Previously we would rely more heavily on Go's garbage collector since when we loaded a block for an underlying stream we would pass references upward to avoimd copies.
Now we always copy when passing back to the upper layers which allows us to not only expire our cache blocks but pool and reuse them.
The upper layers also had changes made to allow the pooling layer at that level to interoperate with the storage layer optionally.
Also fixed some flappers and a bug where de-dupe might not be reformed correctly.
Signed-off-by: Derek Collison <derek@nats.io>
This is the first checkin for JetStream. Has some rudimentary basics working.
TODO
1. Push vs pull mode for observables. (work queues)
2. Disk/File store, memory only for now.
3. clustering code - design shaping up well.
4. Finalize account import semantics.
5. Lots of other little things.
Signed-off-by: Derek Collison <derek@nats.io>
