Benchmarks of sqlite4 variable length integer encoding of 64-bit unsigned integer implementations in Go.
See https://sqlite.org/src4/doc/trunk/www/varint.wiki for details of the encoding and decoding rules.
Three benchmarks are run against the Encode and Decode operations for each implementation.
The *All benchmarks, use a range of values that represent the min and max values, along with values that are at the encoding/decoding rule boundaries and a couple extra cases.
BenchmarkCockroachDBPutUvarintAll 5000000 255 ns/op 31.27 MB/s 0 B/op 0 allocs/op
BenchmarkCockroachDBUvarintAll 5000000 282 ns/op 28.32 MB/s 0 B/op 0 allocs/op
BenchmarkDchestPutUint64All 10000000 156 ns/op 51.18 MB/s 0 B/op 0 allocs/op
BenchmarkDchestUint64All 10000000 159 ns/op 50.27 MB/s 0 B/op 0 allocs/op
BenchmarkMohaePutUvarintAll 10000000 154 ns/op 51.69 MB/s 0 B/op 0 allocs/op
BenchmarkMohaeUvarintAll 10000000 167 ns/op 47.66 MB/s 0 B/op 0 allocs/op
The *MinLen benchmarks use a value that encodes to 1 byte. This shows the best-case scenario for encoding/decoding operations. This is usually the most common case.
BenchmarkCockroachDBPutUvarintMinLen 500000000 3.61 ns/op 2215.80 MB/s 0 B/op 0 allocs/op
BenchmarkCockroachDBUvarintMinLen 300000000 4.17 ns/op 1918.88 MB/s 0 B/op 0 allocs/op
BenchmarkDchestPutUint64MinLen 500000000 3.33 ns/op 2399.68 MB/s 0 B/op 0 allocs/op
BenchmarkDchestUint64MinLen 500000000 3.52 ns/op 2270.33 MB/s 0 B/op 0 allocs/op
BenchmarkMohaePutUvarintMinLen 500000000 3.31 ns/op 2415.08 MB/s 0 B/op 0 allocs/op
BenchmarkMohaeUvarintMinLen 500000000 3.56 ns/op 2246.06 MB/s 0 B/op 0 allocs/op
The *MaxLen benchmarks use a value that encodes to 9 bytes. This shows the worst-case scenario for encoding/decoding operations. This is usually the least common case.
BenchmarkCockroachDBPutUvarintMaxLen 100000000 22.4 ns/op 357.25 MB/s 0 B/op 0 allocs/op
BenchmarkCockroachDBUvarintMaxLen 100000000 22.8 ns/op 350.79 MB/s 0 B/op 0 allocs/op
BenchmarkDchestPutUint64MaxLen 100000000 10.9 ns/op 732.82 MB/s 0 B/op 0 allocs/op
BenchmarkDchestUint64MaxLen 100000000 11.4 ns/op 704.60 MB/s 0 B/op 0 allocs/op
BenchmarkMohaePutUvarintMaxLen 200000000 9.56 ns/op 836.79 MB/s 0 B/op 0 allocs/op
BenchmarkMohaeUvarintMaxLen 100000000 10.6 ns/op 757.42 MB/s 0 B/op 0 allocs/op
These numbers are from running the benchmarks on a VirtualBox VM configured with 1 cpu.
The results of varuint and uvarint should be about the same. The main difference between the two is that Varuint does boundary checks on the slice while Uvarint will panic if the slice isn't of sufficient size. Uvarint behaves this way because a slice of insufficient length is considered a programmer error.
The CockroachDB implementation of SQLite4's varint is copied from https://github.com/cockroachdb/cockroach/blob/77296d6b6c8c7a6c0d26456067a033a0d33bb730/util/encoding/varint.go and can be found in the cockroachdb_varint.go file. This is necessary because the funcs are not exported. The CockroachDB implementation is copyrighted by The Cockroach Authors under the Apache License, Version 2.0 (the "License"). A copy of the license may be obtained at
http://www.apache.org/licenses/LICENSE-2.0
A complete copy of the original copyright notification may be found in the cockroachdb_varint.go file.