While doing a boltdb operation and if the bucket is not found
we should not return a boltdb specific bucket not found error
because this causes leaky abstraction where in the user of libkv
needs to know about boltdb and import boltdb dependencies
neither of which is desirable. Replaced all the bucket not found
errors with the more generic `store.ErrKeyNotFound` error which
is more appropriate.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
When using AtomicPut with 'previous' set at nil, it interprets
that the Key should be created with the AtomicPut. Instead of
returning a generic error, we return store.ErrKeyExists if the
key exists in the store during the operation.
Signed-off-by: Alexandre Beslic <abronan@docker.com>
Currently boltdb uses a handle which can be accessed
concurrently from multiple go routines and all of them
trying to open and close the boldb db handle which can
cause havoc. Use a mutex to serialize db access and
handle access.
Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
This commit migrates the old 'go-etcd' client, which is deprecated
to the new 'coreos/etcd/client'.
One notable change is the ability to specify an 'IsDir' parameter
to the 'Put' call. This allows to circumvent the limitations of etcd
regarding the key/directory distinction while setting up Watches on
a directory. A conservative measure to set up a watch that should be
used the same way for etcd/consul/zookeeper is to enforce the 'IsDir'
parameter with 'WriteOptions' on 'Put' to avoid the 'NotANode' error
thrown by etcd on Watch call. Consul and zookeeper are not using the
'IsDir' parameter.
Signed-off-by: Alexandre Beslic <abronan@docker.com>
AtomicPut can now be used to Compare-and-Swap against the state
where the key doesn't yet exist. E.g. a race where two clients
create the same key: one succeeds, the other fails.
Pass nil for the previous argument of AtomicPut for this
behavior. Before, this would cause an error.
Implements this change for all three backends.
