simgear/README.metakit

With the author's permission, SimGear now bundles MetaKit.  

Important build note:

  Later on when you are linking programs with -lmk4 (i.e. FlightGear or one
  of it's associated programs) if you come across an error similar to the
  following:

     c++  -Wall -O2 -L/usr/local/lib -o gensimple  gensimple.o libAirports.a
          -lsgdebug -lsgmisc -lmk4 -lz -lm 
     /usr/local/lib/libmk4.a(view.o)(.text+0x1c8):view.cpp: multiple definition
          of `c4_View::~c4_View(void)'
    libAirports.a(simple.o)(.text$_$_7c4_View+0x0):simple.cxx: first defined
          here
    collect2: ld returned 1 exit status
    make[2]: *** [gensimple] Error 1
    make[2]: Leaving directory `/home/curt/FlightGear-0.7.7/src/Airports'
    make[1]: *** [all-recursive] Error 1
    make[1]: Leaving directory `/home/curt/FlightGear-0.7.7/src'
    make: *** [all-recursive] Error 1

  Then you need to come back and rebuild Metakit with the -DNDEBUG flag.
  For unix/cygwin systems, modify the unix/Makefile file and add -DNDEBUG
  to the CFLAGS line.

Now we return you to the official metakit readme ... :-)


The MetaKit Library 2.01                                            March 2000
==============================================================================


WHAT IT IS - MetaKit is an embeddable database which runs on Unix, Windows,
    Macintosh, and other platforms.  It lets you build applications which
    store their data efficiently, in a portable way, and which will not need a
    complex runtime installation.  In terms of the data model, MetaKit takes
    the middle ground between RDBMS, OODBMS, and flat-file databases - yet it
    is quite different from each of them.

WHAT IT ISN'T - MetaKit is not: 1) multi-user/-threading, 2) scalable to
    gigabytes, 3) proprietary software, 4) full of bugs, 5) just a toy.

TECHNOLOGY - Everything is stored variable-sized yet with efficient positional
    row access.  Changing an existing datafile structure is as simple as re-
    opening it with that new structure.  All changes are transacted.  You can
    mix and match software written in C++, Python, and Tcl.  Things can't get
    much more flexible...

CORE - The Metakit core library is written in C++.  It has a code footprint of
    just over 100 Kb on Windows.  It can be used as DLL, or linked statically.
    Debug builds include extensive assertion checks to catch problems early.

PYTHON - The binding for Python is called "Mk4py".  It uses SCXX by Gordon
    McMillan as C++ glue interface.  The source is in directory "python/".

TCL/TK - The MK extension for Tcl is called "Mk4tcl".  It is being used in a
    number of commercial projects, for in-house use as well as in commercially
    distributed products.  The source is in directory "tcl/".

LICENSE AND SUPPORT - MetaKit 2.01 is distributed as open source software (the
    X/MIT-style license is at the end of this document).  Commercial support
    is available through an Enterprise License, see the URL mentioned below.

DOCUMENTATION - All documentation uses HTML.  The main page is "MetaKit.html",
    which leads to the rest of the documentation in the "doc/" directory.

WEBSITE URLS - The main pages on the world wide web, for news and downloads:
    Homepage:       http://www.equi4.com/metakit/
    Python news:    http://www.equi4.com/metakit/python.html
    Tcl/Tk news:    http://www.equi4.com/metakit/tcl.html
    License info:   http://www.equi4.com/metakit/license.html
    Contact info:   http://www.equi4.com/contact.html


INSTALLATION
============

Starting with this release, all platform builds and language bindings are now
designed to work from a single common "builds/" directory.  It turns out to
be impossible to keep build side-effects limited to *just* this directory
(CodeWarrior can't be told where to place its temp data, and Visual C++ still
alters a few files next to the project ".dsw" file, to name two offenders).

UNIX

    It is no longer advised to build the Unix code in the "unix/" directory.
    Instead, you should perform the following steps:
        % cd builds
        % ../unix/configure
        % make
        % make test
    And optionally (this only installs the core lib, not script extensions):
        % make install

    By switching to the "builds/" directory, you will keep the distribution
    directory tree 100% unaltered.  All changes are made in this subdir, and
    all final build results are left behind in this same subdir.

    Nastiness: if you build Mk4tcl, please do a "make Mk4tcl.so" as well.
    And if you intend to create the Python extension, do a "make Mk4py.so".
    The "libmk4tcl.so.0.0.0" and "libMk4py.so.0.0.0" targets are bogus ones.

    You will probably have to make changes in the makefile to locate the
    proper includes and libs for Python (Tcl has been fixed, see "--with-tcl).
    You probably only need to adjust "CXX_SWITCHES_PY" to find the headers.

    To build with STL containers and strings, you can do the following:
        make CXXFLAGS='-Dq4_STD' test   # add -O3 etc, as needed
    This passes the test suite on Linux RedHat 5.2 with gcc 2.95-2.

    See below for some platform-specific build notes.

WINDOWS

    There is a "win/" directory which contains subdirectories for a number of
    compiler systems.  MetaKit has been built with many different compilers
    in the past (Microsoft, Borland, Watcom, Symantec, Metrowerks, Optima),
    but to preserve my sanity (there are 12 configurations for MSVC6 alone!),
    I am limiting myself to MSVC6, MWCW5, Borland C++ Builder 4, and Cygwin.

    The MS Visual C++ 6.0 project is "win/msvc60/mksrc.dsw", with subprojects
    for the C++ demo (mkdemo), building dll's (mkdll), static libs (mklib),
    regression tests (mktest), as well as Tcl (mktcl) and Python (mkpython).
    It has been set up to place all intermediate files and final results in
    the "builds/" subdirectory, even though you'll launch it from "win/".

    To build with STL containers and strings under MSVC, define "q4_STD".
    To build with MFC containers and strings under MSVC, define "q4_MFC".

    The Metrowerks Codewarrior project is in the "mac/" directory, and can be
    used to build both Mac and Windows versions (on either Mac *or* Windows).
    The core libraries are built with "mac/cw5.mcp", demos / tests are built
    with "cw5apps.mcp", Tcl is "cw5tcl.mcp", and Python is "cw5python.mcp".

    The Borland C++ Builder projects have not yet been incorporated in this
    release, but the "KitViewer" application is an example of how to use BCB.

    The Cygwin build (B20.1 / gcc 2.95.2) is different, because it uses the
    unix autoconf system, and must be launched as described above for UNIX.
    I have upgraded to the latest development of libtool to be able to build
    DLL's with Cygwin.  You can build the "-mno-cygwin" version by editing
    the Makefile by hand and adding that option to CXXFLAGS.

    Rob Bloodgood adds that the following GCC options are for maximum code
    efficiency on x86 hardware: "-O2 -m486 -malign-loops=2 -malign-jumps=2".
    I have not yet tried this myself, but am passing on the tip.

MACINTOSH

    The Mac version requires Metrowerks CodeWarrior 5.  See the info above
    in the Windows section (MWCW is multi-platform).  The projects are all
    located in the "mac/" folder, which is also where MWCW will place its own
    "... Data" folders with intermediate results.  As with all other setups,
    final results are made to end up in the "builds/" directory.

    Static 68K builds appear to work fine, the 68K CFM variants will need
    some more work (I couldn't get the libraries to export their symbols).


PLATFORM-SPECIFIC NOTES
=======================

* Linux RH 5.2 / gcc 2.95.2

    Builds with gcc 2.95.2 work out of the box.  The Tcl extension ends up as
    ".libs/libmk4tcl.so.0.0.0" (to please libtool), and should be renamed to
    "Mk4tcl.so".  Similarly, ".libs/libMk4py.so.0.0.0" is in fact the Python
    extension, and *must* be renamed to "Mk4py.so" to call it from Python.

    The core MK libs end up as ".libs/libmk4.a" and ".libs/libmk4.so.0.0.0".

* Solaris 2.6 / gcc 2.8.1

    The Solaris builds are nasty for several reasons:

    - I do not own such a machine, and often have to make arrangements
      (or fight limited space on one of the machines I can telnet to).
    - The gcc 2.8.1 optimizer appears to be buggy, I have had to turn off
      the default "-O3" flag to prevent compiler crashes (several files).
      This problems appears to be resolved with gcc 2.95.
    - Locking on Solaris (especially w.r.t NFS) remains a mystery to me.
      The Tcl and Python extensions both use locking (the core not yet).
      See tcl/Mk4tcl.cpp around line 520, and python/PyStorage.cpp around
      line 80 for details.  It's all pretty messy, and not 100% correct.

    Despite this, I'm doing my best to resolve these issues.  Having a solid
    build of the core *and* of Tcl / Python extensions is quite important.

* Other Unix systems

    No further notes, though many systems will build fine out of the box.

* Windows

    MSVC 6 builds MK as static lib and as DLL (universal config, I have not
    yet created build versions with MFC or STL, mainly because MK can now be
    used in all contexts regardless of how it was built).  The Python and Tcl
    extensions build as dynamic extensions (a static build is easy to add).

    MWCW 5 builds MK as static lib and as DLL (interestingly enough, the DLL
    is slightly smaller than MSVC 6 - 102 vs 108 Kb - when their runtimes are
    linked in dynamically as well).  I have not added Win builds for Tcl or
    Python, since MSVC 6 has those already.

    Cygwin B20.1, with gcc 2.95.2 ugrade, also builds MK as static lib and as
    DLL.  Both "pure" Cygwin (i.e. requiring cygwin1.dll) and mingw32 (using
    the -mno-cygwin flag) build, but there are some hairy include issues when
    it comes to choosing the right locking model for Tcl and Python.  These
    issues have not been resolved fully.

* Macintosh

    MWCW 5 builds PPC shared libs, PPC static libs, and 68K static libraries.

    Building 68K CFM libraries leads to a "MetaKit 68K.shlb" which comes out
    of the linker without errors, but the result does not seem to have any
    export symbols defined (despite the fact that the library is over 200 K).
    Because of that, I've been unable to build apps or Mk4tcl/Mk4py so far.

    The other three configurations build, but for some reason MK's regression
    test stops at L03 (everything up to that point looks ok, i.e. over 90%).

    The Mk4tcl PPC extension appears to work (quick manual test), and so does
    the Python extension, "Mk4py.PPC.slb".  I have not yet given these two
    a serious workout, hoping to have a basic test harness in place soon.

* VMS, BeOS, ...

    No news yet, please report your findings with any other platform builds.


WHAT'S MISSING HERE
===================

    - a section on basic concepts (or maybe it doesn't belong here?)
    - a section on getting started (C++, Python, Tcl all differ - point to
      the respective intro pages)
    - maybe a small sample for each of C++ / Tcl / Python, to give an idea
    - mention TclKit, scripted docs (WiKit/Tequila?), VFS?
    - I forgot... please tell me :)


LICENSE AND COPYRIGHT STATEMENT
===============================

Copyright (c) 1996-2000 Jean-Claude Wippler

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.


==============================================================================
-- Jean-Claude Wippler <jcw@equi4.com>