improved handling of nested transactions

add nested transaction support to protocol
allow deferring validation to parent transaction
process each update request within a nested transaction

1 files changed, 25 insertions, 8 deletions

diff --git a/acf/transaction/init.lua b/acf/transaction/init.lua
index eb92c34..e9b8bbc 100644
--- a/acf/transaction/init.lua
+++ b/acf/transaction/init.lua
@@ -11,7 +11,9 @@ local object = require('acf.object')
 local super = object.super
 local pth = require('acf.path')
 local be_mod = require('acf.transaction.backend')
-local copy = require('acf.util').copy
+
+local util = require('acf.util')
+local copy = util.copy
 
 
 local function remove_list_value(list, value)
@@ -30,7 +32,7 @@ end
 
 local Transaction = object.class(be_mod.TransactionBackend)
 
-function Transaction:init(backend)
+function Transaction:init(backend, validate)
    super(self, Transaction):init()
 
    self.backend = backend
@@ -42,7 +44,8 @@ function Transaction:init(backend)
    self.modified = {}
    self.deleted = {}
 
-   self.validate = {}
+   self.validate = validate
+   self.validable = {}
 
    self.root = RootModel(self)
 end
@@ -122,11 +125,15 @@ function Transaction:search(path) return self.root:search(pth.split(path)) end
 function Transaction:commit()
    self:check()
 
-   local errors = ErrorDict()
-   for path, func in pairs(self.validate) do
-      if not self.deleted[path] then errors:collect(func) end
+   if self.validate then
+      local errors = ErrorDict()
+      for path, _ in pairs(copy(self.validable)) do
+	 if not self.deleted[path] then
+	    errors:collect(getmetatable(self:search(path)).validate)
+	 end
+      end
+      errors:raise()
    end
-   errors:raise()
 
    local mods = {}
    local handled = {}
@@ -174,8 +181,18 @@ function Transaction:commit()
    for path, _ in pairs(self.added) do insert_add(path) end
 
    self.backend:comp_and_setm(self.access_time, mods)
+
+
+   if not self.validate then
+      util.update(self.backend.validable, self.validable)
+   end
+   
    self.backend = nil
 end
 
+
 local store = require('acf.persistence').DataStore()
-function start(txn) return Transaction(txn or store) end
+
+function start(txn, defer_validation)
+   return Transaction(txn or store, not (txn and defer_validation))
+end