Added proper graph implementation in central_server.lua

This commit is contained in:
Andrew Lalis 2023-09-14 10:48:55 -04:00
parent 8c5c425a4f
commit dfd8665920
2 changed files with 223 additions and 50 deletions

View File

@ -6,68 +6,130 @@ traffic through.
local RECEIVE_CHANNEL = 45453
-- ONLY FOR DEBUGGING
-- inspect = require("inspect")
local modem = peripheral.wrap("top") or error("Missing top modem")
modem.open(RECEIVE_CHANNEL)
local loadGraph()
local g = nil
local f = io.open("network_graph.tbl", "r")
g = textutils.unserialize(f:read("*a"))
f:close()
local function generateStandardNode(id, edgeIds)
local node = {id = id, connections = {}, type = "JUNCTION"}
for _, edgeId in pairs(edgeIds) do
for _, edgeId2 in pairs(edgeIds) do
if edgeId2 ~= edgeId then
table.insert(node.connections, {from = edgeId, to = edgeId2})
end
end
end
return node
end
local function generateStationNode(id, edgeId)
return {
id = id,
connections = {
{from = nil, to = edgeId},
{from = edgeId, to = nil}
},
type = "STATION"
}
end
local function loadGraph()
-- local g = nil
-- local f = io.open("network_graph.tbl", "r")
-- g = textutils.unserialize(f:read("*a"))
-- f:close()
--return g
return {
nodes = {
{
id = "Junction-HandieVale",
connections = {
{from = "handievale", to = "N1"},
{from = "N1", to = "handievale"},
{from = "handievale", to = "W1"},
{from = "W1", to = "handievale"},
{from = "N1", to = "W1"},
{from = "W1", to = "N1"}
}
},
{
id = "Junction-Middlecross",
connections = {
{from = "W1", to = "W2"},
{from = "W2", to = "W1"},
{from = "N2", to = "S1"},
{from = "S1", to = "N2"}
}
}
generateStandardNode("Junction-HandieVale", {"handievale", "N1", "W1"}),
generateStandardNode("Junction-Middlecross", {"W1", "N2", "W2", "S1"}),
generateStandardNode("Junction-Foundry", {"E1", "N3", "W3", "N2"}),
generateStandardNode("Junction-End", {"E1", "E2", "end"}),
generateStandardNode("Junction-Klausville", {"N3", "N4", "klausville"}),
generateStandardNode("Junction-Foundry-West", {"W3", "foundry", "W4"}),
generateStationNode("station-klausville", "klausville"),
generateStationNode("station-handievale", "handievale"),
generateStationNode("station-end", "end"),
generateStationNode("station-foundry", "foundry")
},
edges = {
{
{id = "handievale", length = 16},
{id = "N1", length = -1},
{id = "W1", length = 300},
{id = "N2", length = 600},
{id = "E1", length = 75},
{id = "end", length = 60},
{id = "W2", length = -1},
{id = "S1", length = -1}
}
{id = "handievale", length = 16},
{id = "end", length = 48},
{id = "foundry", length = 45},
{id = "klausville", length = 12},
{id = "N1", length = nil},
{id = "W1", length = 300},
{id = "N2", length = 600},
{id = "E1", length = 75},
{id = "W2", length = nil},
{id = "S1", length = nil},
{id = "W3", length = 50},
{id = "W4", length = nil},
{id = "N3", length = 350},
{id = "N4", length = nil}
}
}
end
local findNodeById(graph, nodeId)
local function filterTable(arr, func)
local new_index = 1
local size_orig = #arr
for old_index, v in ipairs(arr) do
if func(v, old_index) then
arr[new_index] = v
new_index = new_index + 1
end
end
for i = new_index, size_orig do arr[i] = nil end
end
local function findNodeById(graph, nodeId)
for _, node in pairs(graph.nodes) do
if node.id == nodeId then return node end
end
return nil
end
local findEdgeById(graph, edgeId)
local function findEdgeById(graph, edgeId)
for _, edge in pairs(graph.edges) do
if edge.id == edgeId then return edge end
end
return nil
end
local findNextEdges(graph, edgeId)
local function findEdgeBetweenNodes(graph, fromNode, toNode)
local edgeIdsFrom = {}
for _, conn in pairs(fromNode.connections) do
if conn.to and not tableContains(edgeIdsFrom, conn.to) then
table.insert(edgeIdsFrom, conn.to)
end
end
local edgeIds = {}
for _, conn in pairs(toNode.connections) do
if conn.from and tableContains(edgeIdsFrom, conn.from) and not tableContains(edgeIds, conn.from) then
table.insert(edgeIds, conn.from)
end
end
end
local function tableContains(table, value)
for _, item in pairs(table) do
if item == value then return true end
end
return false
end
local function removeElement(table, value)
local idx = nil
for i, item in pairs(table) do
if item == value then idx = i break end
end
if idx then table.remove(table, idx) end
end
local function findNextEdges(graph, edgeId)
local edges = {}
for _, node in pairs(graph.nodes) do
for _, connection in pairs(node.connections) do
@ -79,23 +141,138 @@ local findNextEdges(graph, edgeId)
return edges
end
local findPath(graph, nodeA, nodeB)
-- Find the set of nodes directly connected to this one via some edges
local function findConnectedNodes(graph, startNode)
local edges = {}
local edgeIds = {}
for _, conn in pairs(startNode.connections) do
if conn.to ~= nil then
local edge = findEdgeById(graph, conn.to)
if edge ~= nil and edge.length ~= nil and not tableContains(edgeIds, edge.id) then
table.insert(edges, edge)
table.insert(edgeIds, edge.id)
end
end
end
local connections = {}
for _, edge in pairs(edges) do
for _, node in pairs(graph.nodes) do
if node.id ~= startNode.id then
for _, conn in pairs(node.connections) do
if conn.from == edge.id then
table.insert(connections, {node = node, distance = edge.length, via = edge.id})
break
end
end
end
end
end
return connections
end
local handleRequest(graph, replyChannel, msg)
if msg.command == "ROUTE" then
local function findPath(graph, startNode, endNode)
local INFINITY = 1000000000
local dist = {}
local prev = {}
local queue = {}
for _, node in pairs(graph.nodes) do
dist[node.id] = INFINITY
prev[node.id] = nil
table.insert(queue, node)
end
dist[startNode.id] = 0
while #queue > 0 do
local minIdx = nil
local minDist = INFINITY + 1
for i, node in pairs(queue) do
if dist[node.id] < minDist then
minIdx = i
minDist = dist[node.id]
end
end
if minIdx == nil then return nil end
local u = table.remove(queue, minIdx)
if u.id == endNode.id and (prev[u.id] or u.id == startNode.id) then
local s = {}
while u ~= nil do
local via = nil
local distance = nil
local node = u
u = nil
if prev[node.id] then
via = prev[node.id].via
distance = prev[node.id].distance
u = prev[node.id].node
end
table.insert(s, 1, {node = node, via = via, distance = distance})
end
return s
end
for _, neighbor in pairs(findConnectedNodes(graph, u)) do
local unvisited = false
for _, node in pairs(queue) do
if node.id == neighbor.node.id then
unvisited = true
break
end
end
if unvisited then
local alt = dist[u.id] + neighbor.distance
if alt < dist[neighbor.node.id] then
dist[neighbor.node.id] = alt
prev[neighbor.node.id] = {node = u, via = neighbor.via, distance = neighbor.distance}
end
end
end
end
return nil
end
local function handleRouteRequest(graph, replyChannel, msg)
if not msg.startNode or not msg.endNode then
modem.transmit(replyChannel, RECEIVE_CHANNEL, {success = false, error = "Invalid request"})
return
end
local startNode = findNodeById(graph, msg.startNode)
local endNode = findNodeById(graph, msg.endNode)
if not startNode or not endNode then
modem.transmit(replyChannel, RECEIVE_CHANNEL, {success = false, error = "Unknown node(s)"})
return
end
local path = findPath(graph, startNode, endNode)
if not path then
modem.transmit(replyChannel, RECEIVE_CHANNEL, {success = false, error = "No valid path"})
return
end
modem.transmit(replyChannel, RECEIVE_CHANNEL, {success = true, route = path})
end
local function handleRequests(graph)
while true do
local event, side, channel, replyChannel, msg, dist = os.pullEvent("modem_message")
if channel == RECEIVE_CHANNEL then
handleRequest(graph, replyChannel, msg)
if channel == RECEIVE_CHANNEL and msg and msg.command and type(msg.command) == "string" then
if msg.command == "ROUTE" then
handleRouteRequest(graph, replyChannel, msg)
else
modem.transmit(replyChannel, RECEIVE_CHANNEL, {success = false, error = "Invalid command"})
end
end
end
end
handleRequests(loadGraph())
-- local graph = loadGraph()
-- print("GRAPH:")
-- print(inspect(graph))
-- local startNode = findNodeById(graph, "station-handievale")
-- local endNode = findNodeById(graph, "station-foundry")
-- print("\n\nPATH:")
-- local path = findPath(graph, startNode, endNode)
-- if path then
-- print("Found path!")
-- for i, element in pairs(path) do
-- print(i..". "..element.node.id.." via edge "..inspect(element.via).." @ "..inspect(element.distance))
-- end
-- end

View File

@ -6,11 +6,7 @@ You should add a "station_config.tbl" file containing:
{
name = "stationname",
displayName = "Station Name",
range = 8,
routes = {
{name = "First", path = {"A", "B", "C"}},
{name = "Second", path = {"D", "A", "C"}}
}
range = 8
}
]]--