增加sql的waf功能

resty/limit/traffic.lua

@@ -0,0 +1,58 @@
+-- Copyright (C) Yichun Zhang (agentzh)
+--
+-- This is an aggregator for various concrete traffic limiter instances
+-- (like instances of the resty.limit.req, resty.limit.count and
+-- resty.limit.conn classes).
+
+
+local max = math.max
+
+
+local _M = {
+    _VERSION = '0.07'
+}
+
+
+-- the states table is user supplied. each element stores the 2nd return value
+-- of each limiter if there is no error returned. for resty.limit.req, the state
+-- is the "excess" value (i.e., the number of excessive requests each second),
+-- and for resty.limit.conn, the state is the current concurrency level
+-- (including the current new connection).
+function _M.combine(limiters, keys, states)
+    local n = #limiters
+    local max_delay = 0
+    for i = 1, n do
+        local lim = limiters[i]
+        local delay, err = lim:incoming(keys[i], i == n)
+        if not delay then
+            return nil, err
+        end
+        if i == n then
+            if states then
+                states[i] = err
+            end
+            max_delay = delay
+        end
+    end
+    for i = 1, n - 1 do
+        local lim = limiters[i]
+        local delay, err = lim:incoming(keys[i], true)
+        if not delay then
+            for j = 1, i - 1 do
+                -- we intentionally ignore any errors returned below.
+                limiters[j]:uncommit(keys[j])
+            end
+            limiters[n]:uncommit(keys[n])
+            return nil, err
+        end
+        if states then
+            states[i] = err
+        end
+
+        max_delay = max(max_delay, delay)
+    end
+    return max_delay
+end
+
+
+return _M