CountMinSketch overflow check causes a lot of allocations

[alexandrnikitin]

It starts from String.valueOf(item) here

stream-lib/src/main/java/com/clearspring/analytics/stream/frequency/CountMinSketch.java

Line 205 in 5868141

checkSizeAfterAdd(String.valueOf(item), count);

String concatenation here

stream-lib/src/main/java/com/clearspring/analytics/stream/frequency/CountMinSketch.java

Line 189 in 5868141

checkSizeAfterOperation(previousSize, "add(" + item + "," + count + ")", size);

and here

stream-lib/src/main/java/com/clearspring/analytics/stream/frequency/CountMinSketch.java

Line 289 in 5868141

checkSizeAfterOperation(previousSize, "merge(" + estimator + ")", size);

Could be related to #140

[abramsm]

I'm not sure. Stream-lib's CountMinSketch has fallen behind what @tdunning has in his repo. Hopefully we can work on pulling in a more recent version. Otherwise we may need to deprecate this class.

[tdunning]

I don't think I have a CMS implementation.

I have t-digest and FloatHistogram. Just had a release last week and some big stuff coming soon beyond that.

[abramsm]

Sorry @tdunning. My memory seems to be failing me... Great news on new releases of T-digest and FloatHistogram.

@alexandrnikitin I'll look into this and #140 as soon as I can.

[alexandrnikitin]

@abramsm Thank you. I'm ready to help with it. Basically I would just remove the overflow check. I can also introduce microbenchmarks to prevent regression. I just need an answer for #140 whether there's something I miss or not? I see it only as an optimization for fast comparison.