Move DirectoryReader::ReadEntries to FileRef::ReadDirectoryEntries

ppapi/cpp/directory_entry.h

+// Copyright (c) 2011 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.
+
+#ifndef PPAPI_CPP_DIRECTORY_ENTRY_H_
+#define PPAPI_CPP_DIRECTORY_ENTRY_H_
+
+#include <vector>
+
+#include "ppapi/c/pp_array_output.h"
+#include "ppapi/c/pp_directory_entry.h"
+#include "ppapi/cpp/array_output.h"
+#include "ppapi/cpp/file_ref.h"
+#include "ppapi/cpp/output_traits.h"
+#include "ppapi/cpp/pass_ref.h"
+
+/// @file
+/// This file defines the API used to handle a directory entry.
+
+namespace pp {
+
+/// The <code>DirectoryEntry</code> class represents information about
+/// a directory entry.
+class DirectoryEntry {
+ public:
+  /// Default constructor for creating an is_null() <code>DirectoryEntry</code>
+  /// object.
+  DirectoryEntry();
+
+  /// A constructor used when you have a <code>PP_DirectoryEntry</code> which
+  /// contains a <code>FileRef</code> that has already been reference counted
+  /// as a return value.
+  ///
+  /// @param[in] data A <code>PP_DirectoryEntry</code> to be copied.
+  DirectoryEntry(PassRef, const PP_DirectoryEntry& data);
+
+  /// A copy constructor for <code>DirectoryEntry</code>. This constructor
+  /// increments a reference count of the <code>FileRef</code> held by this
+  /// DirectoryEntry.
+  ///
+  /// @param[in] other A pointer to a <code>DirectoryEntry</code>.
+  DirectoryEntry(const DirectoryEntry& other);
+
+  /// A destructor that decrements a reference count of the <code>FileRef</code>
+  /// held by this <code>DirectoryEntry</code>.
+  ~DirectoryEntry();
+
+  /// This function assigns one <code>DirectoryEntry</code> object to this
+  /// <code>DirectoryEntry</code> object. This function increases the reference
+  /// count of the <code>FileRef</code> of the other DirectoryEntry while
+  /// decrementing the reference count of the FileRef of this DirectoryEntry.
+  ///
+  /// @param[in] other A pointer to a <code>DirectoryEntry</code>.
+  ///
+  /// @return A new <code>DirectoryEntry</code> object.
+  DirectoryEntry& operator=(const DirectoryEntry& other);
+
+  /// This function determines if this <code>DirectoryEntry</code> is a null
+  /// value.
+  ///
+  /// @return true if this <code>DirectoryEntry</code> is null, otherwise false.
+  bool is_null() const { return !data_.file_ref; }
+
+  /// This function returns the <code>FileRef</code> held by this
+  /// <code>DirectoryEntry</code>.
+  ///
+  /// @return A <code>FileRef</code> of the file.
+  FileRef file_ref() const { return FileRef(data_.file_ref); }
+
+  /// This function returns the <code>PP_FileType</code> of the file referenced
+  /// by this <code>DirectoryEntry</code>.
+  ///
+  /// @return A <code>PP_FileType</code> of the file.
+  PP_FileType file_type() const { return data_.file_type; }
+
+ private:
+  PP_DirectoryEntry data_;
+};
+
+namespace internal {
+
+class DirectoryEntryArrayOutputAdapterWithStorage
+    : public ArrayOutputAdapter<PP_DirectoryEntry> {
+ public:
+  DirectoryEntryArrayOutputAdapterWithStorage();
+  virtual ~DirectoryEntryArrayOutputAdapterWithStorage();
+
+  // Returns the final array of resource objects, converting the
+  // PP_DirectoryEntry written by the browser to pp::DirectoryEntry
+  // objects.
+  //
+  // This function should only be called once or we would end up converting
+  // the array more than once, which would mess up the refcounting.
+  std::vector<DirectoryEntry>& output();
+
+ private:
+  // The browser will write the PP_DirectoryEntrys into this array.
+  std::vector<PP_DirectoryEntry> temp_storage_;
+
+  // When asked for the output, the PP_DirectoryEntrys above will be
+  // converted to the pp::DirectoryEntrys in this array for passing to the
+  // calling code.
+  std::vector<DirectoryEntry> output_storage_;
+};
+
+// A specialization of CallbackOutputTraits to provide the callback system the
+// information on how to handle vectors of pp::DirectoryEntry. This converts
+// PP_DirectoryEntry to pp::DirectoryEntry when passing to the plugin.
+template <>
+struct CallbackOutputTraits< std::vector<DirectoryEntry> > {
+  typedef PP_ArrayOutput APIArgType;
+  typedef DirectoryEntryArrayOutputAdapterWithStorage StorageType;
+
+  static inline APIArgType StorageToAPIArg(StorageType& t) {
+    return t.pp_array_output();
+  }
+
+  static inline std::vector<DirectoryEntry>& StorageToPluginArg(
+      StorageType& t) {
+    return t.output();
+  }
+};
+
+}  // namespace internal
+}  // namespace pp
+
+#endif  // PPAPI_CPP_DIRECTORY_ENTRY_H_