Replaces awesome_nested_set gem with a simple and more robust implementation of nested sets.

The concurrency tests added in this commit trigger dead locks and/or nested set inconsistency with awesome_nested_set.

git-svn-id: http://svn.redmine.org/redmine/trunk@13841 e93f8b46-1217-0410-a6f0-8f06a7374b81

1 files changed, 159 insertions, 0 deletions

diff --git a/lib/redmine/nested_set/project_nested_set.rb b/lib/redmine/nested_set/project_nested_set.rb
new file mode 100644
index 000000000..699927508
--- /dev/null
+++ b/lib/redmine/nested_set/project_nested_set.rb
@@ -0,0 +1,159 @@
+# Redmine - project management software
+# Copyright (C) 2006-2014  Jean-Philippe Lang
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+module Redmine
+  module NestedSet
+    module ProjectNestedSet
+      def self.included(base)
+        base.class_eval do
+          belongs_to :parent, :class_name => self.name
+
+          before_create :add_to_nested_set
+          before_update :move_in_nested_set, :if => lambda {|project| project.parent_id_changed? || project.name_changed?}
+          before_destroy :destroy_children
+        end
+        base.extend ClassMethods
+        base.send :include, Redmine::NestedSet::Traversing
+      end
+
+      private
+
+      def target_lft
+        siblings_rgt = self.class.where(:parent_id => parent_id).where("name < ?", name).maximum(:rgt)
+        if siblings_rgt
+          siblings_rgt + 1
+        elsif parent_id
+          parent_lft = self.class.where(:id => parent_id).pluck(:lft).first
+          raise "Project id=#{id} with parent_id=#{parent_id}: parent missing or without 'lft' value" unless parent_lft
+          parent_lft + 1
+        else
+          1
+        end
+      end
+
+      def add_to_nested_set(lock=true)
+        lock_nested_set if lock
+        self.lft = target_lft
+        self.rgt = lft + 1
+        self.class.where("lft >= ? OR rgt >= ?", lft, lft).update_all([
+          "lft = CASE WHEN lft >= :lft THEN lft + 2 ELSE lft END, " +
+          "rgt = CASE WHEN rgt >= :lft THEN rgt + 2 ELSE rgt END",
+          {:lft => lft}
+        ])
+      end
+
+      def move_in_nested_set
+        lock_nested_set
+        reload_nested_set_values
+        a = lft
+        b = rgt
+        c = target_lft
+        unless c == a
+          if c > a
+            # Moving to the right
+            d = c - (b - a + 1)
+            scope = self.class.where(["lft BETWEEN :a AND :c - 1 OR rgt BETWEEN :a AND :c - 1", {:a => a, :c => c}])
+            scope.update_all([
+              "lft = CASE WHEN lft BETWEEN :a AND :b THEN lft + (:d - :a) WHEN lft BETWEEN :b + 1 AND :c - 1 THEN lft - (:b - :a + 1) ELSE lft END, " +
+              "rgt = CASE WHEN rgt BETWEEN :a AND :b THEN rgt + (:d - :a) WHEN rgt BETWEEN :b + 1 AND :c - 1 THEN rgt - (:b - :a + 1) ELSE rgt END",
+              {:a => a, :b => b, :c => c, :d => d}
+            ])
+          elsif c < a
+            # Moving to the left
+            scope = self.class.where("lft BETWEEN :c AND :b OR rgt BETWEEN :c AND :b", {:a => a, :b => b, :c => c})
+            scope.update_all([
+              "lft = CASE WHEN lft BETWEEN :a AND :b THEN lft - (:a - :c) WHEN lft BETWEEN :c AND :a - 1 THEN lft + (:b - :a + 1) ELSE lft END, " +
+              "rgt = CASE WHEN rgt BETWEEN :a AND :b THEN rgt - (:a - :c) WHEN rgt BETWEEN :c AND :a - 1 THEN rgt + (:b - :a + 1) ELSE rgt END",
+              {:a => a, :b => b, :c => c, :d => d}
+            ])
+          end
+          reload_nested_set_values
+        end
+      end
+
+      def destroy_children
+        unless @without_nested_set_update
+          lock_nested_set
+          reload_nested_set_values
+        end
+        children.each {|c| c.send :destroy_without_nested_set_update}
+        unless @without_nested_set_update
+          self.class.where("lft > ? OR rgt > ?", lft, lft).update_all([
+            "lft = CASE WHEN lft > :lft THEN lft - :shift ELSE lft END, " +
+            "rgt = CASE WHEN rgt > :lft THEN rgt - :shift ELSE rgt END",
+            {:lft => lft, :shift => rgt - lft + 1}
+          ])
+        end
+      end
+
+      def destroy_without_nested_set_update
+        @without_nested_set_update = true
+        destroy
+      end
+
+      def reload_nested_set_values
+        self.lft, self.rgt = Project.where(:id => id).pluck(:lft, :rgt).first
+      end
+
+      def save_nested_set_values
+        self.class.where(:id => id).update_all(:lft => lft, :rgt => rgt)
+      end
+
+      def move_possible?(project)
+        !is_or_is_ancestor_of?(project)
+      end
+
+      def lock_nested_set
+        lock = true
+        if self.class.connection.adapter_name =~ /sqlserver/i
+          lock = "WITH (ROWLOCK HOLDLOCK UPDLOCK)"
+        end
+        self.class.order(:id).lock(lock).ids
+      end
+
+      def nested_set_scope
+        self.class.order(:lft)
+      end
+
+      def same_nested_set_scope?(project)
+        true
+      end
+
+      module ClassMethods
+        def rebuild_tree!
+          transaction do
+            reorder(:id).lock.ids
+            update_all(:lft => nil, :rgt => nil)
+            rebuild_nodes
+          end
+        end
+
+        private
+
+        def rebuild_nodes(parent_id = nil)
+          nodes = Project.where(:parent_id => parent_id).where(:rgt => nil, :lft => nil).reorder(:name)
+
+          nodes.each do |node|
+            node.send :add_to_nested_set, false
+            node.send :save_nested_set_values
+            rebuild_nodes node.id
+          end
+        end
+      end
+    end
+  end
+end