mirror of
https://github.com/TronoSfera/backupy-agent.git
synced 2026-05-18 18:13:30 +03:00
8b0c978337
Source ports from the TronoSfera/backupy-cloud monorepo:
- apps/agent/ — Go agent (WSS client, persistent queue, Docker
discovery, 5 DB drivers: PG/MySQL/Mongo/Redis/SQLite,
pre/post hooks, Prometheus metrics)
- apps/backupy-decrypt/ — standalone CLI for client-side decryption
- packages/proto/ — protobuf wire format (generated .pb.go committed
so the repo builds without protoc)
- docs/ — agent spec + wire-protocol contract
Apache-2.0 license. Image published to ghcr.io/tronosfera/backupy-agent
on every v* tag via .github/workflows/release.yml (multi-arch amd64+arm64).
61 lines
1.5 KiB
Go
61 lines
1.5 KiB
Go
package wss
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import (
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"math/rand"
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"time"
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)
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// Backoff implements the exponential schedule specified in
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// docs/03-agent-spec.md → "Reconnect: exponential backoff 1s → 2s → 4s …
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// → 60s cap, jitter ±20%".
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//
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// The struct is safe for use from a single goroutine. The reconnect loop
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// is single-threaded, so no mutex is needed.
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type Backoff struct {
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Initial time.Duration
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Max time.Duration
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Factor float64
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JitterPC float64 // 0.2 → ±20%
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current time.Duration
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rng *rand.Rand
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}
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// NewBackoff returns a Backoff with spec defaults (1s → 60s, ±20%, ×2).
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func NewBackoff() *Backoff {
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return &Backoff{
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Initial: 1 * time.Second,
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Max: 60 * time.Second,
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Factor: 2.0,
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JitterPC: 0.2,
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// Deterministic-ish but unique per agent: seed from the wall clock.
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rng: rand.New(rand.NewSource(time.Now().UnixNano())), //nolint:gosec // not a security context
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}
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}
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// Next returns the next delay and advances the schedule.
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func (b *Backoff) Next() time.Duration {
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if b.current == 0 {
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b.current = b.Initial
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} else {
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b.current = time.Duration(float64(b.current) * b.Factor)
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if b.current > b.Max {
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b.current = b.Max
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}
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}
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return b.withJitter(b.current)
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}
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// Reset rewinds the schedule. Call on a clean reconnect.
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func (b *Backoff) Reset() {
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b.current = 0
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}
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func (b *Backoff) withJitter(d time.Duration) time.Duration {
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if b.JitterPC <= 0 {
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return d
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}
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// pick uniformly in [-jitter, +jitter]
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jitter := b.JitterPC * (b.rng.Float64()*2 - 1)
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return time.Duration(float64(d) * (1 + jitter))
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}
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