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--[[
Copyright (c) 2012-2014 Kaarle Ritvanen
See LICENSE file for license details
--]]
local pth = require('aconf.path')
local Cache = require('aconf.persistence.backends.volatile')
local util = require('aconf.persistence.util')
local copy = require('aconf.util').copy
local json = require('cjson')
local posix = require('posix')
local backend = require('aconf.object').class()
function backend:init()
-- TODO cache expiration
self.cache = {}
self.dirty = {}
end
function backend:split_path(path)
local fpath = copy(path)
local jpath = {}
local res
while #fpath > 0 do
local fp = pth.join('/', table.unpack(fpath))
if self.cache[fp] then return fp, jpath end
table.insert(jpath, 1, fpath[#fpath])
table.remove(fpath)
end
fpath = '/'
while true do
fpath = pth.join(fpath, jpath[1])
table.remove(jpath, 1)
local t = posix.stat(fpath, 'type')
if t == 'link' then t = posix.stat(posix.readlink(fpath), 'type') end
if not t or not ({directory=true, regular=true})[t] then
error('File or directory does not exist: '..fpath)
end
if t == 'regular' then return fpath, jpath end
assert(#jpath > 0)
end
end
function backend:get(path, top)
local fpath, jpath = self:split_path(path)
if not self.cache[fpath] then
self.cache[fpath] = Cache(json.decode(util.read_file(fpath)))
end
return self.cache[fpath]:get(jpath, top)
end
function backend:set(mods)
local dirty = {}
for _, mod in ipairs(mods) do
local path, value = table.unpack(mod)
local fpath, jpath = self:split_path(path)
self.cache[fpath]:_set(jpath, value)
dirty[fpath] = true
end
for path, _ in pairs(dirty) do
local file = util.open_file(path, 'w')
file:write(json.encode(self.cache[path]:_get{}))
file:close()
end
end
return backend
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