refactor parallel code

openos/apis/filesystem.lua

@@ -0,0 +1,59 @@
+local fs = _G.fs
+
+local function get(path)
+  local label = fs.getDrive(path)
+
+  if label then
+    local proxy = {
+      getLabel = function() return label end,
+      isReadOnly = function() return fs.isReadOnly(path) end,
+      spaceTotal = function() return fs.getSize(path, true) + fs.getFreeSpace(path) end,
+      spaceUsed = function() return fs.getSize(path, true) end,
+    }
+    return proxy, path
+  end
+end
+
+local function mounts()
+  local t = {
+    [ fs.getDrive('/') ] = '/'
+  }
+  for _,path in pairs(fs.list('/')) do
+    local label = fs.getDrive(path)
+    if not t[label] then
+      t[label] = path
+    end
+  end
+
+  return function()
+    local label, path = next(t)
+    if label then
+      t[label] = nil
+      return get(path)
+    end
+  end
+end
+
+local function list(path)
+  local set = fs.list(path)
+  return function()
+    local key, value = next(set)
+    set[key or false] = nil
+    return value
+  end
+end
+
+return {
+  canonical = function(...) return ... end,
+  concat = fs.combine,
+  exists = fs.exists,
+  get = get,
+  isDirectory = fs.isDir,
+  isLink = function() return false end,
+  list = list,
+  mounts = mounts,
+  name = fs.getName,
+  open = function(n, m) return fs.open(n, m or 'r') end,
+  realPath = function(...) return ... end,
+  size = fs.getSize,
+}