kacerrandClaude Fable 5
7219eb5a23
Includes solved 02-worker-pool and 09-safe-counter (mutex, atomic, sharded). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GbnJj9ZqEx9nUvzkjdwfMq
46 lines
1.3 KiB
Go
46 lines
1.3 KiB
Go
// Exercise 03 — Token Bucket Rate Limiter
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//
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// ASSIGNMENT
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// ----------
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// Implement a token-bucket limiter:
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//
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// 1. NewLimiter(rate, burst): capacity `burst` tokens, refilled continuously
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// at `rate` tokens/second. Bucket starts FULL.
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// 2. Allow() consumes one token and returns true, or returns false if no
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// token is available. Must be non-blocking and safe for concurrent use.
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// 3. Refill must be LAZY — no background goroutine, no ticker. Compute the
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// accrued tokens from elapsed time inside Allow().
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// 4. Tokens never exceed `burst` (idle time must not build infinite credit).
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//
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// Run the tests: go test -race ./03-rate-limiter/
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package main
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import (
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"fmt"
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"time"
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)
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type Limiter struct {
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// TODO: fields (mutex, current tokens, max, rate, last refill time)
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}
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// NewLimiter returns a limiter allowing `rate` ops/sec with bursts up to `burst`.
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// TODO: implement me.
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func NewLimiter(rate float64, burst int) *Limiter {
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return &Limiter{}
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}
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// Allow reports whether one operation may proceed now.
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// TODO: implement me.
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func (l *Limiter) Allow() bool {
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return false
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}
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func main() {
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l := NewLimiter(5, 3) // 5/sec, burst 3
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for i := 0; i < 10; i++ {
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fmt.Printf("req %d: allowed=%v\n", i, l.Allow())
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time.Sleep(100 * time.Millisecond)
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}
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}
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