-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi!
Yesterday, I again found myself writing safety workarounds around Sword status reporting, i.e. for the sword::StatusReporter::statusUpdate() callback, which for some reason uses floating point doubles instead of integers. Digging my way into the depths of Sword I noticed that this was implemented this way probably due to libcurl providing similar callbacks with doubles. Looking at the libcurl source code, I noticed that for their upcoming version 7.32.0 they have implemented a better callback for progress. For reference, see https://github.com/bagder/curl/commit/12d01cb6 It should be possible to use some #include <curl/curlver.h> #if LIBCURL_VERSION_NUM >= 0x072000 magic in Sword to provide similar callback alternatives for Sword programs. I suggest that the sword::StatusReporter class be extended with this method: virtual void update(size_t dlTotal, size_t dlNow); keeping the older statusUpdate(double, double) as well. When progress is reported by the new curl callback, both update() and statusUpdate() should be called for backwards compatibility. If using curl 7.32.0 or later, for the update() call, curl_off_t arguments (signed integers of some width) are converted to size_t, and for statusUpdate() call they are converted to double(). If using earlier versions of curl, for the update() call, double arguments are converted to size_t, and for statusUpdate() call they are passed as-is. As you can easily see, both old and new approaches in curl have its deficiencies, since both double and curl_off_t are both signed. An additional caveats come from conversions to or/and from doubles and operations on them, which might involve using the FPU (integer operations are much faster on CPU cores), might yield imprecise values, invalid values or floating point exceptions. The latter might just crash the program in some circumstances. I haven't time to formally analyze whether some or all of these issues affect BibleTime, but our code for statusUpdate() has workarounds in case the passed doubles are negative, if (dlTotal == 0.0), if (dlNow > dlTotal), etc. I guess we could also call fpclassify() etc to work around other corner cases, but in principle, this is not what frontend developers should be dealing with, so I suggest a proper update(size_t done, size_t total) interface be defined, where total > 0u and done <= total always hold. The old statusUpdate(double, double) interface should be deprecated. Blessings, Jaak PS: I'm not sure whether we should to delay the 1.7.0 release for this, although this issue might involve an API change. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.20 (GNU/Linux) iQgcBAEBAgAGBQJR+OHVAAoJEEqsYmEt1rCOY6Q//1LTeiEsfFdN8b/KtOzbFNWR xGpJ5HBP/Dxcbkxibhaw5fbbHUUqrnyq4MA5jtnazcGmhkPsuw6ZyMooBMmht27y tqNQOePPFh2//O+aScDbGJgoTWoVPvV6pbAx53UKwHPxNxTQObiH0nDt3B/cbT14 bHIRDRfAKT0keINd8OZKQ6wizjrvsTbzOj3R52iYHfatIcIt1vrLT/gss4mWk0NO 6OAJx/3tUNetLb44wVEiB4ZRFUJMjreBWiM6/+Rhsmkttwuz1pvbGtW/yzvQEyls UschH8hBCKlyEkxzszR+g2HCD3c5EKDX/EASNbpEIo8xE8+DDi1nLgm3I2UmRY/8 cjeoQNzzP+Pho8ug3fa2S/iJZ3Xey9xgv7xeelliC4ULLlhLC8hjQXZgJe0pwajq FqbyTPVmEfdvrQ4mc4KoNMHcHFnPZKf0nFi0k2Jt86lVtPIQnhnIpRM2rl4vzRiE dpm9zjaefXYZACPH2Jqh7dpktW/MwmHqqL5ziylXnitOUl4y8D8rEv6UKyDxtoeW XktmmaGFGgv8Ct/ZStnYoV7zIX972Mx+UHpPNm1iamUSQZAZNAFEMks2fw6CZ7Mf 5CRi/tqkYZg1Zj3w2Zp8NI+0KXSHOEG1OMrFvQNgRXIu3VW3CvNbLXpDEkuSANlR sdq1OH3/zbw7L+LusiMp5760VkKeOdfXam29fzfNkuVpp060OuECDhQkZYDoo2dB 6E4MTaBQjBjMjnusU2JnXgBkPvMQdNN6o9wY2cXGKYqneSmcgEekfvgvi5vRRiyW ZufHKh1MFwxSK/I5jQcHt9lq744vi65kMW84VPBmdW3DCwyePwFwBWzwHAZ4X087 X62VJeKfoD025Ggj9+6niAhiW8Ue1sX3PIx5qx5n4hnc3oNkiaukfddo9JQXQ32M m+H2ukBtS4inFfXEbVmN/SCBDNOg7pC6H41clypXaKt40TpnXqWDheiyjEP39q+q UMYpaZKIdUVRrjQj5yiH6+kK8TDCneAfdFgiwfMV3/9lo211BG93+t/FTg5Yv5G+ b6pNSBr7rw+rlfx2v2Eyey4j/b/eGLVAuRnuTRhNrgkO345k6uU8NMKtNunpQaAT H0eABPr2qRjZF69SnWs2Wjn5xWvmWcnG+i/IKsVExInSghfX2wHAJMYLszVsG9Cz er8wiLOj5gvccHa3JnJqOihEiiCADq+Tf0xXBw+Jr1TyAeuFgoAYOZEyv28tHucF QN83xOWAh69ELzptQ3ppFAyTFk6gyCizkNrmpPjnn3DCtyAByy/BzoObwpt1rAG8 lr+DfKTNALUQrA0aN4Y/kT4e+LNPIb3um0PQ3CujnD3bfEsGfBeEaw+25edjsRWC thAvej8z2wHLFpidA1WpSy5rJ91ZRqdMPwiTs5oA8MfFrjqUKcLhto7+mk6VITAX 2WScQh4+9UDOEyLgs3BAz4/63gwhu8Ak6/GZNoDG+6LIDRV3waMQbGte36htIu7F SLgc1SqqjT0NW229RNVc+Vf9sS/xxZyCpPYtHUYlSrmwhlVQsKlspvvj2tyFG878 JdslP/6jnCKHXOjhBb8OJroRzsKH+iQnMk/4hz5SQXtXTEIVleOHjtXb0CpwPOl9 qABAhiPpyn4OoTTYDnzYFKun/9QMKCkJCdTmEm69jmhY8t2Rw07pgwK4otSvUFpY 3W4DVMW3FXU1EGrT25Tv2joP9kUyoEU9AnQRPYTxr98AMVQCb+fjhONSBYphhKVw P0HXYqMn/5qBEmL04xFe/TPFcp3CkRJ0XgZtYHPLYJoY5oy3wTtHtVx+KD6XKsx1 +YE9C5U0uVLvA7XBGsOiaw2U8CwAQusVwgaId+IXkjfhBNhTewP1egZWtN7cN/Xb G93FQjHTcVrsKXN62COsOyhmBDgeOt+hAYhQfIJlaMQfwA7cpQKS+gkqCfAJpirt oX3VXcQS462LrDSMBdmjKfz4SmYPhh6tW69P5r/Fw63YGJGj8HZlTrziaEgs4V/q KjwY4xe0jGcKG+Qaau5cFQB6QS6cLnLfW0fUkNXkDFYkiO3r5++Ou0NmcHN/4ssB /7qOTursRDKK7wUpQPopxqf6GI+G+FyuJW0KuDtxm5w+taopN5TBZ/afi6kPHYNs ByKLk+nqN4D6Gh5QVwPLBL1cRGsaF19OwhC3K7d69lURZLYsBVWSVbs+PGar2ZtK 5sEkNA8Ule00mZcYzf6b7AHQIvsDjA34ur+clsX6g06K3Rf7j39YHg3zLL7lZfnB ieCv2TVI3/+xz9syyFGQ0V9yTwk+hbLndE9i0UA4vItFFEbNhNOfD7BmJ1XNveh1 GNAi3N84OtQm0sScOLmFL1JSj0AHMq2+lsUosxw/4pMy5OS3GmlLTyaIhcOt6KS5 S3bKjEmyBzcrX3emeKKDBt4OY8q8AEztMJ3lVXyGtU5fwSmFDtGE2tnG/gNmEy7k /jZ03Szf8KLJIdJTLbp8hHFzxodXNH3cM4hSYezY++gXTaWcdkpai54W3QcDnTdo Op6sFKsy9I23JTqkaUzkhV9rUJBVzCm4Gk+/1CdPs0XFkBuFj1t9PambqkbWjqIV KlCCf4IWNrs3G0XuVR+05WTKHgyWnu/pYB8Zx2vEn2ocOfFwYQf/UBaTWYszY9KB HpfDWMntITJNGLbJzymDdEigC/oHc1MdRm35LXOP85WlSXEAJ93aPAvfzjp1T78y m88Ta1IHVOCmLdGSxMSo =hokR -----END PGP SIGNATURE----- _______________________________________________ sword-devel mailing list: sword-devel@crosswire.org http://www.crosswire.org/mailman/listinfo/sword-devel Instructions to unsubscribe/change your settings at above page
