feat: add utils.lua

src/resty/utils.lua

@@ -1,45 +1,53 @@
-local base        = require("resty.core.base")
-local clear_table   = base.clear_tab
---[[
--- 其实可以做个兼容，这个项目不一定要依赖 luajit/openresty
--- string find 其实可以替换成其他的实现
-local ok, clear_tab = pcall(require, "table.clear")
+local str_byte = string.byte
+local str_find = string.find
+local math_min = math.min
+
+
+local clear_table
+do
+  local ok
+  ok, clear_table = pcall(require, "table.clear")
   if not ok then
-    clear_tab = function (tab)
+    local pairs = pairs
+    clear_table = function (tab)
       for k, _ in pairs(tab) do
         tab[k] = nil
       end
     end
   end
-]]
+end
 
-local ffi = require("ffi")
-local C = ffi.C
-local ffi_cast = ffi.cast
-local ffi_cdef = ffi.cdef
-local str_byte = string.byte
-local math_min = math.min
 
-ffi_cdef[[
-  int memcmp(const void *s1, const void *s2, size_t n);
-]]
+local starts_with
+do
+  local luajit = type(_G.jit) == "table"
+  if luajit then
+    local ffi = require "ffi"
+    local C = ffi.C
+    ffi.cdef[[
+      int memcmp(const void *s1, const void *s2, size_t n);
+    ]]
+    starts_with = function(str, prefix, strn, prefixn)
+      strn = strn or #str
+      prefixn = prefixn or #prefix
 
-local function starts_with(str, prefix, strn, prefixn)
-  strn = strn or #str
-  prefixn = prefixn or #prefix
+      if prefixn == 0 then
+        return true
+      end
 
-  if prefixn == 0 then
-    return true
-  end
+      if strn < prefixn then
+        return false
+      end
 
-  if strn < prefixn then
-    return false
+      local rc = C.memcmp(str, prefix, prefixn)
+      return rc == 0
+    end
+  else
+    local str_sub = string.sub
+    starts_with = function(str, prefix, strn, prefixn)
+      return str_sub(str, 1, #prefix) == prefix
+    end
   end
-
-  -- TODO lua-resty-radixtree 里面还用到了 cast
-  local rc = C.memcmp(str, prefix, prefixn)
-  return rc == 0
-  --return string.sub(s, 1, #prefix) == prefix
 end
 
 
@@ -58,8 +66,8 @@ end
 
 
 local function has_wildcard(path)
-  local idx_wildcard = string.find(path, "*", 1, true)
-  local idx_parameter = string.find(path, ":", 1, true)
+  local idx_wildcard = str_find(path, "*", 1, true)
+  local idx_parameter = str_find(path, ":", 1, true)
   return idx_wildcard or idx_parameter
 end