test(bench): improve go-faster/jx benchmark #1
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ernado
commented
Jan 10, 2022
•
ernado
commented
- Use ObjBytes to avoid key allocations
- Use Skip instead of parsing
- Avoid unrelated allocation (add strToBytes)
* Use ObjBytes to avoid key allocations * Use Skip instead of parsing * Avoid unrelated allocation (add strToBytes)
| @@ -232,15 +234,20 @@ func CalcStatsJsoniterWithPath(str string) (s Stats) { | |||
| return | |||
| } | |||
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| // strToBytes returns byte slice from string without allocations. | |||
| func strToBytes(s string) []byte { | |||
| return unsafe.Slice((*byte)(unsafe.Pointer((*reflect.StringHeader)(unsafe.Pointer(&s)).Data)), len(s)) | |||
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I totally get your point and it sure is a bit unfair to have the extra overhead because of a different input type but I'm still not sure how I feel about introducing unsafe to the party since usually it's not welcome in production code 😕
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Since this library is focusing on processing strings - it's fair to compare only legal and safe methods of use for the context of this library only. If any user of a library requires performance at the cost of the risks of using unsafe then it's his/her responsibility to do so.
However, we can let it pass under the assumption that the user of go-faster/jx is willing to pay that price (which many folks often do) just in order to eliminate the overhead for a fair comparison's sake.
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A bit of a background:
I actually started out with unsafe but quickly encountered a problem on my M1 Max macOS 12.1 Go 1.17.6. Seemingly random bugs started to appear after converting string to []byte using the unsafe method from valyala/fasthttp. I couldn't reproduce them neither on another Intel i7 macOS 12.1 Go 1.17.6 MBP, nor on go.dev/play. Only later did I realize that it's me who did the stupid mistake of using an unsafe []byte -> string method for string -> []byte conversion, which, IMHO, only proves the dangers and cost of utilizing unsafe.
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I agree that it is unsafe, but not sure how to compare libraries fairly, because string -> byte allocation is unrelated.
If you will find another way I'm ok with it!
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Yes, it's unrelated and slightly falsifies the results.
The solution is to just provide a new function:
func Scan(o Options, s []byte, fn func(*IteratorBytes) (err bool)) ErrorThis will be the most widely used function anyway.
| @@ -294,15 +298,15 @@ func CalcStatsGofasterJx(str string) (s Stats) { | |||
| } | |||
| case gofasterjx.Object: | |||
| s.TotalObjects++ | |||
| if err := d.Obj(func(d *gofasterjx.Decoder, key string) error { | |||
| if err := d.ObjBytes(func(d *gofasterjx.Decoder, key []byte) error { | |||
