File

net.http: Send entire HTTP request header as one write When opportunistic writes are enabled this reduces the number of syscalls and TCP packets sent on the wire. Experiments with TCP Fast Open made this even more obvious. That table trick probably wasn't as efficient. Lua generates bytecode for a table with zero array slots and space for two entries in the hash part, plus code to set [2] and [4]. I didn't verify but I suspect it would have had to resize the table when setting [1] and [3], although probably only once. Concatenating the strings directly in Lua is easier to read and involves no extra table or function call.

This file documents the structure of the roster object.

table roster {
  [string bare_jid] = roster_item
}

table roster_item {
  string subscription = "none" | "to" | "from" | "both"
  string name = Opaque string set by client. (optional)
  set groups = a set of opaque strings set by the client
  boolean ask = nil | "subscribe" - a value of true indicates subscription is pending
}

The roster is available as
 hosts[host].sessions[username].roster
and a copy is made to session.roster for all sessions.

All modifications to a roster should be done through the rostermanager.