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/* Copyright 2014 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 mapping and unmapping files into and out of
* memory.
*/
label Chrome {
[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 {
/** 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 {
/**
* 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_FileMapping contains functions for mapping and unmapping files into and
* out of memory.
*/
[singleton]
interface PPB_FileMapping {
/**
* Map() maps the contents from an offset of the file into memory.
*
* @param[in] instance A <code>PP_Instance</code> identifying one instance of
* a module.
* @param[in] file_io A <code>PPB_FileIO</code> <code>PP_Resource</code>
* corresponding to the file that should be mapped in to memory.
* @param[in] length The number of bytes to map.
* @param[in] map_protection A bitfield containing values from
* <code>PP_FileMapProtection</code>, indicating what memory operations
* should be permitted on the mapped region.
* @param[in] map_flags A bitfield containing values from
* <code>PP_FileMapFlags</code>, providing options for the behavior of Map.
* If the region is to be writeable, then exactly one of
* <code>PP_FILEMAPFLAG_SHARED</code> or <code>PP_FILEMAPFLAG_PRIVATE</code>
* 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 <code>*address</code>, 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
* <code>address</code>. Upon Map() completing, <code>*address</code> will
* contain the actual memory location at which the file was mapped. If the
* plugin provides a non-NULL <code>*address</code>, it must be a multiple of
* the map page size as returned by GetMapPageSize().
* @param[in] callback A <code>PP_CompletionCallback</code> 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_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. 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.
* @param[in] callback A <code>PP_CompletionCallback</code> to be called upon
* completion of Unmap().
*
* @return An int32_t containing an error code from <code>pp_errors.h</code>.
*/
int32_t Unmap([in] PP_Instance instance,
[in] mem_t address,
[in] int64_t length,
[in] PP_CompletionCallback callback);
/**
* GetMapPageSize() retrieves the size of pages that Map() uses.
*
* @param[in] instance A <code>PP_Instance</code> identifying the instance.
*
* @return The size of pages that Map() uses. Returns 0 on failure.
*/
[on_failure=0]
int64_t GetMapPageSize(PP_Instance instance);
};
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