Support for incr/decr operations #1
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incr/2 implements the increment command for memcached, decr implements the decrement command. addcounter/1 uses a simple (non-CAS) set to initialized a counter set at zero, which can then be fiddled with via incr/2 and decr/2. This was necessary because merle functions mainly as a key/value store for arbitrary erlang data instead of a general data-store, such as we want for cacti purposes. literal/1 allows the user to submit literal strings over the socket to memcached. This should be used with extreme caution as memcached is intolerant of malformed input, but it is useful for determining what strings sent to memcached should look like and checking assumptions about its behavior. TODO: (optional) need a Check-And-Set version of addcounter so that distributed applications can update the same value with incr/2 and decr/2. This would save client code from having to try changing a value and then making a separate call to initialize it if it does not exist.
All three of the above functions now return more erlang-ish results, in keeping with the rest of merle. addcounter/1 also uses incr/2 to determine if a prospective key exists before creating it. This should be replaced with a CAS-version in the future.
merle:literal/1 is rough and possibly dangerous to leave in production code (why would we let random erlang clients submit arbitrary strings to memcached?), so it is now compiled only when the DEV flag is defined to erlc. Added EDoc segments for addcounter/1, incr/2 and decr/2 have been added
* added incr and decr to listed features * added note to the effect that counters aren't erlang terms * demonstration of incr, decr and addcounter * examples of delete with counters and incr/decr on counters that don't exist
This reverts commit 3c0798a.
This reverts commit 00538e0.
merle is distributed under the MIT license, but doesn't seem to have copy of the text of the MIT license with the code. With the addition of LICENCE.txt, that little wrinkle should be cleared up.
…e in purely list form
…clustering to play nice with added support for increment operations
…rt more than just erlang binary term storage in order to support inc/dec operations
… merle process and let the merle_watcher restart it via the supervisor.
…ge in queue, and move on
…gr dies, all outstanding merle watchers will also die
…ions at any given time
…n the event of a bug
…n the event of a bug
Locked pgs
…tead we initialize on demand.
…merle_client itself. merle_pool merely chooses a client, which is then checked out via the exec function
… along with value
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Please consider merging this branch. Basically added support for incr/decr operations.