[flow] do not use efn

lib/index/core/compact.coffee

@@ -38,19 +38,23 @@ exports.compact = (_callback) ->
     process.nextTick ->
       _callback and _callback err, data
 
-  efn = utils.efn callback
-
   if @lock(=> @compact _callback)
     return
 
   iterate = (callback) ->
-    efn((err, page) ->
+    (err, page) ->
+      if err
+        return @paralell() err
+
       in_leaf = page[0] && page[0][2]
       fns = page.map (item) ->
         ->
-          step (->
+          step ->
             storage.read item[1], @parallel()
-          ), efn((err, data) ->
+          , (err, data) ->
+            if err
+              return @parallel() err
+
             if in_leaf
               # data is actual value
               # remove old revision referense
@@ -59,31 +63,46 @@ exports.compact = (_callback) ->
               return
 
             iterate(@parallel()) null, data
-          ), efn((err, new_pos) ->
+          , (err, new_pos) ->
+            if err
+              return @parallel() err
+
             item[1] = new_pos
             @parallel() null
-          ), @parallel()
+          , @parallel()
+
+      fns.push (err) ->
+        if err
+          return @parallel() err
 
-      fns.push(efn (err) ->
         storage.write page, @parallel()
-      )
+
       fns.push callback
 
       step.apply null, fns
-    )
+
 
-  step (->
+  step ->
     # will allow storage controller
     # to prepare it for
     storage.beforeCompact && storage.beforeCompact @parallel()
     @parallel() null
-  ), efn((err) ->
+  , (err) ->
+    if err
+      return @parallel() err
+
     storage.readRoot iterate @parallel()
-  ), efn((err, new_root_pos) ->
+  , (err, new_root_pos) ->
+    if err
+      return @parallel() err
+
     storage.writeRoot new_root_pos, @parallel()
-  ), efn((err) ->
+  , (err) ->
+    if err
+      return @parallel() err
+
     # @will allow storage to finalize all actions
     storage.afterCompact && storage.afterCompact @parallel()
     @parallel() null
-  ), callback
+  , callback
 

lib/index/core/get.coffee

@@ -34,9 +34,10 @@ step = require 'step'
 exports.get = (key, callback) ->
   sort = @sort
   storage = @storage
-  efn = utils.efn callback
 
-  iterate = efn (err, index) ->
+  iterate = (err, index) ->
+    if err
+      return callback err
 
     item_index = utils.search index, sort, key
     item = index[item_index]
@@ -53,7 +54,10 @@ exports.get = (key, callback) ->
         return callback 'Not found'
 
       # Read actual value
-      storage.read value, efn (err, value) ->
+      storage.read value, (err, value) ->
+        if err
+          return callback err
+
         # value = [value, link-to-previous-value]
         callback null, value[0]
     else
@@ -81,15 +85,16 @@ exports.traverse = (filter) ->
   filter = filter || (kp, callback) -> callback(null, true)
 
   process.nextTick =>
-    efn = utils.efn (err) ->
-      promise.emit 'error', err
-      promise.emit 'end'
-
     sort = @sort
     storage = @storage
 
     iterate = (callback) ->
-      efn (err, page) ->
+      (err, page) ->
+        if err
+          promise.emit 'error', err
+          promise.emit 'end'
+          return
+
         index = -1
         pagelen = page.length
 

lib/index/core/set.coffee

@@ -48,8 +48,6 @@ exports.set = (key, value, _callback) ->
       _callback and _callback err, data
 
 
-  efn = utils.efn callback
-
   iterate = (page, callback) ->
     item_index = utils.search page, sort, key
     item = page[item_index]
@@ -60,9 +58,15 @@ exports.set = (key, value, _callback) ->
       # Read next page and try to insert kv in it
       step ->
         storage.read item[1], @parallel()
-      , efn((err, page) ->
+      , (err, page) ->
+        if err
+          return @parallel() err
+
         iterate page, @parallel()
-      ), efn((err, result) ->
+      , (err, result) ->
+        if err
+          return @parallel() err
+
         if storage.isPosition result
           # Page is just should be overwrited
           page[item_index][1] = result
@@ -80,7 +84,7 @@ exports.set = (key, value, _callback) ->
                       [result.middle_key, result.right_page]
 
           splitPage false, storage, order, page, callback
-      )
+
     else
       # Leaf
       step ->
@@ -91,34 +95,49 @@ exports.set = (key, value, _callback) ->
             return
 
           # Invoke conflictManager
-          step (->
+          step ->
             storage.read item[1], @parallel()
-          ), efn((err, old_value) ->
+          , (err, old_value) ->
+            if err
+              return @parallel() err
+
             @parallel() null, old_value
             that.conflictManager old_value, value, @parallel()
-          ), @parallel()
+          , @parallel()
 
           return
 
         @parallel() null, value
-      , efn((err, value, old_value) ->
+      , (err, value, old_value) ->
+        if err
+          return @parallel() err
+
         # Value should be firstly written in storage
         item_index = if item_index is null then 0 else item_index + 1
         storage.write [value, old_value], @parallel()
-      ), efn((err, value) ->
+      , (err, value) ->
+        if err
+          return @parallel() err
+
         # Than inserted in leaf page
         page.splice item_index, 0, [key, value, 1]
 
         splitPage true, storage, order, page, callback
-      )
+
 
   step ->
     # Read initial data
     storage.readRoot @parallel()
-  , efn((err, root) ->
+  , (err, root) ->
+    if err
+      return @parallel() err
+
     # Initiate sequence
     iterate root, @parallel()
-  ), efn((err, result) ->
+  , (err, result) ->
+    if err
+      return @parallel() err
+
     if storage.isPosition result
       # Write new root
       @parallel() null, result
@@ -128,9 +147,12 @@ exports.set = (key, value, _callback) ->
         [null, result.left_page],
         [result.middle_key, result.right_page]
       ], @parallel()
-  ), efn((err, new_root_pos) ->
+  , (err, new_root_pos) ->
+    if err
+      return @parallel() err
+
     storage.writeRoot new_root_pos, @parallel()
-  ), efn(callback)
+  , callback
 
 ###
   Check page length

lib/index/core/unset.coffee

@@ -36,7 +36,6 @@ exports.unset = (key, _callback) ->
     process.nextTick ->
       _callback and _callback err, data
 
-  efn = utils.efn callback
   storage = @storage
   sort = @sort
 
@@ -67,20 +66,26 @@ exports.unset = (key, _callback) ->
       page.splice item_index, 1
       if page.length > 0
         # If resulting page isn't empty
-        step (->
+        step ->
           storage.write page, @parallel()
-        ), efn(callback)
+        , callback
         return
 
       # Notify that item should be removed from parent index
       callback null, false
     else
       # Index page
-      step (->
+      step ->
         storage.read item[1], @parallel()
-      ), efn((err, page) ->
+      , (err, page) ->
+        if err
+          return @parallel() err
+
         iterate page, @parallel()
-      ), efn((err, result) ->
+      , (err, result) ->
+        if err
+          return @parallel() err
+
         if result is false
           # Delete item from index page
           page.splice item_index, 1
@@ -93,16 +98,22 @@ exports.unset = (key, _callback) ->
           callback null
           return
 
-        step (->
+        step ->
           storage.write page, @parallel()
-        ), efn(callback)
-      )
+        , callback
+
 
-  step (->
+  step ->
     storage.readRoot @parallel()
-  ), efn((err, root) ->
+  , (err, root) ->
+    if err
+      return @parallel() err
+
     iterate root, @parallel()
-  ), efn((err, result) ->
+  , (err, result) ->
+    if err
+      return @parallel() err
+
     if result is false
       # Create new root
       storage.write [], @parallel()
@@ -111,10 +122,13 @@ exports.unset = (key, _callback) ->
       @parallel() null, result
     else
       @parallel() null
-  ), efn((err, position) ->
+  , (err, position) ->
+    if err
+      return @parallel() err
+
     if storage.isPosition position
       storage.writeRoot position, @parallel()
     else
       @parallel() null
-  ), callback
+  , callback
 

lib/index/utils.coffee

@@ -71,21 +71,6 @@ utils.search = (index, sort, key) ->
   else
     null
 
-###
-  Wrapper for asynchronous callback
-###
-utils.efn = (callback) ->
-  (fn) ->
-    # Callback can be empty
-    unless fn
-      fn = -> null
-
-    (err) ->
-      if err
-        return callback err
-
-      fn.apply @, arguments
-
 ###
   Hash function wrapper
 ###