goctx

README

goctx

Get your context value faster

How to use

Replace

v := ctx.Value(key)

With

v := goctx.Value(ctx, key)

Benchmark

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)

Documentation

Index

• func RegisterValueFunc(ctx context.Context, f ValueFunc)
• func Value(ctx context.Context, key interface{}) (v interface{})
• type ValueFunc

Functions

func RegisterValueFunc

func RegisterValueFunc(ctx context.Context, f ValueFunc)

RegisterValueFunc registers a value function

func Value

func Value(ctx context.Context, key interface{}) (v interface{})

Value can replace the `context.Context.Value` call

Types

type ValueFunc

type ValueFunc func(ctx context.Context, key interface{}) (value interface{}, parent context.Context)

ValueFunc takes a context and a key, returns the value and the parent of the context (if exists)