xref: /aosp_15_r20/external/cronet/base/fuchsia/mem_buffer_util.h (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1 // Copyright 2018 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef BASE_FUCHSIA_MEM_BUFFER_UTIL_H_
6 #define BASE_FUCHSIA_MEM_BUFFER_UTIL_H_
7 
8 #include <fuchsia/mem/cpp/fidl.h>
9 
10 #include <optional>
11 #include <string>
12 #include <string_view>
13 
14 #include "base/base_export.h"
15 #include "base/files/file.h"
16 
17 namespace base {
18 
19 // Returns the contents of `buffer` (which must be a valid UTF-8 string), or
20 // null in case of a conversion error.
21 BASE_EXPORT std::optional<std::u16string> ReadUTF8FromVMOAsUTF16(
22     const fuchsia::mem::Buffer& buffer);
23 
24 // Creates a Fuchsia VMO from `data`. The size of the resulting virtual memory
25 // object will be set to the size of the string, and it will be given the name
26 // `name`.
27 BASE_EXPORT zx::vmo VmoFromString(std::string_view data, std::string_view name);
28 
29 // Creates a Fuchsia memory buffer from `data`. The resulting virtual memory
30 // object will be given the name `name`.
31 // `fuchsia::mem::Buffer` is deprecated: for new interfaces, prefer using
32 // a VMO object directly (see `VmoFromString`).
33 BASE_EXPORT fuchsia::mem::Buffer MemBufferFromString(std::string_view data,
34                                                      std::string_view name);
35 
36 // Creates a Fuchsia memory buffer from the UTF-16 string `data`. The resulting
37 // virtual memory object will be given the name `name`.
38 BASE_EXPORT fuchsia::mem::Buffer MemBufferFromString16(std::u16string_view data,
39                                                        std::string_view name);
40 
41 // Returns the contents of `data`, or null if the read operation fails.
42 BASE_EXPORT std::optional<std::string> StringFromVmo(const zx::vmo& vmo);
43 
44 // Returns the contents of `buffer`, or null if the read operation fails.
45 // `fuchsia::mem::Buffer` is deprecated: for new interfaces, prefer using
46 // a VMO object directly (see `StringFromVmo`).
47 BASE_EXPORT std::optional<std::string> StringFromMemBuffer(
48     const fuchsia::mem::Buffer& buffer);
49 
50 // Returns the contents of `data`, or null if the read operation fails.
51 BASE_EXPORT std::optional<std::string> StringFromMemData(
52     const fuchsia::mem::Data& data);
53 
54 // Creates a memory-mapped, read-only Buffer with the contents of `file`. Will
55 // return an empty Buffer if the file could not be opened.
56 BASE_EXPORT fuchsia::mem::Buffer MemBufferFromFile(File file);
57 
58 // Creates a non-resizeable, copy-on-write shared memory clone of `buffer`. The
59 // resulting virtual memory object will be given the name `name`.
60 BASE_EXPORT fuchsia::mem::Buffer CloneBuffer(const fuchsia::mem::Buffer& buffer,
61                                              std::string_view name);
62 
63 }  // namespace base
64 
65 #endif  // BASE_FUCHSIA_MEM_BUFFER_UTIL_H_
66