From 6814216f803f9e8ab5506f3d1753eb0984893bd8 Mon Sep 17 00:00:00 2001
From: Neur0toxine <pashok9825@gmail.com>
Date: Wed, 17 Apr 2024 11:24:02 +0300
Subject: [PATCH] noop limiter & interface for limiter

---
 v1/client.go     |  2 +-
 v1/rate_limit.go | 18 +++++++++++++++++-
 v1/types.go      | 12 ++++++------
 3 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/v1/client.go b/v1/client.go
index 273dc44..f8b9c25 100644
--- a/v1/client.go
+++ b/v1/client.go
@@ -36,7 +36,7 @@ func (c *MgClient) WithLogger(logger BasicLogger) *MgClient {
 }
 
 // WithLimiter sets the provided limiter instance into the Client.
-func (c *MgClient) WithLimiter(limiter *TokensBucket) *MgClient {
+func (c *MgClient) WithLimiter(limiter Limiter) *MgClient {
 	c.limiter = limiter
 	return c
 }
diff --git a/v1/rate_limit.go b/v1/rate_limit.go
index 48e99f0..455443c 100644
--- a/v1/rate_limit.go
+++ b/v1/rate_limit.go
@@ -7,11 +7,21 @@ import (
 	"time"
 )
 
+// NoopLimiter implements Limiter but doesn't limit anything.
+var NoopLimiter Limiter = &noopLimiter{}
+
 type token struct {
 	rps     atomic.Uint32
 	lastUse atomic.Value
 }
 
+// Limiter implements some form of rate limiting.
+type Limiter interface {
+	// Obtain the right to send a request. Should lock the execution if current goroutine needs to wait.
+	Obtain(string)
+}
+
+// TokensBucket implements basic Limiter with fixed window and fixed amount of tokens per window.
 type TokensBucket struct {
 	maxRPS          uint32
 	tokens          sync.Map
@@ -21,7 +31,8 @@ type TokensBucket struct {
 	sleep           sleeper
 }
 
-func NewTokensBucket(maxRPS uint32, unusedTokenTime, checkTokenTime time.Duration) *TokensBucket {
+// NewTokensBucket constructs TokensBucket with provided parameters.
+func NewTokensBucket(maxRPS uint32, unusedTokenTime, checkTokenTime time.Duration) Limiter {
 	bucket := &TokensBucket{
 		maxRPS:          maxRPS,
 		unusedTokenTime: unusedTokenTime,
@@ -79,6 +90,11 @@ func (m *TokensBucket) deleteUnusedToken() {
 	}
 }
 
+type noopLimiter struct{}
+
+func (l *noopLimiter) Obtain(string) {}
+
+// sleeper sleeps. This thing is necessary for tests.
 type sleeper interface {
 	Sleep(time.Duration)
 }
diff --git a/v1/types.go b/v1/types.go
index f4965a3..7535531 100644
--- a/v1/types.go
+++ b/v1/types.go
@@ -78,12 +78,12 @@ const (
 
 // MgClient type.
 type MgClient struct {
-	URL        string        `json:"url"`
-	Token      string        `json:"token"`
-	Debug      bool          `json:"debug"`
-	httpClient *http.Client  `json:"-"`
-	logger     BasicLogger   `json:"-"`
-	limiter    *TokensBucket `json:"-"`
+	URL        string       `json:"url"`
+	Token      string       `json:"token"`
+	Debug      bool         `json:"debug"`
+	httpClient *http.Client `json:"-"`
+	logger     BasicLogger  `json:"-"`
+	limiter    Limiter      `json:"-"`
 }
 
 // Channel type.