[Go] BinaryBuilder AppendValues/AppendStringValues don't invoke ReserveData internally

[drahnreb1]

Describe the usage question you have. Please include as many useful details as possible.

AppendValues and AppendStringValues of BinaryBuilder invoke Reserve internally, but don't invoke ReserveData, e.g. by something like this:

totalLen := 0

for _, vv := range v {
    totalLen += len(vv)
}

b.ReserveData(totalLen)

Is it on purpose that ReserveData is not invoked in these functions because the idea is that users should do this themselves before invoking AppendValues/AppendStringValues?

https://github.com/apache/arrow/blob/469430f50085b4b462fcc7db84a08cb554c698cd/go/arrow/array/binarybuilder.go#L159 https://github.com/apache/arrow/blob/469430f50085b4b462fcc7db84a08cb554c698cd/go/arrow/array/binarybuilder.go#L180

Using ReserveData can significantly improve performance (in case of the benchmark test in reserve_data_test.go.txt by factor 2-3).

Component(s)

Go