add Range to NewIterator

[klim0v]

I see a slowdown when using iterations in the cosmos/iavl#324 (comment) library in the case where the given key cannot be found. I guess this is because the newGoLevelDBIterator function uses Seek(), which has to go through the whole tree to make sure the key is missing.

[klim0v]

Error: requested golangci-lint version 'v1.26' isn't supported: we support only v1.28.3 and later versions

Can you fix the lint/golangci config?

[tac0turtle]

Can you fix the lint/golangci config?

Could you make this PR against master, this error won't arise there, after that it can be back ported?

[melekes]

wow, what a great find!

[erikgrinaker]

Can you add an entry for this in CHANGELOG.md as well please?

[codecov]

Codecov Report

Merging #134 (84135c5) into master (772df13) will decrease coverage by 0.69%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #134      +/-   ##
==========================================
- Coverage   69.47%   68.78%   -0.70%     
==========================================
  Files          27       27              
  Lines        1448     1448              
==========================================
- Hits         1006      996      -10     
- Misses        370      377       +7     
- Partials       72       75       +3     

Impacted Files	Coverage Δ
goleveldb.go	58.33% <100.00%> (ø)
goleveldb_iterator.go	75.43% <0.00%> (-17.55%)	⬇️

Impacted Files	Coverage Δ
goleveldb.go	58.33% <100.00%> (ø)
goleveldb_iterator.go	75.43% <0.00%> (-17.55%)	⬇️

[klim0v]

Can you add an entry for this in CHANGELOG.md as well please?

It's okay?

[erikgrinaker]

Thanks! I'll run some tests with IAVL, Tendermint and the SDK using this change, and if it looks good I'll backport to 0.5.x and cut new releases - won't be able to do this until tomorrow though, since I need to finish up some other work tonight.

[klim0v]

Thank you, I was happy to contribute to the common cause!