Code review fixes

* Removed comment about lua_code_cache directive
* Added array length 'count' into buffer table
* Changed statsd_buffer_size -> statsd_max_buffer_count

README.md

@@ -32,7 +32,7 @@ init_by_lua_block {
     cache_errors = tonumber(os.getenv("IPREPD_CACHE_ERRORS")),
     statsd_host = os.getenv("STATSD_HOST") or nil,
     statsd_port = tonumber(os.getenv("STATSD_PORT")) or 8125,
-    statsd_buffer_size = tonumber(os.getenv("STATSD_BUFFER_SIZE")) or 100,
+    statsd_max_buffer_count = tonumber(os.getenv("STATSD_MAX_BUFFER_COUNT")) or 100,
   })
 }
 
@@ -99,8 +99,8 @@ violations for your environment.
 --                   infrastructure. (defaults to disabled)
 --    statsd_host - Host of statsd collector. Setting this will enable statsd metrics collection
 --    statsd_port - Port of statsd collector. (defaults to 8125)
---    statsd_buffer_size - Statsd buffer table length at which stats should be sent to
---                         the collector. (defaults to 100)
+--    statsd_max_buffer_count - Max number of metrics in buffer before metrics should be submitted
+--                              to statsd (defaults to 100)
 --
 client = require("resty.iprepd").new({
   url = "http://127.0.0.1:8080",
@@ -111,7 +111,7 @@ client = require("resty.iprepd").new({
   cache_errors = 1,
   statsd_host = "127.0.0.1",
   statsd_port = 8125,
-  statsd_buffer_size = 100,
+  statsd_max_buffer_count = 100,
 })
 ```
 
@@ -148,5 +148,5 @@ IPREPD_CACHE_TTL=60 # iprepd response cache ttl in seconds (default is 30s)
 IPREPD_CACHE_ERRORS=1 # enables caching iprepd non-200 responses (1 enables, 0 disables, default is 0)
 STATSD_HOST=127.0.0.1 # statsd host, setting this will also enable statsd metrics collection.
 STATSD_PORT=8125 # statsd port (default is 8125)
-STATSD_BUFFER_SIZE=200 # statsd buffer size (default is 100)
+STATSD_MAX_BUFFER_COUNT=200 # statsd max number of buffer items before submitting (default is 100)
 ```

etc/conf.d/server.conf

@@ -8,7 +8,7 @@ init_by_lua_block {
     cache_errors = tonumber(os.getenv("IPREPD_CACHE_ERRORS")),
     statsd_host = os.getenv("STATSD_HOST") or nil,
     statsd_port = tonumber(os.getenv("STATSD_PORT")) or 8125,
-    statsd_buffer_size = tonumber(os.getenv("STATSD_BUFFER_SIZE")) or 100,
+    statsd_max_buffer_count = tonumber(os.getenv("STATSD_MAX_BUFFER_COUNT")) or 100,
   })
 }
 

lib/resty/iprepd.lua

@@ -47,7 +47,7 @@ function _M.new(options)
     statsd = statsd_client,
     statsd_host = options.statsd_host,
     statsd_port = options.statsd_port or 8125,
-    statsd_buffer_size =  options.statsd_buffer_size or 100,
+    statsd_max_buffer_count =  options.statsd_max_buffer_count or 100,
   }
   return setmetatable(self, mt)
 end
@@ -108,7 +108,7 @@ end
 
 function _M.flush_stats(self)
   if self.statsd then
-    if #self.statsd.buffer >= self.statsd_buffer_size then
+    if self.statsd.buffer_count() >= self.statsd_max_buffer_count then
       self.statsd.flush(self.statsd_host, self.statsd_port)
     end
   end

lib/resty/statsd.lua

@@ -3,28 +3,31 @@
 --
 local _M = {}
 
--- this table will be shared per worker process
--- if lua_code_cache is off, it will be cleared every request
-_M.buffer = {}
+_M.buffer = {count=0}
 
 function _M.flush(host, port)
   if pcall(function()
     local udp = ngx.socket.udp()
     udp:setpeername(host, port)
+    _M.buffer['count'] = nil
     udp:send(_M.buffer)
     udp:close()
   end) then
     -- pass
   else
-    ngx.log(ngx.ERR, "Error sending stats to statsd at " .. host .. ":" .. port)
+    ngx.log(ngx.ERR, 'Error sending stats to statsd at ' .. host .. ':' .. port)
   end
 
-  for k in pairs(_M.buffer) do
-    _M.buffer[k] = nil
-  end
+  -- reset buffer
+  _M.buffer = {count=0}
+end
+
+function _M.buffer_count()
+  return _M.buffer['count']
 end
 
 function _M.register(bucket, suffix)
+  _M.buffer['count'] = _M.buffer['count'] + 1
   table.insert(_M.buffer, bucket .. ':' .. suffix .. '\n')
 end