perf: implement bitpack encoding for LID and MID blocks

[cheb0]

Description

Replaces varint encoding with faster delta bitpacking. Both LID and MID blocks now use bitpack. Currently, intcomp library is used. The lib doesn't utilize SIMD, so we might update to something else in future.

Measurements

compression
bitpack compresses a lot better: for varints zstd compresses with ratio ~1.7-2.0 while it only compresses delta bitpacked data with ratio ~1.3. Therefore we potentially can disable zstd on benchmarks with a slight dataset size overhead.

dataset size
Overall, we reach approximately same dataset size. For some envs there is a small benefit of around -3% of total dataset.

search latency (prod fractions)

Usually, cold search request are affected. I measured search latency on a single repacked fraction. For example,

• message:"XYZ" AND NOT k8s_service_name:"ABC" AND NOT request_host:"google.com" AND NOT cluster_name:"zxc"
  12 ms => 8 ms (cold)

For aggregations the benefit is lower simply because there is more CPU work. It would have higher benefit if

• service:xyz group by k8s_pod
  130 ms => 110 ms (cold)

Overall, the perf improvement is around 5-30% for cold search requests depending on a particular search request.

search latency (logbench)

TODO I will measure it on my PC, since network disk makes measurements of cold search request problematic (results vary a lot).

Fixes #312

---

• I have read and followed all requirements in CONTRIBUTING.md;

[cheb0]

@seqbenchbot up main bulk

[seqbenchbot]

Nice, @cheb0 <(-^,^-)=b!

Your request was successfully served.
Identificator for your ongoing benchmark - dc2d4d40.

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• Live-tailing logs are also available;

Have a great time!

[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

Show table

Name	Previous	Current	Ratio	Verdict
AggDeep/size=10000-4	03387c	b4fae3
	45145.00 ns/op	52104.00 ns/op	1.15	🔴
AndTree/size=1000-4	03387c	b4fae3
	4.26 ns/op	4.85 ns/op	1.14	🔴
Block_Pack-4	------	b4fae3
	NaN B/op	27344.00 B/op	NaN	🔴
	NaN allocs/op	4.00 allocs/op	NaN	🔴
	NaN ns/op	82987.00 ns/op	NaN	🔴
Block_Unpack-4	------	b4fae3
	NaN B/op	262186.00 B/op	NaN	🔴
	NaN allocs/op	2.00 allocs/op	NaN	🔴
	NaN ns/op	80490.00 ns/op	NaN	🔴
FindSequence_Random/small-4	03387c	b4fae3
	6427.67 MB/s	5452.96 MB/s	0.85	🔴
	40.85 ns/op	46.95 ns/op	1.15	🔴

[cheb0]

@seqbenchbot down dc2d4d40

[seqbenchbot]

Nice, @cheb0 <(-^,^-)=b!

The benchmark with identificator dc2d4d40 was finished.
I've prepared a summary for you. Click on Show summary button to see it:

Show summary

Query	Type	mean (ms)			stddev (ms)			p(50) (ms)			p(95) (ms)			p(99) (ms)			iterations
		base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff	base	comp	diff
bulk	warm	60.99	60.79	-0.33%	23.17	22.77	-1.74%	54.00	54.00	0.00%	107.00	107.00	0.00%	146.00	145.00	-0.68%	9694.00	9652.00	-0.43%

Have a great time!

[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

Show table

Name	Previous	Current	Ratio	Verdict
Block_Pack-4	------	035be1
	NaN B/op	27344.00 B/op	NaN	🔴
	NaN allocs/op	4.00 allocs/op	NaN	🔴
	NaN ns/op	72861.00 ns/op	NaN	🔴
Block_Unpack-4	------	035be1
	NaN B/op	262183.00 B/op	NaN	🔴
	NaN allocs/op	2.00 allocs/op	NaN	🔴
	NaN ns/op	73565.00 ns/op	NaN	🔴
Indexer-4	03387c	035be1
	721669786.00 B/op	805572232.00 B/op	1.12	🔴

[github-actions]

🔴 Performance Degradation

Some benchmarks have degraded compared to the previous run.
Click on Show table button to see full list of degraded benchmarks.

Show table

Name	Previous	Current	Ratio	Verdict
AggDeep/size=10000-4	03387c	b3e5ee
	45145.00 ns/op	51940.00 ns/op	1.15	🔴
AggDeep/size=1000000-4	03387c	b3e5ee
	4554859.00 ns/op	5474331.00 ns/op	1.20	🔴
And/size=1000-4	03387c	b3e5ee
	4.29 ns/op	4.83 ns/op	1.13	🔴
Block_Pack-4	------	b3e5ee
	NaN B/op	27344.00 B/op	NaN	🔴
	NaN allocs/op	4.00 allocs/op	NaN	🔴
	NaN ns/op	78396.00 ns/op	NaN	🔴
Block_Unpack-4	------	b3e5ee
	NaN B/op	262177.00 B/op	NaN	🔴
	NaN allocs/op	2.00 allocs/op	NaN	🔴
	NaN ns/op	86552.00 ns/op	NaN	🔴
FindSequence_Random/small-4	03387c	b3e5ee
	6427.67 MB/s	5668.64 MB/s	0.88	🔴
Indexer-4	03387c	b3e5ee
	721669786.00 B/op	805627342.00 B/op	1.12	🔴