lukaszraczylo
f75b2f20e0
universal_cache: stop the write-lock convoy / 100%-CPU spin (observed via pprof: one ServeHTTP goroutine holding c.mu.Lock for hours while 119 requests queued). The per-request populate path (updateLocalCache) PushFronted a duplicate LRU node + overwrote items[key] without removing the prior node; once eviction deleted the key, orphan nodes at Back() were never removable and the eviction loop spun forever under the write lock. Replace the entry in place (mirroring setLocal) and harden evictOldest with a forward-progress guard. Adds universal_cache_orphan_test.go. telemetry: delete the hand-rolled client; call oss-telemetry v0.2.3 (vendored, Yaegi-safe) directly from New(), once per process via sync.Once. version: add version.go + workflow-prepare.sh so the release semver is stamped into source at build time (the value cannot be resolved at runtime under Yaegi). dev/source builds keep the 0.0.0-dev sentinel and emit no telemetry.
oss-telemetry
A tiny Go client that fires one anonymous "this binary started" ping at a central ingest endpoint. Designed to be embedded in your own open-source projects so you can see approximate adoption and version spread without collecting anything that could identify a user.
This is the client library only. The ingest endpoint, server-side deduplication, rate limiting, and metrics are out of scope here.
What it sends
A single HTTP POST per call to Send:
{
"project": "my-tool",
"version": "1.2.3",
"ts": 1747782200
}
No identifiers, no IP, no machine info, no user data. The server dedupes incoming requests; the client just fires and forgets.
Failproof by design
- Never blocks the caller — work runs in a goroutine.
- Never panics — the goroutine recovers internally.
- Never returns errors — bad input and network failures are silently dropped.
- Never retries, never persists state, never reads back.
- 2-second hard timeout on every request.
- Zero third-party dependencies (Go stdlib only).
The endpoint is hardcoded and not overridable from consuming code, by design.
Install
go get github.com/lukaszraczylo/oss-telemetry
Requires Go 1.22+.
Usage
package main
import (
"time"
telemetry "github.com/lukaszraczylo/oss-telemetry"
)
const version = "1.2.3"
func main() {
telemetry.Send("my-tool", version)
// ... your program runs ...
// Only needed for short-lived CLIs that may exit before the goroutine
// finishes its POST. Long-running services do not need this.
telemetry.Wait(2 * time.Second)
}
Call Send once at boot. Calling it more often just sends more pings; the
server deduplicates.
Disabling telemetry
If you ship a binary that imports this library, link your users to this
section (https://github.com/lukaszraczylo/oss-telemetry#disabling-telemetry)
so they can find the opt-out paths.
Any one of these turns it off:
| Mechanism | How |
|---|---|
| Universal opt-out | DO_NOT_TRACK=1 |
| Library-wide opt-out | OSS_TELEMETRY_DISABLED=1 |
| Project-specific opt-out | <UPPER_PROJECT>_DISABLE_TELEMETRY=1 |
Programmatic (e.g. behind a --no-telemetry flag) |
telemetry.Disable() before the first Send |
Project-specific env var derivation: uppercase the project name and replace
- with _. For my-tool the variable is MY_TOOL_DISABLE_TELEMETRY.
Truthy values: 1, true, yes, on (case-insensitive). Anything else is
treated as "not set".
Validation rules (silently dropped if violated)
project: matches^[a-z0-9-]+$, length 1–64.version: matches^[A-Za-z0-9.+_-]+$, length 1–32.
Bad input is a no-op — the library never logs, never errors, never crashes.
API
// Fire a single ping in the background. Returns immediately.
func Send(project, version string)
// Suppress all subsequent Send calls in this process. Idempotent.
func Disable()
// Block until in-flight pings complete or timeout elapses, whichever first.
// Useful for short-lived CLI processes.
func Wait(timeout time.Duration)
Testing
go test -race ./...
License
Pick one before publishing. None bundled.