Add the actual data store

4 files changed, 202 insertions, 0 deletions

diff --git a/lib/chef_zero/data_store/data_already_exists_error.rb b/lib/chef_zero/data_store/data_already_exists_error.rb
new file mode 100644
index 0000000..54116d0
--- /dev/null
+++ b/lib/chef_zero/data_store/data_already_exists_error.rb
@@ -0,0 +1,29 @@
+#
+# Author:: John Keiser (<jkeiser@opscode.com>)
+# Copyright:: Copyright (c) 2013 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'chef_zero/data_store/data_error'
+
+module ChefZero
+  module DataStore
+    class DataAlreadyExistsError < DataError
+      def initialize(path, cause = nil)
+        super
+      end
+    end
+  end
+end
diff --git a/lib/chef_zero/data_store/data_error.rb b/lib/chef_zero/data_store/data_error.rb
new file mode 100644
index 0000000..9822a6b
--- /dev/null
+++ b/lib/chef_zero/data_store/data_error.rb
@@ -0,0 +1,31 @@
+#
+# Author:: John Keiser (<jkeiser@opscode.com>)
+# Copyright:: Copyright (c) 2013 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+module ChefZero
+  module DataStore
+    class DataError < StandardError
+      def initialize(path, cause = nil)
+        @path = path
+        @cause = cause
+      end
+
+      attr_reader :path
+      attr_reader :cause
+    end
+  end
+end
diff --git a/lib/chef_zero/data_store/data_not_found_error.rb b/lib/chef_zero/data_store/data_not_found_error.rb
new file mode 100644
index 0000000..a73d767
--- /dev/null
+++ b/lib/chef_zero/data_store/data_not_found_error.rb
@@ -0,0 +1,29 @@
+#
+# Author:: John Keiser (<jkeiser@opscode.com>)
+# Copyright:: Copyright (c) 2013 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'chef_zero/data_store/data_error'
+
+module ChefZero
+  module DataStore
+    class DataNotFoundError < DataError
+      def initialize(path, cause = nil)
+        super
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/lib/chef_zero/data_store/memory_store.rb b/lib/chef_zero/data_store/memory_store.rb
new file mode 100644
index 0000000..25678e0
--- /dev/null
+++ b/lib/chef_zero/data_store/memory_store.rb
@@ -0,0 +1,113 @@
+#
+# Author:: John Keiser (<jkeiser@opscode.com>)
+# Copyright:: Copyright (c) 2013 Opscode, Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require 'chef_zero/data_store/data_already_exists_error'
+require 'chef_zero/data_store/data_not_found_error'
+
+module ChefZero
+  module DataStore
+    class MemoryStore
+      def initialize
+        @data = {}
+      end
+
+      def create_dir(path, name, *options)
+        parent = _get(path, options.include?(:recursive))
+
+        if parent.has_key?(name)
+          raise DataAlreadyExistsError.new(path + [name])
+        end
+        parent[name] = {}
+      end
+
+      def create(path, name, data, *options)
+        if !data.is_a?(String)
+          raise "set only works with strings"
+        end
+
+        parent = _get(path, options.include?(:create_dir))
+
+        if parent.has_key?(name)
+          raise DataAlreadyExistsError.new(path + [name])
+        end
+        parent[name] = data
+      end
+
+      def get(path)
+        value = _get(path)
+        if value.is_a?(Hash)
+          raise "get() called on directory #{path.join('/')}"
+        end
+        value
+      end
+
+      def set(path, data, *options)
+        if !data.is_a?(String)
+          raise "set only works with strings: #{path} = #{data.inspect}"
+        end
+
+        # Get the parent
+        parent = _get(path[0..-2], options.include?(:create_dir))
+
+        if !options.include?(:create) && !parent[path[-1]]
+          raise DataNotFoundError.new(path)
+        end
+        parent[path[-1]] = data
+      end
+
+      def delete(path)
+        parent = _get(path[0,path.length-1])
+        parent.delete(path[-1])
+      end
+
+      def list(path)
+        dir = _get(path)
+        if !dir.is_a? Hash
+          raise "list only works with directories (#{path} = #{dir.class}"
+        end
+        dir.keys.sort
+      end
+
+      def exists?(path)
+        begin
+          get(path)
+          return true
+        rescue DataNotFoundError
+          return false
+        end
+      end
+
+      private
+
+      def _get(path, create_dir=false)
+        value = @data
+        path.each_with_index do |path_part, index|
+          if !value.has_key?(path_part)
+            if create_dir
+              value[path_part] = {}
+            else
+              raise DataNotFoundError.new(path[0,index+1])
+            end
+          end
+          value = value[path_part]
+        end
+        value
+      end
+    end
+  end
+end
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