Files
minstrel/internal/musicbrainz/pace.go
T
bvandeusenandClaude Opus 5.5 d191a28217 docs: server comments say what the code does, not how it came to be (#6277)
Comment blocks in cmd/minstrel and 30 smaller internal packages, rewritten
to rule 32's standard with each citation read in context: task, milestone
and rule ids go, and so do the stories they were attached to ("used to",
"Before #N", measurements from one install, quotes, pointers to Fabled
Librarian's records and to docs/superpowers files that are not in the
repo). Where a story wrapped a real constraint, the constraint stays as a
present-tense fact.

Comments that had gone stale are corrected:
- taste.Config: the tuned values are overlaid by internal/recsettings;
  it is no longer "a later follow-up".
- StorageConfig: the data dir holds art, caches and the stream secret,
  not only playlist covers.
- the Subsonic album list and getUser comments describe what they do
  today rather than a milestone that would change it.

Checked: the non-comment token stream of every changed file matches
HEAD, and gofmt -l is empty.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-23 12:15:05 -04:00

60 lines
1.4 KiB
Go

// Package musicbrainz is Minstrel's client for the MusicBrainz web service:
// searches and browses for the release catalogue, and the one
// pacer every MusicBrainz request in the process waits on.
package musicbrainz
import (
"context"
"sync"
"time"
)
// MinInterval honours MusicBrainz's 1 request/second ceiling, with headroom.
// The limit is per client address, not per caller, which is why there is one
// pacer for the whole process.
const MinInterval = 1100 * time.Millisecond
// Pacer spaces requests at least Interval apart. Safe for concurrent use;
// callers queue in the order they claim slots.
type Pacer struct {
Interval time.Duration
mu sync.Mutex
next time.Time
}
// Wait blocks until this caller's slot comes up, or ctx ends. A zero
// Interval never waits.
func (p *Pacer) Wait(ctx context.Context) error {
if p == nil || p.Interval <= 0 {
return ctx.Err()
}
p.mu.Lock()
now := time.Now()
slot := p.next
if slot.Before(now) {
slot = now
}
p.next = slot.Add(p.Interval)
p.mu.Unlock()
wait := time.Until(slot)
if wait <= 0 {
return ctx.Err()
}
timer := time.NewTimer(wait)
defer timer.Stop()
select {
case <-ctx.Done():
return ctx.Err()
case <-timer.C:
return nil
}
}
var shared = &Pacer{Interval: MinInterval}
// Shared is the pacer every MusicBrainz request in the process goes through:
// the catalogue's and tag enrichment's alike.
func Shared() *Pacer { return shared }