rename ACF2 to Alpine Configurator (aconf)

1 files changed, 273 insertions, 0 deletions

diff --git a/aconf/persistence/backends/augeas.lua b/aconf/persistence/backends/augeas.lua
new file mode 100644
index 0000000..a448e65
--- /dev/null
+++ b/aconf/persistence/backends/augeas.lua
@@ -0,0 +1,273 @@
+--[[
+Copyright (c) 2012-2014 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+local topology = require('aconf.model.root').topology
+local class = require('aconf.object').class
+local pth = require('aconf.path')
+local tostr = require('aconf.persistence.util').tostring
+
+local util = require('aconf.util')
+local copy = util.copy
+
+
+local stringy = require('stringy')
+
+
+local function array_join(tbl, value)
+   local res = copy(tbl)
+   table.insert(res, value)
+   return res
+end
+
+local function array_without_last(tbl)
+   local res = copy(tbl)
+   res[#res] = nil
+   return res
+end
+
+
+local function basename(path)
+   local res, pred = path:match('^.*/([#%w._-]+)([^/]*)$')
+   assert(res)
+   assert(res ~= '#')
+   assert(pred == '' or pred:match('^%[.+%]$'))
+   return res
+end
+
+local function append_pred(path, pred) return path..'['..pred..']' end
+
+
+local function key_mode(mode) return mode and stringy.startswith(mode, '@') end
+
+local function key(mode)
+   assert(key_mode(mode))
+   return mode == '@' and '.' or mode:sub(2, -1)
+end
+
+local function append_key_pred(path, mode, value)
+   return append_pred(path, key(mode).." = '"..value.."'")
+end
+
+
+local function conv_path(path)
+   local res = '/files'
+   if #path == 0 then return res, nil, {} end
+
+   path = copy(path)
+   local mode
+   local keys = {}
+
+   repeat
+      local comp = path[1]
+
+      if comp == '#' or key_mode(comp) then
+	 assert(not mode)
+	 mode = comp
+      elseif not mode then
+	 res = res..'/'..comp
+	 keys = {}
+      else
+	 if mode == '#' then
+	    assert(type(comp) == 'number')
+	    res = append_pred(res, comp)
+	 else
+	    assert(type(comp) == 'string' and comp:match('^[%w %_-%.]+$'))
+	    res = append_key_pred(res, mode, comp)
+	    table.insert(keys, key(mode))
+	 end
+	 mode = nil
+      end
+
+      table.remove(path, 1)
+   until #path == 0
+
+   return res, mode, keys
+end
+
+
+local function aug_top(path)
+   path = copy(path)
+   table.insert(path, 1, 'augeas')
+   return topology(path)
+end
+
+
+local backend = class()
+
+function backend:init() self.aug = require('augeas').init() end
+
+function backend:get(path, top)
+   local apath, mode, keys = conv_path(path)
+   local existence = top == true
+   if existence or not top then top = aug_top(path) end
+
+   local tpe = top and top.type
+   local leaf = tpe ~= 'table' and not mode
+
+   local matches = self.aug:match(apath..(not leaf and not mode and '/*' or ''))
+
+   if #matches == 0 and not mode then return end
+
+   if mode and #path > 1 and not self:get(
+      array_without_last(array_without_last(path)), true
+   ) then
+      return
+   end
+
+   if not tpe and not mode then
+      if #matches > 1 then
+	 leaf = false
+	 mode = '#'
+      else
+	 local children = self.aug:match(apath..'/*')
+	 if #children > 0 then
+	    leaf = false
+	    matches = children
+	 end
+      end
+   end
+   
+   if leaf then
+      assert(#matches == 1)
+      return self.aug:get(apath)
+   end
+
+   if existence then return true end
+
+   local names = {}
+
+   for i, child in ipairs(matches) do
+      local name
+      if not mode then
+	 name = basename(child)
+	 name = tonumber(name) or name
+	 if util.contains(keys, name) then name = nil end
+      elseif mode == '#' then name = i
+      else
+	 name = self.aug:get(child..(mode == '@' and '' or '/'..key(mode)))
+      end
+
+      if name and self:get(array_join(path, name), true) then
+	 names[name] = true
+      end
+   end
+
+   return util.keys(names)
+end
+
+function backend:set(mods)
+   local gc = {}
+
+   for _, mod in ipairs(mods) do
+      local path, value = unpack(mod)
+
+      local function insert(path, new)
+	 local apath, mode, keys = conv_path(path)
+	 if mode then path[#path] = nil end
+	 if #path == 0 then return apath, keys end
+	 local name = path[#path]
+
+	 local parent = array_without_last(path)
+	 local ppath, pmode = conv_path(parent)
+
+	 if pmode then
+	    gc[pth.join(unpack(array_without_last(parent)))] = false
+	 end
+
+	 if pmode == '#' then
+	    local count = #self.aug:match(ppath)
+	    while count < name do
+	       insert(parent, true)
+	       count = count + 1
+	    end
+	    return apath, keys
+	 end
+
+	 local matches = self.aug:match(apath)
+	 local count = #matches
+
+	 if count > 0 and not new then return apath, keys end
+
+	 if key_mode(pmode) then
+	    apath = pmode == '@' and append_key_pred(
+	       ppath, '@', ''
+	    ) or append_pred(ppath, 'count('..key(pmode)..') = 0')
+
+	    matches = self.aug:match(apath)
+	    assert(#matches < 2)
+	    apath = matches[1] or insert(parent, true)
+
+	    local key = key(pmode)
+	    self.aug:set(apath..'/'..key, name)
+
+	    return apath, keys
+	 end
+
+	 if #matches == 0 then
+	    matches = self.aug:match(ppath..'/*')
+
+	    local function order(path)
+	       local top = aug_top(path)
+	       return top and top.order
+	    end
+	    local ord = order(path)
+
+	    for _, sibling in ipairs(matches) do
+	       local sord = order(array_join(parent, basename(sibling)))
+	       if sord and sord > ord then
+		  self.aug:insert(sibling, name, true)
+		  return apath, keys
+	       end
+	    end
+	 end
+
+	 if #matches == 0 then
+	    if new then self.aug:set(apath, nil) end
+	    return apath, keys
+	 end
+
+	 self.aug:insert(matches[#matches], name)
+	 return append_pred(apath, count + 1), keys
+      end
+
+      local apath, keys = insert(path)
+      local is_table = type(value) == 'table'
+
+      if not (is_table or util.contains(keys, '.')) then
+	 self.aug:set(apath, value ~= nil and tostr(value) or nil)
+      end
+
+      util.setdefault(gc, pth.join(unpack(path)), true)
+   end
+
+   for path, _ in pairs(gc) do
+      local p = pth.split(path)
+      while #p > 0 do
+	 local value = self:get(p)
+
+	 if (
+	    type(value) == 'string' and value ~= ''
+	 ) or (
+	    type(value) == 'table' and #value > 0
+	 ) then
+	    break
+	 end
+
+	 if gc[pth.join(unpack(p))] ~= false then self.aug:rm(conv_path(p)) end
+	 p[#p] = nil
+      end
+   end
+
+   if self.aug:save() ~= 0 then
+      print('Augeas save failed')
+      for _, ep in ipairs(self.aug:match('/augeas//error')) do
+	 print(ep, self.aug:get(ep))
+      end
+      assert(false)
+   end
+end
+
+
+return backend