/* We always allocate an extra word following an _IO_FILE. This contains a pointer to the function jump table used. This is for compatibility with C++ streambuf; the word can be used to smash to a pointer to a virtual function table. */
void _IO_new_file_init (struct _IO_FILE_plus *fp) { /* POSIX.1 allows another file handle to be used to change the position of our file descriptor. Hence we actually don't know the actual position before we do the first fseek (and until a following fflush). */ fp->file._offset = _IO_pos_BAD; fp->file._IO_file_flags |= CLOSED_FILEBUF_FLAGS;
_IO_size_t _IO_fwrite (constvoid *buf, _IO_size_t size, _IO_size_t count, _IO_FILE *fp) { _IO_size_t request = size * count; _IO_size_t written = 0; CHECK_FILE (fp, 0); if (request == 0) return0; _IO_acquire_lock (fp); if (_IO_vtable_offset (fp) != 0 || _IO_fwide (fp, -1) == -1) written = _IO_sputn (fp, (constchar *) buf, request); _IO_release_lock (fp); /* We have written all of the input in case the return value indicates this or EOF is returned. The latter is a special case where we simply did not manage to flush the buffer. But the data is in the buffer and therefore written as far as fwrite is concerned. */ if (written == request || written == EOF) return count; else return written / size; } libc_hidden_def (_IO_fwrite)
if (n <= 0) return0; /* This is an optimized implementation. If the amount to be written straddles a block boundary (or the filebuf is unbuffered), use sys_write directly. */
/* First figure out how much space is available in the buffer. */ if ((f->_flags & _IO_LINE_BUF) && (f->_flags & _IO_CURRENTLY_PUTTING)) { count = f->_IO_buf_end - f->_IO_write_ptr; if (count >= n) { constchar *p; for (p = s + n; p > s; ) { if (*--p == '\n') { count = p - s + 1; must_flush = 1; break; } } } } elseif (f->_IO_write_end > f->_IO_write_ptr) count = f->_IO_write_end - f->_IO_write_ptr; /* Space available. */
/* Then fill the buffer. */ if (count > 0) { if (count > to_do) count = to_do; #ifdef _LIBC f->_IO_write_ptr = __mempcpy (f->_IO_write_ptr, s, count); #else memcpy (f->_IO_write_ptr, s, count); f->_IO_write_ptr += count; #endif s += count; to_do -= count; } if (to_do + must_flush > 0) { _IO_size_t block_size, do_write; /* Next flush the (full) buffer. */ if (_IO_OVERFLOW (f, EOF) == EOF) /* If nothing else has to be written we must not signal the caller that everything has been written. */ return to_do == 0 ? EOF : n - to_do;
/* Try to maintain alignment: write a whole number of blocks. */ block_size = f->_IO_buf_end - f->_IO_buf_base; do_write = to_do - (block_size >= 128 ? to_do % block_size : 0);
if (do_write) { count = new_do_write (f, s, do_write); to_do -= count; if (count < do_write) return n - to_do; }
/* Now write out the remainder. Normally, this will fit in the buffer, but it's somewhat messier for line-buffered files, so we let _IO_default_xsputn handle the general case. */ if (to_do) to_do -= _IO_default_xsputn (f, s+do_write, to_do); } return n - to_do; } libc_hidden_ver (_IO_new_file_xsputn, _IO_file_xsputn)
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