PPAPI: Implement PPB_FileMapping on POSIX

ppapi/api/ppb_file_mapping.idl

 /* 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.
  */
 
 
 /**
  * This file defines methods for use with a PPB_FileIO resource that may become
  * stable in the future. For now, they can be used only in plugins with DEV
  * permissions.
  */
+[generate_thunk]
 
 label Chrome {
-  M31 = 0.1
+  [channel=dev] M34 = 0.1
 };
 
 /**
  * The PP_FileMapProtection values indicate the permissions requested for the
  * file mapping. These should be used in a uint32_t bitfield.
  */
 [assert_size(4)]
- enum PP_FileMapProtection {
+enum PP_FileMapProtection {
   /** Requests read access to the mapped address. */
   PP_FILEMAPPROTECTION_READ = 1u << 0,
 
   /** Requests write access to the mapped address. */
   PP_FILEMAPPROTECTION_WRITE = 1u << 1
 };
 
 /**
  * The PP_FileMapFlags contain flag values for use with Map().
  */
 [assert_size(4)]
- enum PP_FileMapFlags {
+enum PP_FileMapFlags {
   /**
    * Requests a shared mapping. If this flag is set, changes written to the
    * memory region will be reflected in the underlying file and will thus
    * eventually be visible to other processes which have opened the file. The
    * file may not actually be updated until Unmap() is called. This is only
    * valid if the PPB_FileIO resource was opened with write permission.
    */
   PP_FILEMAPFLAG_SHARED = 1u << 0,
 
   /**
    * Requests a copy-on-write mapping. If this flag is set, changes are not
    * written to the underlying file, but only in the memory of the process
    * (copy-on-write).
    */
   PP_FILEMAPFLAG_PRIVATE = 1u << 1,
 
   /**
    * Forces Map() to map the file contents at the provided |address|. If Map()
    * can not comply, Map() will fail.
    */
   PP_FILEMAPFLAG_FIXED = 1u << 2
 };
 
 /**
- *  PPB_FileIO_Dev contains functions that are usable with PPB_FileIO resources
+ *  PPB_FileMapping contains functions that are usable with PPB_FileIO resources
  *  but aren't yet considered stable yet and thus are not supported for general
  *  NaCl or PNaCl apps yet. Features here are being tested and refined for
  *  possible future inclusion in (stable) PPB_FileIO.
  */
-interface PPB_FileIO_Dev {
+[singleton]
+interface PPB_FileMapping {
   /**
    * Map() maps the contents from an offset of the file into memory.
    *
    * @param[in] file_io A PP_Resource corresponding to a file.
    * @param[in] length The number of bytes to map.
    * @param[in] map_protection A bitfield containing values from
    * PP_FileMapProtection, indicating what memory operations should be permitted
    * on the mapped region.
    * @param[in] map_flags A bitfield containing values from
    * PP_FileMapFlags, providing options for the behavior of Map. If the region
    * is to be writeable, then exactly one of PP_FILEMAPFLAG_SHARED or
    * PP_FILEMAPFLAG_PRIVATE must be set.
    * @param[in] offset The offset into the file. Must be a multiple of the
    * Map page size as returned by GetMapPageSize.
    * @param[inout] address The value of |*address|, if non-NULL, will be used as
    * a hint to determine where in memory the file should be mapped. If the value
    * is NULL, the host operating system will choose |address|. Upon
    * Map() completing, |*address| will contain the actual memory location at
    * which the file was mapped. If the plugin provides a non-NULL |*address|, it
    * must be a multiple of the map page size as returned by GetMapPageSize().
    * @param[in] callback A PP_CompletionCallback to be called upon
    * completion of Map().
    *
    * @return An int32_t containing an error code from <code>pp_errors.h</code>.
    */
-  int32_t Map([in] PP_Resource file_io,
+[singleton]
+  int32_t Map([in] PP_Instance instance,
+              [in] PP_Resource file_io,
               [in] int64_t length,
               [in] uint32_t map_protection,
               [in] uint32_t map_flags,
               [in] int64_t offset,
               [inout] mem_ptr_t address,
               [in] PP_CompletionCallback callback);
 
   /**
-   * Unmap() deletes the mapping of the specified address address to a
-   * file io.  The specified address must have been retrieved with
-   * Map().
-   * @param[in] file_io A PP_Resource corresponding to a file.
+   * Unmap() deletes the mapping of the specified address.  The specified
+   * address must have been retrieved with Map().
+   * @param[in] instance A <code>PP_Instance</code> identifying the instance.
    * @param[in] address The starting address of the address in memory to
    * be unmapped.
    * @param[in] length The length of the region to unmap.
    */
-  void Unmap(PP_Resource file_io, mem_t address, int64_t length);
+  void Unmap(PP_Instance file_io, mem_t address, int64_t length);
 
   /**
    * GetMapPageSize() returns the size of pages that Map() uses. Returns 0 on
    * failure.
+   * @param[in] instance A <code>PP_Instance</code> identifying the instance.
    */
   [on_failure=0]
-  int64_t GetMapPageSize(PP_Resource file_io);
+  int64_t GetMapPageSize(PP_Instance file_io);
 };