jsonpath/lua/jsonpath.lua
2019-09-22 22:10:25 +09:00

60 lines
1.3 KiB
Lua

local ffi = require('ffi')
ffi.cdef [[
const char* ffi_select(const char *json_str, const char *path);
void *ffi_path_compile(const char *path);
const char* ffi_select_with_compiled_path(void *ptr, const char *json_str);
]]
local jsonpath
local cache = {}
local module = {}
local function existsVaiable(var)
for k, _ in pairs(_G) do
if k == var then
return true
end
end
end
local _ngx
if existsVaiable('ngx') then
_ngx = ngx
else
_ngx = {}
_ngx.log = function(level, msg)
print('['..level..'] ' .. msg)
end
end
function module.compile(path)
assert(jsonpath, '"libjsonpath_lib" is not loaded')
if(cache[path] == nil) then
cache[path] = jsonpath.ffi_path_compile(path)
_ngx.log(_ngx.INFO, 'compile : [' .. path .. ']')
end
end
function module.exec(path)
local compiledPath = cache[path]
if(cache[path] == nil) then
assert(jsonpath, path .. ": is not compiled")
end
return function(jsonStr)
local result = jsonpath.ffi_select_with_compiled_path(compiledPath, jsonStr)
return ffi.string(result);
end
end
function module.init(path)
if jsonpath == nil then
jsonpath = ffi.load(path)
_ngx.log(_ngx.INFO, '"' .. path .. '" initialized')
end
end
return module