This appears to be mmap-friendly. Since arrays have length values it's possible to jump around in a large messagepack-serialized structure without having to sca

This appears to be mmap-friendly. Since arrays have length values it's possible to jump around in a large messagepack-serialized structure without having to scan it. In JSON if you want to get to element 2 of an array you have to scan to the end of element 1. If there's a length value at the beginning of element 1 (as it looks like there is with msgpack) then you can seek straight past it.