The MetaKit Library 2.0 December 1999 ============================================================================== 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) an SQL database, 2) multi-user/-threading, 3) scalable to gigabytes, 4) proprietary software, 5) 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 2.0 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 Tcl, adjust "CXX_SWITCHES_TCL", and insert the proper "-L/lib" before "-ltclstub8.2" (twice). For Python 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, contact me to obtain a copy. 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). - 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 notes yet, more details expected when the new release is tried on other Unix systems. * 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, since this release has not yet been built on any of them. 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) 1996-1999 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