DisableCAS

README.md

@@ -27,6 +27,21 @@ func main() {
 }
 ```
 
+## Disabling CAS Support
+
+By default, the client uses `gets` commands to support CAS (Compare-And-Swap) operations.
+If your memcached setup does not support CAS or you want to disable it (e.g., for performance or compatibility),
+you can set the `DisableCAS` field on the client:
+
+```go
+mc := memcache.New("127.0.0.1:11211")
+mc.DisableCAS = true
+```
+
+When `DisableCAS` is enabled:
+- The client will use `get` instead of `gets` when fetching items.
+- CAS-based methods (like `CompareAndSwap`) will either be no-ops or fall back to simpler operations (e.g., `Set`).
+
 ## Full docs, see:
 
 See https://pkg.go.dev/github.com/bradfitz/gomemcache/memcache
@@ -36,4 +51,3 @@ Or run:
 ```shell
 $ godoc github.com/bradfitz/gomemcache/memcache
 ```
-

memcache/memcache.go

@@ -153,6 +153,9 @@ type Client struct {
 	// be set to a number higher than your peak parallel requests.
 	MaxIdleConns int
 
+	// DisableCAS makes the client use "get" instead of "gets", so CAS IDs won't be fetched.
+	DisableCAS bool
+
 	selector ServerSelector
 
 	mu       sync.Mutex
@@ -382,7 +385,11 @@ func (c *Client) withKeyRw(key string, fn func(*conn) error) error {
 func (c *Client) getFromAddr(addr net.Addr, keys []string, cb func(*Item)) error {
 	return c.withAddrRw(addr, func(conn *conn) error {
 		rw := conn.rw
-		if _, err := fmt.Fprintf(rw, "gets %s\r\n", strings.Join(keys, " ")); err != nil {
+		cmd := "gets"
+		if c.DisableCAS {
+			cmd = "get"
+		}
+		if _, err := fmt.Fprintf(rw, "%s %s\r\n", cmd, strings.Join(keys, " ")); err != nil {
 			return err
 		}
 		if err := rw.Flush(); err != nil {