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1/* Copyright (c) 2013 The Chromium Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6
7/**
8 * This file defines methods for use with a PPB_FileIO resource that may become
9 * stable in the future. For now, they can be used only in plugins with DEV
10 * permissions.
11 */
12
13label Chrome {
14  M31 = 0.1
15};
16
17/**
18 * The PP_FileMapProtection values indicate the permissions requested for the
19 * file mapping. These should be used in a uint32_t bitfield.
20 */
21[assert_size(4)]
22 enum PP_FileMapProtection {
23  /** Requests read access to the mapped address. */
24  PP_FILEMAPPROTECTION_READ = 1u << 0,
25
26  /** Requests write access to the mapped address. */
27  PP_FILEMAPPROTECTION_WRITE = 1u << 1
28};
29
30/**
31 * The PP_FileMapFlags contain flag values for use with Map().
32 */
33[assert_size(4)]
34 enum PP_FileMapFlags {
35  /**
36   * Requests a shared mapping. If this flag is set, changes written to the
37   * memory region will be reflected in the underlying file and will thus
38   * eventually be visible to other processes which have opened the file. The
39   * file may not actually be updated until Unmap() is called. This is only
40   * valid if the PPB_FileIO resource was opened with write permission.
41   */
42  PP_FILEMAPFLAG_SHARED = 1u << 0,
43
44  /**
45   * Requests a copy-on-write mapping. If this flag is set, changes are not
46   * written to the underlying file, but only in the memory of the process
47   * (copy-on-write).
48   */
49  PP_FILEMAPFLAG_PRIVATE = 1u << 1,
50
51  /**
52   * Forces Map() to map the file contents at the provided |address|. If Map()
53   * can not comply, Map() will fail.
54   */
55  PP_FILEMAPFLAG_FIXED = 1u << 2
56};
57
58/**
59 *  PPB_FileIO_Dev contains functions that are usable with PPB_FileIO resources
60 *  but aren't yet considered stable yet and thus are not supported for general
61 *  NaCl or PNaCl apps yet. Features here are being tested and refined for
62 *  possible future inclusion in (stable) PPB_FileIO.
63 */
64interface PPB_FileIO_Dev {
65  /**
66   * Map() maps the contents from an offset of the file into memory.
67   *
68   * @param[in] file_io A PP_Resource corresponding to a file.
69   * @param[in] length The number of bytes to map.
70   * @param[in] map_protection A bitfield containing values from
71   * PP_FileMapProtection, indicating what memory operations should be permitted
72   * on the mapped region.
73   * @param[in] map_flags A bitfield containing values from
74   * PP_FileMapFlags, providing options for the behavior of Map. If the region
75   * is to be writeable, then exactly one of PP_FILEMAPFLAG_SHARED or
76   * PP_FILEMAPFLAG_PRIVATE must be set.
77   * @param[in] offset The offset into the file. Must be a multiple of the
78   * Map page size as returned by GetMapPageSize.
79   * @param[inout] address The value of |*address|, if non-NULL, will be used as
80   * a hint to determine where in memory the file should be mapped. If the value
81   * is NULL, the host operating system will choose |address|. Upon
82   * Map() completing, |*address| will contain the actual memory location at
83   * which the file was mapped. If the plugin provides a non-NULL |*address|, it
84   * must be a multiple of the map page size as returned by GetMapPageSize().
85   * @param[in] callback A PP_CompletionCallback to be called upon
86   * completion of Map().
87   *
88   * @return An int32_t containing an error code from <code>pp_errors.h</code>.
89   */
90  int32_t Map([in] PP_Resource file_io,
91              [in] int64_t length,
92              [in] uint32_t map_protection,
93              [in] uint32_t map_flags,
94              [in] int64_t offset,
95              [inout] mem_ptr_t address,
96              [in] PP_CompletionCallback callback);
97
98  /**
99   * Unmap() deletes the mapping of the specified address address to a
100   * file io.  The specified address must have been retrieved with
101   * Map().
102   * @param[in] file_io A PP_Resource corresponding to a file.
103   * @param[in] address The starting address of the address in memory to
104   * be unmapped.
105   * @param[in] length The length of the region to unmap.
106   */
107  void Unmap(PP_Resource file_io, mem_t address, int64_t length);
108
109  /**
110   * GetMapPageSize() returns the size of pages that Map() uses. Returns 0 on
111   * failure.
112   */
113  [on_failure=0]
114  int64_t GetMapPageSize(PP_Resource file_io);
115};
116
117