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Reactos
1
2//
3// _getbuf.cpp
4//
5// Copyright (c) Microsoft Corporation. All rights reserved.
6//
7// Defines __acrt_stdio_allocate_buffer_nolock(), which allocates a buffer for a stream.
8//
9#include <corecrt_internal_stdio.h>
10
11
12
13// Allocates a buffer for the provided stream. This function assumes that the
14// caller has already checked to ensure that the stream does not already have a
15// buffer.
16extern "C" void __cdecl __acrt_stdio_allocate_buffer_nolock(FILE* const public_stream)
17{
18 _ASSERTE(public_stream != nullptr);
19
20 __crt_stdio_stream const stream(public_stream);
21
22 #ifndef CRTDLL
23 ++_cflush; // Force the library pre-termination procedure to run
24 #endif
25
26 // Try to get a big buffer:
27 stream->_base = _calloc_crt_t(char, _INTERNAL_BUFSIZ).detach();
28 if (stream->_base != nullptr)
29 {
30 stream.set_flags(_IOBUFFER_CRT);
31 stream->_bufsiz = _INTERNAL_BUFSIZ;
32 }
33 // If we couldn't get a big buffer, use single character buffering:
34 else
35 {
36 stream.set_flags(_IOBUFFER_NONE);
37 stream->_base = reinterpret_cast<char *>(&stream->_charbuf);
38 stream->_bufsiz = 2;
39 }
40
41 stream->_ptr = stream->_base;
42 stream->_cnt = 0;
43}