cas¶

Protocols: memcached text · meta ms C(token)

Compare-and-swap: stores the value only if the entry's current CAS matches the one supplied. Use this with gets to do safe lockless updates.

Synopsis¶

cas <key> <flags> <exptime> <bytes> <cas-token> [noreply]\r\n
<data>\r\n

Token	Meaning
`STORED`	CAS matched and value was replaced
`EXISTS`	CAS did not match — someone else mutated the key
`NOT_FOUND`	The key does not exist

> set k 0 60 1
> A
< STORED
> gets k
< VALUE k 0 1 1
< A
< END
> cas k 0 60 1 1
> B
< STORED
> cas k 0 60 1 1
> C
< EXISTS