view tests/test-hybridencode.py @ 33207:895ecec31c70

revlog: add an experimental option to mitigated delta issues (issue5480)

The general delta heuristic to select a delta do not scale with the number of
branch. The delta base is frequently too far away to be able to reuse a chain
according to the "distance" criteria. This leads to insertion of larger delta (or
even full text) that themselves push the bases for the next delta further away
leading to more large deltas and full texts. This full text and frequent
recomputation throw Mercurial performance in disarray.

For example of a slightly large repository

  280 000 files (2 150 000 versions)
  430 000 changesets (10 000 topological heads)

Number below compares repository with and without the distance criteria:

manifest size:
    with:    21.4 GB
    without:  0.3 GB

store size:
    with:    28.7 GB
    without   7.4 GB

bundle last 15 00 revisions:
    with:    800 seconds
             971 MB
    without:  50 seconds
              73 MB

unbundle time (of the last 15K revisions):
    with:    1150 seconds (~19 minutes)
    without:   35 seconds

Similar issues has been observed in other repositories.


Adding a new option or "feature" on stable is uncommon. However, given that this
issues is making Mercurial practically unusable, I'm exceptionally targeting
this patch for stable.

What is actually needed is a full rework of the delta building and reading
logic. However, that will be a longer process and churn not suitable for stable.

In the meantime, we introduces a quick and dirty mitigation of this in the
'experimental' config space. The new option introduces a way to set the maximum
amount of memory usable to store a diff in memory. This extend the ability for
Mercurial to create chains without removing all safe guard regarding memory
access. The option should be phased out when core has a more proper solution
available.

Setting the limit to '0' remove all limits, setting it to '-1' use the default
limit (textsize x 4).

from __future__ import absolute_import, print_function
from mercurial import (
    store,
)

def show(s):
    # show test input
    print("A = '%s'" % s.encode("string_escape"))

    # show the result of the C implementation, if available
    h = store._pathencode(s)
    print("B = '%s'" % h.encode("string_escape"))

    # compare it with reference implementation in Python
    r = store._hybridencode(s, True)
    if h != r:
        print("R = '%s'" % r.encode("string_escape"))
    print()

show("data/abcdefghijklmnopqrstuvwxyz0123456789 !#%&'()+,-.;=[]^`{}")

print("uppercase char X is encoded as _x")
show("data/ABCDEFGHIJKLMNOPQRSTUVWXYZ")

print("underbar is doubled")
show("data/_")

print("tilde is character-encoded")
show("data/~")

print("characters in ASCII code range 1..31")
show('data/\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f'
          '\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f')

print("characters in ASCII code range 126..255")
show('data/\x7e\x7f'
          '\x80\x81\x82\x83\x84\x85\x86\x87\x88\x89\x8a\x8b\x8c\x8d\x8e\x8f'
          '\x90\x91\x92\x93\x94\x95\x96\x97\x98\x99\x9a\x9b\x9c\x9d\x9e\x9f')
show('data/\xa0\xa1\xa2\xa3\xa4\xa5\xa6\xa7\xa8\xa9\xaa\xab\xac\xad\xae\xaf'
          '\xb0\xb1\xb2\xb3\xb4\xb5\xb6\xb7\xb8\xb9\xba\xbb\xbc\xbd\xbe\xbf')
show('data/\xc0\xc1\xc2\xc3\xc4\xc5\xc6\xc7\xc8\xc9\xca\xcb\xcc\xcd\xce\xcf'
          '\xd0\xd1\xd2\xd3\xd4\xd5\xd6\xd7\xd8\xd9\xda\xdb\xdc\xdd\xde\xdf')
show('data/\xe0\xe1\xe2\xe3\xe4\xe5\xe6\xe7\xe8\xe9\xea\xeb\xec\xed\xee\xef'
          '\xf0\xf1\xf2\xf3\xf4\xf5\xf6\xf7\xf8\xf9\xfa\xfb\xfc\xfd\xfe\xff')

print("Windows reserved characters")
show('data/less <, greater >, colon :, double-quote ", backslash \\'
           ', pipe |, question-mark ?, asterisk *')

print("encoding directories ending in .hg, .i or .d with '.hg' suffix")
show('data/x.h.i/x.hg/x.i/x.d/foo')
show('data/a.hg/a.i/a.d/foo')
show('data/au.hg/au.i/au.d/foo')
show('data/aux.hg/aux.i/aux.d/foo')
show('data/auxy.hg/auxy.i/auxy.d/foo')

print("but these are not encoded on *filenames*")
show('data/foo/x.hg')
show('data/foo/x.i')
show('data/foo/x.d')
show('data/foo/a.hg')
show('data/foo/a.i')
show('data/foo/a.d')
show('data/foo/au.hg')
show('data/foo/au.i')
show('data/foo/au.d')
show('data/foo/aux.hg')
show('data/foo/aux.i')
show('data/foo/aux.d')
show('data/foo/auxy.hg')
show('data/foo/auxy.i')
show('data/foo/auxy.d')

print("plain .hg, .i and .d directories have the leading dot encoded")
show('data/.hg/.i/.d/foo')

show('data/aux.bla/bla.aux/prn/PRN/lpt/com3/nul/coma/foo.NUL/normal.c.i')

show('data/AUX/SECOND/X.PRN/FOURTH/FI:FTH/SIXTH/SEVENTH/EIGHTH/NINETH/'
     'TENTH/ELEVENTH/LOREMIPSUM.TXT.i')
show('data/enterprise/openesbaddons/contrib-imola/corba-bc/netbeansplugin/'
     'wsdlExtension/src/main/java/META-INF/services/org.netbeans.modules'
     '.xml.wsdl.bindingsupport.spi.ExtensibilityElementTemplateProvider.i')
show('data/AUX.THE-QUICK-BROWN-FOX-JU:MPS-OVER-THE-LAZY-DOG-THE-QUICK-'
     'BROWN-FOX-JUMPS-OVER-THE-LAZY-DOG.TXT.i')
show('data/Project Planning/Resources/AnotherLongDirectoryName/'
     'Followedbyanother/AndAnother/AndThenAnExtremelyLongFileName.txt')
show('data/Project.Planning/Resources/AnotherLongDirectoryName/'
     'Followedbyanother/AndAnother/AndThenAnExtremelyLongFileName.txt')
show('data/foo.../foo   / /a./_. /__/.x../    bla/.FOO/something.i')

show('data/c/co/com/com0/com1/com2/com3/com4/com5/com6/com7/com8/com9')
show('data/C/CO/COM/COM0/COM1/COM2/COM3/COM4/COM5/COM6/COM7/COM8/COM9')
show('data/c.x/co.x/com.x/com0.x/com1.x/com2.x/com3.x/com4.x/com5.x'
                                        '/com6.x/com7.x/com8.x/com9.x')
show('data/x.c/x.co/x.com0/x.com1/x.com2/x.com3/x.com4/x.com5'
                                        '/x.com6/x.com7/x.com8/x.com9')
show('data/cx/cox/comx/com0x/com1x/com2x/com3x/com4x/com5x'
                                            '/com6x/com7x/com8x/com9x')
show('data/xc/xco/xcom0/xcom1/xcom2/xcom3/xcom4/xcom5'
                                            '/xcom6/xcom7/xcom8/xcom9')

show('data/l/lp/lpt/lpt0/lpt1/lpt2/lpt3/lpt4/lpt5/lpt6/lpt7/lpt8/lpt9')
show('data/L/LP/LPT/LPT0/LPT1/LPT2/LPT3/LPT4/LPT5/LPT6/LPT7/LPT8/LPT9')
show('data/l.x/lp.x/lpt.x/lpt0.x/lpt1.x/lpt2.x/lpt3.x/lpt4.x/lpt5.x'
                                        '/lpt6.x/lpt7.x/lpt8.x/lpt9.x')
show('data/x.l/x.lp/x.lpt/x.lpt0/x.lpt1/x.lpt2/x.lpt3/x.lpt4/x.lpt5'
                                        '/x.lpt6/x.lpt7/x.lpt8/x.lpt9')
show('data/lx/lpx/lptx/lpt0x/lpt1x/lpt2x/lpt3x/lpt4x/lpt5x'
                                            '/lpt6x/lpt7x/lpt8x/lpt9x')
show('data/xl/xlp/xlpt/xlpt0/xlpt1/xlpt2/xlpt3/xlpt4/xlpt5'
                                            '/xlpt6/xlpt7/xlpt8/xlpt9')

show('data/con/p/pr/prn/a/au/aux/n/nu/nul')
show('data/CON/P/PR/PRN/A/AU/AUX/N/NU/NUL')
show('data/con.x/p.x/pr.x/prn.x/a.x/au.x/aux.x/n.x/nu.x/nul.x')
show('data/x.con/x.p/x.pr/x.prn/x.a/x.au/x.aux/x.n/x.nu/x.nul')
show('data/conx/px/prx/prnx/ax/aux/auxx/nx/nux/nulx')
show('data/xcon/xp/xpr/xprn/xa/xau/xaux/xn/xnu/xnul')

show('data/a./au./aux./auxy./aux.')
show('data/c./co./con./cony./con.')
show('data/p./pr./prn./prny./prn.')
show('data/n./nu./nul./nuly./nul.')
show('data/l./lp./lpt./lpt1./lpt1y./lpt1.')
show('data/lpt9./lpt9y./lpt9.')
show('data/com./com1./com1y./com1.')
show('data/com9./com9y./com9.')

show('data/a /au /aux /auxy /aux ')

print("largest unhashed path")
show('data/123456789-123456789-123456789-123456789-123456789-'
          'unhashed--xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("shortest hashed path")
show('data/123456789-123456789-123456789-123456789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("changing one char in part that's hashed away produces a different hash")
show('data/123456789-123456789-123456789-123456789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxy-'
          '123456789-123456')

print("uppercase hitting length limit due to encoding")
show('data/A23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/Z23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("compare with lowercase not hitting limit")
show('data/a23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/z23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("not hitting limit with any of these")
show("data/abcdefghijklmnopqrstuvwxyz0123456789 !#%&'()+,-.;="
          "[]^`{}xxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-"
          "123456789-12345")

print("underbar hitting length limit due to encoding")
show('data/_23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("tilde hitting length limit due to encoding")
show('data/~23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("Windows reserved characters hitting length limit")
show('data/<23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/>23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/:23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/"23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/\\23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/|23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/?23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/*23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("initial space hitting length limit")
show('data/ 23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("initial dot hitting length limit")
show('data/.23456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("trailing space in filename hitting length limit")
show('data/123456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-1234 ')

print("trailing dot in filename hitting length limit")
show('data/123456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-1234.')

print("initial space in directory hitting length limit")
show('data/ x/456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("initial dot in directory hitting length limit")
show('data/.x/456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("trailing space in directory hitting length limit")
show('data/x /456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("trailing dot in directory hitting length limit")
show('data/x./456789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("with directories that need direncoding, hitting length limit")
show('data/x.i/56789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/x.d/56789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/x.hg/5789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("Windows reserved filenames, hitting length limit")
show('data/con/56789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/prn/56789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/aux/56789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/nul/56789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/com1/6789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/com9/6789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/lpt1/6789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')
show('data/lpt9/6789-123456789-123456789-123456789-123456789-'
          'xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("non-reserved names, just not hitting limit")
show('data/123456789-123456789-123456789-123456789-123456789-'
          '/com/com0/lpt/lpt0/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12345')

print("hashed path with largest untruncated 1st dir")
show('data/12345678/-123456789-123456789-123456789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with smallest truncated 1st dir")
show('data/123456789/123456789-123456789-123456789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with largest untruncated two dirs")
show('data/12345678/12345678/9-123456789-123456789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with smallest truncated two dirs")
show('data/123456789/123456789/123456789-123456789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with largest untruncated three dirs")
show('data/12345678/12345678/12345678/89-123456789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with smallest truncated three dirs")
show('data/123456789/123456789/123456789/123456789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with largest untruncated four dirs")
show('data/12345678/12345678/12345678/12345678/789-123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with smallest truncated four dirs")
show('data/123456789/123456789/123456789/123456789/123456789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with largest untruncated five dirs")
show('data/12345678/12345678/12345678/12345678/12345678/6789-'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with smallest truncated five dirs")
show('data/123456789/123456789/123456789/123456789/123456789/'
          'hashed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with largest untruncated six dirs")
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/ed----xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with smallest truncated six dirs")
show('data/123456789/123456789/123456789/123456789/123456789/'
          '123456789/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with largest untruncated seven dirs")
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/xxxxxx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with smallest truncated seven dirs")
show('data/123456789/123456789/123456789/123456789/123456789/'
          '123456789/123456789/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with largest untruncated eight dirs")
print("(directory 8 is dropped because it hits _maxshortdirslen)")
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345678/xxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with smallest truncated eight dirs")
print("(directory 8 is dropped because it hits _maxshortdirslen)")
show('data/123456789/123456789/123456789/123456789/123456789/'
          '123456789/123456789/123456789/xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with largest non-dropped directory 8")
print("(just not hitting the _maxshortdirslen boundary)")
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("...adding one truncated char to dir 1..7 won't drop dir 8")
show('data/12345678x/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')
show('data/12345678/12345678x/12345678/12345678/12345678/12345'
          '678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')
show('data/12345678/12345678/12345678x/12345678/12345678/12345'
          '678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')
show('data/12345678/12345678/12345678/12345678x/12345678/12345'
          '678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')
show('data/12345678/12345678/12345678/12345678/12345678x/12345'
          '678/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678x/12345678/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678x/12345/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path with shortest dropped directory 8")
print("(just hitting the _maxshortdirslen boundary)")
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/123456/xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("hashed path that drops dir 8 due to dot or space at end is")
print("encoded, and thus causing to hit _maxshortdirslen")
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/1234./-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/1234 /-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print("... with dir 8 short enough for encoding")
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12./xx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12 /xx-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-123456')

print('''Extensions are replicated on hashed paths. Note that
we only get to encode files that end in .i or .d inside the
store. Encoded filenames are thus bound in length.''')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.345.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.345.d')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.34567.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.345678.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456789.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456789-.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456789-1.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456789-12.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456789-123.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456789-1234.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456789-12345.i')
show('data/12345678/12345678/12345678/12345678/12345678/12345'
          '678/12345678/12345/-xxxxxxxxx-xxxxxxxxx-xxxxxxxxx-'
          '123456789-12.3456789-12345-ABCDEFGHIJKLMNOPRSTUVWX'
          'YZ-abcdefghjiklmnopqrstuvwxyz-ABCDEFGHIJKLMNOPRSTU'
          'VWXYZ-1234567890-xxxxxxxxx-xxxxxxxxx-xxxxxxxx-xxxx'
          'xxxxx-wwwwwwwww-wwwwwwwww-wwwwwwwww-wwwwwwwww-wwww'
          'wwwww-wwwwwwwww-wwwwwwwww-wwwwwwwww-wwwwwwwww.i')

print("paths outside data/ can be encoded")
show('metadata/dir/00manifest.i')
show('metadata/12345678/12345678/12345678/12345678/12345678/'
          '12345678/12345678/12345678/12345678/12345678/12345678/'
          '12345678/12345678/00manifest.i')