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package throttled_test
import (
"fmt"
"log"
"net/http"
"github.com/throttled/throttled"
"github.com/throttled/throttled/store/memstore"
)
var myHandler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("hi there!"))
})
// ExampleHTTPRateLimiter demonstrates the usage of HTTPRateLimiter
// for rate-limiting access to an http.Handler to 20 requests per path
// per minute with a maximum burst of 5 requests.
func ExampleHTTPRateLimiter() {
store, err := memstore.New(65536)
if err != nil {
log.Fatal(err)
}
// Maximum burst of 5 which refills at 20 tokens per minute.
quota := throttled.RateQuota{throttled.PerMin(20), 5}
rateLimiter, err := throttled.NewGCRARateLimiter(store, quota)
if err != nil {
log.Fatal(err)
}
httpRateLimiter := throttled.HTTPRateLimiter{
RateLimiter: rateLimiter,
VaryBy: &throttled.VaryBy{Path: true},
}
http.ListenAndServe(":8080", httpRateLimiter.RateLimit(myHandler))
}
// Demonstrates direct use of GCRARateLimiter's RateLimit function (and the
// more general RateLimiter interface). This should be used anywhere where
// granular control over rate limiting is required.
func ExampleGCRARateLimiter() {
store, err := memstore.New(65536)
if err != nil {
log.Fatal(err)
}
// Maximum burst of 5 which refills at 1 token per hour.
quota := throttled.RateQuota{throttled.PerHour(1), 5}
rateLimiter, err := throttled.NewGCRARateLimiter(store, quota)
if err != nil {
log.Fatal(err)
}
// Bucket according to the number i / 10 (so 1 falls into the bucket 0
// while 11 falls into the bucket 1). This has the effect of allowing a
// burst of 5 plus 1 (a single emission interval) on every ten iterations
// of the loop. See the output for better clarity here.
//
// We also refill the bucket at 1 token per hour, but that has no effect
// for the purposes of this example.
for i := 0; i < 20; i++ {
bucket := fmt.Sprintf("by-order:%v", i/10)
limited, result, err := rateLimiter.RateLimit(bucket, 1)
if err != nil {
log.Fatal(err)
}
if limited {
fmt.Printf("Iteration %2v; bucket %v: FAILED. Rate limit exceeded.\n",
i, bucket)
} else {
fmt.Printf("Iteration %2v; bucket %v: Operation successful (remaining=%v).\n",
i, bucket, result.Remaining)
}
}
// Output:
// Iteration 0; bucket by-order:0: Operation successful (remaining=5).
// Iteration 1; bucket by-order:0: Operation successful (remaining=4).
// Iteration 2; bucket by-order:0: Operation successful (remaining=3).
// Iteration 3; bucket by-order:0: Operation successful (remaining=2).
// Iteration 4; bucket by-order:0: Operation successful (remaining=1).
// Iteration 5; bucket by-order:0: Operation successful (remaining=0).
// Iteration 6; bucket by-order:0: FAILED. Rate limit exceeded.
// Iteration 7; bucket by-order:0: FAILED. Rate limit exceeded.
// Iteration 8; bucket by-order:0: FAILED. Rate limit exceeded.
// Iteration 9; bucket by-order:0: FAILED. Rate limit exceeded.
// Iteration 10; bucket by-order:1: Operation successful (remaining=5).
// Iteration 11; bucket by-order:1: Operation successful (remaining=4).
// Iteration 12; bucket by-order:1: Operation successful (remaining=3).
// Iteration 13; bucket by-order:1: Operation successful (remaining=2).
// Iteration 14; bucket by-order:1: Operation successful (remaining=1).
// Iteration 15; bucket by-order:1: Operation successful (remaining=0).
// Iteration 16; bucket by-order:1: FAILED. Rate limit exceeded.
// Iteration 17; bucket by-order:1: FAILED. Rate limit exceeded.
// Iteration 18; bucket by-order:1: FAILED. Rate limit exceeded.
// Iteration 19; bucket by-order:1: FAILED. Rate limit exceeded.
}
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