path: root/ppapi/proxy/ppb_file_ref_proxy.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/ppb_file_ref_proxy.h"

#include <map>

#include "base/bind.h"
#include "ppapi/c/pp_errors.h"
#include "ppapi/c/ppb_file_ref.h"
#include "ppapi/c/private/ppb_file_ref_private.h"
#include "ppapi/c/private/ppb_proxy_private.h"
#include "ppapi/proxy/enter_proxy.h"
#include "ppapi/proxy/host_dispatcher.h"
#include "ppapi/proxy/plugin_dispatcher.h"
#include "ppapi/proxy/ppapi_messages.h"
#include "ppapi/proxy/serialized_var.h"
#include "ppapi/shared_impl/ppb_file_ref_shared.h"
#include "ppapi/shared_impl/tracked_callback.h"
#include "ppapi/thunk/resource_creation_api.h"
#include "ppapi/thunk/thunk.h"

using ppapi::thunk::EnterResourceNoLock;
using ppapi::thunk::PPB_FileRef_API;
using ppapi::thunk::ResourceCreationAPI;

namespace ppapi {
namespace proxy {

class FileRef : public PPB_FileRef_Shared {
 public:
  explicit FileRef(const PPB_FileRef_CreateInfo& info);
  virtual ~FileRef();

  // Resource overrides.
  virtual void LastPluginRefWasDeleted() OVERRIDE;

  // PPB_FileRef_API implementation (not provided by PPB_FileRef_Shared).
  virtual PP_Resource GetParent() OVERRIDE;
  virtual int32_t MakeDirectory(
      PP_Bool make_ancestors,
      scoped_refptr<TrackedCallback> callback) OVERRIDE;
  virtual int32_t Touch(PP_Time last_access_time,
                        PP_Time last_modified_time,
                        scoped_refptr<TrackedCallback> callback) OVERRIDE;
  virtual int32_t Delete(scoped_refptr<TrackedCallback> callback) OVERRIDE;
  virtual int32_t Rename(PP_Resource new_file_ref,
                         scoped_refptr<TrackedCallback> callback) OVERRIDE;
  virtual PP_Var GetAbsolutePath() OVERRIDE;

  // Executes the pending callback with the given ID. See pending_callbacks_.
  void ExecuteCallback(int callback_id, int32_t result);

 private:
  PluginDispatcher* GetDispatcher() const {
    return PluginDispatcher::GetForResource(this);
  }

  // Adds a callback to the list and returns its ID.
  int SendCallback(scoped_refptr<TrackedCallback> callback);

  // This class can have any number of out-standing requests with completion
  // callbacks, in contrast to most resources which have one possible pending
  // callback pending (like a Flush callback).
  //
  // To keep track of them, assign integer IDs to the callbacks, which is how
  // the callback will be identified when it's passed to the host and then
  // back here. Use unsigned so that overflow is well-defined.
  unsigned int next_callback_id_;
  typedef std::map<unsigned int,
                   scoped_refptr<TrackedCallback> > PendingCallbackMap;
  PendingCallbackMap pending_callbacks_;

  DISALLOW_IMPLICIT_CONSTRUCTORS(FileRef);
};

FileRef::FileRef(const PPB_FileRef_CreateInfo& info)
    : PPB_FileRef_Shared(OBJECT_IS_PROXY, info),
      next_callback_id_(0u) {
}

FileRef::~FileRef() {
  // The callbacks map should have been cleared by LastPluginRefWasDeleted.
  DCHECK(pending_callbacks_.empty());
}

void FileRef::LastPluginRefWasDeleted() {
  // The callback tracker will abort our callbacks for us.
  pending_callbacks_.clear();
}

PP_Resource FileRef::GetParent() {
  PPB_FileRef_CreateInfo create_info;
  GetDispatcher()->Send(new PpapiHostMsg_PPBFileRef_GetParent(
      API_ID_PPB_FILE_REF, host_resource(), &create_info));
  return PPB_FileRef_Proxy::DeserializeFileRef(create_info);
}

int32_t FileRef::MakeDirectory(PP_Bool make_ancestors,
                               scoped_refptr<TrackedCallback> callback) {
  GetDispatcher()->Send(new PpapiHostMsg_PPBFileRef_MakeDirectory(
      API_ID_PPB_FILE_REF, host_resource(), make_ancestors,
      SendCallback(callback)));
  return PP_OK_COMPLETIONPENDING;
}

int32_t FileRef::Touch(PP_Time last_access_time,
                       PP_Time last_modified_time,
                       scoped_refptr<TrackedCallback> callback) {
  GetDispatcher()->Send(new PpapiHostMsg_PPBFileRef_Touch(
      API_ID_PPB_FILE_REF, host_resource(), last_access_time,
      last_modified_time, SendCallback(callback)));
  return PP_OK_COMPLETIONPENDING;
}

int32_t FileRef::Delete(scoped_refptr<TrackedCallback> callback) {
  GetDispatcher()->Send(new PpapiHostMsg_PPBFileRef_Delete(
      API_ID_PPB_FILE_REF, host_resource(), SendCallback(callback)));
  return PP_OK_COMPLETIONPENDING;
}

int32_t FileRef::Rename(PP_Resource new_file_ref,
                        scoped_refptr<TrackedCallback> callback) {
  Resource* new_file_ref_object =
      PpapiGlobals::Get()->GetResourceTracker()->GetResource(new_file_ref);
  if (!new_file_ref_object ||
      new_file_ref_object->host_resource().instance() != pp_instance())
    return PP_ERROR_BADRESOURCE;

  GetDispatcher()->Send(new PpapiHostMsg_PPBFileRef_Rename(
      API_ID_PPB_FILE_REF, host_resource(),
      new_file_ref_object->host_resource(), SendCallback(callback)));
  return PP_OK_COMPLETIONPENDING;
}

PP_Var FileRef::GetAbsolutePath() {
  ReceiveSerializedVarReturnValue result;
  GetDispatcher()->Send(new PpapiHostMsg_PPBFileRef_GetAbsolutePath(
      API_ID_PPB_FILE_REF, host_resource(), &result));
  return result.Return(GetDispatcher());
}

void FileRef::ExecuteCallback(int callback_id, int32_t result) {
  PendingCallbackMap::iterator found = pending_callbacks_.find(callback_id);
  if (found == pending_callbacks_.end()) {
    // This will happen when the plugin deletes its resource with a pending
    // callback. The callback will be locally issued with an ABORTED call while
    // the operation may still be pending in the renderer.
    return;
  }

  // Executing the callback may mutate the callback list.
  scoped_refptr<TrackedCallback> callback = found->second;
  pending_callbacks_.erase(found);
  callback->Run(result);
}

int FileRef::SendCallback(scoped_refptr<TrackedCallback> callback) {
  // In extreme cases the IDs may wrap around, so avoid duplicates.
  while (pending_callbacks_.count(next_callback_id_))
    ++next_callback_id_;

  pending_callbacks_[next_callback_id_] = callback;
  return next_callback_id_++;
}

PPB_FileRef_Proxy::PPB_FileRef_Proxy(Dispatcher* dispatcher)
    : InterfaceProxy(dispatcher),
      callback_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
}

PPB_FileRef_Proxy::~PPB_FileRef_Proxy() {
}

// static
PP_Resource PPB_FileRef_Proxy::CreateProxyResource(PP_Resource file_system,
                                                   const char* path) {
  Resource* file_system_object =
      PpapiGlobals::Get()->GetResourceTracker()->GetResource(file_system);
  if (!file_system_object)
    return 0;

  PPB_FileRef_CreateInfo create_info;
  PluginDispatcher::GetForResource(file_system_object)->Send(
      new PpapiHostMsg_PPBFileRef_Create(
          API_ID_PPB_FILE_REF, file_system_object->host_resource(),
          path, &create_info));
  return PPB_FileRef_Proxy::DeserializeFileRef(create_info);
}

bool PPB_FileRef_Proxy::OnMessageReceived(const IPC::Message& msg) {
  bool handled = true;
  IPC_BEGIN_MESSAGE_MAP(PPB_FileRef_Proxy, msg)
    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileRef_Create, OnMsgCreate)
    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileRef_GetParent, OnMsgGetParent)
    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileRef_MakeDirectory,
                        OnMsgMakeDirectory)
    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileRef_Touch, OnMsgTouch)
    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileRef_Delete, OnMsgDelete)
    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileRef_Rename, OnMsgRename)
    IPC_MESSAGE_HANDLER(PpapiHostMsg_PPBFileRef_GetAbsolutePath,
                        OnMsgGetAbsolutePath)

    IPC_MESSAGE_HANDLER(PpapiMsg_PPBFileRef_CallbackComplete,
                        OnMsgCallbackComplete)
    IPC_MESSAGE_UNHANDLED(handled = false)
  IPC_END_MESSAGE_MAP()
  return handled;
}

// static
void PPB_FileRef_Proxy::SerializeFileRef(PP_Resource file_ref,
                                         PPB_FileRef_CreateInfo* result) {
  EnterResourceNoLock<PPB_FileRef_API> enter(file_ref, false);
  if (enter.succeeded())
    *result = enter.object()->GetCreateInfo();
}

// static
PP_Resource PPB_FileRef_Proxy::DeserializeFileRef(
    const PPB_FileRef_CreateInfo& serialized) {
  if (serialized.resource.is_null())
    return 0;  // Resource invalid.
  return (new FileRef(serialized))->GetReference();
}

void PPB_FileRef_Proxy::OnMsgCreate(const HostResource& file_system,
                                    const std::string& path,
                                    PPB_FileRef_CreateInfo* result) {
  thunk::EnterResourceCreation enter(file_system.instance());
  if (enter.failed())
    return;
  PP_Resource resource = enter.functions()->CreateFileRef(
      file_system.host_resource(), path.c_str());
  if (!resource)
    return;  // CreateInfo default constructor initializes to 0.
  SerializeFileRef(resource, result);
}

void PPB_FileRef_Proxy::OnMsgGetParent(const HostResource& host_resource,
                                       PPB_FileRef_CreateInfo* result) {
  EnterHostFromHostResource<PPB_FileRef_API> enter(host_resource);
  if (enter.succeeded())
    SerializeFileRef(enter.object()->GetParent(), result);
}

void PPB_FileRef_Proxy::OnMsgMakeDirectory(const HostResource& host_resource,
                                           PP_Bool make_ancestors,
                                           int callback_id) {
  EnterHostFromHostResourceForceCallback<PPB_FileRef_API> enter(
      host_resource, callback_factory_,
      &PPB_FileRef_Proxy::OnCallbackCompleteInHost, host_resource, callback_id);
  if (enter.succeeded()) {
    enter.SetResult(enter.object()->MakeDirectory(make_ancestors,
                                                  enter.callback()));
  }
}

void PPB_FileRef_Proxy::OnMsgTouch(const HostResource& host_resource,
                                   PP_Time last_access,
                                   PP_Time last_modified,
                                   int callback_id) {
  EnterHostFromHostResourceForceCallback<PPB_FileRef_API> enter(
      host_resource, callback_factory_,
      &PPB_FileRef_Proxy::OnCallbackCompleteInHost, host_resource, callback_id);
  if (enter.succeeded()) {
    enter.SetResult(enter.object()->Touch(last_access, last_modified,
                                          enter.callback()));
  }
}

void PPB_FileRef_Proxy::OnMsgDelete(const HostResource& host_resource,
                                    int callback_id) {
  EnterHostFromHostResourceForceCallback<PPB_FileRef_API> enter(
      host_resource, callback_factory_,
      &PPB_FileRef_Proxy::OnCallbackCompleteInHost, host_resource, callback_id);
  if (enter.succeeded())
    enter.SetResult(enter.object()->Delete(enter.callback()));
}

void PPB_FileRef_Proxy::OnMsgRename(const HostResource& file_ref,
                                    const HostResource& new_file_ref,
                                    int callback_id) {
  EnterHostFromHostResourceForceCallback<PPB_FileRef_API> enter(
      file_ref, callback_factory_,
      &PPB_FileRef_Proxy::OnCallbackCompleteInHost, file_ref, callback_id);
  if (enter.succeeded()) {
    enter.SetResult(enter.object()->Rename(new_file_ref.host_resource(),
                                           enter.callback()));
  }
}

void PPB_FileRef_Proxy::OnMsgGetAbsolutePath(const HostResource& host_resource,
                                             SerializedVarReturnValue result) {
  EnterHostFromHostResource<PPB_FileRef_API> enter(host_resource);
  if (enter.succeeded())
    result.Return(dispatcher(), enter.object()->GetAbsolutePath());
}

void PPB_FileRef_Proxy::OnMsgCallbackComplete(
    const HostResource& host_resource,
    int callback_id,
    int32_t result) {
  // Forward the callback info to the plugin resource.
  EnterPluginFromHostResource<PPB_FileRef_API> enter(host_resource);
  if (enter.succeeded())
    static_cast<FileRef*>(enter.object())->ExecuteCallback(callback_id, result);
}

void PPB_FileRef_Proxy::OnCallbackCompleteInHost(
    int32_t result,
    const HostResource& host_resource,
    int callback_id) {
  // Execute OnMsgCallbackComplete in the plugin process.
  Send(new PpapiMsg_PPBFileRef_CallbackComplete(
      API_ID_PPB_FILE_REF, host_resource, callback_id, result));
}

}  // namespace proxy
}  // namespace ppapi