openfoam/applications/test/ICharStream1/Test-ICharStream1.C
Mark Olesen a341d09afc ENH: update and enhancement of memory-streams
- soft renames (ie, old names still available via typedefs) for more
  reasonable names and more coverage with std stream variants.

  The old names could be a bit cryptic.
  For example, uiliststream (== an unallocated/external list storage),
  which is written as std::ispanstream for C++23.

  Could similarly argue that IListStream is better named as
  ICharStream, since it is an input stream of characters and the
  internal storage mechanism (List or something else) is mostly
  irrelevant.

  Extending the coverage to include all std stream variants, and
  simply rewrap them for OpenFOAM IOstream types. This simplifies the
  inheritance patterns and allows reuse of icharstream/ocharstream as
  a drop-in replace for istringstream/ostringstream in other wrappers.

  Classes:
    * icharstream / ICharStream   [old: none / IListStream]
    * ocharstream / OCharStream   [old: none / OListStream]
    * ispanstream / ISpanStream   [old: uiliststream / UIListStream]
    * ospanstream / OSpanStream   [old: none / UOListStream]

  Possible new uses : read file contents into a buffer, broadcast
  buffer contents to other ranks and then transfer into an icharstream
  to be read from. This avoid the multiple intermediate copies that
  would be associated when using an istringstream.

- Use size doubling instead of block-wise incremental for ocharstream
  (OCharStream). This corresponds to the sizing behaviour as per
  std::stringstream (according to gcc-11 includes)

STYLE: drop Foam_IOstream_extras constructors for memory streams

- transitional/legacy constructors but not used in any code
2023-09-01 14:44:49 +00:00

240 lines
5.2 KiB
C

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | www.openfoam.com
\\/ M anipulation |
-------------------------------------------------------------------------------
Copyright (C) 2017-2023 OpenCFD Ltd.
-------------------------------------------------------------------------------
License
This file is part of OpenFOAM.
OpenFOAM 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 3 of the License, or
(at your option) any later version.
OpenFOAM 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 OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
Description
\*---------------------------------------------------------------------------*/
#include "SpanStream.H"
#include "wordList.H"
#include "IOstreams.H"
#include "argList.H"
#include <cctype>
#include <cstdio>
using namespace Foam;
Ostream& writeList(Ostream& os, const UList<char>& list)
{
char buf[4];
os << list.size() << '(';
for (const char c : list)
{
if (isprint(c))
{
os << c;
}
else if (c == '\t')
{
os << "\\t";
}
else if (c == '\n')
{
os << "\\n";
}
else
{
::snprintf(buf, 4, "%02X", c);
os << "\\x" << buf;
}
}
os << ')';
return os;
}
Ostream& toString(Ostream& os, const UList<char>& list)
{
os << '"';
for (const char c : list)
{
os << c;
}
os << '"';
return os;
}
template<class BufType>
void printInfo(const BufType& buf)
{
Info<< nl << "=========================" << endl;
buf.print(Info);
toString(Info, buf.list());
Info<< nl << "=========================" << endl;
}
template<>
void printInfo(const List<char>& buf)
{
Info<< nl << "=========================" << endl;
toString(Info, buf);
Info<< nl << "=========================" << endl;
}
void printTokens(Istream& is)
{
label count = 0;
token t;
while (is.good())
{
is >> t;
if (t.good())
{
++count;
Info<<"token: " << t << endl;
}
}
Info<< count << " tokens" << endl;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
// Main program:
int main(int argc, char *argv[])
{
// Buffer storage
DynamicList<char> storage(16);
OCharStream obuf(std::move(storage));
obuf << 1002 << " " << "abcd" << " " << "def" << " " << 3.14159 << ";\n";
// Move contents to output buffer
printInfo(obuf);
Info<<nl << "as string: ";
toString(Info, obuf.list()) << endl;
Info<< "transfer contents to a List" << endl;
ICharStream ibuf;
// Reclaim data storage from OCharStream -> ICharStream
{
List<char> data;
obuf.swap(data);
ibuf.swap(data);
}
Info<< nl;
Info<< nl << "input string:";
printInfo(ibuf);
Info<< nl << "orig output:";
printInfo(obuf);
printTokens(ibuf);
Info<<nl << "after:";
printInfo(ibuf);
// This should also work
ibuf.list() = 'X';
Info<<nl << "overwritten with const value:";
printInfo(ibuf);
// Can also change content like this:
{
const int n = min(26, ibuf.size());
for (int i=0; i<n; ++i)
{
ibuf.list()[i] = 'A' + i;
}
}
Info<<nl << "directly written:";
printInfo(ibuf);
// Swap in/out an entirely new list storage:
List<char> newvalues(52);
{
for (int i=0; i<26; ++i)
{
newvalues[2*i+0] = char('a' + i);
newvalues[2*i+1] = char('A' + i);
}
}
ibuf.swap(newvalues);
Info<<nl << "after swap:";
printInfo(ibuf);
Info<<nl << "swapped out:";
printInfo(newvalues);
{
iliststream is(std::move(newvalues));
char c = 0;
Info<< nl
<< "getting values from iliststream of "
<< is.list() << endl;
// Info<< " (" << is.tellg() << " " << is.remaining() << ")";
// Info<< "get:";
while (is.get(c))
{
Info<< ' ' << c;
// Info<< " (" << is.tellg() << " " << is.remaining() << ")";
}
Info<< " - end" << nl;
// Info<< "remaining: " << is.list() << endl;
// Info<< "remaining: " << is.remaining() << endl;
// Manipulate the list view
{
UList<char> chars(is.list());
Foam::reverse(chars);
}
is.rewind();
Info<< "get:";
while (is.get(c))
{
Info<< ' ' << c;
}
Info<< " - end" << nl;
}
Info<< "\nEnd\n" << endl;
return 0;
}
// ************************************************************************* //