Move DirectoryReader::ReadEntries to FileRef::ReadDirectoryEntries

ppapi/api/ppb_file_ref.idl

 /* 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.
  */
 
 /**
  * This file defines the API to create a file reference or "weak pointer" to a
  * file in a file system.
  */
 
@@ skipping 150 matching lines @@
    * file reference.
    * @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
    * completion of Rename().
    *
    * @return An int32_t containing an error code from <code>pp_errors.h</code>.
    */
   int32_t Rename([in] PP_Resource file_ref,
                  [in] PP_Resource new_file_ref,
                  [in] PP_CompletionCallback callback);
 
-  /*
+  /**
    * Query() queries info about a file or directory. You must have access to
    * read this file or directory if it exists in the external filesystem.
    *
    * @param[in] file_ref A <code>PP_Resource</code> corresponding to a file
    * reference.
    * @param[out] info A pointer to a <code>PP_FileInfo</code> which will be
    * populated with information about the file or directory.
    * @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
    * completion of Query().
    *
    * @return An int32_t containing an error code from <code>pp_errors.h</code>.
    */
   [version=1.1]
   int32_t Query([in] PP_Resource file_ref,
                 [out] PP_FileInfo info,
                 [in] PP_CompletionCallback callback);
+
+  /**
+   * Reads all entries in a directory.
+   *
+   * @param[in] file_ref A <code>PP_Resource</code> corresponding to a directory
+   * reference.
+   * @param[in] output An output array which will receive

[palmer, 2013/05/03 00:07:24]

Shouldn't this be [out], then?

[hamaji, 2013/05/03 01:10:34]

I'm not sure, but I think this should be [in], because PP_ArrayOutput is a
handle like file descriptors. We pass a file descriptor by value to write(2),
though write(2) will modify underlying data structures.

As you may know, this is code rather than a comment because we are in an IDL
file. If we change this, the interface of this function will change.

Anyway, I think I want inputs from pepper folks because they know how the
original code (DirectoryReader) is introduced. Dave, do you have any opinion?

[dmichael (off chromium), 2013/05/03 02:54:57]

We use [in] for PP_ArrayOutput parameters. It's a little confusing, given that
PP_ArrayOutput is used to send data out, but the call doesn't actually write to
the PP_ArrayOutput. The PP_ArrayOutput just gives PPAPI a way to allocate a
buffer to pass to the plugin.

+   * <code>PP_DirectoryEntry</code> objects on success.
+   * @param[in] callback A <code>PP_CompletionCallback</code> to run on
+   * completion.
+   *
+   * @return An int32_t containing an error code from <code>pp_errors.h</code>.
+   */
+  [version=1.1]
+  int32_t ReadEntries([in] PP_Resource file_ref,
+                      [in] PP_ArrayOutput output,
+                      [in] PP_CompletionCallback callback);
 };