container/ring: fix example_test.go

The Len method is a linear operation. CL 73090 used Len to iterate over
a ring, resulting in a quadratic time operation.

Change-Id: Ib69c19190ba648311e6c345d8cb26292b50121ee
Reviewed-on: https://go-review.googlesource.com/74390
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

diff --git a/src/container/ring/example_test.go b/src/container/ring/example_test.go
index ebea1e2713d05348dd937747e865a1dcdb685c47..30bd0d74c9eee01d444f50d15ef69ab8fefec24c 100644 (file)
--- a/src/container/ring/example_test.go
+++ b/src/container/ring/example_test.go
@@ -24,14 +24,17 @@ func ExampleRing_Next() {
        // Create a new ring of size 5
        r := ring.New(5)
 
+       // Get the length of the ring
+       n := r.Len()
+
        // Initialize the ring with some integer values
-       for i := 0; i < r.Len(); i++ {
+       for i := 0; i < n; i++ {
                r.Value = i
                r = r.Next()
        }
 
        // Iterate through the ring and print its contents
-       for j := 0; j < r.Len(); j++ {
+       for j := 0; j < n; j++ {
                fmt.Println(r.Value)
                r = r.Next()
        }
@@ -48,14 +51,17 @@ func ExampleRing_Prev() {
        // Create a new ring of size 5
        r := ring.New(5)
 
+       // Get the length of the ring
+       n := r.Len()
+
        // Initialize the ring with some integer values
-       for i := 0; i < r.Len(); i++ {
+       for i := 0; i < n; i++ {
                r.Value = i
                r = r.Next()
        }
 
        // Iterate through the ring backwards and print its contents
-       for j := 0; j < r.Len(); j++ {
+       for j := 0; j < n; j++ {
                r = r.Prev()
                fmt.Println(r.Value)
        }
@@ -72,8 +78,11 @@ func ExampleRing_Do() {
        // Create a new ring of size 5
        r := ring.New(5)
 
+       // Get the length of the ring
+       n := r.Len()
+
        // Initialize the ring with some integer values
-       for i := 0; i < r.Len(); i++ {
+       for i := 0; i < n; i++ {
                r.Value = i
                r = r.Next()
        }
@@ -95,8 +104,11 @@ func ExampleRing_Move() {
        // Create a new ring of size 5
        r := ring.New(5)
 
+       // Get the length of the ring
+       n := r.Len()
+
        // Initialize the ring with some integer values
-       for i := 0; i < r.Len(); i++ {
+       for i := 0; i < n; i++ {
                r.Value = i
                r = r.Next()
        }
@@ -122,14 +134,18 @@ func ExampleRing_Link() {
        r := ring.New(2)
        s := ring.New(2)
 
+       // Get the length of the ring
+       lr := r.Len()
+       ls := s.Len()
+
        // Initialize r with 0s
-       for i := 0; i < r.Len(); i++ {
+       for i := 0; i < lr; i++ {
                r.Value = 0
                r = r.Next()
        }
 
        // Initialize s with 1s
-       for j := 0; j < s.Len(); j++ {
+       for j := 0; j < ls; j++ {
                s.Value = 1
                s = s.Next()
        }
@@ -153,8 +169,11 @@ func ExampleRing_Unlink() {
        // Create a new ring of size 6
        r := ring.New(6)
 
+       // Get the length of the ring
+       n := r.Len()
+
        // Initialize the ring with some integer values
-       for i := 0; i < r.Len(); i++ {
+       for i := 0; i < n; i++ {
                r.Value = i
                r = r.Next()
        }