October 2007 - cxml-devel - mailman3.common-lisp.net

[cxml-devel] New cxml releases
by David Lichteblau 21 Oct '07

21 Oct '07

Hi, a new cxml release is available. This is the first release that depends on closure-common, found in cxml CVS as a separate module and as a tarball in cxml's download directory. Users of cxml-stp and cxml-rng should also upgrade to the newest versions of these systems for compatibility with this cxml release. Other changes in this release: * Incompatible SAX changes: Added new classes sax:abstract-handler, sax:content-handler, sax:default-handler. Implementations of SAX handlers should now subclass one of these classes. * fixed make-source :buffering nil, thanks to Magnus Henoch for the report * fixed time and space usage in cases where entity references follow each other (thanks to Ivan Shvedunov for the report) * In the DOM builder, grow a buffer for string normalization exponentially, fixing a long-standing speed issue. David

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[cxml-devel] Where is the closure-common system?
by Ralf Mattes 09 Oct '07

09 Oct '07

After a recent CVS update SBCL is unable to load cxml, complaining: debugger invoked on a MISSING-DEPENDENCY in thread #<THREAD "initial thread" {A806671}>: component :CLOSURE-COMMON not found, required by CXML Type HELP for debugger help, or (SB-EXT:QUIT) to exit from SBCL. restarts (invokable by number or by possibly-abbreviated name): 0: [ABORT] Exit debugger, returning to top level. (SB-INT:SIMPLE-EVAL-IN-LEXENV (ERROR 'MISSING-DEPENDENCY :REQUIRED-BY :CXML :VERSION NIL :REQUIRES :CLOSURE-COMMON) #<NULL-LEXENV>) 0] 0 This did not happen with earlier versions. I can check out a closure-common module from CVS but that doesn't conatain a ASDF definition .... TIA Ralf Mattes

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[cxml-devel] CXML::P/CONTENT causes heap exhaustion due to deep recursion where there are too many entity references
by Ivan Shvedunov 03 Oct '07

03 Oct '07

Hi. I've noticed that parsing XML that contains many entity references may cause CXML to eat up all available heap space and crash. This can be easily reproduced: (cxml:parse-rod (format nil "<xml>~{~a~}</xml>" (loop repeat 4000 collect "<p>zz")) (cxml-dom:make-dom-builder)) (tested on SBCL / Linux) Looking at the code, I've noticed that xml/xml-parse.lisp relies on the tail recursion a lot (though always having proper tail recursion is frankly speaking somewhat dubious expectation when working with Common Lisp). What's worse, P/CONTENT function is non-tail-recursive when an entity reference is encountered, and this is exactly the cause of aforementioned crash. I've attached the patch which helped me solve the problem (it's made against cxml-2007-08-05). I've just noticed that recurse-on-entity returns NIL most of time and used that fact to cut off most of recursion. As of now my brain is somewhat foggy due to continuing coding race, so I didn't learn what recurse-on-entity actually does and how often can it return a non-NIL value. Overall I don't think this is a proper solution, most likely xml-parse.lisp needs some serious rework to make it more reliable. But I think at least this hack will help in most cases. Ivan

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