transaction: split Transaction class into two parts

model-dependent functions moved to ModelTransaction

4 files changed, 251 insertions, 226 deletions

diff --git a/acf2/persistence/init.lua b/acf2/persistence/init.lua
index 74ca447..fee408a 100644
--- a/acf2/persistence/init.lua
+++ b/acf2/persistence/init.lua
@@ -1,10 +1,8 @@
 --[[
-Copyright (c) 2012-2013 Kaarle Ritvanen
+Copyright (c) 2012-2014 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
-local M = {}
-
 local loadmods = require('acf2.loader')
 local topology = require('acf2.model.root').topology
 local object = require('acf2.object')
@@ -18,7 +16,7 @@ local stringy = require('stringy')
 
 
 local DataStore = object.class(
-   require('acf2.transaction.backend').TransactionBackend
+   require('acf2.transaction.base').TransactionBackend
 )
 
 function DataStore:init()
diff --git a/acf2/transaction/backend.lua b/acf2/transaction/backend.lua
deleted file mode 100644
index 79ea83a..0000000
--- a/acf2/transaction/backend.lua
+++ /dev/null
@@ -1,70 +0,0 @@
---[[
-Copyright (c) 2012-2013 Kaarle Ritvanen
-See LICENSE file for license details
---]]
-
-local M = {}
-
-local err = require('acf2.error')
-
--- TODO each transaction backend (i.e. persistence manager or
--- transaction proper) should be implemented as a thread or have its
--- internal state stored in shared storage (with appropriate locking)
-
-
-local generation = 0
-function M.gen_number()
-   generation = generation + 1
-   return generation
-end
-
-
-M.TransactionBackend = require('acf2.object').class()
-
-function M.TransactionBackend:init() self.mod_time = {} end
-
-function M.TransactionBackend:get_if_older(path, timestamp)
-   local value, ts = self:get(path)
-   if ts > timestamp then err.raise('conflict', path) end
-   return value, ts
-end
-
-function M.TransactionBackend:set(path, value)
-   self:set_multiple{{path, value}}
-end
-
-function M.TransactionBackend:set_multiple(mods)
-   -- TODO delegate to PM backends?
-   local timestamp = M.gen_number()
-   local effective = {}
-
-   local function tostr(s) return s ~= nil and tostring(s) or nil end
-
-   for _, mod in ipairs(mods) do
-      local path, value = unpack(mod)
-
-      if type(value) == 'table' or type(
-	 self:get(path)
-      ) == 'table' or self:get(path) ~= value then
-
-	 table.insert(effective, mod)
-	 self.mod_time[path] = timestamp
-      end
-   end
-
-   self:_set_multiple(effective)
-end
-
--- TODO should be atomic, mutex with set_multiple
-function M.TransactionBackend:comp_and_setm(accessed, mods)
-   local errors = err.ErrorDict()
-   for path, timestamp in pairs(accessed) do
-      errors:collect(self.get_if_older, self, path, timestamp)
-   end
-   errors:raise()
-
-   self:set_multiple(mods)
-end
-
-
-return M
diff --git a/acf2/transaction/base.lua b/acf2/transaction/base.lua
new file mode 100644
index 0000000..142b0a5
--- /dev/null
+++ b/acf2/transaction/base.lua
@@ -0,0 +1,221 @@
+--[[
+Copyright (c) 2012-2014 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+local M = {}
+
+local err = require('acf2.error')
+
+local object = require('acf2.object')
+local class = object.class
+
+local pth = require('acf2.path')
+local copy = require('acf2.util').copy
+
+-- TODO each transaction backend (i.e. persistence manager or
+-- transaction proper) should be implemented as a thread or have its
+-- internal state stored in shared storage (with appropriate locking)
+
+
+local generation = 0
+local function gen_number()
+   generation = generation + 1
+   return generation
+end
+
+
+M.TransactionBackend = class()
+
+function M.TransactionBackend:init() self.mod_time = {} end
+
+function M.TransactionBackend:get_if_older(path, timestamp)
+   local value, ts = self:get(path)
+   if ts > timestamp then err.raise('conflict', path) end
+   return value, ts
+end
+
+function M.TransactionBackend:set(path, value)
+   self:set_multiple{{path, value}}
+end
+
+function M.TransactionBackend:set_multiple(mods)
+   -- TODO delegate to PM backends?
+   local timestamp = gen_number()
+   local effective = {}
+
+   local function tostr(s) return s ~= nil and tostring(s) or nil end
+
+   for _, mod in ipairs(mods) do
+      local path, value = unpack(mod)
+
+      if type(value) == 'table' or type(
+	 self:get(path)
+      ) == 'table' or self:get(path) ~= value then
+
+	 table.insert(effective, mod)
+	 self.mod_time[path] = timestamp
+      end
+   end
+
+   self:_set_multiple(effective)
+end
+
+-- TODO should be atomic, mutex with set_multiple
+function M.TransactionBackend:comp_and_setm(accessed, mods)
+   local errors = err.ErrorDict()
+   for path, timestamp in pairs(accessed) do
+      errors:collect(self.get_if_older, self, path, timestamp)
+   end
+   errors:raise()
+
+   self:set_multiple(mods)
+end
+
+
+
+local function remove_list_value(list, value)
+   value = tostring(value)
+
+   for i, v in ipairs(list) do
+      if tostring(v) == value then
+	 table.remove(list, i)
+	 return
+      end
+   end
+end
+
+
+M.Transaction = class(M.TransactionBackend)
+
+function M.Transaction:init(backend)
+   object.super(self, M.Transaction):init()
+
+   self.backend = backend
+
+   self.started = gen_number()
+   self.access_time = {}
+
+   self.added = {}
+   self.modified = {}
+   self.deleted = {}
+end
+
+function M.Transaction:get(path)
+   if self.deleted[path] then return nil, self.mod_time[path] end
+   for _, tbl in ipairs{self.added, self.modified} do
+      if tbl[path] ~= nil then
+	 return copy(tbl[path]), self.mod_time[path]
+      end
+   end
+
+   local value, timestamp = self.backend:get_if_older(path, self.started)
+   self.access_time[path] = timestamp
+   return value, timestamp
+end
+
+function M.Transaction:_set_multiple(mods)
+
+   local function set(path, value, new)
+      local delete = value == nil
+
+      if self.added[path] == nil and (not new or self.deleted[path]) then
+	 self.modified[path] = value
+	 self.deleted[path] = delete
+      else self.added[path] = value end
+   end
+
+   for _, mod in ipairs(mods) do
+      local path, value = unpack(mod)
+
+      local ppath = pth.parent(path)
+      local parent = self:get(ppath)
+      if parent == nil then
+	 parent = {}
+	 self:set(ppath, parent)
+      end
+
+      local name = pth.name(path)
+      local old = self:get(path)
+
+      local is_table = type(value) == 'table'
+      local delete = value == nil
+
+      if delete then self:check_deleted(path) end
+
+      if type(old) == 'table' then
+	 if delete then
+	    for _, child in ipairs(old) do self:set(pth.join(path, child)) end
+	 elseif is_table then return
+	 elseif #old > 0 then
+	    error('Cannot assign a primitive value to non-leaf node '..path)
+	 end
+      end
+
+      if is_table then value = {} end
+      set(path, value, old == nil)
+
+      local function set_parent()
+	 set(ppath, parent)
+	 self.mod_time[ppath] = self.mod_time[path]
+      end
+
+      if old == nil and not delete then
+	 table.insert(parent, name)
+	 set_parent()
+      elseif old ~= nil and delete then
+	 remove_list_value(parent, name)
+	 set_parent()
+      end
+   end
+end
+
+function M.Transaction:check_deleted(path) end
+
+function M.Transaction:commit()
+   local mods = {}
+   local handled = {}
+
+   local function insert(path, value)
+      assert(not handled[path])
+      table.insert(mods, {path, value})
+      handled[path] = true
+   end
+
+   local function insert_add(path)
+      if not handled[path] then
+	 local pp = pth.parent(path)
+	 if self.added[pp] then insert_add(pp) end
+	 insert(path, self.added[path])
+      end
+   end
+
+   local function insert_del(path)
+      if not handled[path] then
+	 local value = self.backend:get(path)
+	 if type(value) == 'table' then
+	    for _, child in ipairs(value) do
+	       local cp = pth.join(path, child)
+	       assert(self.deleted[cp])
+	       insert_del(cp)
+	    end
+	 end
+	 insert(path)
+      end
+   end
+
+   for path, deleted in pairs(self.deleted) do
+      if deleted then insert_del(path) end
+   end
+
+   for path, value in pairs(self.modified) do
+      if type(value) ~= 'table' then insert(path, value) end
+   end
+
+   for path, _ in pairs(self.added) do insert_add(path) end
+
+   self.backend:comp_and_setm(self.access_time, mods)
+end
+
+
+return M
diff --git a/acf2/transaction/init.lua b/acf2/transaction/init.lua
index ec8da59..482c00e 100644
--- a/acf2/transaction/init.lua
+++ b/acf2/transaction/init.lua
@@ -1,5 +1,5 @@
 --[[
-Copyright (c) 2012-2013 Kaarle Ritvanen
+Copyright (c) 2012-2014 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
@@ -10,37 +10,17 @@ local object = require('acf2.object')
 local super = object.super
 
 local pth = require('acf2.path')
-local be_mod = require('acf2.transaction.backend')
 
 local util = require('acf2.util')
 local copy = util.copy
 
 
-local function remove_list_value(list, value)
-   value = tostring(value)
+local ModelTransaction = object.class(
+   require('acf2.transaction.base').Transaction
+)
 
-   for i, v in ipairs(list) do
-      if tostring(v) == value then
-	 table.remove(list, i)
-	 return
-      end
-   end
-end
-
-
-local Transaction = object.class(be_mod.TransactionBackend)
-
-function Transaction:init(backend, validate)
-   super(self, Transaction):init()
-
-   self.backend = backend
-
-   self.started = be_mod.gen_number()
-   self.access_time = {}
-
-   self.added = {}
-   self.modified = {}
-   self.deleted = {}
+function ModelTransaction:init(backend, validate)
+   super(self, ModelTransaction):init(backend)
 
    self.validate = validate
    self.validable = {}
@@ -48,29 +28,21 @@ function Transaction:init(backend, validate)
    self.root = root.RootModel(self)
 end
 
-function Transaction:committing() return self.commit_val and true or false end
+function ModelTransaction:committing()
+   return self.commit_val and true or false
+end
 
-function Transaction:check()
+function ModelTransaction:check()
    if not self.backend then error('Transaction already committed') end
 end
 
-function Transaction:get(path)
+function ModelTransaction:get(path)
    self:check()
-
-   if self.deleted[path] then return nil, self.mod_time[path] end
-   for _, tbl in ipairs{self.added, self.modified} do
-      if tbl[path] ~= nil then
-	 return copy(tbl[path]), self.mod_time[path]
-      end
-   end
-   
-   local value, timestamp = self.backend:get_if_older(path, self.started)
-   self.access_time[path] = timestamp
-   return value, timestamp
+   return super(self, ModelTransaction):get(path)
 end
 
-function Transaction:set_multiple(mods)
-   super(self, Transaction):set_multiple(mods)
+function ModelTransaction:set_multiple(mods)
+   super(self, ModelTransaction):set_multiple(mods)
    for _, mod in ipairs(mods) do
       local addr, value = unpack(mod)
       if value == nil then
@@ -93,79 +65,25 @@ function Transaction:set_multiple(mods)
    end
 end
 
-function Transaction:_set_multiple(mods)
-
-   local function set(path, value, new)
-      local delete = value == nil
-
-      if self.added[path] == nil and (not new or self.deleted[path]) then
-	 self.modified[path] = value
-	 self.deleted[path] = delete
-      else self.added[path] = value end
-   end
-
-   for _, mod in ipairs(mods) do
-      local path, value = unpack(mod)
-
-      local ppath = pth.parent(path)
-      local parent = self:get(ppath)
-      if parent == nil then
-	 parent = {}
-	 self:set(ppath, parent)
-      end
-
-      local name = pth.name(path)
-      local old = self:get(path)
-
-      local is_table = type(value) == 'table'
-      local delete = value == nil
-
-      if delete then
-	 -- assume one-level refs for now
-	 local top = root.topology(ppath)
-	 if top then
-	    local errors = ErrorDict()
-	    for _, refs in ipairs(top.referrers) do
-	       for _, ref in ipairs(self.root:search_refs(refs)) do
-		  errors:collect(ref.deleted, ref, path)
-	       end
-	    end
-	    errors:raise()
-	 end
-      end
-
-      if type(old) == 'table' then
-	 if delete then
-	    for _, child in ipairs(old) do self:set(pth.join(path, child)) end
-	 elseif is_table then return
-	 elseif #old > 0 then
-	    error('Cannot assign a primitive value to non-leaf node '..path)
+function ModelTransaction:check_deleted(path)
+   -- assume one-level refs for now
+   local top = root.topology(pth.parent(path))
+   if top then
+      local errors = ErrorDict()
+      for _, refs in ipairs(top.referrers) do
+	 for _, ref in ipairs(self.root:search_refs(refs)) do
+	    errors:collect(ref.deleted, ref, path)
 	 end
       end
-
-      if is_table then value = {} end
-      set(path, value, old == nil)
-
-      local function set_parent()
-	 set(ppath, parent)
-	 self.mod_time[ppath] = self.mod_time[path]
-      end
-
-      if old == nil and not delete then
-	 table.insert(parent, name)
-	 set_parent()
-      elseif old ~= nil and delete then
-	 remove_list_value(parent, name)
-	 set_parent()
-      end
+      errors:raise()
    end
 end
 
-function Transaction:fetch(path) return self.root:fetch(path) end
+function ModelTransaction:fetch(path) return self.root:fetch(path) end
 
-function Transaction:meta(path) return self.root:meta(path) end
+function ModelTransaction:meta(path) return self.root:meta(path) end
 
-function Transaction:commit()
+function ModelTransaction:commit()
    self:check()
 
    if self.validate then
@@ -184,49 +102,7 @@ function Transaction:commit()
       errors:raise()
    end
 
-   local mods = {}
-   local handled = {}
-
-   local function insert(path, value)
-      assert(not handled[path])
-      table.insert(mods, {path, value})
-      handled[path] = true
-   end
-
-   local function insert_add(path)
-      if not handled[path] then
-	 local pp = pth.parent(path)
-	 if self.added[pp] then insert_add(pp) end
-	 insert(path, self.added[path])
-      end
-   end
-
-   local function insert_del(path)
-      if not handled[path] then
-	 local value = self.backend:get(path)
-	 if type(value) == 'table' then
-	    for _, child in ipairs(value) do
-	       local cp = pth.join(path, child)
-	       assert(self.deleted[cp])
-	       insert_del(cp)
-	    end
-	 end
-	 insert(path)
-      end
-   end
-
-   for path, deleted in pairs(self.deleted) do
-      if deleted then insert_del(path) end
-   end
-
-   for path, value in pairs(self.modified) do
-      if type(value) ~= 'table' then insert(path, value) end
-   end
-
-   for path, _ in pairs(self.added) do insert_add(path) end
-
-   self.backend:comp_and_setm(self.access_time, mods)
-
+   super(self, ModelTransaction):commit()
 
    if not self.validate then
       util.update(self.backend.validable, self.validable)
@@ -239,5 +115,5 @@ end
 local store = require('acf2.persistence')
 
 return function(txn, defer_validation)
-	  return Transaction(txn or store, not (txn and defer_validation))
+	  return ModelTransaction(txn or store, not (txn and defer_validation))
        end