forward relevant error messages to client

11 files changed, 171 insertions, 34 deletions

diff --git a/acf/error.lua b/acf/error.lua
new file mode 100644
index 0000000..26dfb86
--- /dev/null
+++ b/acf/error.lua
@@ -0,0 +1,97 @@
+--[[
+Copyright (c) 2012-2013 Kaarle Ritvanen
+See LICENSE file for license details
+--]]
+
+module(..., package.seeall)
+
+local object = require('acf.object')
+local class = object.class
+
+local util = require('acf.util')
+
+require 'json'
+
+
+local function pack(...) return arg end
+
+
+local ErrorTable = class()
+
+function ErrorTable:init() self.errors = {} end
+
+function ErrorTable:success() return not next(self.errors) end
+
+function ErrorTable:raise()
+   if not self:success() then error(json.encode(self.errors)) end
+end
+
+
+ErrorList = class(ErrorTable)
+
+function ErrorList:init(label)
+   object.super(self, ErrorList):init()
+   self.label = label
+end
+
+function ErrorList:insert(msg)
+   table.insert(util.setdefault(self.errors, self.label, {}), msg)
+end
+
+
+ErrorDict = class(ErrorTable)
+
+function ErrorDict:collect(func, ...)
+   local function pack(success, ...)
+      return success, success and arg or arg[1]
+   end
+
+   local success, res = pack(
+      xpcall(
+	 function() return func(unpack(arg)) end,
+	 function(err)
+	    local _, _, data = string.find(err, '.-: (.+)')
+	    local success, res = pcall(json.decode, data)
+	    if success and type(res) == 'table' then return res end
+	    return data..'\n'..debug.traceback()
+	 end
+      )
+   )
+
+   if success then return unpack(res) end
+
+   if type(res) == 'table' then
+      for label, errors in pairs(res) do
+	 for _, err in ipairs(errors) do
+	    table.insert(util.setdefault(self.errors, label, {}), err)
+	 end
+      end
+   else error(res) end
+end
+
+
+function raise(label, msg)
+   local err = ErrorList(label)
+   err:insert(msg)
+   err:raise()
+end
+
+function relabel(label, ...)
+   local err = ErrorDict()
+   local res = pack(err:collect(unpack(arg)))
+   if err:success() then return unpack(res) end
+
+   elist = ErrorList(label)
+   for lbl, el in pairs(err.errors) do
+      for _, e in ipairs(el) do elist:insert(lbl..': '..e) end
+   end
+   elist:raise()
+end
+
+function call(...)
+   local err = ErrorDict()
+   local res = pack(err:collect(unpack(arg)))
+   if err:success() then return true, unpack(res) end
+   if err.errors.system then error(err.errors.system[1]) end
+   return false, err.errors
+end
diff --git a/acf/init.lua b/acf/init.lua
index 3358571..8f89c08 100644
--- a/acf/init.lua
+++ b/acf/init.lua
@@ -1,5 +1,5 @@
 --[[
-Copyright (c) 2012 Kaarle Ritvanen
+Copyright (c) 2012-2013 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
@@ -8,6 +8,7 @@ module(..., package.seeall)
 require('acf.util').loadmods('modules')
 
 require 'acf.model'
+call = require('acf.error').call
 require 'acf.object'
 require 'acf.path'
 require 'acf.transaction'
diff --git a/acf/model/field.lua b/acf/model/field.lua
index d2e62a5..e1bdeaf 100644
--- a/acf/model/field.lua
+++ b/acf/model/field.lua
@@ -1,10 +1,13 @@
 --[[
-Copyright (c) 2012 Kaarle Ritvanen
+Copyright (c) 2012-2013 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
 module(..., package.seeall)
 
+local err = require('acf.error')
+local raise = err.raise
+
 local node = require('acf.model.node')
 
 local object = require('acf.object')
@@ -63,10 +66,10 @@ end
 
 function Field:_validate(txn, path, value)
    if self.required and value == nil then
-      error('Required value not set: '..path)
+      raise(path, 'Required value not set')
    end
    if self.choice and value ~= nil and not contains(self.choice, value) then
-      error('Invalid value for '..path..': '..value)
+      raise(path, 'Invalid value')
    end
    if value ~= nil then self:validate(txn, path, value) end
    return value
@@ -92,16 +95,27 @@ function TreeNode:save(txn, path, addr, value)
 
    if object.isinstance(value, node.TreeNode) then
       -- TODO clone if TreeNode has wrong path
-      assert(node.path(value) == path)
+      if node.path(value) ~= path then
+	 raise(path, 'Attempted to assign foreign object as value')
+      end
       return
    end
 
    txn:set(addr)
+
    if value then
-      assert(type(value) == 'table')
+      if type(value) ~= 'table' then
+	 raise(path, 'Cannot assign primitive value')
+      end
+
       txn:set(addr, 'table')
       local new = self:load(txn, path, addr, true)
-      for k, v in pairs(value) do new[k] = v end
+
+      local errors = err.ErrorDict()
+      for k, v in pairs(value) do
+	 errors:collect(function() new[k] = v end)
+      end
+      errors:raise()
    end
 end
 
diff --git a/acf/model/init.lua b/acf/model/init.lua
index f333886..44b1f5e 100644
--- a/acf/model/init.lua
+++ b/acf/model/init.lua
@@ -5,6 +5,10 @@ See LICENSE file for license details
 
 module(..., package.seeall)
 
+error = require('acf.error')
+local raise = error.raise
+local relabel = error.relabel
+
 local fld = require('acf.model.field')
 local Field = fld.Field
 
@@ -34,7 +38,7 @@ local Primitive = class(Field)
 
 function Primitive:validate(txn, path, value)
    local t = self.dtype
-   if type(value) ~= t then error('Not a '..t..': '..tostring(value)) end
+   if type(value) ~= t then raise(path, 'Not a '..t) end
 end
 
 
@@ -48,7 +52,7 @@ end
 function String:validate(txn, path, value)
    super(self, String):validate(txn, path, value)
    if self['max-length'] and string.len(value) > self['max-length'] then
-      error('Maximum length exceeded: '..value)
+      raise(path, 'Maximum length exceeded')
    end
 end
 
@@ -79,7 +83,7 @@ Integer = class(Number)
 
 function Integer:validate(txn, path, value)
    super(self, Integer):validate(txn, path, value)
-   if math.floor(value) ~= value then error('Not an integer: '..value) end
+   if math.floor(value) ~= value then raise(path, 'Not an integer') end
 end
 
 
@@ -101,7 +105,7 @@ end
 
 function Range:validate(txn, path, value)
    local comps = stringy.split(value, '-')
-   if #comps > 2 then error('Invalid range') end
+   if #comps > 2 then raise(path, 'Invalid range') end
    for _, v in ipairs(comps) do
       to_field(self.type):_validate(txn, path, v)
    end
@@ -124,8 +128,9 @@ function Reference:meta(txn, path, addr)
    local res = super(self, Reference):meta(txn, path, addr)
    res.scope = self:abs_scope(path)
 
-   local base = txn:search(res.scope)
-   local objs = base and txn:get(getmetatable(base).addr) or {}
+   local objs = txn:get(
+      getmetatable(relabel('system', txn.search, txn, res.scope)).addr
+   ) or {}
    res.choice = map(function(p) return pth.join(res.scope, p) end, objs)
    res['ui-choice'] = objs
 
@@ -153,17 +158,18 @@ function Reference:_validate(txn, path, value)
       local scope = self:abs_scope(path)
       local prefix = scope..'/'
       if not stringy.startswith(value, prefix) then
-	 error('Reference out of scope ('..scope..')')
+	 raise(path, 'Reference out of scope ('..scope..')')
       end
       value = string.sub(value, string.len(prefix) + 1, -1)
    end
 
    -- assume one-level ref for now
-   assert(not string.find(value, '/'))
-   if not self:follow(txn, path, value) then
-      error('Does not exist: '..value)
+   if string.find(value, '/') then
+      raise(path, 'Subtree references not yet supported')
    end
+
    -- TODO check instance type
+   relabel(path, self.follow, self, txn, path, value)
 
    return value
 end
diff --git a/acf/model/model.lua b/acf/model/model.lua
index 2efcb6f..6186d04 100644
--- a/acf/model/model.lua
+++ b/acf/model/model.lua
@@ -1,10 +1,12 @@
 --[[
-Copyright (c) 2012 Kaarle Ritvanen
+Copyright (c) 2012-2013 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
 module(..., package.seeall)
 
+local raise = require('acf.error').raise
+
 local fld = require('acf.model.field')
 local Field = fld.Field
 
@@ -88,7 +90,7 @@ function Model:init(txn, path, addr)
 
    function mt.__newindex(t, k, v)
       local f = mt.field(k)
-      if not f then error('Field named '..k..' does not exist') end
+      if not f then raise(mt.path, 'Field named '..k..' does not exist') end
       f:save(v)
       txn.validate[mt.path] = function() self:validate() end
    end
diff --git a/acf/model/node.lua b/acf/model/node.lua
index 083757c..3459fce 100644
--- a/acf/model/node.lua
+++ b/acf/model/node.lua
@@ -5,6 +5,7 @@ See LICENSE file for license details
 
 module(..., package.seeall)
 
+local raise = require('acf.error').raise
 local object = require('acf.object')
 local class = object.class
 local super = object.super
@@ -51,9 +52,13 @@ end
 
 function TreeNode:search(path)
    if #path == 0 then return self end
-   local next = path[1]
+   local name = path[1]
+   local next = self[name]
+   if next == nil then
+      raise(getmetatable(self).path, 'Subordinate does not exist: '..name)
+   end
    table.remove(path, 1)
-   return TreeNode.search(self[next], path)
+   return TreeNode.search(next, path)
 end
 
 
@@ -65,7 +70,7 @@ function Collection:init(txn, path, addr, field, required)
    if required then
       txn.validate[path] = function()
 			      if #txn:get(addr) == 0 then
-				 error('Collection cannot be empty: '..path)
+				 raise(path, 'Collection cannot be empty')
 			      end
 			   end
    end
@@ -100,7 +105,7 @@ function PrimitiveList:init(txn, path, addr, field, required)
 	 assert(i == tonumber(j))
 	 if mt.field:load(i) == k then return k end
       end
-      error('Value does not exist: '..k)
+      raise(path, 'Value does not exist: '..k)
    end
 end
 
diff --git a/acf/modules/awall.lua b/acf/modules/awall.lua
index 0b73f9c..dbb335a 100644
--- a/acf/modules/awall.lua
+++ b/acf/modules/awall.lua
@@ -21,14 +21,14 @@ function IPv4Addr:validate(txn, path, value)
       end
    end
    if test(string.match(value, '(%d+)%.(%d+)%.(%d+)%.(%d+)')) then
-      error('Invalid IP address: '..value)
+      M.error.raise(path, 'Invalid IP address')
    end
 end
 
 Port = class(M.Integer)
 function Port:validate(txn, path, value)
    super(self, Port):validate(txn, path, value)
-   if value < 0 or value > 65535 then error('Invalid port: '..value) end
+   if value < 0 or value > 65535 then M.error.raise(path, 'Invalid port') end
 end
 
 PortRange = class(M.Range)
diff --git a/acf/persistence/init.lua b/acf/persistence/init.lua
index f674e9c..2533560 100644
--- a/acf/persistence/init.lua
+++ b/acf/persistence/init.lua
@@ -1,5 +1,5 @@
 --[[
-Copyright (c) 2012 Kaarle Ritvanen
+Copyright (c) 2012-2013 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
@@ -39,8 +39,7 @@ function DataStore:set_multiple(mods)
    for _, mod in ipairs(mods) do
       local path, t, value = unpack(mod)
       local backend, comps = self:split_path(path)
-      if not bms[backend] then bms[backend] = {} end
-      table.insert(bms[backend], {comps, t, value})
+      table.insert(util.setdefault(bms, backend, {}), {comps, t, value})
    end
 
    for backend, bm in pairs(bms) do backend:set(bm) end
diff --git a/acf/transaction/backend.lua b/acf/transaction/backend.lua
index 5b8c53f..e907c6f 100644
--- a/acf/transaction/backend.lua
+++ b/acf/transaction/backend.lua
@@ -1,10 +1,12 @@
 --[[
-Copyright (c) 2012 Kaarle Ritvanen
+Copyright (c) 2012-2013 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
 module(..., package.seeall)
 
+local err = require('acf.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)
@@ -23,7 +25,7 @@ function TransactionBackend:init() self.mod_time = {} end
 
 function TransactionBackend:get_if_older(path, timestamp)
    local value, ts = self:get(path)
-   if ts > timestamp then error('Concurrent modification: '..path) end
+   if ts > timestamp then err.raise('conflict', path) end
    return value, ts
 end
 
@@ -41,8 +43,11 @@ end
 
 -- TODO should be atomic, mutex with set_multiple
 function TransactionBackend:comp_and_setm(accessed, mods)
+   local errors = err.ErrorDict()
    for path, timestamp in pairs(accessed) do
-      self:get_if_older(path, timestamp)
+      errors:collect(self.get_if_older, self, path, timestamp)
    end
+   errors:raise()
+
    self:set_multiple(mods)
 end
diff --git a/acf/transaction/init.lua b/acf/transaction/init.lua
index 7f2f6b9..99b8b9d 100644
--- a/acf/transaction/init.lua
+++ b/acf/transaction/init.lua
@@ -1,10 +1,11 @@
 --[[
-Copyright (c) 2012 Kaarle Ritvanen
+Copyright (c) 2012-2013 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
 module(..., package.seeall)
 
+local ErrorDict = require('acf.error').ErrorDict
 local RootModel = require('acf.model').RootModel
 local object = require('acf.object')
 local super = object.super
@@ -121,7 +122,9 @@ function Transaction:search(path) return self.root:search(pth.split(path)) end
 function Transaction:commit()
    self:check()
 
-   for _, func in pairs(self.validate) do func() end
+   local errors = ErrorDict()
+   for path, func in pairs(self.validate) do errors:collect(func) end
+   errors:raise()
 
    local mods = {}
    local handled = {}
diff --git a/acf/util.lua b/acf/util.lua
index cbea072..9788c81 100644
--- a/acf/util.lua
+++ b/acf/util.lua
@@ -1,10 +1,15 @@
 --[[
-Copyright (c) 2012 Kaarle Ritvanen
+Copyright (c) 2012-2013 Kaarle Ritvanen
 See LICENSE file for license details
 --]]
 
 module(..., package.seeall)
 
+function setdefault(t, k, v)
+   if t[k] == nil then t[k] = v end
+   return t[k]
+end
+
 function setdefaults(dst, src)
    for k, v in pairs(src) do if dst[k] == nil then dst[k] = v end end
    return dst