unicode/utf8.RuneCountInString
standard libraryThe 1062nd most-called standard-library function by production calls. Called 1,070 times across 190 modules; 608 of those run outside tests and generated code.
- prod calls
- 608
- non-test, non-generated
- all calls
- 1,070
- total callsites
- modules
- 190
- distinct callers
- in loop
- 31%
- of prod calls
- in tests
- 10%
- 102 calls
- resolved
- 100%
- to a known target
resolution mix
How each call resolves
How each call was attributed. Only resolved kinds, where the target function is known, count toward the ranking. Interface dispatch and unresolved receivers are reported separately and never guessed. Read the taxonomy →
- Package function100%A direct call to an exported package function, resolved by type.
estimate
Estimated relative cost
Roughly 0.00× the estimated relative cost of fmt.Sprintf . Benchmarked at 30.81 ns/op × 608 production calls, normalized so fmt.Sprintf = 1.0.
This is not dollars and not a verdict. Per-op time depends heavily on inputs (argument sizes, contention, patterns), the benchmark ran on a single machine (darwin/arm64 (Apple Silicon), go1.26.0), and static call counts are not runtime frequency. How this is estimated →
who calls this
Notable callers
Production calls into RuneCountInString from notable Go projects. Open one on the map to see what else it hammers.
- Prometheus 15 2%
- MinIO 12 2%
- Kubernetes 9 1%
- CockroachDB 8 1%
- Grafana 8 1%
where it's called
Callsites in the wild
12 representative callsites of 1,070, prioritizing in-loop and non-test usage. We link to source, never display it.
-
cilium/proxy @v0.0.0-20260721220516-ab0596f228a0
in loop -
cockroachdb/cockroach @v19.2.12+incompatible
in loop -
connectrpc.com/connect @v1.20.0
cmd/protoc-gen-connect-go/main.go:697
in loop - in loop
- in loop
-
gitea.dev @v1.27.1
services/webhook/discord.go:169
in loop -
NoFxAiOS/nofx @v0.0.0-20260730005637-d3de5e82aa02
in loop - in loop
-
TheAlgorithms/Go @v0.0.3-alpha
in loop -
alecthomas/chroma @v0.10.0
in loop -
alecthomas/chroma/v2 @v2.27.0
in loop -
alecthomas/kong @v1.16.0
in loop
top callers
The modules that reach for it
The modules that call RuneCountInString most in this snapshot.
- github.com/envoyproxy/go-control-plane/envoy31329%
- github.com/Tencent/WeKnora484%
- github.com/chenhg5/cc-connect394%
- github.com/pinchtab/pinchtab394%
- github.com/envoyproxy/go-control-plane/contrib313%
siblings
More from unicode/utf8
The other most-called functions in this package. See all →