Added new policy Schema classes.

components/policy/core/common/schema.h

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_POLICY_CORE_COMMON_SCHEMA_H_
+#define COMPONENTS_POLICY_CORE_COMMON_SCHEMA_H_
+
+#include "base/basictypes.h"
+#include "base/values.h"
+#include "components/policy/policy_export.h"
+
+namespace policy {
+
+namespace schema {
+
+// TODO: internal stuff just needs to be forward declared here.
+namespace internal {
+
+struct POLICY_EXPORT SchemaNode {
+  base::Value::Type type;
+
+  // If type is TYPE_LIST then this is a SchemaNode*.
+  // If type is TYPE_DICTIONARY then this is a PropertiesNode*.
+  // Otherwise it's NULL.
+  const void* extra;

[Mattias Nissler (ping if slow), 2013/09/13 12:56:48]

Use a union here?

+};
+
+struct POLICY_EXPORT PropertyNode {
+  const char* key;
+  const SchemaNode* schema;
+};
+
+struct POLICY_EXPORT PropertiesNode {
+  const PropertyNode* begin;
+  const PropertyNode* end;
+  const SchemaNode* additional;
+};
+
+}  // namespace internal
+
+class Schema {
+ public:
+  explicit Schema(const internal::SchemaNode* schema);
+  Schema(const Schema& schema);
+
+  Schema& operator=(const Schema& schema);
+
+  bool valid() const { return schema_ != NULL; }
+  base::Value::Type type() const;
+
+  class Iterator {
+   public:
+    explicit Iterator(const internal::PropertiesNode* properties);
+    Iterator(const Iterator& iterator);
+    ~Iterator();
+
+    Iterator& operator=(const Iterator& iterator);
+
+    bool IsAtEnd() const;
+    void Advance();
+
+    const char* key() const;
+    Schema schema() const;
+
+   private:
+    const internal::PropertyNode* it_;
+    const internal::PropertyNode* end_;
+  };
+
+  // These methods can be called only if type() == TYPE_DICTIONARY.
+  Iterator GetPropertiesIterator() const;
+  Schema GetKnownProperty(const std::string& key) const;
+  Schema GetAdditionalProperties() const;
+  Schema GetProperty(const std::string& key) const;
+
+  // This method can be called only if type() == TYPE_LIST.
+  Schema GetItems() const;
+
+ private:
+  const internal::SchemaNode* schema_;
+};
+
+class PolicySchema {
+ public:
+  virtual ~PolicySchema() {}
+
+  // The returned Schema is valid only during the lifetime of the PolicySchema
+  // that created it.
+  virtual Schema schema() const = 0;
+
+  static scoped_ptr<PolicySchema> GetChromePolicySchema();
+
+  static scoped_ptr<PolicySchema> Parse(const std::string& schema,
+                                        std::string* error);
+};
+
+}  // namespace schema
+
+}  // namespace policy
+
+#endif  // COMPONENTS_POLICY_CORE_COMMON_SCHEMA_H_