_filbuf.cpp File Reference

#include <corecrt_internal_stdio.h>

Include dependency graph for _filbuf.cpp:

Go to the source code of this file.

Classes
struct	anonymous_namespace{_filbuf.cpp}::filwbuf_context

Namespaces
namespace	anonymous_namespace{_filbuf.cpp}

Functions
static int	get_context_nolock (__crt_stdio_stream const, char) throw ()
static filwbuf_context	get_context_nolock (__crt_stdio_stream const stream, wchar_t) throw ()
static bool	is_buffer_valid_nolock (__crt_stdio_stream const stream, char) throw ()
static bool	is_buffer_valid_nolock (__crt_stdio_stream const stream, wchar_t) throw ()
static unsigned char	read_character_nolock (__crt_stdio_stream const stream, int, char) throw ()
static wchar_t	read_character_nolock (__crt_stdio_stream const stream, filwbuf_context const context, wchar_t) throw ()
template<typename Character >
static int __cdecl	common_refill_and_read_nolock (__crt_stdio_stream const stream) throw ()
int __cdecl	__acrt_stdio_refill_and_read_narrow_nolock (FILE *const stream)
int __cdecl	__acrt_stdio_refill_and_read_wide_nolock (FILE *const stream)

Function Documentation

__acrt_stdio_refill_and_read_narrow_nolock()

int __cdecl __acrt_stdio_refill_and_read_narrow_nolock

(

FILE *const

stream

)

Definition at line 178 of file _filbuf.cpp.

{
    return common_refill_and_read_nolock<char>(__crt_stdio_stream(stream));
}

Referenced by __DEFINE_CPP_OVERLOAD_STANDARD_FUNC_0_0(), _fgetc_nolock(), and _fread_nolock_s().

__acrt_stdio_refill_and_read_wide_nolock()

int __cdecl __acrt_stdio_refill_and_read_wide_nolock

(

FILE *const

stream

)

Definition at line 185 of file _filbuf.cpp.

{
    return common_refill_and_read_nolock<wchar_t>(__crt_stdio_stream(stream));
}

Referenced by __DEFINE_CPP_OVERLOAD_STANDARD_FUNC_0_0(), and _fgetwc_nolock().

common_refill_and_read_nolock()

template<typename Character >

static int __cdecl common_refill_and_read_nolock ( __crt_stdio_stream const  stream ) throw ( )

static

Definition at line 122 of file _filbuf.cpp.

{
    typedef __acrt_stdio_char_traits<Character> stdio_traits;
 
    _VALIDATE_RETURN(stream.valid(), EINVAL, stdio_traits::eof);
 
    if (!stream.is_in_use() || stream.is_string_backed())
        return stdio_traits::eof;
 
    if (stream.has_all_of(_IOWRITE))
    {
        stream.set_flags(_IOERROR);
        return stdio_traits::eof;
    }
 
    stream.set_flags(_IOREAD);
 
    // Get a buffer, if necessary:
    if (!stream.has_any_buffer())
        __acrt_stdio_allocate_buffer_nolock(stream.public_stream());
 
    auto const context = get_context_nolock(stream, Character());
 
    stream->_ptr = stream->_base;
    stream->_cnt = _read(_fileno(stream.public_stream()), stream->_base, stream->_bufsiz);
 
    if (!is_buffer_valid_nolock(stream, Character()))
    {
        stream.set_flags(stream->_cnt != 0 ? _IOERROR : _IOEOF);
        stream->_cnt = 0;
        return stdio_traits::eof;
    }
 
    if (!stream.has_any_of(_IOWRITE | _IOUPDATE) &&
        ((_osfile_safe(_fileno(stream.public_stream())) & (FTEXT | FEOFLAG)) == (FTEXT | FEOFLAG)))
    {
        stream.set_flags(_IOCTRLZ);
    }
 
    // Check for small _bufsiz (_SMALL_BUFSIZ). If it is small and if it is our
    // buffer, then this must be the first call to this function after an fseek
    // on a read-access-only stream. Restore _bufsiz to its larger value
    // (_INTERNAL_BUFSIZ) so that the next call to this function, if one is made,
    // will fill the whole buffer.
    if (stream->_bufsiz == _SMALL_BUFSIZ &&
        stream.has_crt_buffer() &&
        !stream.has_all_of(_IOBUFFER_SETVBUF))
    {
        stream->_bufsiz = _INTERNAL_BUFSIZ;
    }
 
    return read_character_nolock(stream, context, Character());
}

get_context_nolock() [1/2]

static filwbuf_context get_context_nolock ( __crt_stdio_stream const  stream, wchar_t    ) throw ( )

static

Definition at line 31 of file _filbuf.cpp.

{
    // When reading wide character elements, we must handle the case where a two
    // byte character straddles the buffer boundary, with the low order byte at
    // the end of the old buffer and the high order byte at the start of the new
    // buffer.
    //
    // We do this here:  if there is exactly one character left in the buffer, we
    // store that and set a flag so we know to pick it up later.
    filwbuf_context context;
    if (stream->_cnt == 1)
    {
        context._is_split_character = true;
        context._leftover_low_order_byte = static_cast<unsigned char>(*stream->_ptr);
    }
    else
    {
        context._is_split_character = false;
        context._leftover_low_order_byte = 0;
    }
    return context;
}

get_context_nolock() [2/2]

static int get_context_nolock ( __crt_stdio_stream const  , char    ) throw ( )

static

Definition at line 26 of file _filbuf.cpp.

{
    return 0;
}

Referenced by common_refill_and_read_nolock().

is_buffer_valid_nolock() [1/2]

static bool is_buffer_valid_nolock ( __crt_stdio_stream const  stream, char    ) throw ( )

static

Definition at line 56 of file _filbuf.cpp.

{
    return stream->_cnt !=  0
        && stream->_cnt != -1;
}

Referenced by common_refill_and_read_nolock().

is_buffer_valid_nolock() [2/2]

static bool is_buffer_valid_nolock ( __crt_stdio_stream const  stream, wchar_t    ) throw ( )

static

Definition at line 62 of file _filbuf.cpp.

{
    return stream->_cnt !=  0
        && stream->_cnt !=  1
        && stream->_cnt != -1;
}

read_character_nolock() [1/2]

static wchar_t read_character_nolock ( __crt_stdio_stream const  stream, filwbuf_context const  context, wchar_t    ) throw ( )

static

Definition at line 81 of file _filbuf.cpp.

{
    if (context._is_split_character)
    {
        // If the character was split across buffers, we read only one byte
        // from the new buffer and or it with the leftover byte from the old
        // buffer.
        unsigned char high_order_byte = static_cast<unsigned char>(*stream->_ptr);
        wchar_t result = (high_order_byte << 8) | context._leftover_low_order_byte;
 
        --stream->_cnt;
        ++stream->_ptr;
        return (result);
    }
    else
    {
        wchar_t const result = 0xffff & reinterpret_cast<wchar_t const&>(*stream->_ptr);
 
        stream->_cnt -= sizeof(wchar_t);
        stream->_ptr += sizeof(wchar_t);
 
        return result;
    }
}

read_character_nolock() [2/2]

static unsigned char read_character_nolock ( __crt_stdio_stream const  stream, int  , char    ) throw ( )

static

Definition at line 73 of file _filbuf.cpp.

{
    --stream->_cnt;
    return static_cast<unsigned char>(*stream->_ptr++);
}

Referenced by common_refill_and_read_nolock().