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Diffstat (limited to 'libio/ioextend.cc')
| -rw-r--r-- | libio/ioextend.cc | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/libio/ioextend.cc b/libio/ioextend.cc new file mode 100644 index 00000000000..a31ff36e6e5 --- /dev/null +++ b/libio/ioextend.cc @@ -0,0 +1,132 @@ +/* +Copyright (C) 1993 Free Software Foundation + +This file is part of the GNU IO Library. This library is free +software; you can redistribute it and/or modify it under the +terms of the GNU General Public License as published by the +Free Software Foundation; either version 2, or (at your option) +any later version. + +This library is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with this library; see the file COPYING. If not, write to the Free +Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +As a special exception, if you link this library with files +compiled with a GNU compiler to produce an executable, this does not cause +the resulting executable to be covered by the GNU General Public License. +This exception does not however invalidate any other reasons why +the executable file might be covered by the GNU General Public License. */ + +#include <iostream.h> + +static int __xalloc = 0; + +int ios::xalloc() +{ + return __xalloc++; +} + +static ios::fmtflags __used_fmt_flags += ios::skipws | ios::left | ios::right | ios::internal +| ios::dec | ios::oct | ios::hex | ios::showbase | ios::showpoint +| ios::uppercase | ios::showpos | ios::scientific | ios::fixed +#ifndef _IO_NEW_STREAMS +| ios::dont_close +#endif +| ios::unitbuf | ios::stdio; + +ios::fmtflags ios::bitalloc() +{ + fmtflags bit_to_try = (fmtflags)1; + for (; bit_to_try; bit_to_try <<= 1) + { + if ((__used_fmt_flags & bit_to_try) == 0) + { + __used_fmt_flags |= bit_to_try; + return bit_to_try; + } + } + return 0; +} + +// NOTE: This implementation of ios::iword and ios::pword assumes +// that these methods are seldom used, so we want to minimize +// the space and time overhead when NOT using these methods. +// +// ANSI specifies two conceptually-infinite arrays, one whose +// elements are longs, and one whose elements are (void*)s. +// We implement this as a single array, each of whose element is +// a (struct ptr_and_long), which has space for both a long and a void*. +// We also specify that (the i field of) the 0'th element of the array +// contains the allocated length of the array (not counting that +// initial element). + +struct ptr_and_long { + void *p; + long i; +}; + +static struct ptr_and_long& +get_array_element(ios& io, int index) +{ + if (index < 0) + io._throw_failure(); + register struct ptr_and_long *array = (ptr_and_long*)io._arrays; + int old_length = array == NULL ? 0 : array[0].i; + if (index >= old_length) + { + register int i; + int new_length = index + 10; + register struct ptr_and_long *new_array + = new ptr_and_long[1 + new_length]; + if (array != NULL) + { + for (i = 1; i <= old_length; i++) + new_array[i] = array[i]; + delete [] array; + } + for (i = old_length + 1; i <= new_length; i++) + { + new_array[i].i = 0; + new_array[i].p = NULL; + } + new_array[0].i = new_length; + new_array[0].p = NULL; + io._arrays = (void*)new_array; + array = new_array; + } + return array[index+1]; +} + +long& ios::iword(int index) +{ + return get_array_element(*this, index).i; +} + +void*& ios::pword(int index) +{ + return get_array_element(*this, index).p; +} + +long ios::iword(int index) const +{ + if (index < 0) + _throw_failure(); + register struct ptr_and_long *pl_array = (ptr_and_long*)_arrays; + int len = pl_array == NULL ? 0 : pl_array[0].i; + return index >= len ? 0 : pl_array[index+1].i; +} + +void* ios::pword(int index) const +{ + if (index < 0) + _throw_failure(); + register struct ptr_and_long *pl_array = (ptr_and_long*)_arrays; + int len = pl_array == NULL ? 0 : pl_array[0].i; + return index >= len ? 0 : pl_array[index+1].p; +} |