text: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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.
   */
  
  #ifndef avro_Node_hh__
  #define avro_Node_hh__
  
  #include <cassert>
  #include <boost/noncopyable.hpp>
  #include <boost/shared_ptr.hpp>
  
  #include "Exception.hh"
  #include "Types.hh"
  #include "SchemaResolution.hh"
  
  namespace avro {
  
  class Node;
  
  typedef boost::shared_ptr<Node> NodePtr;
  
  
  /// Node is the building block for parse trees.  Each node represents an avro
  /// type.  Compound types have leaf nodes that represent the types they are
  /// composed of.
  ///
  /// The user does not use the Node object directly, they interface with Schema
  /// objects.
  ///
  /// The Node object uses reference-counted pointers.  This is so that schemas 
  /// may be reused in other other schemas, without needing to worry about memory
  /// deallocation for nodes that are added to multiple schema parse trees.
  ///
  /// Node has minimal implementation, serving as an abstract base class for
  /// different node types.
  ///
  
  class Node : private boost::noncopyable
  {
    public:
  
      Node(Type type) :
          type_(type),
          locked_(false)
      {}
  
      virtual ~Node();
  
      Type type() const {
          return type_;
      }
  
      void lock() {
          locked_ = true;
      }
  
      bool locked() const {
          return locked_;
      }
  
      virtual bool hasName() const = 0;
  
      void setName(const std::string &name) {
          checkLock();
          checkName(name);
          doSetName(name);
      }
      virtual const std::string &name() const = 0;
  
      void addLeaf(const NodePtr &newLeaf) {
          checkLock();
          doAddLeaf(newLeaf);
      }
      virtual size_t leaves() const = 0;
      virtual const NodePtr& leafAt(int index) const = 0;
  
      void addName(const std::string &name) {
          checkLock();
          checkName(name);
          doAddName(name);
      }
      virtual size_t names() const = 0;
      virtual const std::string &nameAt(int index) const = 0;
      virtual bool nameIndex(const std::string &name, size_t &index) const = 0;
  
      void setFixedSize(int size) {
          checkLock();
          doSetFixedSize(size);
      }
      virtual int fixedSize() const = 0;
  
      virtual bool isValid() const = 0;
  
      virtual SchemaResolution resolve(const Node &reader) const = 0;
  
      virtual void printJson(std::ostream &os, int depth) const = 0;
  
      virtual void printBasicInfo(std::ostream &os) const = 0;
  
    protected:
  
      friend class ValidSchema;
  
      virtual void setLeafToSymbolic(int index, const NodePtr &node) = 0;
  
      void checkLock() const {
          if(locked()) {
              throw Exception("Cannot modify locked schema");
          }
      }
  
      void checkName(const std::string &name) const;
  
      virtual void doSetName(const std::string &name) = 0;
      virtual void doAddLeaf(const NodePtr &newLeaf) = 0;
      virtual void doAddName(const std::string &name) = 0;
      virtual void doSetFixedSize(int size) = 0;
  
    private:
  
      const Type type_;
      bool locked_;
  };
  
  } // namespace avro
  
  #endif
  