3 files changed, 204 insertions, 0 deletions
diff --git a/acf/persistence/backends/augeas.lua b/acf/persistence/backends/augeas.lua
new file mode 100644
index 0000000..34d7df8
--- /dev/null
+++ b/acf/persistence/backends/augeas.lua
@@ -0,0 +1,26 @@
+--[[
+Copyright (c) 2012 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+module(..., package.seeall)
+
+local pth = require('acf.path')
+local map = require('acf.util').map
+
+backend = require('acf.object').class()
+
+function backend:init() self.aug = require('augeas').init() end
+
+function backend:get(path)
+   path = '/'..pth.join(unpack(path))
+   local _, count = self.aug:match(path)
+   if count == 0 then return end
+
+   local value = self.aug:get(path)
+   if value ~= nil then return value end
+
+   return map(pth.name, self.aug:match(path..'/*'))
+end
+
+-- TODO implement set function
diff --git a/acf/persistence/backends/files.lua b/acf/persistence/backends/files.lua
new file mode 100644
index 0000000..8e59ab9
--- /dev/null
+++ b/acf/persistence/backends/files.lua
@@ -0,0 +1,68 @@
+--[[
+Copyright (c) 2012 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+module(..., package.seeall)
+
+local pth = require('acf.path')
+local util = require('acf.persistence.util')
+
+require 'lfs'
+
+
+backend = require('acf.object').class()
+
+-- TODO cache expiration
+function backend:init() self.cache = {} end
+
+function backend:get(path)
+   local name = pth.join('/', unpack(path))
+
+   if not self.cache[name] then
+      local attrs = lfs.attributes(name)
+      if not attrs then return end
+
+      if attrs.mode == 'file' then
+	 self.cache[name] = util.read_file(name)
+
+      elseif attrs.mode == 'directory' then
+	 local res = {}
+	 for fname in lfs.dir(name) do
+	    if not ({['.']=true, ['..']=true})[fname] then
+	       table.insert(res, fname)
+	    end
+	 end
+	 return res
+
+      else error('Unsupported file type: '..name) end
+
+      -- TODO present symlinks as references
+   end
+
+   return self.cache[name]
+end
+
+function backend:set(mods)
+   for _, mod in pairs(mods) do
+      local path, t, value = unpack(mod)
+      local name = pth.join('/', unpack(path))
+
+      -- TODO save references (t == 'reference') as symlinks
+
+      if not t then
+	 -- TODO del files & dirs
+	 print('DEL', name)
+
+      elseif t == 'table' then
+	 lfs.mkdir(name)
+
+      else
+	 local file = util.open_file(name, 'w')
+	 file:write(value)
+	 file:close()
+
+	 self.cache[name] = value
+      end
+   end
+end
diff --git a/acf/persistence/backends/json.lua b/acf/persistence/backends/json.lua
new file mode 100644
index 0000000..7300ce9
--- /dev/null
+++ b/acf/persistence/backends/json.lua
@@ -0,0 +1,110 @@
+--[[
+Copyright (c) 2012 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+module(..., package.seeall)
+
+local pth = require('acf.path')
+local util = require('acf.persistence.util')
+local copy = require('acf.util').copy
+
+require 'json'
+require 'lfs'
+
+
+local function keys(tbl)
+   local res = {}
+   for k, v in pairs(tbl) do table.insert(res, k) end
+   return res
+end
+
+
+backend = require('acf.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('/', 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 attrs = lfs.attributes(fpath)
+      if not attrs or not ({directory=true, file=true})[attrs.mode] then
+	 error('File or directory does not exist: '..fpath)
+      end
+
+      if attrs.mode == 'file' then return fpath, jpath end
+
+      assert(#jpath > 0)
+   end
+end
+
+function backend:_get(path)
+   local fpath, jpath = self:split_path(path)
+
+   if not self.cache[fpath] then
+      self.cache[fpath] = json.decode(util.read_file(fpath))
+   end
+
+   local res = self.cache[fpath]
+
+   while #jpath > 0 do
+      if res == nil then return end
+      assert(type(res) == 'table')
+      local next = jpath[1]
+      res = res[tonumber(next) or next]
+      table.remove(jpath, 1)
+   end
+
+   return res
+end
+
+function backend:get(path)
+   local res = self:_get(path)
+   return type(res) == 'table' and keys(res) or res
+end
+
+function backend:set(mods)
+   local dirty = {}
+
+   for _, mod in ipairs(mods) do
+      local p, t, value = unpack(mod)
+      local fpath, jpath = self:split_path(p)
+      if t == 'table' then value = {} end
+
+      if #jpath == 0 then self.cache[fpath] = value
+
+      else
+	 local comps = copy(p)
+	 local name = comps[#comps]
+	 table.remove(comps)
+	 self:_get(comps)[tonumber(name) or name] = value
+      end
+
+      dirty[fpath] = true
+   end
+
+   for path, _ in pairs(dirty) do
+      local file = util.open_file(path, 'w')
+      file:write(json.encode(self.cache[path]))
+      file:close()
+   end
+end