libs/sys: improve efficiency of sys.net.defaultroute(), can save hundreds of KB memor...

diff --git a/libs/sys/luasrc/sys.lua b/libs/sys/luasrc/sys.lua
index c9f0bcc884474f89c8289da4227d2ba537192c36..c978fb70f5ed37f01051bf7a6437d8ace3bef3ce 100644 (file)
--- a/libs/sys/luasrc/sys.lua
+++ b/libs/sys/luasrc/sys.lua
@@ -296,12 +296,14 @@ end
 --                     { "dest", "gateway", "metric", "refcount", "usecount", "irtt",
 --                       "flags", "device" }
 function net.defaultroute()
-       local route = nil
-       for _, r in pairs(net.routes()) do
-               if r.dest:prefix() == 0 and (not route or route.metric > r.metric) then
-                       route = r
+       local route
+
+       net.routes(function(rt)
+               if rt.dest:prefix() == 0 and (not route or route.metric > rt.metric) then
+                       route = rt
                end
-       end
+       end)
+
        return route
 end
 
@@ -371,7 +373,7 @@ end
 --                     The following fields are defined for route entry tables:
 --                     { "dest", "gateway", "metric", "refcount", "usecount", "irtt",
 --                       "flags", "device" }
-function net.routes()
+function net.routes(callback)
        local routes = { }
 
        for line in io.lines("/proc/net/route") do
@@ -389,7 +391,7 @@ function net.routes()
                                dst_ip, dst_mask:prefix(dst_mask), luci.ip.FAMILY_INET4
                        )
 
-                       routes[#routes+1] = {
+                       local rt = {
                                dest     = dst_ip,
                                gateway  = gateway,
                                metric   = tonumber(metric),
@@ -401,6 +403,12 @@ function net.routes()
                                flags    = tonumber(flags, 16),
                                device   = dev
                        }
+
+                       if callback then
+                               callback(rt)
+                       else
+                               routes[#routes+1] = rt
+                       end
                end
        end