content/renderer/pepper/ppb_file_ref_impl.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 "content/renderer/pepper/ppb_file_ref_impl.h"

#include "base/files/file_util_proxy.h"
#include "base/platform_file.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "content/child/fileapi/file_system_dispatcher.h"
#include "content/common/view_messages.h"
#include "content/renderer/pepper/common.h"
#include "content/renderer/pepper/pepper_file_system_host.h"
#include "content/renderer/pepper/plugin_module.h"
#include "content/renderer/pepper/renderer_ppapi_host_impl.h"
#include "content/renderer/render_thread_impl.h"
#include "net/base/escape.h"
#include "ppapi/c/pp_errors.h"
#include "ppapi/c/ppb_file_io.h"
#include "ppapi/host/ppapi_host.h"
#include "ppapi/shared_impl/file_type_conversion.h"
#include "ppapi/shared_impl/time_conversion.h"
#include "ppapi/shared_impl/var.h"
#include "ppapi/thunk/enter.h"
#include "ppapi/thunk/ppb_file_system_api.h"
#include "url/gurl.h"
#include "webkit/common/fileapi/directory_entry.h"
#include "webkit/common/fileapi/file_system_util.h"

using ppapi::HostResource;
using ppapi::PPB_FileRef_CreateInfo;
using ppapi::PPTimeToTime;
using ppapi::StringVar;
using ppapi::TrackedCallback;
using ppapi::thunk::EnterResourceNoLock;
using ppapi::thunk::PPB_FileRef_API;
using ppapi::thunk::PPB_FileSystem_API;

namespace content {

namespace {

bool IsValidLocalPath(const std::string& path) {
  // The path must start with '/'
  if (path.empty() || path[0] != '/')
    return false;

  // The path must contain valid UTF-8 characters.
  if (!IsStringUTF8(path))
    return false;

#if defined(OS_WIN)
  base::FilePath::StringType path_win(path.begin(), path.end());
  base::FilePath file_path(path_win);
#else
  base::FilePath file_path(path);
#endif
  if (file_path.ReferencesParent())
    return false;

  return true;
}

void TrimTrailingSlash(std::string* path) {
  // If this path ends with a slash, then normalize it away unless path is the
  // root path.
  if (path->size() > 1 && path->at(path->size() - 1) == '/')
    path->erase(path->size() - 1, 1);
}

std::string GetNameForExternalFilePath(const base::FilePath& in_path) {
  const base::FilePath::StringType& path = in_path.value();
  size_t pos = path.rfind(base::FilePath::kSeparators[0]);
  CHECK(pos != base::FilePath::StringType::npos);
#if defined(OS_WIN)
  return WideToUTF8(path.substr(pos + 1));
#elif defined(OS_POSIX)
  return path.substr(pos + 1);
#else
#error "Unsupported platform."
#endif
}

std::string GetNameForVirtualFilePath(const std::string& path) {
  if (path.size() == 1 && path[0] == '/')
    return path;

  // There should always be a leading slash at least!
  size_t pos = path.rfind('/');
  CHECK(pos != std::string::npos);
  return path.substr(pos + 1);
}

void IgnoreCloseCallback(base::PlatformFileError error_code) {
}

void PlatformFileInfoToPPFileInfo(
    const base::PlatformFileInfo& file_info,
    PP_FileSystemType file_system_type,
    PP_FileInfo* info) {
  DCHECK(info);
  ppapi::PlatformFileInfoToPepperFileInfo(file_info, file_system_type, info);
}

void GetFileInfoCallback(
    scoped_refptr<base::TaskRunner> task_runner,
    base::PlatformFile file,
    linked_ptr<PP_FileInfo> info,
    scoped_refptr<TrackedCallback> callback,
    base::PlatformFileError error_code,
    const base::PlatformFileInfo& file_info) {
  base::FileUtilProxy::Close(
      task_runner.get(), file, base::Bind(&IgnoreCloseCallback));

  if (!TrackedCallback::IsPending(callback))
    return;

  int32_t pp_error = ppapi::PlatformFileErrorToPepperError(error_code);
  if (pp_error != PP_OK) {
    callback->Run(pp_error);
    return;
  }

  PlatformFileInfoToPPFileInfo(
      file_info, PP_FILESYSTEMTYPE_EXTERNAL, info.get());

  callback->Run(PP_OK);
}

void QueryCallback(scoped_refptr<base::TaskRunner> task_runner,
                   linked_ptr<PP_FileInfo> info,
                   scoped_refptr<TrackedCallback> callback,
                   base::PlatformFileError error_code,
                   base::PassPlatformFile passed_file) {
  if (!TrackedCallback::IsPending(callback))
    return;

  int32_t pp_error = ppapi::PlatformFileErrorToPepperError(error_code);
  if (pp_error != PP_OK) {
    callback->Run(pp_error);
    return;
  }
  base::PlatformFile file = passed_file.ReleaseValue();

  if (!base::FileUtilProxy::GetFileInfoFromPlatformFile(
          task_runner.get(),
          file,
          base::Bind(
              &GetFileInfoCallback, task_runner, file, info, callback))) {
    base::FileUtilProxy::Close(
        task_runner.get(), file, base::Bind(&IgnoreCloseCallback));
    callback->Run(PP_ERROR_FAILED);
  }
}

void DidReadMetadata(
    scoped_refptr<ppapi::TrackedCallback> callback,
    linked_ptr<PP_FileInfo> info,
    PP_FileSystemType file_system_type,
    const base::PlatformFileInfo& file_info) {
  if (!TrackedCallback::IsPending(callback))
    return;

  PlatformFileInfoToPPFileInfo(file_info, file_system_type, info.get());
  callback->Run(PP_OK);
}

void DidReadDirectory(
    scoped_refptr<ppapi::TrackedCallback> callback,
    PPB_FileRef_Impl* dir_ref,
    linked_ptr<std::vector<ppapi::PPB_FileRef_CreateInfo> > dir_files,
    linked_ptr<std::vector<PP_FileType> > dir_file_types,
    const std::vector<fileapi::DirectoryEntry>& entries,
    bool has_more) {
  if (!TrackedCallback::IsPending(callback))
    return;

  // The current filesystem backend always returns false.
  DCHECK(!has_more);

  DCHECK(dir_ref);
  DCHECK(dir_files.get());
  DCHECK(dir_file_types.get());

  std::string dir_path = dir_ref->GetCreateInfo().path;
  if (dir_path.empty() || dir_path[dir_path.size() - 1] != '/')
    dir_path += '/';

  for (size_t i = 0; i < entries.size(); ++i) {
    const fileapi::DirectoryEntry& entry = entries[i];
    scoped_refptr<PPB_FileRef_Impl> file_ref(PPB_FileRef_Impl::CreateInternal(
        dir_ref->pp_instance(),
        dir_ref->file_system_resource(),
        dir_path + fileapi::FilePathToString(base::FilePath(entry.name))));
    dir_files->push_back(file_ref->GetCreateInfo());
    dir_file_types->push_back(
        entry.is_directory ? PP_FILETYPE_DIRECTORY : PP_FILETYPE_REGULAR);
    // Add a ref count on behalf of the plugin side.
    file_ref->GetReference();
  }
  CHECK_EQ(dir_files->size(), dir_file_types->size());

  callback->Run(PP_OK);
}

void DidFinishFileOperation(
    scoped_refptr<ppapi::TrackedCallback> callback,
    base::PlatformFileError error_code) {
  if (callback->completed())
    return;
  callback->Run(ppapi::PlatformFileErrorToPepperError(error_code));
}

}  // namespace

PPB_FileRef_Impl::PPB_FileRef_Impl(const PPB_FileRef_CreateInfo& info,
                                   PP_Resource file_system)
    : PPB_FileRef_Shared(ppapi::OBJECT_IS_IMPL, info),
      file_system_(file_system),
      external_file_system_path_(),
      routing_id_(MSG_ROUTING_NONE) {
  if (RenderThreadImpl::current()) {  // NULL in tests.
    routing_id_ = RenderThreadImpl::current()->GenerateRoutingID();
    ChildThread::current()->AddRoute(routing_id_, this);
  }
}

PPB_FileRef_Impl::PPB_FileRef_Impl(const PPB_FileRef_CreateInfo& info,
                                   const base::FilePath& external_file_path)
    : PPB_FileRef_Shared(ppapi::OBJECT_IS_IMPL, info),
      file_system_(),
      external_file_system_path_(external_file_path),
      routing_id_(MSG_ROUTING_NONE) {
  if (RenderThreadImpl::current()) {  // NULL in tests.
    routing_id_ = RenderThreadImpl::current()->GenerateRoutingID();
    ChildThread::current()->AddRoute(routing_id_, this);
  }
}

PPB_FileRef_Impl::~PPB_FileRef_Impl() {
  if (RenderThreadImpl::current())
    ChildThread::current()->RemoveRoute(routing_id_);
}

// static
PPB_FileRef_Impl* PPB_FileRef_Impl::CreateInternal(PP_Instance instance,
                                                   PP_Resource pp_file_system,
                                                   const std::string& path) {
  PepperFileSystemHost* fs_host = GetFileSystemHostInternal(
      instance, pp_file_system);
  if (!fs_host)
    return 0;

  PP_FileSystemType type = fs_host->GetType();
  if (type != PP_FILESYSTEMTYPE_LOCALPERSISTENT &&
      type != PP_FILESYSTEMTYPE_LOCALTEMPORARY &&
      type != PP_FILESYSTEMTYPE_EXTERNAL &&
      type != PP_FILESYSTEMTYPE_ISOLATED)
    return 0;

  PPB_FileRef_CreateInfo info;
  info.resource = HostResource::MakeInstanceOnly(instance);
  info.file_system_plugin_resource = pp_file_system;
  info.file_system_type = type;

  // Validate the path.
  info.path = path;
  if (!IsValidLocalPath(info.path))
    return 0;
  TrimTrailingSlash(&info.path);

  info.name = GetNameForVirtualFilePath(info.path);

  PPB_FileRef_Impl* file_ref = new PPB_FileRef_Impl(info, pp_file_system);

  RendererPpapiHostImpl* renderer_host =
      RendererPpapiHostImpl::GetForPPInstance(instance);
  if (renderer_host && renderer_host->IsRunningInProcess())
    file_ref->AddFileSystemRefCount();
  return file_ref;
}

// static
PPB_FileRef_Impl* PPB_FileRef_Impl::CreateExternal(
    PP_Instance instance,
    const base::FilePath& external_file_path,
    const std::string& display_name) {
  PPB_FileRef_CreateInfo info;
  info.resource = HostResource::MakeInstanceOnly(instance);
  info.file_system_plugin_resource = 0;
  info.file_system_type = PP_FILESYSTEMTYPE_EXTERNAL;
  if (display_name.empty())
    info.name = GetNameForExternalFilePath(external_file_path);
  else
    info.name = display_name;

  return new PPB_FileRef_Impl(info, external_file_path);
}

PP_Resource PPB_FileRef_Impl::GetParent() {
  if (GetFileSystemType() == PP_FILESYSTEMTYPE_EXTERNAL)
    return 0;

  const std::string& virtual_path = GetCreateInfo().path;

  // There should always be a leading slash at least!
  size_t pos = virtual_path.rfind('/');
  CHECK(pos != std::string::npos);

  // If the path is "/foo", then we want to include the slash.
  if (pos == 0)
    pos++;
  std::string parent_path = virtual_path.substr(0, pos);

  scoped_refptr<PPB_FileRef_Impl> parent_ref(
      CreateInternal(pp_instance(), file_system_, parent_path));
  if (!parent_ref.get())
    return 0;
  return parent_ref->GetReference();
}

int32_t PPB_FileRef_Impl::MakeDirectory(
    PP_Bool make_ancestors,
    scoped_refptr<TrackedCallback> callback) {
  if (!IsValidNonExternalFileSystem())
    return PP_ERROR_NOACCESS;

  FileSystemDispatcher* file_system_dispatcher =
      ChildThread::current()->file_system_dispatcher();
  file_system_dispatcher->CreateDirectory(
      GetFileSystemURL(), false /* exclusive */, PP_ToBool(make_ancestors),
      base::Bind(&DidFinishFileOperation, callback));
  return PP_OK_COMPLETIONPENDING;
}

int32_t PPB_FileRef_Impl::Touch(PP_Time last_access_time,
                                PP_Time last_modified_time,
                                scoped_refptr<TrackedCallback> callback) {
  if (!IsValidNonExternalFileSystem())
    return PP_ERROR_NOACCESS;

  FileSystemDispatcher* file_system_dispatcher =
      ChildThread::current()->file_system_dispatcher();
  file_system_dispatcher->TouchFile(
      GetFileSystemURL(),
      PPTimeToTime(last_access_time),
      PPTimeToTime(last_modified_time),
      base::Bind(&DidFinishFileOperation, callback));
  return PP_OK_COMPLETIONPENDING;
}

int32_t PPB_FileRef_Impl::Delete(scoped_refptr<TrackedCallback> callback) {
  if (!IsValidNonExternalFileSystem())
    return PP_ERROR_NOACCESS;

  FileSystemDispatcher* file_system_dispatcher =
      ChildThread::current()->file_system_dispatcher();
  file_system_dispatcher->Remove(
      GetFileSystemURL(),
      false /* recursive */,
      base::Bind(&DidFinishFileOperation, callback));
  return PP_OK_COMPLETIONPENDING;
}

int32_t PPB_FileRef_Impl::Rename(PP_Resource new_pp_file_ref,
                                 scoped_refptr<TrackedCallback> callback) {
  EnterResourceNoLock<PPB_FileRef_API> enter(new_pp_file_ref, true);
  if (enter.failed())
    return PP_ERROR_BADRESOURCE;
  PPB_FileRef_Impl* new_file_ref =
      static_cast<PPB_FileRef_Impl*>(enter.object());

  if (!IsValidNonExternalFileSystem() ||
      file_system_ != new_file_ref->file_system_)
    return PP_ERROR_NOACCESS;

  // TODO(viettrungluu): Also cancel when the new file ref is destroyed?
  // http://crbug.com/67624
  FileSystemDispatcher* file_system_dispatcher =
      ChildThread::current()->file_system_dispatcher();
  file_system_dispatcher->Move(
      GetFileSystemURL(), new_file_ref->GetFileSystemURL(),
      base::Bind(&DidFinishFileOperation, callback));
  return PP_OK_COMPLETIONPENDING;
}

PP_Var PPB_FileRef_Impl::GetAbsolutePath() {
  if (GetFileSystemType() != PP_FILESYSTEMTYPE_EXTERNAL)
    return GetPath();
  if (!external_path_var_.get()) {
    external_path_var_ =
        new StringVar(external_file_system_path_.AsUTF8Unsafe());
  }
  return external_path_var_->GetPPVar();
}

base::FilePath PPB_FileRef_Impl::GetSystemPath() const {
  if (GetFileSystemType() != PP_FILESYSTEMTYPE_EXTERNAL) {
    NOTREACHED();
    return base::FilePath();
  }
  return external_file_system_path_;
}

GURL PPB_FileRef_Impl::GetFileSystemURL() const {
  if (GetFileSystemType() != PP_FILESYSTEMTYPE_LOCALPERSISTENT &&
      GetFileSystemType() != PP_FILESYSTEMTYPE_LOCALTEMPORARY &&
      GetFileSystemType() != PP_FILESYSTEMTYPE_EXTERNAL &&
      GetFileSystemType() != PP_FILESYSTEMTYPE_ISOLATED) {
    NOTREACHED();
    return GURL();
  }

  const std::string& virtual_path = GetCreateInfo().path;
  CHECK(!virtual_path.empty());  // Should always be at least "/".

  // Since |virtual_path_| starts with a '/', it looks like an absolute path.
  // We need to trim off the '/' before calling Resolve, as FileSystem URLs
  // start with a storage type identifier that looks like a path segment.

  PepperFileSystemHost* host = GetFileSystemHost();
  if (!host)
    return GURL();

  return GURL(host->GetRootUrl()).Resolve(net::EscapePath(
      virtual_path.substr(1)));
}

bool PPB_FileRef_Impl::OnMessageReceived(const IPC::Message& msg) {
  bool handled = true;
  IPC_BEGIN_MESSAGE_MAP(PPB_FileRef_Impl, msg)
    IPC_MESSAGE_HANDLER(ViewMsg_AsyncOpenPepperFile_ACK, OnAsyncFileOpened)
    IPC_MESSAGE_UNHANDLED(handled = false)
  IPC_END_MESSAGE_MAP()
  return handled;
}

void PPB_FileRef_Impl::OnAsyncFileOpened(
    base::PlatformFileError error_code,
    IPC::PlatformFileForTransit file_for_transit,
    int message_id) {
  AsyncOpenFileCallback* callback =
      pending_async_open_files_.Lookup(message_id);
  DCHECK(callback);
  pending_async_open_files_.Remove(message_id);

  base::PlatformFile file =
      IPC::PlatformFileForTransitToPlatformFile(file_for_transit);
  callback->Run(error_code, base::PassPlatformFile(&file));
  // Make sure we won't leak file handle if the requester has died.
  if (file != base::kInvalidPlatformFileValue) {
    base::FileUtilProxy::Close(
        RenderThreadImpl::current()->GetFileThreadMessageLoopProxy().get(),
        file,
        base::FileUtilProxy::StatusCallback());
  }
  delete callback;
}

bool PPB_FileRef_Impl::IsValidNonExternalFileSystem() const {
  PepperFileSystemHost* host = GetFileSystemHost();
  return HasValidFileSystem() && host &&
      host->GetType() != PP_FILESYSTEMTYPE_EXTERNAL;
}

bool PPB_FileRef_Impl::HasValidFileSystem() const {
  PepperFileSystemHost* host = GetFileSystemHost();
  return host && host->IsOpened();
}

int32_t PPB_FileRef_Impl::Query(PP_FileInfo* info,
                                scoped_refptr<TrackedCallback> callback) {
  NOTREACHED();
  return PP_ERROR_FAILED;
}

int32_t PPB_FileRef_Impl::QueryInHost(
    linked_ptr<PP_FileInfo> info,
    scoped_refptr<TrackedCallback> callback) {
  if (!file_system_) {
    // External file system
    // We have to do something totally different for external file systems.

    // TODO(teravest): Use the SequencedWorkerPool instead.
    scoped_refptr<base::TaskRunner> task_runner =
        RenderThreadImpl::current()->GetFileThreadMessageLoopProxy();

    int message_id = pending_async_open_files_.Add(new AsyncOpenFileCallback(
        base::Bind(&QueryCallback, task_runner, info, callback)));
    RenderThreadImpl::current()->Send(new ViewHostMsg_AsyncOpenPepperFile(
        routing_id_,
        GetSystemPath(),
        PP_FILEOPENFLAG_READ,
        message_id));
  } else {
    // Non-external file system
    if (!HasValidFileSystem())
      return PP_ERROR_NOACCESS;

    PP_FileSystemType file_system_type = GetFileSystemHost()->GetType();
    FileSystemDispatcher* file_system_dispatcher =
        ChildThread::current()->file_system_dispatcher();
    file_system_dispatcher->ReadMetadata(
        GetFileSystemURL(),
        base::Bind(&DidReadMetadata, callback, info, file_system_type),
        base::Bind(&DidFinishFileOperation, callback));
  }
  return PP_OK_COMPLETIONPENDING;
}

int32_t PPB_FileRef_Impl::ReadDirectoryEntries(
    const PP_ArrayOutput& output,
    scoped_refptr<TrackedCallback> callback) {
  NOTREACHED();
  return PP_ERROR_FAILED;
}

int32_t PPB_FileRef_Impl::ReadDirectoryEntriesInHost(
    linked_ptr<std::vector<ppapi::PPB_FileRef_CreateInfo> > files,
    linked_ptr<std::vector<PP_FileType> > file_types,
    scoped_refptr<TrackedCallback> callback) {
  if (!IsValidNonExternalFileSystem())
    return PP_ERROR_NOACCESS;

  // TODO(yzshen): Passing base::Unretained(this) to the callback could
  // be dangerous.
  FileSystemDispatcher* file_system_dispatcher =
      ChildThread::current()->file_system_dispatcher();
  file_system_dispatcher->ReadDirectory(
      GetFileSystemURL(),
      base::Bind(&DidReadDirectory,
                 callback, base::Unretained(this), files, file_types),
      base::Bind(&DidFinishFileOperation, callback));
  return PP_OK_COMPLETIONPENDING;
}

PepperFileSystemHost* PPB_FileRef_Impl::GetFileSystemHost() const {
  return GetFileSystemHostInternal(pp_instance(), file_system_);
}

PepperFileSystemHost* PPB_FileRef_Impl::GetFileSystemHostInternal(
    PP_Instance instance, PP_Resource resource) {
  const ppapi::host::PpapiHost* ppapi_host =
      RendererPpapiHost::GetForPPInstance(instance)->GetPpapiHost();
  if (!resource || !ppapi_host)
    return NULL;
  ppapi::host::ResourceHost* resource_host =
      ppapi_host->GetResourceHost(resource);
  if (resource_host && resource_host->IsFileSystemHost())
    return static_cast<PepperFileSystemHost*>(resource_host);
  return NULL;
}

}  // namespace content