lang/csharp/src/apache/main/Schema/Field.cs - avro - Git at Google

 /**
  * 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.
  */
 using System;
 using System.Collections.Generic;
 using System.Text;
 using Newtonsoft.Json.Linq;
 using Newtonsoft.Json;

 namespace Avro
 {

     /// <summary>
     /// Class for fields defined in a record
     /// </summary>
     public class Field
     {
         /// <summary>
         /// Enum for the sorting order of record fields
         /// </summary>
         public enum SortOrder
         {
             ascending,
             descending,
             ignore
         }

         /// <summary>
         /// Name of the field.
         /// </summary>
         public readonly string Name;

         /// <summary>
         /// List of aliases for the field name
         /// </summary>
         public readonly IList<string> aliases;

         /// <summary>
         /// Position of the field within its record.
         /// </summary>
         public int Pos { get; private set; }

         /// <summary>
         /// Documentation for the field, if any. Null if there is no documentation.
         /// </summary>
         public string Documentation { get; private set; }

         /// <summary>
         /// The default value for the field stored as JSON object, if defined. Otherwise, null.
         /// </summary>
         public JToken DefaultValue { get; private set; }

         /// <summary>
         /// Order of the field
         /// </summary>
         public SortOrder? Ordering { get; private set; }

         /// <summary>
         /// Field type's schema
         /// </summary>
         public Schema Schema { get; private set; }

         /// <summary>
         /// Custom properties for the field. We don't store the fields custom properties in
         /// the field type's schema because if the field type is only a reference to the schema
         /// instead of an actual schema definition, then the schema could already have it's own set
         /// of custom properties when it was previously defined.
         /// </summary>
         private readonly PropertyMap Props;

         /// <summary>
         /// Static comparer object for JSON objects such as the fields default value
         /// </summary>
         internal static JTokenEqualityComparer JtokenEqual = new JTokenEqualityComparer();

         /// <summary>
         /// A flag to indicate if reader schema has a field that is missing from writer schema and has a default value
         /// This is set in CanRead() which is always be called before deserializing data
         /// </summary>

         /// <summary>
         /// Constructor for the field class
         /// </summary>
         /// <param name="schema">schema for the field type</param>
         /// <param name="name">name of the field</param>
         /// <param name="aliases">list of aliases for the name of the field</param>
         /// <param name="pos">position of the field</param>
         /// <param name="doc">documentation for the field</param>
         /// <param name="defaultValue">field's default value if it exists</param>
         /// <param name="sortorder">sort order of the field</param>
         internal Field(Schema schema, string name, IList<string> aliases, int pos, string doc,
                         JToken defaultValue, SortOrder sortorder, PropertyMap props)
         {
             if (string.IsNullOrEmpty(name)) throw new ArgumentNullException("name", "name cannot be null.");
             if (null == schema) throw new ArgumentNullException("type", "type cannot be null.");
             this.Schema = schema;
             this.Name = name;
             this.aliases = aliases;
             this.Pos = pos;
             this.Documentation = doc;
             this.DefaultValue = defaultValue;
             this.Ordering = sortorder;
             this.Props = props;
         }

         /// <summary>
         /// Writes the Field class in JSON format
         /// </summary>
         /// <param name="writer">JSON writer</param>
         /// <param name="names">list of named schemas already written</param>
         /// <param name="encspace">enclosing namespace for the field</param>
         protected internal void writeJson(JsonTextWriter writer, SchemaNames names, string encspace)
         {
             writer.WriteStartObject();
             JsonHelper.writeIfNotNullOrEmpty(writer, "name", this.Name);
             JsonHelper.writeIfNotNullOrEmpty(writer, "doc", this.Documentation);

             if (null != this.DefaultValue)
             {
                 writer.WritePropertyName("default");
                 this.DefaultValue.WriteTo(writer, null);
             }
             if (null != this.Schema)
             {
                 writer.WritePropertyName("type");
                 Schema.WriteJson(writer, names, encspace);
             }

             if (null != this.Props)
                 this.Props.WriteJson(writer);

             if (null != aliases)
             {
                 writer.WritePropertyName("aliases");
                 writer.WriteStartArray();
                 foreach (string name in aliases)
                     writer.WriteValue(name);
                 writer.WriteEndArray();
             }

             writer.WriteEndObject();
         }

         /// <summary>
         /// Parses the 'aliases' property from the given JSON token
         /// </summary>
         /// <param name="jtok">JSON object to read</param>
         /// <returns>List of string that represents the list of alias. If no 'aliases' specified, then it returns null.</returns>
         internal static IList<string> GetAliases(JToken jtok)
         {
             JToken jaliases = jtok["aliases"];
             if (null == jaliases)
                 return null;

             if (jaliases.Type != JTokenType.Array)
                 throw new SchemaParseException("Aliases must be of format JSON array of strings");

             var aliases = new List<string>();
             foreach (JToken jalias in jaliases)
             {
                 if (jalias.Type != JTokenType.String)
                     throw new SchemaParseException("Aliases must be of format JSON array of strings");

                 aliases.Add((string)jalias);
             }
             return aliases;
         }

         /// <summary>
         /// Returns the field's custom property value given the property name
         /// </summary>
         /// <param name="key">custom property name</param>
         /// <returns>custom property value</returns>
         public string GetProperty(string key)
         {
             if (null == this.Props) return null;
             string v;
             return (this.Props.TryGetValue(key, out v)) ? v : null;
         }

         /// <summary>
         /// Compares two field objects
         /// </summary>
         /// <param name="obj">field to compare with this field</param>
         /// <returns>true if two fields are equal, false otherwise</returns>
         public override bool Equals(object obj)
         {
             if (obj == this) return true;
             if (obj != null && obj is Field)
             {
                 Field that = obj as Field;
                 return areEqual(that.Name, Name) && that.Pos == Pos && areEqual(that.Documentation, Documentation)
                     && areEqual(that.Ordering, Ordering) && JtokenEqual.Equals(that.DefaultValue, DefaultValue)
                     && that.Schema.Equals(Schema) && areEqual(that.Props, this.Props);
             }
             return false;
         }

         /// <summary>
         /// Compares two objects
         /// </summary>
         /// <param name="o1">first object</param>
         /// <param name="o2">second object</param>
         /// <returns>true if two objects are equal, false otherwise</returns>
         private static bool areEqual(object o1, object o2)
         {
             return o1 == null ? o2 == null : o1.Equals(o2);
         }

         /// <summary>
         /// Hash code function
         /// </summary>
         /// <returns></returns>
         public override int GetHashCode()
         {
             return 17 * Name.GetHashCode() + Pos + 19 * getHashCode(Documentation) +
                    23 * getHashCode(Ordering) + 29 * getHashCode(DefaultValue) + 31 * Schema.GetHashCode() +
                    37 * getHashCode(Props);
         }

         /// <summary>
         /// Hash code helper function
         /// </summary>
         /// <param name="obj"></param>
         /// <returns></returns>
         private static int getHashCode(object obj)
         {
             return obj == null ? 0 : obj.GetHashCode();
         }
     }
 }
	/**
	* 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.
	*/
	using System;
	using System.Collections.Generic;
	using System.Text;
	using Newtonsoft.Json.Linq;
	using Newtonsoft.Json;

	namespace Avro
	{

	/// <summary>
	/// Class for fields defined in a record
	/// </summary>
	public class Field
	{
	/// <summary>
	/// Enum for the sorting order of record fields
	/// </summary>
	public enum SortOrder
	{
	ascending,
	descending,
	ignore
	}

	/// <summary>
	/// Name of the field.
	/// </summary>
	public readonly string Name;

	/// <summary>
	/// List of aliases for the field name
	/// </summary>
	public readonly IList<string> aliases;

	/// <summary>
	/// Position of the field within its record.
	/// </summary>
	public int Pos { get; private set; }

	/// <summary>
	/// Documentation for the field, if any. Null if there is no documentation.
	/// </summary>
	public string Documentation { get; private set; }

	/// <summary>
	/// The default value for the field stored as JSON object, if defined. Otherwise, null.
	/// </summary>
	public JToken DefaultValue { get; private set; }

	/// <summary>
	/// Order of the field
	/// </summary>
	public SortOrder? Ordering { get; private set; }

	/// <summary>
	/// Field type's schema
	/// </summary>
	public Schema Schema { get; private set; }

	/// <summary>
	/// Custom properties for the field. We don't store the fields custom properties in
	/// the field type's schema because if the field type is only a reference to the schema
	/// instead of an actual schema definition, then the schema could already have it's own set
	/// of custom properties when it was previously defined.
	/// </summary>
	private readonly PropertyMap Props;

	/// <summary>
	/// Static comparer object for JSON objects such as the fields default value
	/// </summary>
	internal static JTokenEqualityComparer JtokenEqual = new JTokenEqualityComparer();

	/// <summary>
	/// A flag to indicate if reader schema has a field that is missing from writer schema and has a default value
	/// This is set in CanRead() which is always be called before deserializing data
	/// </summary>

	/// <summary>
	/// Constructor for the field class
	/// </summary>
	/// <param name="schema">schema for the field type</param>
	/// <param name="name">name of the field</param>
	/// <param name="aliases">list of aliases for the name of the field</param>
	/// <param name="pos">position of the field</param>
	/// <param name="doc">documentation for the field</param>
	/// <param name="defaultValue">field's default value if it exists</param>
	/// <param name="sortorder">sort order of the field</param>
	internal Field(Schema schema, string name, IList<string> aliases, int pos, string doc,
	JToken defaultValue, SortOrder sortorder, PropertyMap props)
	{
	if (string.IsNullOrEmpty(name)) throw new ArgumentNullException("name", "name cannot be null.");
	if (null == schema) throw new ArgumentNullException("type", "type cannot be null.");
	this.Schema = schema;
	this.Name = name;
	this.aliases = aliases;
	this.Pos = pos;
	this.Documentation = doc;
	this.DefaultValue = defaultValue;
	this.Ordering = sortorder;
	this.Props = props;
	}

	/// <summary>
	/// Writes the Field class in JSON format
	/// </summary>
	/// <param name="writer">JSON writer</param>
	/// <param name="names">list of named schemas already written</param>
	/// <param name="encspace">enclosing namespace for the field</param>
	protected internal void writeJson(JsonTextWriter writer, SchemaNames names, string encspace)
	{
	writer.WriteStartObject();
	JsonHelper.writeIfNotNullOrEmpty(writer, "name", this.Name);
	JsonHelper.writeIfNotNullOrEmpty(writer, "doc", this.Documentation);

	if (null != this.DefaultValue)
	{
	writer.WritePropertyName("default");
	this.DefaultValue.WriteTo(writer, null);
	}
	if (null != this.Schema)
	{
	writer.WritePropertyName("type");
	Schema.WriteJson(writer, names, encspace);
	}

	if (null != this.Props)
	this.Props.WriteJson(writer);

	if (null != aliases)
	{
	writer.WritePropertyName("aliases");
	writer.WriteStartArray();
	foreach (string name in aliases)
	writer.WriteValue(name);
	writer.WriteEndArray();
	}

	writer.WriteEndObject();
	}

	/// <summary>
	/// Parses the 'aliases' property from the given JSON token
	/// </summary>
	/// <param name="jtok">JSON object to read</param>
	/// <returns>List of string that represents the list of alias. If no 'aliases' specified, then it returns null.</returns>
	internal static IList<string> GetAliases(JToken jtok)
	{
	JToken jaliases = jtok["aliases"];
	if (null == jaliases)
	return null;

	if (jaliases.Type != JTokenType.Array)
	throw new SchemaParseException("Aliases must be of format JSON array of strings");

	var aliases = new List<string>();
	foreach (JToken jalias in jaliases)
	{
	if (jalias.Type != JTokenType.String)
	throw new SchemaParseException("Aliases must be of format JSON array of strings");

	aliases.Add((string)jalias);
	}
	return aliases;
	}

	/// <summary>
	/// Returns the field's custom property value given the property name
	/// </summary>
	/// <param name="key">custom property name</param>
	/// <returns>custom property value</returns>
	public string GetProperty(string key)
	{
	if (null == this.Props) return null;
	string v;
	return (this.Props.TryGetValue(key, out v)) ? v : null;
	}

	/// <summary>
	/// Compares two field objects
	/// </summary>
	/// <param name="obj">field to compare with this field</param>
	/// <returns>true if two fields are equal, false otherwise</returns>
	public override bool Equals(object obj)
	{
	if (obj == this) return true;
	if (obj != null && obj is Field)
	{
	Field that = obj as Field;
	return areEqual(that.Name, Name) && that.Pos == Pos && areEqual(that.Documentation, Documentation)
	&& areEqual(that.Ordering, Ordering) && JtokenEqual.Equals(that.DefaultValue, DefaultValue)
	&& that.Schema.Equals(Schema) && areEqual(that.Props, this.Props);
	}
	return false;
	}

	/// <summary>
	/// Compares two objects
	/// </summary>
	/// <param name="o1">first object</param>
	/// <param name="o2">second object</param>
	/// <returns>true if two objects are equal, false otherwise</returns>
	private static bool areEqual(object o1, object o2)
	{
	return o1 == null ? o2 == null : o1.Equals(o2);
	}

	/// <summary>
	/// Hash code function
	/// </summary>
	/// <returns></returns>
	public override int GetHashCode()
	{
	return 17 * Name.GetHashCode() + Pos + 19 * getHashCode(Documentation) +
	23 * getHashCode(Ordering) + 29 * getHashCode(DefaultValue) + 31 * Schema.GetHashCode() +
	37 * getHashCode(Props);
	}

	/// <summary>
	/// Hash code helper function
	/// </summary>
	/// <param name="obj"></param>
	/// <returns></returns>
	private static int getHashCode(object obj)
	{
	return obj == null ? 0 : obj.GetHashCode();
	}
	}
	}