[mkgmap-dev] PATCH reduce index size

Sun Dec 5 15:32:04 GMT 2021

Hi Felix,

yes, I think it works as documented. Those entries can come from labels which start with M0. , so it's not an additional entry produced by the --split-name-index option. I also tried to remove the full entry but then the search didn't work any more.

Check what happens when you remove the clause "st.getNameOffset() > 0 && " .

Gerd

________________________________________
Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von Felix Hartmann <extremecarver at gmail.com>
Gesendet: Sonntag, 5. Dezember 2021 15:57
An: Development list for mkgmap
Betreff: Re: [mkgmap-dev] PATCH reduce index size

are you sure this works fully?
I still have some strings in the display.jar output.
I updated the gmapsupp.img here: https://openmtbmap.org/gmapsupp.img

The log file from display.jar decreased by around 15% in size - but there are still entries like:
00036727 | 00300e | 4d 30 2e 20             | [1082] str: M0.
0003672b | 003012 | eb 28                   | Index?  10475
0003672d | 003014 | 4d 31 2e 20             | [1083] str: M1.
00036731 | 003018 | ec 28                   | Index?  10476
00036733 | 00301a | 4d 32 2e 20             | [1084] str: M2.
00036737 | 00301e | ed 28                   | Index?  10477
00036739 | 003020 | 4d 33 2e 20             | [1085] str: M3.
0003673d | 003024 | ee 28                   | Index?  10478
0003673f | 003026 | 4d 34 2e 20             | [1086] str: M4.

Another thing which could be optimized - no number only entries. I don*t know any country where you would have an address with the street consisting of numbers only. Maybe this should be optional with another switch?
I know addresses without a street name at all - it*s just name of the place plus a number. But I do not know streets with only number as name. Maybe some countries have that? Most definitely do no.
Even one letter and numbers is a bit strange. I think most streets have ref and name (e.g. B11 myname) - not sure if some searches for say B11 housenumber instead of myname housenumber. Maybe they would search for B11 myname housenumber.

On Sun, 5 Dec 2021 at 11:24, Gerd Petermann <GPetermann_muenchen at hotmail.com<mailto:GPetermann_muenchen at hotmail.com>> wrote:
Hi all,

as a result of the discussion with Felix in this thread https://www.mkgmap.org.uk/pipermail/mkgmap-dev/2021q4/033394.html
I've created a rather small patch to change the meaning of the --mdr7-del option.

With this patch the option has one more effect:
If --split-name-idex is in use, any additional entry produced by that
option which starts with a string that appears in the given list is skipped.

I think this is probably wanted by all users and it should not cause trouble with existing scripts.

For Felix sample with a single tile the PC index size decreases from 449.536 bytes to 409.600,
index in gmapsupp it's about 31kb bytes smaller.

With the default style the change should be much smaller.

Gerd

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