Get your context value faster
Replace
v := ctx.Value(key)With
v := goctx.Value(ctx, key)There will be little difference when there is only 1~2 context.WithXXX calls
With 5 context.WithXXX calls
| BenchmarkValue/5/non_parallel/std-8 | 35313684 | 34.2 ns/op |
| BenchmarkValue/5/non_parallel/goctx-8 | 42801348 | 30.0 ns/op |
| BenchmarkValue/5/non_parallel/pure_map-8 | 16655377 | 72.8 ns/op |
| BenchmarkValue/5/parallel/std-8 | 168420460 | 7.09 ns/op |
| BenchmarkValue/5/parallel/goctx-8 | 185695462 | 6.35 ns/op |
| BenchmarkValue/5/parallel/pure_map-8 | 67944997 | 17.6 ns/op |
With 20 context.WithXXX calls
| BenchmarkValue/20/non_parallel/std-8 | 7137338 | 168 ns/op |
| BenchmarkValue/20/non_parallel/goctx-8 | 14623730 | 81.4 ns/op |
| BenchmarkValue/20/non_parallel/pure_map-8 | 5282458 | 235 ns/op |
| BenchmarkValue/20/parallel/std-8 | 42826857 | 27.9 ns/op |
| BenchmarkValue/20/parallel/goctx-8 | 79149823 | 15.1 ns/op |
| BenchmarkValue/20/parallel/pure_map-8 | 22206717 | 53.8 ns/op |
As we can see from the benchmark test, the map implementation is slower than the
standard one, so it is not recommended to use RegisterValueFunc to register a
context value function, unless you do not want to see nested stack with Value method
call (That's also the reason why RegisterValueFunc is kept even it is not fast)