AVRO-2211: SchemaBuilder equivalent or other means of schema creation

lang/csharp/src/apache/main/AssemblyInfo.cs

@@ -0,0 +1,20 @@
+/*
+ * 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
+ *
+ *     https://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.Runtime.CompilerServices;
+
+[assembly: InternalsVisibleTo("Avro.test, PublicKey=00240000048000009400000006020000002400005253413100040000010001001145636d1b96168c2781abfd60478f45d010fe83dd0f318404cbf67252bca8cd827f24648d47ff682f35e60307c05d3cd89f0b063729cf8d2ebe6510b9e7d295dec6707ec91719d859458981f7ca1cbbea79b702b2fb64d1dbf0881887315345b70fa50fcf91b59e6a937c8d23919d409ee2f1f234cc4c8dbf5a29d3d670f3c9")]

lang/csharp/src/apache/main/Schema/Aliases.cs

@@ -0,0 +1,36 @@
+/*
+ * 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
+ *
+ *     https://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.Collections.Generic;
+using System.Linq;
+
+namespace Avro
+{
+    internal static class Aliases
+    {
+        internal static IList<SchemaName> GetSchemaNames(IEnumerable<string> aliases, string enclosingTypeName, string enclosingTypeNamespace)
+        {
+            if (aliases == null)
+            {
+                return null;
+            }
+
+            SchemaName enclosingSchemaName = new SchemaName(enclosingTypeName, enclosingTypeNamespace, null, null);
+            return aliases.Select(alias => new SchemaName(alias, enclosingSchemaName.Namespace, null, null)).ToList();
+        }
+    }
+}

lang/csharp/src/apache/main/Schema/ArraySchema.cs

@@ -29,7 +29,7 @@ public class ArraySchema : UnnamedSchema
         /// <summary>
         /// Schema for the array 'type' attribute
         /// </summary>
-        public Schema ItemSchema { get; set;  }
+        public Schema ItemSchema { get; set; }
 
         /// <summary>
         /// Static class to return a new instance of ArraySchema
@@ -48,11 +48,23 @@ internal static ArraySchema NewInstance(JToken jtok, PropertyMap props, SchemaNa
         }
 
         /// <summary>
-        /// Constructor
+        /// Creates a new <see cref="ArraySchema"/>
         /// </summary>
-        /// <param name="items">schema for the array items type</param>
-        /// <param name="props">dictionary that provides access to custom properties</param>
-        private ArraySchema(Schema items, PropertyMap props) : base(Type.Array, props)
+        /// <param name="items">Schema for the array items type</param>
+        /// <param name="customAttributes">Dictionary that provides access to custom properties</param>
+        /// <returns></returns>
+        public static ArraySchema Create(Schema items, PropertyMap customAttributes = null)
+        {
+            return new ArraySchema(items, customAttributes);
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ArraySchema"/> class.
+        /// </summary>
+        /// <param name="items">Schema for the array items type</param>
+        /// <param name="customAttributes">Dictionary that provides access to custom properties</param>
+        private ArraySchema(Schema items, PropertyMap customAttributes)
+            : base(Type.Array, customAttributes)
         {
             if (null == items) throw new ArgumentNullException(nameof(items));
             this.ItemSchema = items;

lang/csharp/src/apache/main/Schema/EnumSchema.cs

@@ -17,7 +17,8 @@
  */
 using System;
 using System.Collections.Generic;
-using System.Text;
+using System.Linq;
+using System.Text.RegularExpressions;
 using Newtonsoft.Json.Linq;
 
 namespace Avro
@@ -30,7 +31,7 @@ public class EnumSchema : NamedSchema
         /// <summary>
         /// List of strings representing the enum symbols
         /// </summary>
-        public IList<string> Symbols { get; private set;  }
+        public IList<string> Symbols { get; private set; }
 
         /// <summary>
         /// The default token to use when deserializing an enum when the provided token is not found
@@ -47,6 +48,34 @@ public class EnumSchema : NamedSchema
         /// </summary>
         public int Count { get { return Symbols.Count; } }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="EnumSchema"/> class.
+        /// </summary>
+        /// <param name="name">Name of enum</param>
+        /// <param name="space">Namespace of enum</param>
+        /// <param name="aliases">List of aliases for the name</param>
+        /// <param name="symbols">List of enum symbols</param>
+        /// <param name="customProperties">Custom properties on this schema</param>
+        /// <param name="doc">Documentation for this named schema</param>
+        /// <param name="defaultSymbol"></param>
+        public static EnumSchema Create(string name,
+            IEnumerable<string> symbols,
+            string space = null,
+            IEnumerable<string> aliases = null,
+            PropertyMap customProperties = null,
+            string doc = null,
+            string defaultSymbol = null)
+        {
+            return new EnumSchema(new SchemaName(name, space, null, doc),
+                  Aliases.GetSchemaNames(aliases, name, space),
+                  symbols.ToList(),
+                  CreateSymbolsMap(symbols),
+                  customProperties,
+                  new SchemaNames(),
+                  doc,
+                  defaultSymbol);
+        }
+
         /// <summary>
         /// Static function to return new instance of EnumSchema
         /// </summary>
@@ -81,7 +110,7 @@ internal static EnumSchema NewInstance(JToken jtok, PropertyMap props, SchemaNam
                 return new EnumSchema(name, aliases, symbols, symbolMap, props, names,
                     JsonHelper.GetOptionalString(jtok, "doc"), JsonHelper.GetOptionalString(jtok, "default"));
             }
-            catch (SchemaParseException e)
+            catch (AvroException e)
             {
                 throw new SchemaParseException($"{e.Message} at '{jtok.Path}'", e);
             }
@@ -103,15 +132,49 @@ private EnumSchema(SchemaName name, IList<SchemaName> aliases, List<string> symb
                             string doc, string defaultSymbol)
                             : base(Type.Enumeration, name, aliases, props, names, doc)
         {
-            if (null == name.Name) throw new SchemaParseException("name cannot be null for enum schema.");
+            if (null == name.Name) throw new AvroException("name cannot be null for enum schema.");
             this.Symbols = symbols;
             this.symbolMap = symbolMap;
 
             if (null != defaultSymbol && !symbolMap.ContainsKey(defaultSymbol))
-                throw new SchemaParseException($"Default symbol: {defaultSymbol} not found in symbols");
+                throw new AvroException($"Default symbol: {defaultSymbol} not found in symbols");
             Default = defaultSymbol;
         }
 
+        /// <summary>
+        /// Creates symbols map from specified list of symbols.
+        /// Symbol map contains the names of the symbols and their index.
+        /// </summary>
+        /// <param name="symbols">List of symbols</param>
+        /// <returns>Symbol map</returns>
+        /// <exception cref="AvroException">Is thrown if the symbols list contains invalid symbol name or duplicate symbols</exception>
+        private static IDictionary<string, int> CreateSymbolsMap(IEnumerable<string> symbols)
+        {
+            IDictionary<string, int> symbolMap = new Dictionary<string, int>();
+            int i = 0;
+            foreach (var symbol in symbols)
+            {
+                ValidateSymbolName(symbol);
+
+                if (symbolMap.ContainsKey(symbol))
+                {
+                    throw new AvroException($"Duplicate symbol: {symbol}");
+                }
+
+                symbolMap[symbol] = i++;
+            }
+
+            return symbolMap;
+        }
+
+        private static void ValidateSymbolName(string symbol)
+        {
+            if(string.IsNullOrEmpty(symbol) || !Regex.IsMatch(symbol, "^([A-Za-z_][A-Za-z0-9_]*)$"))
+            {
+                throw new AvroException($"Invalid symbol name: {symbol}");
+            }
+        }
+
         /// <summary>
         /// Writes enum schema in JSON format
         /// </summary>
@@ -127,7 +190,7 @@ protected internal override void WriteJsonFields(Newtonsoft.Json.JsonTextWriter
             foreach (string s in this.Symbols)
                 writer.WriteValue(s);
             writer.WriteEndArray();
-            if (null != Default) 
+            if (null != Default)
             {
                 writer.WritePropertyName("default");
                 writer.WriteValue(Default);

lang/csharp/src/apache/main/Schema/Field.cs

@@ -103,7 +103,39 @@ public enum SortOrder
         /// <summary>
         /// Static comparer object for JSON objects such as the fields default value
         /// </summary>
-        internal static JTokenEqualityComparer JtokenEqual = new JTokenEqualityComparer();
+        internal readonly static JTokenEqualityComparer JtokenEqual = new JTokenEqualityComparer();
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="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>
+        /// <param name="customProperties">dictionary that provides access to custom properties.</param>
+        public Field(Schema schema,
+            string name,
+            int pos,
+            IList<string> aliases = null,
+            string doc = null,
+            JToken defaultValue = null,
+            SortOrder sortorder = SortOrder.ignore,
+            PropertyMap customProperties = null)
+            : this(schema, name, aliases, pos, doc, defaultValue, sortorder, customProperties)
+        {
+        }
+
+        /// <summary>
+        /// Creates a new field based on the specified field, with a different position.
+        /// </summary>
+        /// <returns>A clone of this field with new position.</returns>
+        internal Field ChangePosition(int newPosition)
+        {
+            return new Field(Schema, Name, newPosition, Aliases, Documentation, DefaultValue, Ordering ?? SortOrder.ignore, Props);
+        }
 
         /// <summary>
         /// A flag to indicate if reader schema has a field that is missing from writer schema and has a default value

lang/csharp/src/apache/main/Schema/FixedSchema.cs

@@ -32,6 +32,20 @@ public class FixedSchema : NamedSchema
         /// </summary>
         public int Size { get; set; }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="FixedSchema"/> class.
+        /// </summary>
+        /// <param name="name">Name of the fixed schema</param>
+        /// <param name="aliases">List of aliases for the name</param>
+        /// <param name="size">Fixed size</param>
+        /// <param name="space">Namespace of fixed</param>
+        /// <param name="customProperties">Custom properties on this schema</param>
+        /// <param name="doc">Documentation for this named schema</param>
+        public static FixedSchema Create(string name, int size, string space = null, IEnumerable<string> aliases = null, PropertyMap customProperties = null, string doc = null)
+        {
+            return new FixedSchema(new SchemaName(name, space, null, doc), Aliases.GetSchemaNames(aliases, name, space), size, customProperties, new SchemaNames(), doc);
+        }
+
         /// <summary>
         /// Static function to return new instance of the fixed schema class
         /// </summary>

lang/csharp/src/apache/main/Schema/MapSchema.cs

@@ -36,10 +36,11 @@ public class MapSchema : UnnamedSchema
         /// Creates a new <see cref="MapSchema"/> from the given schema.
         /// </summary>
         /// <param name="type">Schema to create the map schema from.</param>
+        /// <param name="customProperties">Dictionary that provides access to custom properties</param>
         /// <returns>A new <see cref="MapSchema"/>.</returns>
-        public static MapSchema CreateMap(Schema type)
+        public static MapSchema CreateMap(Schema type, PropertyMap customProperties = null)
         {
-            return new MapSchema(type,null);
+            return new MapSchema(type, customProperties);
         }
 
         /// <summary>
@@ -67,9 +68,10 @@ internal static MapSchema NewInstance(JToken jtok, PropertyMap props, SchemaName
         /// <summary>
         /// Constructor for map schema class
         /// </summary>
-        /// <param name="valueSchema">schema for map values type</param>
-        /// <param name="props">dictionary that provides access to custom properties</param>
-        private MapSchema(Schema valueSchema, PropertyMap props) : base(Type.Map, props)
+        /// <param name="valueSchema">Schema for map values type</param>
+        /// <param name="cutsomProperties">Dictionary that provides access to custom properties</param>
+        private MapSchema(Schema valueSchema, PropertyMap cutsomProperties)
+            : base(Type.Map, cutsomProperties)
         {
             if (null == valueSchema) throw new ArgumentNullException(nameof(valueSchema), "valueSchema cannot be null.");
             this.ValueSchema = valueSchema;

lang/csharp/src/apache/main/Schema/PrimitiveSchema.cs

@@ -30,9 +30,21 @@ public sealed class PrimitiveSchema : UnnamedSchema
         /// Constructor for primitive schema
         /// </summary>
         /// <param name="type"></param>
-        /// <param name="props">dictionary that provides access to custom properties</param>
-        private PrimitiveSchema(Type type, PropertyMap props) : base(type, props)
+        /// <param name="customProperties">dictionary that provides access to custom properties</param>
+        private PrimitiveSchema(Type type, PropertyMap customProperties)
+            : base(type, customProperties)
+        {
+        }
+
+        /// <summary>
+        /// Creates a new instance of <see cref="PrimitiveSchema"/>
+        /// </summary>
+        /// <param name="type">The primitive type to create</param>
+        /// <param name="customProperties">Dictionary that provides access to custom properties</param>
+        /// <returns></returns>
+        public static PrimitiveSchema Create(Type type, PropertyMap customProperties = null)
         {
+            return new PrimitiveSchema(type, customProperties);
         }
 
         /// <summary>