rate-limiter is a package for implementing a distributed rate limiter, supporting various storage backends such as Redis and PostgreSQL. It allows you to limit the frequency of operations using the "leaky bucket" algorithm.
Install the main package and the necessary adapters using go get:
go get github.com/anboo/rate-limiter
go get github.com/anboo/rate-limiter/redis
go get github.com/anboo/rate-limiter/postgresqlpackage main
import (
"context"
"github.com/anboo/rate-limiter"
)
var limit = ratelimiter.Limit{
Key: "example_key",
Rate: 5, // tokens per second
Limit: 10, // bucket size
}Usage:
package main
import (
"context"
"fmt"
"time"
"github.com/anboo/rate-limiter/in_memory"
)
func main() {
ctx := context.Background()
limiter := in_memory.NewInMemoryRateLimiter(10, time.Second)
err := limiter.Wait(ctx)
if err != nil {
fmt.Printf("Error: %v\n", err)
return
}
fmt.Println("Request allowed")
}Installation:
go get github.com/anboo/rate-limiter/redisUsage:
package main
import (
"context"
"fmt"
"github.com/anboo/rate-limiter"
"github.com/anboo/rate-limiter/redis"
)
func main() {
ctx := context.Background()
redisClient := redis.NewClient(&redis.Options{
Addr: "localhost:6379",
})
limiter := redis.NewLimiter(redisClient)
result, err := limiter.Wait(ctx, limit)
if err != nil {
fmt.Printf("Error: %v\n", err)
return
}
if result.NeedWait == 0 {
fmt.Println("Request allowed")
} else {
fmt.Printf("Request denied. Please wait %s.\n", result.NeedWait)
}
}Installation:
go get github.com/anboo/rate-limiter/postgresqlUsage:
package main
import (
"context"
"fmt"
"github.com/anboo/rate-limiter"
"github.com/anboo/rate-limiter/postgresql"
)
func main() {
connStr := "user=username dbname=mydb sslmode=disable"
db, err := sql.Open("postgres", connStr)
if err != nil {
log.Fatal(err)
}
ctx := context.Background()
limiter := postgresql.NewLimiter(db)
result, err := limiter.Wait(ctx, limit)
if err != nil {
fmt.Printf("Error: %v\n", err)
return
}
if result.NeedWait == 0 {
fmt.Println("Request allowed")
} else {
fmt.Printf("Request denied. Please wait %s.\n", result.NeedWait)
}
}Usage: Usage:
package main
import (
"context"
"fmt"
"github.com/anboo/rate-limiter"
"github.com/anboo/rate-limiter/in_memory"
"github.com/anboo/rate-limiter/postgresql"
)
func main() {
connStr := "user=username dbname=mydb sslmode=disable"
db, err := sql.Open("postgres", connStr)
if err != nil {
log.Fatal(err)
}
ctx := context.Background()
limiter := rate_limiter.NewDecoratorLimiter(
in_memory.NewInMemoryRateLimiter(),
postgresql.NewLimiter(db),
)
result, err := limiter.Wait(ctx, limit)
if err != nil {
fmt.Printf("Error: %v\n", err)
return
}
if result.NeedWait == 0 {
fmt.Println("Request allowed")
} else {
fmt.Printf("Request denied. Please wait %s.\n", result.NeedWait)
}
}