+2003-05-15 Paolo Carlini <pcarlini@unitus.it>
+ Nathan Myers <ncm@cantrip.org>
+
+ * include/bits/fstream.tcc (_M_overflow): Rewrote to call
+ _M_convert_to_external only once (_M_buf_size is now the size of
+ the put area + 1 for the overflow char of a full area); call
+ _M_set_buffer instead of _M_set_indeterminate.
+ (setbuf): Don't accept a buffer smaller than 2 chars.
+ (_M_underflow): Refill _M_buf_size - 1 chars; call _M_set_buffer,
+ instead of _M_set_determinate.
+ (open): Call _M_set_buffer, instead of _M_set_indeterminate.
+ (seekoff): Likewise.
+ * include/ext/stdio_filebuf.h (stdio_filebuf(int,
+ std::ios_base::openmode, bool, size_t),
+ stdio_filebuf(std::__c_file*, std::ios_base::openmode, size_t):
+ Likewise.
+ * include/std/std_fstream.h (_M_set_indeterminate): Remove.
+ (_M_set_determinate): Rename as _M_set_buffer, _M_buf_size ->
+ _M_buf_size - 1.
+ * include/std/std_streambuf.h: Tweak _M_out_lim comment.
+ * testsuite/27_io/basic_filebuf/sgetn/char/1.cc: Tweak, taking
+ into account that, for _M_buf_size == BUFSIZ == 8192, the size of
+ the put area is now BUFSIZ - 1.
+ * testsuite/ext/stdio_filebuf_2.cc: Tweak, taking into account
+ that now the smallest _M_buf_size is 2 (still fails, for the same
+ reason, with 3.2.3)
+
2003-05-14 Loren J. Rittle <ljrittle@acm.org>
* testsuite/thread/pthread4.cc: Tweak test.
basic_filebuf<_CharT, _Traits>::
_M_allocate_internal_buffer()
{
- if (!this->_M_buf && this->_M_buf_size)
+ if (!_M_buf_allocated && this->_M_buf_size)
{
// Allocate internal buffer.
this->_M_buf = new char_type[this->_M_buf_size];
this->_M_mode = __mode;
// Setup initial position of buffer.
- _M_set_indeterminate();
+ _M_set_buffer(0);
- if ((__mode & ios_base::ate)
+ if ((__mode & ios_base::ate)
&& this->seekoff(0, ios_base::end, __mode) < 0)
// 27.8.1.3,4
this->close();
ios_base::in);
}
- if (_M_buf_size)
+ if (_M_buf_size > 1)
{
streamsize __elen = 0;
streamsize __ilen = 0;
if (__check_facet(_M_codecvt).always_noconv())
{
- __elen = _M_file.xsgetn(reinterpret_cast<char*>(this->_M_in_beg), _M_buf_size);
+ __elen = _M_file.xsgetn(reinterpret_cast<char*>(this->_M_in_beg), _M_buf_size - 1);
__ilen = __elen;
}
else
{
- char* __buf = static_cast<char*>(__builtin_alloca(_M_buf_size));
- __elen = _M_file.xsgetn(__buf, _M_buf_size);
+ char* __buf = static_cast<char*>(__builtin_alloca(_M_buf_size - 1));
+ __elen = _M_file.xsgetn(__buf, _M_buf_size - 1);
const char* __eend;
char_type* __iend;
codecvt_base::result __r;
__r = _M_codecvt->in(_M_state_cur, __buf, __buf + __elen,
__eend, this->_M_in_beg,
- this->_M_in_beg + _M_buf_size, __iend);
+ this->_M_in_beg + _M_buf_size - 1,
+ __iend);
if (__r == codecvt_base::ok)
__ilen = __iend - this->_M_in_beg;
else if (__r == codecvt_base::noconv)
if (0 < __ilen)
{
- _M_set_determinate(__ilen);
+ _M_set_buffer(__ilen);
__ret = traits_type::to_int_type(*this->_M_in_cur);
if (__bump)
_M_move_in_cur(1);
_M_overflow(int_type __c)
{
int_type __ret = traits_type::eof();
+ const bool __testeof = traits_type::eq_int_type(__c, __ret);
const bool __testput = this->_M_out_beg < this->_M_out_lim;
if (__testput)
- {
- // Need to restore current position. The position of the external
- // byte sequence (_M_file) corresponds to _M_filepos, and we need
- // to move it to _M_out_beg for the write.
- if (_M_filepos && _M_filepos != this->_M_out_beg)
- {
- off_type __off = this->_M_out_beg - _M_filepos;
- _M_file.seekoff(__off, ios_base::cur);
- }
-
- // Convert internal buffer to external representation, output.
- if (_M_convert_to_external(this->_M_out_beg,
- this->_M_out_lim - this->_M_out_beg))
+ {
+ // Need to restore current position. The position of the
+ // external byte sequence (_M_file) corresponds to
+ // _M_filepos, and we need to move it to _M_out_beg for the
+ // write.
+ if (_M_filepos != this->_M_out_beg)
+ _M_file.seekoff(this->_M_out_beg - _M_filepos, ios_base::cur);
+
+ // If appropriate, append the overflow char.
+ if (!__testeof)
+ *this->_M_out_lim++ = traits_type::to_char_type(__c);
+
+ // Convert pending sequence to external representation,
+ // output.
+ if (_M_convert_to_external(this->_M_out_beg,
+ this->_M_out_lim - this->_M_out_beg)
+ && (!__testeof || (__testeof && !_M_file.sync())))
{
- // Convert pending sequence to external representation, output.
- // If eof, then just attempt sync.
- if (!traits_type::eq_int_type(__c, traits_type::eof()))
- {
- // User code must flush when switching modes (thus
- // don't sync).
- char_type __pending = traits_type::to_char_type(__c);
- if (_M_convert_to_external(&__pending, 1))
- {
- _M_set_indeterminate();
- __ret = traits_type::not_eof(__c);
- }
- }
- else if (!_M_file.sync())
- {
- _M_set_indeterminate();
- __ret = traits_type::not_eof(__c);
- }
+ _M_set_buffer(0);
+ __ret = traits_type::not_eof(__c);
}
}
_M_last_overflowed = true;
const bool __testput = this->_M_out_cur < this->_M_out_end;
const bool __testout = this->_M_mode & ios_base::out;
+ // Perhaps set below in _M_overflow.
+ _M_last_overflowed = false;
+
if (__testout)
{
if (traits_type::eq_int_type(__c, traits_type::eof()))
__ret = traits_type::not_eof(__c);
else if (__testput)
{
- *this->_M_out_cur = traits_type::to_char_type(__c);
+ *this->_M_out_cur = traits_type::to_char_type(__c);
_M_move_out_cur(1);
__ret = traits_type::not_eof(__c);
}
else
__ret = this->_M_overflow(__c);
}
- _M_last_overflowed = false; // Set in _M_overflow, below.
return __ret;
}
{
if (!this->is_open() && __s == 0 && __n == 0)
this->_M_buf_size = 0;
- else if (__s && __n)
+ else if (__s && __n > 1)
{
- // This is implementation-defined behavior, and assumes
- // that an external char_type array of length (__s + __n)
- // exists and has been pre-allocated. If this is not the
- // case, things will quickly blow up.
+ // This is implementation-defined behavior, and assumes that
+ // an external char_type array of length (__s + __n) exists
+ // and has been pre-allocated. If this is not the case,
+ // things will quickly blow up. The length argument __n must
+ // be greater than 1 because __n - 1 positions will be used
+ // for the get and put areas, and 1 position is needed to
+ // host the overflow char of a full put area.
// Step 1: Destroy the current internal array.
_M_destroy_internal_buffer();
// Step 2: Use the external array.
this->_M_buf = __s;
this->_M_buf_size = __n;
- _M_set_indeterminate();
+ _M_set_buffer(0);
}
_M_last_overflowed = false;
return this;
// Return pos_type(off_type(-1)) in case of failure.
__ret = _M_file.seekoff(__computed_off, __way, __mode);
- _M_set_indeterminate();
+ _M_set_buffer(0);
}
else
{
* @param mode Same meaning as in a standard filebuf.
* @param del Whether to close the file on destruction.
* @param size Optimal or preferred size of internal buffer, in bytes.
+ * Note that it includes a position for the overflow char,
+ * therefore, can't be smaller than 2.
*
* This constructor associates a file stream buffer with an open
* POSIX file descriptor. Iff @a del is true, then the associated
* file will be closed when the stdio_filebuf is closed/destroyed.
*/
stdio_filebuf(int __fd, std::ios_base::openmode __mode, bool __del,
- size_t __size);
+ size_t __size = static_cast<size_t>(BUFSIZ));
/**
* @param f An open @c FILE*.
* @param mode Same meaning as in a standard filebuf.
* @param size Optimal or preferred size of internal buffer, in bytes.
- * Defaults to system's @c BUFSIZ.
+ * Defaults to system's @c BUFSIZ. Note that it includes
+ * a position for the overflow char, therefore, can't be
+ * smaller than 2.
*
* This constructor associates a file stream buffer with an open
* C @c FILE*. The @c FILE* will not be automatically closed when the
this->_M_mode = __mode;
this->_M_buf_size = __size;
_M_allocate_internal_buffer();
- _M_set_indeterminate();
+ _M_set_buffer(0);
}
}
this->_M_mode = __mode;
this->_M_buf_size = __size;
_M_allocate_internal_buffer();
- _M_set_indeterminate();
+ _M_set_buffer(0);
}
}
} // namespace __gnu_cxx
/**
* @if maint
- * Actual size of internal buffer.
+ * Actual size of internal buffer. This number is equal to the size
+ * of the put area + 1 position, reserved for the overflow char of
+ * a full area.
* @endif
*/
size_t _M_buf_size;
void
_M_output_unshift();
- // These two functions are used to clarify internal buffer
- // maintenance. After an overflow, or after a seekoff call that
- // started at beg or end, or possibly when the stream becomes
- // unbuffered, and a myrid other obscure corner cases, the
- // internal buffer does not truly reflect the contents of the
- // external buffer. At this point, for whatever reason, it is in
- // an indeterminate state.
- /**
- * @if maint
- * @doctodo
- * @endif
- */
- void
- _M_set_indeterminate(void)
- { _M_set_determinate(off_type(0)); }
-
- /**
- * @if maint
- * @doctodo
- * @endif
- */
- void
- _M_set_determinate(off_type __off)
- {
- const bool __testin = this->_M_mode & ios_base::in;
- const bool __testout = this->_M_mode & ios_base::out;
- if (__testin)
- this->setg(this->_M_buf, this->_M_buf, this->_M_buf + __off);
- if (__testout)
+ // This function sets the pointers of the internal buffer, both get
+ // and put areas. Typically, __off == _M_in_end - _M_in_beg upon
+ // _M_underflow; __off == 0 upon _M_overflow, seekoff, open, setbuf.
+ //
+ // NB: _M_out_end - _M_out_beg == _M_buf_size - 1, since _M_buf_size
+ // reflects the actual allocated memory and the last cell is reserved
+ // for the overflow char of a full put area.
+ void
+ _M_set_buffer(streamsize __off)
+ {
+ const bool __testin = this->_M_mode & ios_base::in;
+ const bool __testout = this->_M_mode & ios_base::out;
+ if (_M_buf_size)
{
- this->setp(this->_M_buf, this->_M_buf + this->_M_buf_size);
- this->_M_out_lim += __off;
+ if (__testin)
+ this->setg(this->_M_buf, this->_M_buf, this->_M_buf + __off);
+ if (__testout)
+ {
+ this->setp(this->_M_buf, this->_M_buf + this->_M_buf_size - 1);
+ this->_M_out_lim += __off;
+ }
+ _M_filepos = this->_M_buf + __off;
}
- _M_filepos = this->_M_buf + __off;
- }
+ }
};
// [27.8.1.5] Template class basic_ifstream
//@{
/**
* @if maint
- * _M_set_indeterminate and setp set it equal to _M_out_beg, then
- * at each put operation it may be moved forward (toward _M_out_end)
- * by _M_out_cur_move.
+ * setp (and _M_set_buffer(0) in basic_filebuf) set it equal to
+ * _M_out_beg, then at each put operation it may be moved
+ * forward (toward _M_out_end) by _M_out_cur_move.
* @endif
*/
char_type* _M_out_lim; // End limit of used put area.
VERIFY( c7 == c2 ); // n != i
strmsz_1 = fb_03.sgetn(carray1, 10);
VERIFY( !strmsz_1 ); //zero
- strmsz_1 = fb_01.in_avail();
+ strmsz_1 = fb_01.in_avail(); // N.B.: _M_in_end - _M_in_beg == BUFSIZ - 1
strmsz_2 = fb_01.sgetn(carray2, strmsz_1 + 5);
VERIFY( strmsz_1 == strmsz_2 - 5 );
c4 = fb_01.sgetc(); // buffer should have underflowed from above.
- VERIFY( c4 == 'i' );
+ VERIFY( c4 == 'h' );
strmsz_1 = fb_01.in_avail();
VERIFY( strmsz_1 > 0 );
strmsz_2 = fb_01.sgetn(carray2, strmsz_1 + 5);
// out by _M_really_overflow upon overflow.
void test01()
{
-
using namespace std;
bool test = true;
FILE* file = fopen(name, "w");
{
using namespace __gnu_cxx;
-
- // One char big stack-based buffer.
- stdio_filebuf<char> sbuf(file, ios_base::out, 1);
+ stdio_filebuf<char> sbuf(file, ios_base::out, 2);
sbuf.sputc('T');
sbuf.sputc('S');
+ sbuf.sputc('P');
}
fclose(file);
streamsize n = fbuf.sgetn(buf, sizeof(buf));
fbuf.close();
- VERIFY( n == 2 );
- VERIFY( !memcmp(buf, "TS", 2) );
+ VERIFY( n == 3 );
+ VERIFY( !memcmp(buf, "TSP", 3) );
}
int main()