Atomic increment, decrement and replace operations?

[greenlion]

I am trying to implement a drop-in replacement PHP Class for Memcache using HandlerSocket, but there are a few technical problems that I can't seem to work around without using external locking mechanisms which hurt performance.

Memcache supports atomic increment and decrement. Since HandlerSocket uses different connections for reading and writing, I can't figure out how to increment/decrement a value without a race condition.

Memcache also supports replace operations. If pipelined operations act as a transaction, then replace can be mapped to delete followed by insert, but it is unclear from the documentation if this is the case. Can you please clarify this?

Thanks.

[ahiguti]

You can't implement atomic increment nor atomic replace ops using the current version of HandlerSocket. A bunch of pipelined requests does not act as a transaction.