Series of small perf improvement

gateway/src/apicast/configuration/service.lua

@@ -238,17 +238,21 @@ end
 -- @return @{credentials_v1}, @{credentials_v2}, or @{credentials_oauth}
 -- @return[opt] error message why credentials could not be extracted
 function _M:extract_credentials()
-  local backend_version = tostring(self.backend_version)
   local credentials = rawget(self, 'credentials')
 
   if not credentials then
     return nil, 'missing credentials'
   end
 
-  local extractor = backend_version_credentials['version_' .. backend_version]
+  local extractor = self.credentials_extractor
 
   if not extractor then
-   return nil, 'invalid backend version: ' .. backend_version
+    local backend_version = tostring(self.backend_version)
+    extractor = backend_version_credentials['version_' .. backend_version]
+    if not extractor then
+      return nil, 'invalid backend version: ' .. backend_version
+    end
+    self.credentials_extractor = extractor
   end
 
   return extractor(credentials)

gateway/src/apicast/mapping_rule.lua

@@ -85,8 +85,8 @@ local function matches_querystring_params(params, args)
   return match
 end
 
-local function matches_uri(rule_pattern, uri)
-  return re_match(uri, format("^%s", rule_pattern), 'oj')
+local function matches_uri(anchored_pattern, uri)
+  return re_match(uri, anchored_pattern, 'oj')
 end
 
 local function new(http_method, pattern, params, querystring_params, metric, delta, last, owner_id, owner_type)
@@ -97,6 +97,7 @@ local function new(http_method, pattern, params, querystring_params, metric, del
   self.method = http_method
   self.pattern = pattern
   self.regexpified_pattern = regexpify(pattern)
+  self.anchored_pattern = format("^%s", self.regexpified_pattern)
   self.parameters = params
   self.system_name = metric or error('missing metric name of rule')
   self.delta = delta
@@ -152,7 +153,7 @@ end
 -- @treturn boolean Whether the mapping rule matches the given request.
 function _M:matches(method, uri, args)
   local match = (self.method == self.any_method or self.method == method) and
-      matches_uri(self.regexpified_pattern, uri) and
+      matches_uri(self.anchored_pattern, uri) and
       self.querystring_params(args)
 
   -- match can be nil. Convert to boolean.

gateway/src/apicast/policy/upstream/upstream.lua

@@ -47,7 +47,7 @@ function _M:rewrite(context)
   local req_uri = ngx.var.uri
 
   for _, rule in ipairs(self.rules) do
-    if match(req_uri, rule.regex) then
+    if match(req_uri, rule.regex, 'oj') then
       ngx.log(ngx.DEBUG, 'upstream policy uri: ', req_uri, ' regex: ', rule.regex, ' match: true')
       -- better to allocate new object for each request as it is going to get mutated
       context[self] = Upstream.new(rule.url)