Initial checkin of YAML substances.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@3772 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 75 insertions, 0 deletions

diff --git a/lib/yaml/store.rb b/lib/yaml/store.rb
new file mode 100644
index 0000000000..b2924b0660
--- /dev/null
+++ b/lib/yaml/store.rb
@@ -0,0 +1,75 @@
+#
+# YAML::Store
+#
+require 'yaml'
+require 'pstore'
+
+module YAML
+
+	class Store < PStore
+		#
+		# Constructor
+		# 
+		def initialize( *o )
+			@opt = YAML::DEFAULTS.dup
+            if String === o.first
+                super(o.pop)
+            end
+            if o.last.is_a? Hash
+                @opt.update(o.pop)
+            end
+        end
+
+		#
+		# Override Pstore#transaction
+		#
+		def transaction
+			raise YAML::Error, "nested transaction" if @transaction
+			raise YAML::Error, "no filename for transaction" unless @filename
+			begin
+				@transaction = true
+				value = nil
+				backup = @filename+"~"
+				if File::exist?(@filename)
+					file = File::open(@filename, "rb+")
+					orig = true
+				else
+					@table = {}
+					file = File::open(@filename, "wb+")
+					file.write( @table.to_yaml( @opt ) )
+				end
+				file.flock(File::LOCK_EX)
+				if orig
+					File::copy @filename, backup
+					@table = YAML::load( file )
+				end
+				begin
+					catch(:pstore_abort_transaction) do
+						value = yield(self)
+					end
+				rescue Exception
+					@abort = true
+					raise
+				ensure
+					unless @abort
+						begin
+							file.rewind
+							file.write( @table.to_yaml( @opt ) )
+							file.truncate(file.pos)
+						rescue
+							File::rename backup, @filename if File::exist?(backup)
+							raise
+						end
+					end
+					@abort = false
+				end
+			ensure
+				@table = nil
+				@transaction = false
+				file.close if file
+			end
+			value
+		end
+	end
+
+end