What about this API for snapshots

db#snapshot()

Create a new snapshot.

snapshot#get(key, value[, opts])

Read a single value from a snapshot.

snapshot#create{Read,Key,Value}Stream

Read multiple values from a snapshot.

snapshot#dispose()

Delete the snapshot.

Maybe also:

snapshot#{del,createWriteStream,...}

Just forwarded to db#*

Usage

For a consistend read stream this would be:

var snapshot() = db.snapshot();
snapshot.createReadStream()
  .pipe(...)
  .on('close', shapshot.dispose.bind(snapshot));