luci/libs/core/luasrc/util.lua

436 lines
9.2 KiB
Lua

--[[
LuCI - Utility library
Description:
Several common useful Lua functions
FileId:
$Id$
License:
Copyright 2008 Steven Barth <steven@midlink.org>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
]]--
module("luci.util", package.seeall)
-- Lua simplified Python-style OO class support emulation
function class(base)
local class = {}
local create = function(class, ...)
local inst = {}
setmetatable(inst, {__index = class})
if inst.__init__ then
local stat, err = copcall(inst.__init__, inst, ...)
if not stat then
error(err)
end
end
return inst
end
local classmeta = {__call = create}
if base then
classmeta.__index = base
end
setmetatable(class, classmeta)
return class
end
-- Clones an object (deep on-demand)
function clone(object, deep)
local copy = {}
for k, v in pairs(object) do
if deep and type(v) == "table" then
v = clone(v, deep)
end
copy[k] = v
end
setmetatable(copy, getmetatable(object))
return copy
end
-- Combines two or more numerically indexed tables into one
function combine(...)
local result = {}
for i, a in ipairs(arg) do
for j, v in ipairs(a) do
table.insert(result, v)
end
end
return result
end
-- Checks whether a table has an object "value" in it
function contains(table, value)
for k, v in pairs(table) do
if value == v then
return k
end
end
return false
end
-- Dumps and strips a Lua-Function
function dump(f)
local d = string.dump(f)
return d and strip_bytecode(d)
end
-- Dumps a table to stdout (useful for testing and debugging)
function dumptable(t, i)
i = i or 0
for k,v in pairs(t) do
print(string.rep("\t", i) .. tostring(k), tostring(v))
if type(v) == "table" then
dumptable(v, i+1)
end
end
end
-- Escapes all occurences of c in s
function escape(s, c)
c = c or "\\"
return s:gsub(c, "\\" .. c)
end
-- Populate obj in the scope of f as key
function extfenv(f, key, obj)
local scope = getfenv(f)
scope[key] = obj
end
-- Checks whether an object is an instanceof class
function instanceof(object, class)
local meta = getmetatable(object)
while meta and meta.__index do
if meta.__index == class then
return true
end
meta = getmetatable(meta.__index)
end
return false
end
-- Creates valid XML PCDATA from a string
function pcdata(value)
value = value:gsub("&", "&amp;")
value = value:gsub('"', "&quot;")
value = value:gsub("'", "&apos;")
value = value:gsub("<", "&lt;")
return value:gsub(">", "&gt;")
end
-- Returns an error message to stdout
function perror(obj)
io.stderr:write(tostring(obj) .. "\n")
end
-- Resets the scope of f doing a shallow copy of its scope into a new table
function resfenv(f)
setfenv(f, clone(getfenv(f)))
end
-- Splits a string into an array
function split(str, pat, max, regex)
pat = pat or "\n"
max = max or #str
local t = {}
local c = 1
if #str == 0 then
return {""}
end
if #pat == 0 then
return nil
end
if max == 0 then
return str
end
repeat
local s, e = str:find(pat, c, not regex)
table.insert(t, str:sub(c, s and s - 1))
max = max - 1
c = e and e + 1 or #str + 1
until not s or max < 0
return t
end
-- Strips lua bytecode
-- Original version by Peter Cawley (http://lua-users.org/lists/lua-l/2008-02/msg01158.html)
function strip_bytecode(dump)
local version, format, endian, int, size, ins, num, lnum = dump:byte(5, 12)
local subint
if endian == 1 then
subint = function(dump, i, l)
local val = 0
for n = l, 1, -1 do
val = val * 256 + dump:byte(i + n - 1)
end
return val, i + l
end
else
subint = function(dump, i, l)
local val = 0
for n = 1, l, 1 do
val = val * 256 + dump:byte(i + n - 1)
end
return val, i + l
end
end
local strip_function
strip_function = function(dump)
local count, offset = subint(dump, 1, size)
local stripped, dirty = string.rep("\0", size), offset + count
offset = offset + count + int * 2 + 4
offset = offset + int + subint(dump, offset, int) * ins
count, offset = subint(dump, offset, int)
for n = 1, count do
local t
t, offset = subint(dump, offset, 1)
if t == 1 then
offset = offset + 1
elseif t == 4 then
offset = offset + size + subint(dump, offset, size)
elseif t == 3 then
offset = offset + num
elseif t == 254 or t == 9 then
offset = offset + lnum
end
end
count, offset = subint(dump, offset, int)
stripped = stripped .. dump:sub(dirty, offset - 1)
for n = 1, count do
local proto, off = strip_function(dump:sub(offset, -1))
stripped, offset = stripped .. proto, offset + off - 1
end
offset = offset + subint(dump, offset, int) * int + int
count, offset = subint(dump, offset, int)
for n = 1, count do
offset = offset + subint(dump, offset, size) + size + int * 2
end
count, offset = subint(dump, offset, int)
for n = 1, count do
offset = offset + subint(dump, offset, size) + size
end
stripped = stripped .. string.rep("\0", int * 3)
return stripped, offset
end
return dump:sub(1,12) .. strip_function(dump:sub(13,-1))
end
-- Creates a new threadlocal store
function threadlocal()
local tbl = {}
local function get(self, key)
local c = coroutine.running()
local thread = coxpt[c] or c or 0
if not rawget(self, thread) then
return nil
end
return rawget(self, thread)[key]
end
local function set(self, key, value)
local c = coroutine.running()
local thread = coxpt[c] or c or 0
if not rawget(self, thread) then
rawset(self, thread, {})
end
rawget(self, thread)[key] = value
end
setmetatable(tbl, {__index = get, __newindex = set, __mode = "k"})
return tbl
end
-- Removes whitespace from beginning and end of a string
function trim(str)
local s = str:gsub("^%s*(.-)%s*$", "%1")
return s
end
-- Updates given table with new values
function update(t, updates)
for k, v in pairs(updates) do
t[k] = v
end
end
-- Updates the scope of f with "extscope"
function updfenv(f, extscope)
update(getfenv(f), extscope)
end
-- Parse units from a string and return integer value
function parse_units(ustr)
local val = 0
-- unit map
local map = {
-- date stuff
y = 60 * 60 * 24 * 366,
m = 60 * 60 * 24 * 31,
w = 60 * 60 * 24 * 7,
d = 60 * 60 * 24,
h = 60 * 60,
min = 60,
-- storage sizes
kb = 1024,
mb = 1024 * 1024,
gb = 1024 * 1024 * 1024,
-- storage sizes (si)
kib = 1000,
mib = 1000 * 1000,
gib = 1000 * 1000 * 1000
}
-- parse input string
for spec in ustr:lower():gmatch("[0-9%.]+[a-zA-Z]*") do
local num = spec:gsub("[^0-9%.]+$","")
local spn = spec:gsub("^[0-9%.]+", "")
if map[spn] or map[spn:sub(1,1)] then
val = val + num * ( map[spn] or map[spn:sub(1,1)] )
else
val = val + num
end
end
return val
end
-- Provide various sorting iterators
function _sortiter( t, f )
local keys = { }
for k, v in pairs(t) do
table.insert( keys, k )
end
local _pos = 0
local _len = table.getn( keys )
table.sort( keys, f )
return function()
_pos = _pos + 1
if _pos <= _len then
return keys[_pos], t[keys[_pos]]
end
end
end
-- Return key, value pairs sorted by provided callback function
function spairs(t,f)
return _sortiter( t, f )
end
-- Return key, value pairs sorted by keys
function kspairs(t)
return _sortiter( t )
end
-- Return key, value pairs sorted by values
function vspairs(t)
return _sortiter( t, function (a,b) return t[a] < t[b] end )
end
-- Coroutine safe xpcall and pcall versions modified for Luci
-- original version:
-- coxpcall 1.13 - Copyright 2005 - Kepler Project (www.keplerproject.org)
local performResume, handleReturnValue
local oldpcall, oldxpcall = pcall, xpcall
coxpt = {}
setmetatable(coxpt, {__mode = "kv"})
function handleReturnValue(err, co, status, ...)
if not status then
return false, err(debug.traceback(co, (...)), ...)
end
if coroutine.status(co) == 'suspended' then
return performResume(err, co, coroutine.yield(...))
else
return true, ...
end
end
function performResume(err, co, ...)
return handleReturnValue(err, co, coroutine.resume(co, ...))
end
function coxpcall(f, err, ...)
local res, co = oldpcall(coroutine.create, f)
if not res then
local params = {...}
local newf = function() return f(unpack(params)) end
co = coroutine.create(newf)
end
local c = coroutine.running()
coxpt[co] = coxpt[c] or c or 0
return performResume(err, co, ...)
end
local function id(trace, ...)
return ...
end
function copcall(f, ...)
return coxpcall(f, id, ...)
end