thunk/ppb_file_ref_api.h"
+
+using ppapi::proxy::PPB_FileRef_Proxy;
+
+namespace ppapi {
+namespace proxy {
+
+DirectoryReaderResource::DirectoryReaderResource(
+    Connection connection,
+    PP_Instance instance,
+    PP_Resource directory_ref)
+    : PluginResource(connection, instance),
+      directory_ref_(directory_ref),
+      has_more_(true) {}

[yzshen1, 2013/01/24 21:55:43]

please init |entry_|.

[nhiroki, 2013/01/25 12:27:17]

Done.

+
+thunk::PPB_DirectoryReader_API*
+DirectoryReaderResource::AsPPB_DirectoryReader_API() {
+  return this;
+}
+
+int32_t DirectoryReaderResource::GetNextEntry(
+    PP_DirectoryEntry_Dev* entry,
+    scoped_refptr<TrackedCallback> callback) {
+  if (TrackedCallback::IsPending(callback_))
+    return PP_ERROR_INPROGRESS;
+
+  entry_ = entry;
+  callback_ = callback;
+
+  if (FillUpEntry())
+    return PP_OK;
+
+  if (!sent_create_to_renderer())
+    SendCreate(RENDERER, PpapiHostMsg_DirectoryReader_Create());
+
+  ppapi::ResourceTracker* tracker = PpapiGlobals::Get()->GetResourceTracker();
+  PpapiHostMsg_DirectoryReader_GetNextEntry msg(
+      tracker->GetResource(directory_ref_)->host_resource());
+  Call<PpapiPluginMsg_DirectoryReader_GetNextEntryReply>(
+      RENDERER, msg,
+      base::Bind(&DirectoryReaderResource::OnPluginMsgGetNextEntryReply, this));
+  return PP_OK_COMPLETIONPENDING;
+}
+
+void DirectoryReaderResource::OnPluginMsgGetNextEntryReply(
+    const ResourceMessageReplyParams& params,
+    const std::vector<ppapi::PPB_FileRef_CreateInfo> infos,
+    const std::vector<PP_FileType> file_types) {
+  DCHECK_EQ(infos.size(), file_types.size());

[yzshen1, 2013/01/24 21:55:43]

Please make it a CHECK. Something must be really wrong.

[nhiroki, 2013/01/25 12:27:17]

Done.

+
+  for (std::vector<ppapi::PPB_FileRef_CreateInfo>::size_type i = 0;
+       i < infos.size(); ++i) {
+    PP_DirectoryEntry_Dev entry;
+    entry.file_ref = PPB_FileRef_Proxy::DeserializeFileRef(infos[i]);

[yzshen1, 2013/01/24 21:55:43]

Where do you release the ref? If the ref is not returned to the plugin by any
GetNextEntry() call, you have to release it yourself.

Please be careful with refs, it is very hard to catch issues later.

[nhiroki, 2013/01/25 12:27:17]

Added release routine into the dtor.

+    entry.file_type = file_types[i];
+    entries_.push(entry);
+  }
+
+  // Current implementation returns all entries at once.
+  // TODO(nhiroki): DirectoryReader should return directory entries in multiple
+  // chunks.
+  has_more_ = false;
+
+  FillUpEntry();

[yzshen1, 2013/01/24 21:55:43]

[optional]
Please check that callback_ is still pending before filing up the entry.

Currently it should be safe, when the last plugin ref is deleted (which causes
the callback to be aborted), I think this object should be destroyed and this
method won't be called after that. But I would rather not rely on this fact.

[nhiroki, 2013/01/25 12:27:17]

Done.

+  entry_ = NULL;
+
+  callback_->Run(params.result());
+}
+
+bool DirectoryReaderResource::FillUpEntry() {
+  DCHECK(entry_);
+  if (!entries_.empty()) {
+    *entry_ = entries_.front();
+    entries_.pop();
+    return true;
+  }
+
+  if (!has_more_) {
+    entry_->file_ref = 0;

[yzshen1, 2013/01/24 21:55:43]

Please also init the other field in |entry_|.

[nhiroki, 2013/01/25 12:27:17]

Done.

+    return true;
+  }
+
+  return false;
+}
+
+}  // namespace proxy
+}  // namespace ppapi