bugfix: should force convert weight to a number since it may cause dead loop when weight is a string type "0". (openresty#40)

Author: doujiang

README.markdown

@@ -135,6 +135,7 @@ The `id` should be `table.concat({host, string.char(0), port})` like the nginx c
 when we need to keep consistency with nginx chash.
 
 The `id` can be any string value when we do not need to keep consistency with nginx chash.
+The `weight` should be a non negative integer.
 
 ```lua
 local nodes = {

lib/resty/balancer/utils.lua

@@ -11,27 +11,10 @@ do
         new_tab = function (narr, nrec) return {} end
     end
 end
-
 _M.new_tab = new_tab
 
-local copy
-do
-    local ok
-    ok, copy = pcall(require, "table.clone")
-    if not ok or type(copy) ~= "function" then
-        copy = function(nodes)
-            local newnodes = new_tab(0, 0)
-            for id, weight in pairs(nodes) do
-                newnodes[id] = weight
-            end
-
-            return newnodes
-        end
-    end
-end
-_M.copy = copy
 
-local nkeys
+local nkeys, tab_nkeys
 do
     local ok
     ok, nkeys = pcall(require, "table.nkeys")
@@ -43,9 +26,22 @@ do
             end
             return count
         end
+
+    else
+        tab_nkeys = nkeys
     end
 end
-
 _M.nkeys = nkeys
 
+
+function _M.copy(nodes)
+    local newnodes = new_tab(0, tab_nkeys and tab_nkeys(nodes) or 4)
+    for id, weight in pairs(nodes) do
+        newnodes[id] = tonumber(weight)
+    end
+
+    return newnodes
+end
+
+
 return _M

t/roundrobin.t

@@ -146,3 +146,69 @@ GET /t
 false
 --- no_error_log
 [error]
+
+
+
+=== TEST 4: weight is "0"
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua_block {
+            math.randomseed(9975098)
+
+            local roundrobin = require "resty.roundrobin"
+
+            local servers = {
+                ["server1"] = "0",
+                ["server2"] = "1",
+                ["server3"] = "0",
+                ["server4"] = "0",
+            }
+
+            local rr = roundrobin:new(servers, true)
+            local id = rr:find()
+
+            ngx.say("id: ", id)
+        }
+    }
+--- request
+GET /t
+--- response_body
+id: server2
+--- no_error_log
+[error]
+
+
+
+=== TEST 5: all weights are 0, behavior like weights are 1.
+It's not recommends to use 0, this test just make sure it won't be worse, like crash.
+--- http_config eval: $::HttpConfig
+--- config
+    location /t {
+        content_by_lua_block {
+            math.randomseed(9975098)
+
+            local roundrobin = require "resty.roundrobin"
+
+            local servers = {
+                ["server1"] = 0,
+                ["server2"] = 0,
+                ["server3"] = 0,
+                ["server4"] = 0,
+            }
+
+            local rr = roundrobin:new(servers, true)
+
+            for i = 1, 4 do
+                local id = rr:find()
+            end
+
+            ngx.say("ok")
+        }
+    }
+--- request
+GET /t
+--- response_body
+ok
+--- no_error_log
+[error]