performance of regular expression in minvisitors.py

[kevingill1966]

I tried to use slimit in a tool chain for delivering javascript content. However, I ran into a performance problem. The problem seems to be a regular expression in minvisitors.py, this is the code I tried to isolate the issue:

from slimit.visitors.minvisitor import _HAS_ID_MATCH
import time
timeStart = time.time()
_HAS_ID_MATCH('withdrawal_from_monitoring.withdrawal_from_monitoring')
print 'duration', time.time() - timeStart

On my laptop looking up this identifier takes 31 seconds to resolve

duration 31.2419760227

[ztane]

@kevingill1966 This I guess is somehow related to Ply version. My stuff works swiftly on Ply 3.4, fails outright on 3.6 and works sluggishly on 3.8!

[ztane]

Ah not even...

[ztane]

The regex in question happens to be:

(?:[a-zA-Z$]|[\u0041-\u005A\u0061-\u007A\u00AA\u00B5\u00BA\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02C1\u02C6-\u02D1\u02E0-\u02E4\u02EC\u02EE\u0370-\u0374\u0376\u0377\u037A-\u037D\u0386\u0388-\u038A\u038C\u038E-\u03A1\u03A3-\u03F5\u03F7-\u0481\u048A-\u0523\u0531-\u0556\u0559\u0561-\u0587\u05D0-\u05EA\u05F0-\u05F2\u0621-\u064A\u066E\u066F\u0671-\u06D3\u06D5\u06E5\u06E6\u06EE\u06EF\u06FA-\u06FC\u06FF\u0710\u0712-\u072F\u074D-\u07A5\u07B1\u07CA-\u07EA\u07F4\u07F5\u07FA\u0904-\u0939\u093D\u0950\u0958-\u0961\u0971\u0972\u097B-\u097F\u0985-\u098C\u098F\u0990\u0993-\u09A8\u09AA-\u09B0\u09B2\u09B6-\u09B9\u09BD\u09CE\u09DC\u09DD\u09DF-\u09E1\u09F0\u09F1\u0A05-\u0A0A\u0A0F\u0A10\u0A13-\u0A28\u0A2A-\u0A30\u0A32\u0A33\u0A35\u0A36\u0A38\u0A39\u0A59-\u0A5C\u0A5E\u0A72-\u0A74\u0A85-\u0A8D\u0A8F-\u0A91\u0A93-\u0AA8\u0AAA-\u0AB0\u0AB2\u0AB3\u0AB5-\u0AB9\u0ABD\u0AD0\u0AE0\u0AE1\u0B05-\u0B0C\u0B0F\u0B10\u0B13-\u0B28\u0B2A-\u0B30\u0B32\u0B33\u0B35-\u0B39\u0B3D\u0B5C\u0B5D\u0B5F-\u0B61\u0B71\u0B83\u0B85-\u0B8A\u0B8E-\u0B90\u0B92-\u0B95\u0B99\u0B9A\u0B9C\u0B9E\u0B9F\u0BA3\u0BA4\u0BA8-\u0BAA\u0BAE-\u0BB9\u0BD0\u0C05-\u0C0C\u0C0E-\u0C10\u0C12-\u0C28\u0C2A-\u0C33\u0C35-\u0C39\u0C3D\u0C58\u0C59\u0C60\u0C61\u0C85-\u0C8C\u0C8E-\u0C90\u0C92-\u0CA8\u0CAA-\u0CB3\u0CB5-\u0CB9\u0CBD\u0CDE\u0CE0\u0CE1\u0D05-\u0D0C\u0D0E-\u0D10\u0D12-\u0D28\u0D2A-\u0D39\u0D3D\u0D60\u0D61\u0D7A-\u0D7F\u0D85-\u0D96\u0D9A-\u0DB1\u0DB3-\u0DBB\u0DBD\u0DC0-\u0DC6\u0E01-\u0E30\u0E32\u0E33\u0E40-\u0E46\u0E81\u0E82\u0E84\u0E87\u0E88\u0E8A\u0E8D\u0E94-\u0E97\u0E99-\u0E9F\u0EA1-\u0EA3\u0EA5\u0EA7\u0EAA\u0EAB\u0EAD-\u0EB0\u0EB2\u0EB3\u0EBD\u0EC0-\u0EC4\u0EC6\u0EDC\u0EDD\u0F00\u0F40-\u0F47\u0F49-\u0F6C\u0F88-\u0F8B\u1000-\u102A\u103F\u1050-\u1055\u105A-\u105D\u1061\u1065\u1066\u106E-\u1070\u1075-\u1081\u108E\u10A0-\u10C5\u10D0-\u10FA\u10FC\u1100-\u1159\u115F-\u11A2\u11A8-\u11F9\u1200-\u1248\u124A-\u124D\u1250-\u1256\u1258\u125A-\u125D\u1260-\u1288\u128A-\u128D\u1290-\u12B0\u12B2-\u12B5\u12B8-\u12BE\u12C0\u12C2-\u12C5\u12C8-\u12D6\u12D8-\u1310\u1312-\u1315\u1318-\u135A\u1380-\u138F\u13A0-\u13F4\u1401-\u166C\u166F-\u1676\u1681-\u169A\u16A0-\u16EA\u1700-\u170C\u170E-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176C\u176E-\u1770\u1780-\u17B3\u17D7\u17DC\u1820-\u1877\u1880-\u18A8\u18AA\u1900-\u191C\u1950-\u196D\u1970-\u1974\u1980-\u19A9\u19C1-\u19C7\u1A00-\u1A16\u1B05-\u1B33\u1B45-\u1B4B\u1B83-\u1BA0\u1BAE\u1BAF\u1C00-\u1C23\u1C4D-\u1C4F\u1C5A-\u1C7D\u1D00-\u1DBF\u1E00-\u1F15\u1F18-\u1F1D\u1F20-\u1F45\u1F48-\u1F4D\u1F50-\u1F57\u1F59\u1F5B\u1F5D\u1F5F-\u1F7D\u1F80-\u1FB4\u1FB6-\u1FBC\u1FBE\u1FC2-\u1FC4\u1FC6-\u1FCC\u1FD0-\u1FD3\u1FD6-\u1FDB\u1FE0-\u1FEC\u1FF2-\u1FF4\u1FF6-\u1FFC\u2071\u207F\u2090-\u2094\u2102\u2107\u210A-\u2113\u2115\u2119-\u211D\u2124\u2126\u2128\u212A-\u212D\u212F-\u2139\u213C-\u213F\u2145-\u2149\u214E\u2183\u2184\u2C00-\u2C2E\u2C30-\u2C5E\u2C60-\u2C6F\u2C71-\u2C7D\u2C80-\u2CE4\u2D00-\u2D25\u2D30-\u2D65\u2D6F\u2D80-\u2D96\u2DA0-\u2DA6\u2DA8-\u2DAE\u2DB0-\u2DB6\u2DB8-\u2DBE\u2DC0-\u2DC6\u2DC8-\u2DCE\u2DD0-\u2DD6\u2DD8-\u2DDE\u2E2F\u3005\u3006\u3031-\u3035\u303B\u303C\u3041-\u3096\u309D-\u309F\u30A1-\u30FA\u30FC-\u30FF\u3105-\u312D\u3131-\u318E\u31A0-\u31B7\u31F0-\u31FF\u3400\u4DB5\u4E00\u9FC3\uA000-\uA48C\uA500-\uA60C\uA610-\uA61F\uA62A\uA62B\uA640-\uA65F\uA662-\uA66E\uA67F-\uA697\uA717-\uA71F\uA722-\uA788\uA78B\uA78C\uA7FB-\uA801\uA803-\uA805\uA807-\uA80A\uA80C-\uA822\uA840-\uA873\uA882-\uA8B3\uA90A-\uA925\uA930-\uA946\uAA00-\uAA28\uAA40-\uAA42\uAA44-\uAA4B\uAC00\uD7A3\uF900-\uFA2D\uFA30-\uFA6A\uFA70-\uFAD9\uFB00-\uFB06\uFB13-\uFB17\uFB1D\uFB1F-\uFB28\uFB2A-\uFB36\uFB38-\uFB3C\uFB3E\uFB40\uFB41\uFB43\uFB44\uFB46-\uFBB1\uFBD3-\uFD3D\uFD50-\uFD8F\uFD92-\uFDC7\uFDF0-\uFDFB\uFE70-\uFE74\uFE76-\uFEFC\uFF21-\uFF3A\uFF41-\uFF5A\uFF66-\uFFBE\uFFC2-\uFFC7\uFFCA-\uFFCF\uFFD2-\uFFD7\uFFDA-\uFFDC])+(?:[\u0300-\u036F\u0483-\u0487\u0591-\u05BD\u05BF\u05C1\u05C2\u05C4\u05C5\u05C7\u0610-\u061A\u064B-\u065E\u0670\u06D6-\u06DC\u06DF-\u06E4\u06E7\u06E8\u06EA-\u06ED\u0711\u0730-\u074A\u07A6-\u07B0\u07EB-\u07F3\u0816-\u0819\u081B-\u0823\u0825-\u0827\u0829-\u082D\u0900-\u0902\u093C\u0941-\u0948\u094D\u0951-\u0955\u0962\u0963\u0981\u09BC\u09C1-\u09C4\u09CD\u09E2\u09E3\u0A01\u0A02\u0A3C\u0A41\u0A42\u0A47\u0A48\u0A4B-\u0A4D\u0A51\u0A70\u0A71\u0A75\u0A81\u0A82\u0ABC\u0AC1-\u0AC5\u0AC7\u0AC8\u0ACD\u0AE2\u0AE3\u0B01\u0B3C\u0B3F\u0B41-\u0B44\u0B4D\u0B56\u0B62\u0B63\u0B82\u0BC0\u0BCD\u0C3E-\u0C40\u0C46-\u0C48\u0C4A-\u0C4D\u0C55\u0C56\u0C62\u0C63\u0CBC\u0CBF\u0CC6\u0CCC\u0CCD\u0CE2\u0CE3\u0D41-\u0D44\u0D4D\u0D62\u0D63\u0DCA\u0DD2-\u0DD4\u0DD6\u0E31\u0E34-\u0E3A\u0E47-\u0E4E\u0EB1\u0EB4-\u0EB9\u0EBB\u0EBC\u0EC8-\u0ECD\u0F18\u0F19\u0F35\u0F37\u0F39\u0F71-\u0F7E\u0F80-\u0F84\u0F86\u0F87\u0F90-\u0F97\u0F99-\u0FBC\u0FC6\u102D-\u1030\u1032-\u1037\u1039\u103A\u103D\u103E\u1058\u1059\u105E-\u1060\u1071-\u1074\u1082\u1085\u1086\u108D\u109D\u135F\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17B7-\u17BD\u17C6\u17C9-\u17D3\u17DD\u180B-\u180D\u18A9\u1920-\u1922\u1927\u1928\u1932\u1939-\u193B\u1A17\u1A18\u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[ztane]

The branches will cause backtracking. I did

l = Lexer.identifier
l = l.replace(']|[', '')

to force everything into one character class and it is really swift!

[ztane]

duration 0.00381302833557