From e5b7766b7304a4f8f832a015f88af415321e9fc4 Mon Sep 17 00:00:00 2001
From: Luc Talatinian <102624213+lucix-aws@users.noreply.github.com>
Date: Mon, 18 Mar 2024 14:22:28 -0400
Subject: [PATCH] add ratelimit.None (#2562)

---
 .../df6f67adcf634eb48c3c35f3cc763f09.json     |  8 ++++++++
 aws/ratelimit/none.go                         | 20 +++++++++++++++++++
 aws/retry/standard.go                         | 11 ++++++++++
 3 files changed, 39 insertions(+)
 create mode 100644 .changelog/df6f67adcf634eb48c3c35f3cc763f09.json
 create mode 100644 aws/ratelimit/none.go

diff --git a/.changelog/df6f67adcf634eb48c3c35f3cc763f09.json b/.changelog/df6f67adcf634eb48c3c35f3cc763f09.json
new file mode 100644
index 00000000000..04c11d4dba4
--- /dev/null
+++ b/.changelog/df6f67adcf634eb48c3c35f3cc763f09.json
@@ -0,0 +1,8 @@
+{
+    "id": "df6f67ad-cf63-4eb4-8c3c-35f3cc763f09",
+    "type": "feature",
+    "description": "Add no-op rate limiting implementation `ratelimit.None`, which allows disabling of client-side retry quota behavior.",
+    "modules": [
+        "."
+    ]
+}
\ No newline at end of file
diff --git a/aws/ratelimit/none.go b/aws/ratelimit/none.go
new file mode 100644
index 00000000000..8c78364105b
--- /dev/null
+++ b/aws/ratelimit/none.go
@@ -0,0 +1,20 @@
+package ratelimit
+
+import "context"
+
+// None implements a no-op rate limiter which effectively disables client-side
+// rate limiting (also known as "retry quotas").
+//
+// GetToken does nothing and always returns a nil error. The returned
+// token-release function does nothing, and always returns a nil error.
+//
+// AddTokens does nothing and always returns a nil error.
+var None = &none{}
+
+type none struct{}
+
+func (*none) GetToken(ctx context.Context, cost uint) (func() error, error) {
+	return func() error { return nil }, nil
+}
+
+func (*none) AddTokens(v uint) error { return nil }
diff --git a/aws/retry/standard.go b/aws/retry/standard.go
index 25abffc8128..d5ea93222ed 100644
--- a/aws/retry/standard.go
+++ b/aws/retry/standard.go
@@ -123,6 +123,17 @@ type StandardOptions struct {
 
 	// Provides the rate limiting strategy for rate limiting attempt retries
 	// across all attempts the retryer is being used with.
+	//
+	// A RateLimiter operates as a token bucket with a set capacity, where
+	// attempt failures events consume tokens. A retry attempt that attempts to
+	// consume more tokens than what's available results in operation failure.
+	// The default implementation is parameterized as follows:
+	//   - a capacity of 500 (DefaultRetryRateTokens)
+	//   - a retry caused by a timeout costs 10 tokens (DefaultRetryCost)
+	//   - a retry caused by other errors costs 5 tokens (DefaultRetryTimeoutCost)
+	//   - an operation that succeeds on the 1st attempt adds 1 token (DefaultNoRetryIncrement)
+	//
+	// You can disable rate limiting by setting this field to ratelimit.None.
 	RateLimiter RateLimiter
 
 	// The cost to deduct from the RateLimiter's token bucket per retry.