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diff --git a/doc/context/sources/general/manuals/libraries/libraries-mkiv.tex b/doc/context/sources/general/manuals/libraries/libraries-mkiv.tex new file mode 100644 index 000000000..67ca75966 --- /dev/null +++ b/doc/context/sources/general/manuals/libraries/libraries-mkiv.tex @@ -0,0 +1,199 @@ +% language=uk + +% author : Hans Hagen +% copyright : PRAGMA ADE & ConTeXt Development Team +% license : Creative Commons Attribution ShareAlike 4.0 International +% reference : pragma-ade.nl | contextgarden.net | texlive (related) distributions +% origin : the ConTeXt distribution +% +% comment : Because this manual is distributed with TeX distributions it comes with a rather +% liberal license. We try to adapt these documents to upgrades in the (sub)systems +% that they describe. Using parts of the content otherwise can therefore conflict +% with existing functionality and we cannot be held responsible for that. Many of +% the manuals contain characteristic graphics and personal notes or examples that +% make no sense when used out-of-context. +% +% comment : Some chapters might have been published in TugBoat, the NTG Maps, the ConTeXt +% Group journal or otherwise. Thanks to the editors for corrections. Also thanks +% to users for testing, feedback and corrections. + +\usemodule[art-01,abr-02] + +\definecolor + [maincolor] + [r=.4] + +\definecolor + [extracolor] + [g=.4] + +\setupbodyfont + [11pt] + +\setuptype + [color=maincolor] + +\setuptyping + [color=maincolor] + +\definefontsynonym + [TitlePageMono] + [file:lmmonoproplt10-bold*default] + +\setuphead + [color=maincolor] + +\usesymbols + [cc] + +\setupinteraction + [hidden] + +\loadfontgoodies[lm] + +\startdocument + [metadata:author=Hans Hagen, + metadata:title=Libraries in ConTeXt, + author=Hans Hagen, + affiliation=PRAGMA ADE, + location=Hasselt NL, + title=Libraries in \ConTeXt, + support=www.contextgarden.net, + website=www.pragma-ade.nl] + +\startluasetups[swiglib] + context.nohyphens() + for i=1,640 do + context.definedfont { string.formatters["TitlePageMono at %p"](65536*(10+math.random(5))) } + context("Libraries ") + end + context.removeunwantedspaces() +\stopluasetups + +\startMPpage + +StartPage ; + + fill Page enlarged 1cm withcolor \MPcolor{extracolor} ; + + draw textext("\framed[loffset=2pt,roffset=2pt,frame=off,width=\paperwidth,align={normal,paragraph,verytolerant,stretch}]{\luasetup{swiglib}}") + xysized (PaperWidth,PaperHeight) + shifted center Page + withcolor .8white ; + + draw textext.ulft("\definedfont[TitlePageMono]basics") + xsized .75PaperWidth + shifted lrcorner Page + shifted (-1cm,2cm) + withcolor \MPcolor{maincolor} ; + + % draw textext.ulft("\definedfont[TitlePageMono]in context mkiv") + % xsized .6PaperWidth + % shifted lrcorner Page + % shifted (-1cm,6cm) + % withcolor \MPcolor{maincolor} ; + +StopPage ; + +\stopMPpage + +\dontcomplain + +\startsubject[title=Contents] + +\placelist[section][alternative=a] + +\stopsubject + +\startsection[title=Introduction] + +Not long after we released \LUATEX\ 1.0, we started experimenting a bit more with +so called foreign function interface: \FFI. Originally that interface to external +libraries was only available in \LUAJITTEX, but a good and compatible alternative +is now also available in the normal engine too. For users it is not that relevant +to know how it works, as long as it works. It means that in addition to \SWIGLIB\ +we have a method that doesn't demand compilation as it uses normal (public) +libraries. + +Of course one needs to make sure that the right version of a library is used. +And, as there is the danger of the \API\ having been changed in an incompatible +way one can wonder if such a dependency is really what one wants. On the other +hand one can expect \CONTEXT\ to keep up. + +Do you really need libraries? For instance does it really make sense to use curl, +ghostscript or graphicmagic libraries while the command line version is +(normally) just as efficient and avoids a dependency. This is even more true if +you realizes that for instance a fetch or conversion only needs to happen once +per run or in fact only when there is some change in the resource. + +On the other hand, when accessing databases one can avoid the often slower +command line calls and save the hassle of intermediate files. Here efficiency +wins. Also, when \CONTEXT\ is used in a high performance database backend +application a distribution and the used libraries are not updated on a daily +basis. + +\stopsection + +\startsection[title=Supported] + +Apart from some experiments we currently can use \FFI\ interfaced libraries in: + +\starttabulate[|l|l|l|l|l|] +\FL +\BC module \BC library \BC windows \BC unix \NC \NR +\ML +\NC util-crl \NC curl \NC libcurl \NC libcurl \NC \NR % todo: client and ffi +\NC util-sql-imp-ffi \NC mysql \NC libmysql \NC libmysqlclient \NC \NR +\NC util-sql-imp-sqlite \NC sqlite \NC sqlite3 \NC sqlite3 \NC \NR +%NC font-phb-imp-library \NC harfbuzz \NC libharfbuzz \NC libharfbuzz \NC \NR % for testing uniscribe (idris fonts) +%NC \NC ghostscript \NC \NC \NC \NR % only a few experiments +%NC \NC graphicmagick \NC \NC \NC \NR % only a few experiments +\LL +\stoptabulate + +The profiler that we occasionally use to identify bottlenecks in the engine (for +instance when we upgrade \LUA) uses \FFI\ to provide access to the high resolution +timers but this is typically different per platform. + +One problem with libraries, especially on \WINDOWS\ is that the library is found on +some system path and it can happen that multiple programs ship the same library but in +different versions. You can try to play safe and put libraries in the \TEX\ tree, for +instance on my system they are in: + +\starttyping +c:/data/tex-context/tex/texmf-win64/bin/lib/luatex/lua/whatever/libwhatever.dll +\stoptyping + +You can trace where libraries are looked for with: + +\starttyping +\enabletrackers[resolvers.ffilib] +\stoptyping + +or in \LUA\ with: + +\starttyping +trackers.enable("resolvers.ffilib") +\stoptyping + +The library is first located on one of the valid \TDS\ paths (these are sort of +standardized in \TEX\ distributions) and then using the normal \FFI\ loader. + +As this is all still experimental in \LUATEX\ there is not much more to say about +it now. Of course this kind of specialized support to a large degree depends on +the need to use it. + +\stopsection + +\startsection[title=Colofon] + +\starttabulate[|B|p|] +\NC author \NC \getvariable{document}{author}, \getvariable{document}{affiliation}, \getvariable{document}{location} \NC \NR +\NC version \NC \currentdate \NC \NR +\NC website \NC \getvariable{document}{website} \endash\ \getvariable{document}{support} \NC \NR +\NC comment \NC many thanks to Luigi Scarso for taking care of ffi support in the engines \NC \NR +\stoptabulate + +\stopsection + +\stopdocument |