fusionpbx/resources/install/scripts/resources/functions/cache.lua

104 lines
2.4 KiB
Lua

-- @usage cache = require "resources.functions.cache"
-- value = cache.get(key)
-- if not value then
-- ...
-- cache.set(key, value, expire)
-- end
--
require "resources.functions.trim";
local api = api
if (not api) and freeswitch then api = freeswitch.API() else
api = {}
function api:execute()
return '-ERR UNSUPPORTTED'
end
end
local function send_event(action, key)
local event = freeswitch.Event("MEMCACHE", action);
event:addHeader("API-Command", "memcache");
event:addHeader("API-Command-Argument", action .. " " .. key);
event:fire()
end
local Cache = {}
local function check_error(result)
result = trim(result or '')
if result and result:sub(1, 4) == '-ERR' then
return nil, trim(result:sub(5))
end
if result == 'INVALID COMMAND!' and not Cache.support() then
return nil, 'INVALID COMMAND'
end
return result
end
function Cache.support()
-- assume it is not unloadable
if Cache._support then
return true
end
Cache._support = (trim(api:execute('module_exists', 'mod_memcache')) == 'true')
return Cache._support
end
--- Get element from cache
--
-- @tparam key string
-- @return[1] string value
-- @return[2] nil
-- @return[2] error string `e.g. 'NOT FOUND'
-- @note error string does not contain `-ERR` prefix
function Cache.get(key)
local result, err = check_error(api:execute('memcache', 'get ' .. key))
if not result then return nil, err end
return (result:gsub("'", "'"))
end
function Cache.set(key, value, expire)
value = value:gsub("'", "'"):gsub("\\", "\\\\")
expire = expire and tostring(expire) or ""
local ok, err = check_error(api:execute("memcache", "set " .. key .. " '" .. value .. "' " .. expire))
if not ok then return nil, err end
return ok == '+OK'
end
function Cache.del(key)
send_event('delete', key)
local result, err = check_error(api:execute("memcache", "delete " .. key))
if not result then
if err == 'NOT FOUND' then
return true
end
return nil, err
end
return result == '+OK'
end
function Cache._self_test()
assert(Cache.support())
Cache.del("a")
local ok, err = Cache.get("a")
assert(nil == ok)
assert(err == "NOT FOUND")
local s = "hello \\ ' world"
assert(true == Cache.set("a", s))
assert(s == Cache.get("a"))
assert(true == Cache.del("a"))
end
-- if debug.self_test then
-- Cache._self_test()
-- end
return Cache