added programs to export and import filesystems over the network

exec/exportfs.lua

@@ -0,0 +1,11 @@
+local rpcs = require "rpc"
+local ufs = require "unionfs"
+
+local tA = {...}
+local path = "/"..table.concat(fs.segments(tA[1]),"/")
+
+local px = ufs.create(path)
+for k,v in pairs(px) do
+ rpcs.register(path.."_"..k,v)
+ print(path.."_"..k)
+end

exec/importfs.lua

@@ -0,0 +1,9 @@
+local rpc = require "rpc"
+local tA = {...}
+local host, rpath, lpath = tA[1], tA[2], tA[3]
+
+local px = rpc.proxy(host,rpath.."_")
+function px.getLabel()
+ return host..":"..rpath
+end
+fs.mount(lpath,px)

lib/rpc.lua

@@ -0,0 +1,79 @@
+local serial = require "serialization"
+local minitel = require "minitel"
+local event = require "event"
+local rpc = {}
+_G.rpcf = {}
+rpc.port = 111
+
+local function rpcexec(_, from, port, data)
+ if port == rpc.port then
+  local rpcrq = serial.unserialize(data)
+  local rpcn, rpcid = table.remove(rpcrq,1), table.remove(rpcrq,1)
+  if rpcf[rpcn] then
+   local rt = {pcall(rpcf[rpcn],table.unpack(rpcrq))}
+   if rt[1] == true then
+    table.remove(rt,1)
+   end
+   minitel.send(from,port,serial.serialize({rpcid,table.unpack(rt)}))
+  else
+  end
+ end
+end
+function rpcf.list()
+ local rt = {}
+ for k,v in pairs(rpcf) do
+  rt[#rt+1] = k
+ end
+ return rt
+end
+
+function rpc.call(hostname,fn,...)
+ if hostname == "localhost" then
+  return rpcf[fn](...)
+ end
+ local rv = minitel.genPacketID()
+ minitel.rsend(hostname,rpc.port,serial.serialize({fn,rv,...}),true)
+ local st = computer.uptime()
+ local rt = {}
+ repeat
+  local _, from, port, data = event.pull(30, "net_msg", hostname, rpc.port)
+  rt = serial.unserialize(data) or {}
+ until rt[1] == rv or computer.uptime() > st + 30
+ if table.remove(rt,1) == rv then
+  return table.unpack(rt)
+ end
+ return false
+end
+function rpc.proxy(hostname,filter)
+ filter=(filter or "").."(.+)"
+ local fnames = rpc.call(hostname,"list")
+ if not fnames then return false end
+ local rt = {}
+ for k,v in pairs(fnames) do
+  fv = v:match(filter)
+  if fv then
+   rt[fv] = function(...)
+    return rpc.call(hostname,v,...)
+   end
+  end
+ end
+ return rt
+end
+function rpc.register(name,fn)
+ local rpcrunning = false
+ for k,v in pairs(os.tasks()) do
+  if os.taskInfo(v).name == "rpc daemon" then
+   rpcrunning = true
+  end
+ end
+ if not rpcrunning then
+  os.spawn(function()
+   while true do
+    rpcexec(event.pull("net_msg"))
+   end
+  end,"rpc daemon")
+ end
+ rpcf[name] = fn
+end
+
+return rpc