kafka-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From gwens...@apache.org
Subject [5/7] kafka git commit: KAFKA-2366; Initial patch for Copycat
Date Fri, 14 Aug 2015 23:01:09 GMT
http://git-wip-us.apache.org/repos/asf/kafka/blob/f6acfb08/copycat/data/src/main/java/org/apache/kafka/copycat/data/SchemaBuilder.java
----------------------------------------------------------------------
diff --git a/copycat/data/src/main/java/org/apache/kafka/copycat/data/SchemaBuilder.java b/copycat/data/src/main/java/org/apache/kafka/copycat/data/SchemaBuilder.java
new file mode 100644
index 0000000..f4a76a1
--- /dev/null
+++ b/copycat/data/src/main/java/org/apache/kafka/copycat/data/SchemaBuilder.java
@@ -0,0 +1,2415 @@
+/**
+ * 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.
+ **/
+
+
+
+package org.apache.kafka.copycat.data;
+
+import org.apache.kafka.copycat.data.Schema.Field;
+
+import java.nio.ByteBuffer;
+import java.util.*;
+
+/**
+ * <p>
+ * A fluent interface for building {@link Schema} instances. The flow of the API
+ * is designed to mimic the <a
+ * href="http://avro.apache.org/docs/current/spec.html#schemas">Avro Schema
+ * Specification</a>
+ * </p>
+ * For example, the below JSON schema and the fluent builder code to create it
+ * are very similar:
+ *
+ * <pre>
+ * {
+ *   "type": "record",
+ *   "name": "HandshakeRequest", "namespace":"org.apache.avro.ipc",
+ *   "fields": [
+ *     {"name": "clientHash",
+ *      "type": {"type": "fixed", "name": "MD5", "size": 16}},
+ *     {"name": "clientProtocol", "type": ["null", "string"]},
+ *     {"name": "serverHash", "type": "MD5"},
+ *     {"name": "meta", "type": ["null", {"type": "map", "values": "bytes"}]}
+ *   ]
+ * }
+ * </pre>
+ *
+ * <pre>
+ *   Schema schema = SchemaBuilder
+ *   .record("HandshakeRequest").namespace("org.apache.avro.ipc)
+ *   .fields()
+ *     .name("clientHash").type().fixed("MD5").size(16).noDefault()
+ *     .name("clientProtocol").type().nullable().stringType().noDefault()
+ *     .name("serverHash").type("MD5")
+ *     .name("meta").type().nullable().map().values().bytesType().noDefault()
+ *   .endRecord();
+ * </pre>
+ * <p/>
+ *
+ * <h5>Usage Guide</h5>
+ * SchemaBuilder chains together many smaller builders and maintains nested
+ * context in order to mimic the Avro Schema specification. Every Avro type in
+ * JSON has required and optional JSON properties, as well as user-defined
+ * properties.
+ * <p/>
+ * <h6>Selecting and Building an Avro Type</h6>
+ * The API analogy for the right hand side of the Avro Schema JSON
+ * <pre>
+ * "type":
+ * </pre>
+ * is a {@link TypeBuilder}, {@link FieldTypeBuilder}, or
+ * {@link UnionFieldTypeBuilder}, depending on the context. These types all
+ * share a similar API for selecting and building types.
+ * <p/>
+ * <h5>Primitive Types</h5>
+ * All Avro primitive types are trivial to configure. A primitive type in 
+ * Avro JSON can be declared two ways, one that supports custom properties
+ * and one that does not:
+ * <pre>
+ * {"type":"int"}
+ * {"type":{"name":"int"}}
+ * {"type":{"name":"int", "customProp":"val"}}
+ * </pre>
+ * The analogous code form for the above three JSON lines are the below
+ * three lines:
+ * <pre>
+ *  .intType()
+ *  .intBuilder().endInt()
+ *  .intBuilder().prop("customProp", "val").endInt()
+ * </pre>
+ * Every primitive type has a shortcut to create the trivial type, and
+ * a builder when custom properties are required.  The first line above is
+ * a shortcut for the second, analogous to the JSON case.
+ * <h6>Named Types</h6>
+ * Avro named types have names, namespace, aliases, and doc.  In this API
+ * these share a common parent, {@link NamespacedBuilder}.
+ * The builders for named types require a name to be constructed, and optional
+ * configuration via:
+ * <li>{@link NamespacedBuilder#doc()}</li>
+ * <li>{@link NamespacedBuilder#namespace(String)}</li>
+ * <li>{@link NamespacedBuilder#aliases(String...)}</li>
+ * <li>{@link PropBuilder#prop(String, Object)}</li>
+ * <p/>
+ * Each named type completes configuration of the optional properties
+ * with its own method:
+ * <li>{@link FixedBuilder#size(int)}</li>
+ * <li>{@link EnumBuilder#symbols(String...)}</li>
+ * <li>{@link RecordBuilder#fields()}</li>
+ * Example use of a named type with all optional parameters:
+ * <pre>
+ * .enumeration("Suit").namespace("org.apache.test")
+ *   .aliases("org.apache.test.OldSuit")
+ *   .doc("CardSuits")
+ *   .prop("customProp", "val")
+ *   .symbols("SPADES", "HEARTS", "DIAMONDS", "CLUBS")
+ * </pre>
+ * Which is equivalent to the JSON:
+ * <pre>
+ * { "type":"enum",
+ *   "name":"Suit", "namespace":"org.apache.test",
+ *   "aliases":["org.apache.test.OldSuit"],
+ *   "doc":"Card Suits",
+ *   "customProp":"val",
+ *   "symbols":["SPADES", "HEARTS", "DIAMONDS", "CLUBS"]
+ * }
+ * </pre>
+ * <h6>Nested Types</h6>
+ * The Avro nested types, map and array, can have custom properties like
+ * all avro types, are not named, and must specify a nested type.
+ * After configuration of optional properties, an array or map 
+ * builds or selects its nested type with {@link ArrayBuilder#items()}
+ * and {@link MapBuilder#values()}, respectively.
+ *
+ * <h6>Fields</h6>
+ * {@link RecordBuilder#fields()} returns a {@link FieldAssembler} for 
+ * defining the fields of the record and completing it.
+ * Each field must have a name, specified via {@link FieldAssembler#name(String)},
+ * which returns a {@link FieldBuilder} for defining aliases, custom properties,
+ * and documentation of the field.  After configuring these optional values for
+ * a field, the type is selected or built with {@link FieldBuilder#type()}.
+ * <p/>
+ * Fields have default values that must be specified to complete the field.
+ * {@link FieldDefault#noDefault()} is available for all field types, and
+ * a specific method is available for each type to use a default, for example
+ * {@link IntDefault#intDefault(int)}
+ * <p/>
+ * There are field shortcut methods on {@link FieldAssembler} for primitive types.
+ * These shortcuts create required, optional, and nullable fields, but do not 
+ * support field aliases, doc, or custom properties.
+ *
+ * <h6>Unions</h6>
+ * Union types are built via {@link TypeBuilder#unionOf()} or
+ * {@link FieldTypeBuilder#unionOf()} in the context of type selection.
+ * This chains together multiple types, in union order.  For example:
+ * <pre>
+ * .unionOf()
+ *   .fixed("IPv4").size(4).and()
+ *   .fixed("IPv6").size(16).and()
+ *   .nullType().endUnion()
+ * </pre>
+ * is equivalent to the Avro schema JSON:
+ * <pre>
+ * [
+ *   {"type":"fixed", "name":"IPv4", "size":4},
+ *   {"type":"fixed", "name":"IPv6", "size":16},
+ *   "null"
+ * ]
+ * </pre>
+ * In a field context, the first type of a union defines what default type
+ * is allowed.
+ * </p>
+ * Unions have two shortcuts for common cases.  nullable()
+ * creates a union of a type and null.  In a field type context, optional()
+ * is available and creates a union of null and a type, with a null default.
+ * The below two are equivalent:
+ * <pre>
+ *   .unionOf().intType().and().nullType().endUnion()
+ *   .nullable().intType()
+ * </pre>
+ * The below two field declarations are equivalent:
+ * <pre>
+ *   .name("f").type().unionOf().nullType().and().longType().endUnion().nullDefault()
+ *   .name("f").type().optional().longType()
+ * </pre>
+ *
+ * <h6>Explicit Types and Types by Name</h6>
+ * Types can also be specified explicitly by passing in a Schema, or by name:
+ * <pre>
+ *   .type(Schema.create(Schema.Type.INT)) // explicitly specified
+ *   .type("MD5")                       // reference by full name or short name
+ *   .type("MD5", "org.apache.avro.test")  // reference by name and namespace
+ * </pre>
+ * When a type is specified by name, and the namespace is absent or null, the
+ * namespace is inherited from the enclosing context.  A namespace will
+ * propagate as a default to child fields, nested types, or later defined types
+ * in a union.  To specify a name that has no namespace and ignore the inherited
+ * namespace, set the namespace to "".
+ * <p/>
+ * {@link SchemaBuilder#builder(String)} returns a type builder with a default
+ * namespace.  {@link SchemaBuilder#builder()} returns a type builder with no
+ * default namespace.
+ */
+public class SchemaBuilder {
+
+    private SchemaBuilder() {
+    }
+
+    /**
+     * Create a builder for Avro schemas.
+     */
+    public static TypeBuilder<Schema> builder() {
+        return new TypeBuilder<Schema>(new SchemaCompletion(), new NameContext());
+    }
+
+    /**
+     * Create a builder for Avro schemas with a default namespace. Types created
+     * without namespaces will inherit the namespace provided.
+     */
+    public static TypeBuilder<Schema> builder(String namespace) {
+        return new TypeBuilder<Schema>(new SchemaCompletion(),
+                new NameContext().namespace(namespace));
+    }
+
+    /**
+     * Create a builder for an Avro enum with the specified name and symbols (values).
+     * This is equivalent to:
+     * <pre>
+     *   builder().enumeration(name);
+     * </pre>
+     * @param name the enum name
+     */
+    public static EnumBuilder<Schema> enumeration(String name) {
+        return builder().enumeration(name);
+    }
+
+    /**
+     * Create a builder for an Avro array
+     * This is equivalent to:
+     * <pre>
+     *   builder().array();
+     * </pre>
+     */
+    public static ArrayBuilder<Schema> array() {
+        return builder().array();
+    }
+
+    /**
+     * Create a builder for an Avro map
+     * This is equivalent to:
+     * <pre>
+     *   builder().map();
+     * </pre>
+     */
+    public static MapBuilder<Schema> map() {
+        return builder().map();
+    }
+
+    /**
+     * Create a builder for an Avro union
+     * This is equivalent to:
+     * <pre>
+     *   builder().unionOf();
+     * </pre>
+     */
+    public static BaseTypeBuilder<UnionAccumulator<Schema>> unionOf() {
+        return builder().unionOf();
+    }
+
+    /**
+     * Create a builder for a union of a type and null.
+     * This is a shortcut for:
+     * <pre>
+     *   builder().nullable();
+     * </pre>
+     * and the following two lines are equivalent:
+     * <pre>
+     *   nullable().intType();
+     * </pre>
+     * <pre>
+     *   unionOf().intType().and().nullType().endUnion();
+     * </pre>
+     */
+    public static BaseTypeBuilder<Schema> nullable() {
+        return builder().nullable();
+    }
+
+
+    /**
+     * An abstract builder for all Avro types.  All Avro types
+     * can have arbitrary string key-value properties.
+     */
+    public static abstract class PropBuilder<S extends PropBuilder<S>> {
+        private Map<String, Object> props = null;
+
+        protected PropBuilder() {
+        }
+
+        public final S prop(String name, Object val) {
+            if (!hasProps()) {
+                props = new HashMap<String, Object>();
+            }
+            props.put(name, val);
+            return self();
+        }
+
+        private boolean hasProps() {
+            return (props != null);
+        }
+
+        final <T extends ObjectProperties> T addPropsTo(T jsonable) {
+            if (hasProps()) {
+                for (Map.Entry<String, Object> prop : props.entrySet()) {
+                    jsonable.addProp(prop.getKey(), prop.getValue());
+                }
+            }
+            return jsonable;
+        }
+
+        /** a self-type for chaining builder subclasses.  Concrete subclasses
+         * must return 'this' **/
+        protected abstract S self();
+    }
+
+    /**
+     * An abstract type that provides builder methods for configuring the name,
+     * doc, and aliases of all Avro types that have names (fields, Fixed, Record,
+     * and Enum).
+     * <p/>
+     * All Avro named types and fields have 'doc', 'aliases', and 'name'
+     * components. 'name' is required, and provided to this builder. 'doc' and
+     * 'alises' are optional.
+     */
+    public static abstract class NamedBuilder<S extends NamedBuilder<S>> extends
+            PropBuilder<S> {
+        private final String name;
+        private final NameContext names;
+        private String doc;
+        private String[] aliases;
+
+        protected NamedBuilder(NameContext names, String name) {
+            checkRequired(name, "Type must have a name");
+            this.names = names;
+            this.name = name;
+        }
+
+        /** configure this type's optional documentation string **/
+        public final S doc(String doc) {
+            this.doc = doc;
+            return self();
+        }
+
+        /** configure this type's optional name aliases **/
+        public final S aliases(String... aliases) {
+            this.aliases = aliases;
+            return self();
+        }
+
+        final String doc() {
+            return doc;
+        }
+
+        final String name() {
+            return name;
+        }
+
+        final NameContext names() {
+            return names;
+        }
+
+        final Schema addAliasesTo(Schema schema) {
+            if (null != aliases) {
+                for (String alias : aliases) {
+                    schema.addAlias(alias);
+                }
+            }
+            return schema;
+        }
+
+        final Field addAliasesTo(Field field) {
+            if (null != aliases) {
+                for (String alias : aliases) {
+                    field.addAlias(alias);
+                }
+            }
+            return field;
+        }
+    }
+
+    /**
+     * An abstract type that provides builder methods for configuring the
+     * namespace for all Avro types that have namespaces (Fixed, Record, and
+     * Enum).
+     */
+    public static abstract class NamespacedBuilder<R, S extends NamespacedBuilder<R, S>>
+            extends NamedBuilder<S> {
+        private final Completion<R> context;
+        private String namespace;
+
+        protected NamespacedBuilder(Completion<R> context, NameContext names,
+                                    String name) {
+            super(names, name);
+            this.context = context;
+        }
+
+        /**
+         * Set the namespace of this type. To clear the namespace, set empty string.
+         * <p/>
+         * When the namespace is null or unset, the namespace of the type defaults
+         * to the namespace of the enclosing context.
+         **/
+        public final S namespace(String namespace) {
+            this.namespace = namespace;
+            return self();
+        }
+
+        final String space() {
+            if (null == namespace) {
+                return names().namespace;
+            }
+            return namespace;
+        }
+
+        final Schema completeSchema(Schema schema) {
+            addPropsTo(schema);
+            addAliasesTo(schema);
+            names().put(schema);
+            return schema;
+        }
+
+        final Completion<R> context() {
+            return context;
+        }
+    }
+
+    /**
+     * An abstraction for sharing code amongst all primitive type builders.
+     */
+    private static abstract class PrimitiveBuilder<R, P extends PrimitiveBuilder<R, P>>
+            extends PropBuilder<P> {
+        private final Completion<R> context;
+        private final Schema immutable;
+
+        protected PrimitiveBuilder(Completion<R> context, NameContext names,
+                                   Schema.Type type) {
+            this.context = context;
+            this.immutable = names.getFullname(type.getName());
+        }
+
+        private R end() {
+            Schema schema = immutable;
+            if (super.hasProps()) {
+                schema = Schema.create(immutable.getType());
+                addPropsTo(schema);
+            }
+            return context.complete(schema);
+        }
+    }
+
+    /**
+     * Builds an Avro boolean type with optional properties. Set properties with
+     * {@link #prop(String, Object)}, and finalize with {@link #endBoolean()}
+     **/
+    public static final class BooleanBuilder<R> extends
+            PrimitiveBuilder<R, BooleanBuilder<R>> {
+        private BooleanBuilder(Completion<R> context, NameContext names) {
+            super(context, names, Schema.Type.BOOLEAN);
+        }
+
+        private static <R> BooleanBuilder<R> create(Completion<R> context,
+                                                    NameContext names) {
+            return new BooleanBuilder<R>(context, names);
+        }
+
+        @Override
+        protected BooleanBuilder<R> self() {
+            return this;
+        }
+
+        /** complete building this type, return control to context **/
+        public R endBoolean() {
+            return super.end();
+        }
+    }
+
+    /**
+     * Builds an Avro int type with optional properties. Set properties with
+     * {@link #prop(String, Object)}, and finalize with {@link #endInt()}
+     **/
+    public static final class IntBuilder<R> extends
+            PrimitiveBuilder<R, IntBuilder<R>> {
+        private IntBuilder(Completion<R> context, NameContext names) {
+            super(context, names, Schema.Type.INT);
+        }
+
+        private static <R> IntBuilder<R> create(Completion<R> context,
+                                                NameContext names) {
+            return new IntBuilder<R>(context, names);
+        }
+
+        @Override
+        protected IntBuilder<R> self() {
+            return this;
+        }
+
+        /** complete building this type, return control to context **/
+        public R endInt() {
+            return super.end();
+        }
+    }
+
+    /**
+     * Builds an Avro long type with optional properties. Set properties with
+     * {@link #prop(String, Object)}, and finalize with {@link #endLong()}
+     **/
+    public static final class LongBuilder<R> extends
+            PrimitiveBuilder<R, LongBuilder<R>> {
+        private LongBuilder(Completion<R> context, NameContext names) {
+            super(context, names, Schema.Type.LONG);
+        }
+
+        private static <R> LongBuilder<R> create(Completion<R> context,
+                                                 NameContext names) {
+            return new LongBuilder<R>(context, names);
+        }
+
+        @Override
+        protected LongBuilder<R> self() {
+            return this;
+        }
+
+        /** complete building this type, return control to context **/
+        public R endLong() {
+            return super.end();
+        }
+    }
+
+    /**
+     * Builds an Avro float type with optional properties. Set properties with
+     * {@link #prop(String, Object)}, and finalize with {@link #endFloat()}
+     **/
+    public static final class FloatBuilder<R> extends
+            PrimitiveBuilder<R, FloatBuilder<R>> {
+        private FloatBuilder(Completion<R> context, NameContext names) {
+            super(context, names, Schema.Type.FLOAT);
+        }
+
+        private static <R> FloatBuilder<R> create(Completion<R> context,
+                                                  NameContext names) {
+            return new FloatBuilder<R>(context, names);
+        }
+
+        @Override
+        protected FloatBuilder<R> self() {
+            return this;
+        }
+
+        /** complete building this type, return control to context **/
+        public R endFloat() {
+            return super.end();
+        }
+    }
+
+    /**
+     * Builds an Avro double type with optional properties. Set properties with
+     * {@link #prop(String, Object)}, and finalize with {@link #endDouble()}
+     **/
+    public static final class DoubleBuilder<R> extends
+            PrimitiveBuilder<R, DoubleBuilder<R>> {
+        private DoubleBuilder(Completion<R> context, NameContext names) {
+            super(context, names, Schema.Type.DOUBLE);
+        }
+
+        private static <R> DoubleBuilder<R> create(Completion<R> context,
+                                                   NameContext names) {
+            return new DoubleBuilder<R>(context, names);
+        }
+
+        @Override
+        protected DoubleBuilder<R> self() {
+            return this;
+        }
+
+        /** complete building this type, return control to context **/
+        public R endDouble() {
+            return super.end();
+        }
+    }
+
+    /**
+     * Builds an Avro string type with optional properties. Set properties with
+     * {@link #prop(String, Object)}, and finalize with {@link #endString()}
+     **/
+    public static final class StringBldr<R> extends
+            PrimitiveBuilder<R, StringBldr<R>> {
+        private StringBldr(Completion<R> context, NameContext names) {
+            super(context, names, Schema.Type.STRING);
+        }
+
+        private static <R> StringBldr<R> create(Completion<R> context,
+                                                NameContext names) {
+            return new StringBldr<R>(context, names);
+        }
+
+        @Override
+        protected StringBldr<R> self() {
+            return this;
+        }
+
+        /** complete building this type, return control to context **/
+        public R endString() {
+            return super.end();
+        }
+    }
+
+    /**
+     * Builds an Avro bytes type with optional properties. Set properties with
+     * {@link #prop(String, Object)}, and finalize with {@link #endBytes()}
+     **/
+    public static final class BytesBuilder<R> extends
+            PrimitiveBuilder<R, BytesBuilder<R>> {
+        private BytesBuilder(Completion<R> context, NameContext names) {
+            super(context, names, Schema.Type.BYTES);
+        }
+
+        private static <R> BytesBuilder<R> create(Completion<R> context,
+                                                  NameContext names) {
+            return new BytesBuilder<R>(context, names);
+        }
+
+        @Override
+        protected BytesBuilder<R> self() {
+            return this;
+        }
+
+        /** complete building this type, return control to context **/
+        public R endBytes() {
+            return super.end();
+        }
+    }
+
+    /**
+     * Builds an Avro null type with optional properties. Set properties with
+     * {@link #prop(String, Object)}, and finalize with {@link #endNull()}
+     **/
+    public static final class NullBuilder<R> extends
+            PrimitiveBuilder<R, NullBuilder<R>> {
+        private NullBuilder(Completion<R> context, NameContext names) {
+            super(context, names, Schema.Type.NULL);
+        }
+
+        private static <R> NullBuilder<R> create(Completion<R> context,
+                                                 NameContext names) {
+            return new NullBuilder<R>(context, names);
+        }
+
+        @Override
+        protected NullBuilder<R> self() {
+            return this;
+        }
+
+        /** complete building this type, return control to context **/
+        public R endNull() {
+            return super.end();
+        }
+    }
+
+    /**
+     * Builds an Avro Enum type with optional properties, namespace, doc, and
+     * aliases.
+     * <p/>
+     * Set properties with {@link #prop(String, Object)}, namespace with
+     * {@link #namespace(String)}, doc with {@link #doc(String)}, and aliases with
+     * {@link #aliases(String[])}.
+     * <p/>
+     * The Enum schema is finalized when its required symbols are set via
+     * {@link #symbols(String[])}.
+     **/
+    public static final class EnumBuilder<R> extends
+            NamespacedBuilder<R, EnumBuilder<R>> {
+        private EnumBuilder(Completion<R> context, NameContext names, String name) {
+            super(context, names, name);
+        }
+
+        private static <R> EnumBuilder<R> create(Completion<R> context,
+                                                 NameContext names, String name) {
+            return new EnumBuilder<R>(context, names, name);
+        }
+
+        @Override
+        protected EnumBuilder<R> self() {
+            return this;
+        }
+
+        /** Configure this enum type's symbols, and end its configuration. **/
+        public R symbols(String... symbols) {
+            Schema schema = Schema.createEnum(name(), doc(), space(),
+                    Arrays.asList(symbols));
+            completeSchema(schema);
+            return context().complete(schema);
+        }
+
+    }
+
+    /**
+     * Builds an Avro Map type with optional properties.
+     * <p/>
+     * Set properties with {@link #prop(String, Object)}.
+     * <p/>
+     * The Map schema's properties are finalized when {@link #values()} or
+     * {@link #values(Schema)} is called.
+     **/
+    public static final class MapBuilder<R> extends PropBuilder<MapBuilder<R>> {
+        private final Completion<R> context;
+        private final NameContext names;
+
+        private MapBuilder(Completion<R> context, NameContext names) {
+            this.context = context;
+            this.names = names;
+        }
+
+        private static <R> MapBuilder<R> create(Completion<R> context,
+                                                NameContext names) {
+            return new MapBuilder<R>(context, names);
+        }
+
+        @Override
+        protected MapBuilder<R> self() {
+            return this;
+        }
+
+        /**
+         * Return a type builder for configuring the map's nested values schema.
+         * This builder will return control to the map's enclosing context when
+         * complete.
+         **/
+        public TypeBuilder<R> values() {
+            return new TypeBuilder<R>(new MapCompletion<R>(this, context), names);
+        }
+
+        /**
+         * Complete configuration of this map, setting the schema of the map values
+         * to the schema provided. Returns control to the enclosing context.
+         **/
+        public R values(Schema valueSchema) {
+            return new MapCompletion<R>(this, context).complete(valueSchema);
+        }
+    }
+
+    /**
+     * Builds an Avro Array type with optional properties.
+     * <p/>
+     * Set properties with {@link #prop(String, Object)}.
+     * <p/>
+     * The Array schema's properties are finalized when {@link #items()} or
+     * {@link #items(Schema)} is called.
+     **/
+    public static final class ArrayBuilder<R> extends
+            PropBuilder<ArrayBuilder<R>> {
+        private final Completion<R> context;
+        private final NameContext names;
+
+        public ArrayBuilder(Completion<R> context, NameContext names) {
+            this.context = context;
+            this.names = names;
+        }
+
+        private static <R> ArrayBuilder<R> create(Completion<R> context,
+                                                  NameContext names) {
+            return new ArrayBuilder<R>(context, names);
+        }
+
+        @Override
+        protected ArrayBuilder<R> self() {
+            return this;
+        }
+
+        /**
+         * Return a type builder for configuring the array's nested items schema.
+         * This builder will return control to the array's enclosing context when
+         * complete.
+         **/
+        public TypeBuilder<R> items() {
+            return new TypeBuilder<R>(new ArrayCompletion<R>(this, context), names);
+        }
+
+        /**
+         * Complete configuration of this array, setting the schema of the array
+         * items to the schema provided. Returns control to the enclosing context.
+         **/
+        public R items(Schema itemsSchema) {
+            return new ArrayCompletion<R>(this, context).complete(itemsSchema);
+        }
+    }
+
+    /**
+     * internal class for passing the naming context around. This allows for the
+     * following:
+     * <li>Cache and re-use primitive schemas when they do not set
+     * properties.</li>
+     * <li>Provide a default namespace for nested contexts (as
+     * the JSON Schema spec does).</li>
+     * <li>Allow previously defined named types or primitive types
+     * to be referenced by name.</li>
+     **/
+    private static class NameContext {
+        private static final Set<String> PRIMITIVES = new HashSet<String>();
+
+        {
+            PRIMITIVES.add("null");
+            PRIMITIVES.add("boolean");
+            PRIMITIVES.add("int");
+            PRIMITIVES.add("long");
+            PRIMITIVES.add("float");
+            PRIMITIVES.add("double");
+            PRIMITIVES.add("bytes");
+            PRIMITIVES.add("string");
+        }
+
+        private final HashMap<String, Schema> schemas;
+        private final String namespace;
+
+        private NameContext() {
+            this.schemas = new HashMap<String, Schema>();
+            this.namespace = null;
+            schemas.put("null", Schema.create(Schema.Type.NULL));
+            schemas.put("boolean", Schema.create(Schema.Type.BOOLEAN));
+            schemas.put("int", Schema.create(Schema.Type.INT));
+            schemas.put("long", Schema.create(Schema.Type.LONG));
+            schemas.put("float", Schema.create(Schema.Type.FLOAT));
+            schemas.put("double", Schema.create(Schema.Type.DOUBLE));
+            schemas.put("bytes", Schema.create(Schema.Type.BYTES));
+            schemas.put("string", Schema.create(Schema.Type.STRING));
+        }
+
+        private NameContext(HashMap<String, Schema> schemas, String namespace) {
+            this.schemas = schemas;
+            this.namespace = "".equals(namespace) ? null : namespace;
+        }
+
+        private NameContext namespace(String namespace) {
+            return new NameContext(schemas, namespace);
+        }
+
+        private Schema get(String name, String namespace) {
+            return getFullname(resolveName(name, namespace));
+        }
+
+        private Schema getFullname(String fullName) {
+            Schema schema = schemas.get(fullName);
+            if (schema == null) {
+                throw new SchemaParseException("Undefined name: " + fullName);
+            }
+            return schema;
+        }
+
+        private void put(Schema schema) {
+            String fullName = schema.getFullName();
+            if (schemas.containsKey(fullName)) {
+                throw new SchemaParseException("Can't redefine: " + fullName);
+            }
+            schemas.put(fullName, schema);
+        }
+
+        private String resolveName(String name, String space) {
+            if (PRIMITIVES.contains(name) && space == null) {
+                return name;
+            }
+            int lastDot = name.lastIndexOf('.');
+            if (lastDot < 0) { // short name
+                if (space == null) {
+                    space = namespace;
+                }
+                if (space != null && !"".equals(space)) {
+                    return space + "." + name;
+                }
+            }
+            return name;
+        }
+    }
+
+    /**
+     * A common API for building types within a context. BaseTypeBuilder can build
+     * all types other than Unions. {@link TypeBuilder} can additionally build
+     * Unions.
+     * <p/>
+     * The builder has two contexts:
+     * <li>A naming context provides a default namespace and allows for previously
+     * defined named types to be referenced from {@link #type(String)}</li>
+     * <li>A completion context representing the scope that the builder was
+     * created in. A builder created in a nested context (for example,
+     * {@link MapBuilder#values()} will have a completion context assigned by the
+     * {@link MapBuilder}</li>
+     **/
+    public static class BaseTypeBuilder<R> {
+        private final Completion<R> context;
+        private final NameContext names;
+
+        private BaseTypeBuilder(Completion<R> context, NameContext names) {
+            this.context = context;
+            this.names = names;
+        }
+
+        /** Use the schema provided as the type. **/
+        public final R type(Schema schema) {
+            return context.complete(schema);
+        }
+
+        /**
+         * Look up the type by name. This type must be previously defined in the
+         * context of this builder.
+         * <p/>
+         * The name may be fully qualified or a short name. If it is a short name,
+         * the default namespace of the current context will additionally be
+         * searched.
+         **/
+        public final R type(String name) {
+            return type(name, null);
+        }
+
+        /**
+         * Look up the type by name and namespace. This type must be previously
+         * defined in the context of this builder.
+         * <p/>
+         * The name may be fully qualified or a short name. If it is a fully
+         * qualified name, the namespace provided is ignored. If it is a short name,
+         * the namespace provided is used if not null, else the default namespace of
+         * the current context will be used.
+         **/
+        public final R type(String name, String namespace) {
+            return type(names.get(name, namespace));
+        }
+
+        /**
+         * A plain boolean type without custom properties. This is equivalent to:
+         * <pre>
+         * booleanBuilder().endBoolean();
+         * </pre>
+         */
+        public final R booleanType() {
+            return booleanBuilder().endBoolean();
+        }
+
+        /**
+         * Build a boolean type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #booleanType()}.
+         */
+        public final BooleanBuilder<R> booleanBuilder() {
+            return BooleanBuilder.create(context, names);
+        }
+
+        /**
+         * A plain int type without custom properties. This is equivalent to:
+         * <pre>
+         * intBuilder().endInt();
+         * </pre>
+         */
+        public final R intType() {
+            return intBuilder().endInt();
+        }
+
+        /**
+         * Build an int type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #intType()}.
+         */
+        public final IntBuilder<R> intBuilder() {
+            return IntBuilder.create(context, names);
+        }
+
+        /**
+         * A plain long type without custom properties. This is equivalent to:
+         * <pre>
+         * longBuilder().endLong();
+         * </pre>
+         */
+        public final R longType() {
+            return longBuilder().endLong();
+        }
+
+        /**
+         * Build a long type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #longType()}.
+         */
+        public final LongBuilder<R> longBuilder() {
+            return LongBuilder.create(context, names);
+        }
+
+        /**
+         * A plain float type without custom properties. This is equivalent to:
+         * <pre>
+         * floatBuilder().endFloat();
+         * </pre>
+         */
+        public final R floatType() {
+            return floatBuilder().endFloat();
+        }
+
+        /**
+         * Build a float type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #floatType()}.
+         */
+        public final FloatBuilder<R> floatBuilder() {
+            return FloatBuilder.create(context, names);
+        }
+
+        /**
+         * A plain double type without custom properties. This is equivalent to:
+         * <pre>
+         * doubleBuilder().endDouble();
+         * </pre>
+         */
+        public final R doubleType() {
+            return doubleBuilder().endDouble();
+        }
+
+        /**
+         * Build a double type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #doubleType()}.
+         */
+        public final DoubleBuilder<R> doubleBuilder() {
+            return DoubleBuilder.create(context, names);
+        }
+
+        /**
+         * A plain string type without custom properties. This is equivalent to:
+         * <pre>
+         * stringBuilder().endString();
+         * </pre>
+         */
+        public final R stringType() {
+            return stringBuilder().endString();
+        }
+
+        /**
+         * Build a string type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #stringType()}.
+         */
+        public final StringBldr<R> stringBuilder() {
+            return StringBldr.create(context, names);
+        }
+
+        /**
+         * A plain bytes type without custom properties. This is equivalent to:
+         * <pre>
+         * bytesBuilder().endBytes();
+         * </pre>
+         */
+        public final R bytesType() {
+            return bytesBuilder().endBytes();
+        }
+
+        /**
+         * Build a bytes type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #bytesType()}.
+         */
+        public final BytesBuilder<R> bytesBuilder() {
+            return BytesBuilder.create(context, names);
+        }
+
+        /**
+         * A plain null type without custom properties. This is equivalent to:
+         * <pre>
+         * nullBuilder().endNull();
+         * </pre>
+         */
+        public final R nullType() {
+            return nullBuilder().endNull();
+        }
+
+        /**
+         * Build a null type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #nullType()}.
+         */
+        public final NullBuilder<R> nullBuilder() {
+            return NullBuilder.create(context, names);
+        }
+
+        /** Build an Avro map type  Example usage:
+         * <pre>
+         * map().values().intType()
+         * </pre>
+         * Equivalent to Avro JSON Schema:
+         * <pre>
+         * {"type":"map", "values":"int"}
+         * </pre>
+         **/
+        public final MapBuilder<R> map() {
+            return MapBuilder.create(context, names);
+        }
+
+        /** Build an Avro array type  Example usage:
+         * <pre>
+         * array().items().longType()
+         * </pre>
+         * Equivalent to Avro JSON Schema:
+         * <pre>
+         * {"type":"array", "values":"long"}
+         * </pre>
+         **/
+        public final ArrayBuilder<R> array() {
+            return ArrayBuilder.create(context, names);
+        }
+
+        /** Build an Avro enum type. Example usage:
+         * <pre>
+         * enumeration("Suits").namespace("org.cards").doc("card suit names")
+         *   .symbols("HEART", "SPADE", "DIAMOND", "CLUB")
+         * </pre>
+         * Equivalent to Avro JSON Schema:
+         * <pre>
+         * {"type":"enum", "name":"Suits", "namespace":"org.cards",
+         *  "doc":"card suit names", "symbols":[
+         *    "HEART", "SPADE", "DIAMOND", "CLUB"]}
+         * </pre>
+         **/
+        public final EnumBuilder<R> enumeration(String name) {
+            return EnumBuilder.create(context, names, name);
+        }
+
+        /** Build an Avro union schema type. Example usage:
+         * <pre>unionOf().stringType().and().bytesType().endUnion()</pre>
+         **/
+        protected BaseTypeBuilder<UnionAccumulator<R>> unionOf() {
+            return UnionBuilder.create(context, names);
+        }
+
+        /** A shortcut for building a union of a type and null.
+         * <p/>
+         * For example, the code snippets below are equivalent:
+         * <pre>nullable().booleanType()</pre>
+         * <pre>unionOf().booleanType().and().nullType().endUnion()</pre>
+         **/
+        protected BaseTypeBuilder<R> nullable() {
+            return new BaseTypeBuilder<R>(new NullableCompletion<R>(context), names);
+        }
+
+    }
+
+    /** A Builder for creating any Avro schema type.
+     **/
+    public static final class TypeBuilder<R> extends BaseTypeBuilder<R> {
+        private TypeBuilder(Completion<R> context, NameContext names) {
+            super(context, names);
+        }
+
+        @Override
+        public BaseTypeBuilder<UnionAccumulator<R>> unionOf() {
+            return super.unionOf();
+        }
+
+        @Override
+        public BaseTypeBuilder<R> nullable() {
+            return super.nullable();
+        }
+    }
+
+    /** A special builder for unions.  Unions cannot nest unions directly **/
+    private static final class UnionBuilder<R> extends
+            BaseTypeBuilder<UnionAccumulator<R>> {
+        private UnionBuilder(Completion<R> context, NameContext names) {
+            this(context, names, new ArrayList<Schema>());
+        }
+
+        private static <R> UnionBuilder<R> create(Completion<R> context, NameContext names) {
+            return new UnionBuilder<R>(context, names);
+        }
+
+        private UnionBuilder(Completion<R> context, NameContext names, List<Schema> schemas) {
+            super(new UnionCompletion<R>(context, names, schemas), names);
+        }
+    }
+
+    /**
+     * A special Builder for Record fields. The API is very similar to
+     * {@link BaseTypeBuilder}. However, fields have their own names, properties,
+     * and default values.
+     * <p/>
+     * The methods on this class create builder instances that return their
+     * control to the {@link FieldAssembler} of the enclosing record context after
+     * configuring a default for the field.
+     * <p/>
+     * For example, an int field with default value 1:
+     * <pre>
+     * intSimple().withDefault(1);
+     * </pre>
+     * or an array with items that are optional int types:
+     * <pre>
+     * array().items().optional().intType();
+     * </pre>
+     */
+    public static class BaseFieldTypeBuilder<R> {
+        protected final FieldBuilder<R> bldr;
+        protected final NameContext names;
+        private final CompletionWrapper wrapper;
+
+        protected BaseFieldTypeBuilder(FieldBuilder<R> bldr, CompletionWrapper wrapper) {
+            this.bldr = bldr;
+            this.names = bldr.names();
+            this.wrapper = wrapper;
+        }
+
+        /**
+         * A plain boolean type without custom properties. This is equivalent to:
+         * <pre>
+         * booleanBuilder().endBoolean();
+         * </pre>
+         */
+        public final BooleanDefault<R> booleanType() {
+            return booleanBuilder().endBoolean();
+        }
+
+        /**
+         * Build a boolean type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #booleanType()}.
+         */
+        public final BooleanBuilder<BooleanDefault<R>> booleanBuilder() {
+            return BooleanBuilder.create(wrap(new BooleanDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain int type without custom properties. This is equivalent to:
+         * <pre>
+         * intBuilder().endInt();
+         * </pre>
+         */
+        public final IntDefault<R> intType() {
+            return intBuilder().endInt();
+        }
+
+        /**
+         * Build an int type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #intType()}.
+         */
+        public final IntBuilder<IntDefault<R>> intBuilder() {
+            return IntBuilder.create(wrap(new IntDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain long type without custom properties. This is equivalent to:
+         * <pre>
+         * longBuilder().endLong();
+         * </pre>
+         */
+        public final LongDefault<R> longType() {
+            return longBuilder().endLong();
+        }
+
+        /**
+         * Build a long type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #longType()}.
+         */
+        public final LongBuilder<LongDefault<R>> longBuilder() {
+            return LongBuilder.create(wrap(new LongDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain float type without custom properties. This is equivalent to:
+         * <pre>
+         * floatBuilder().endFloat();
+         * </pre>
+         */
+        public final FloatDefault<R> floatType() {
+            return floatBuilder().endFloat();
+        }
+
+        /**
+         * Build a float type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #floatType()}.
+         */
+        public final FloatBuilder<FloatDefault<R>> floatBuilder() {
+            return FloatBuilder.create(wrap(new FloatDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain double type without custom properties. This is equivalent to:
+         * <pre>
+         * doubleBuilder().endDouble();
+         * </pre>
+         */
+        public final DoubleDefault<R> doubleType() {
+            return doubleBuilder().endDouble();
+        }
+
+        /**
+         * Build a double type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #doubleType()}.
+         */
+        public final DoubleBuilder<DoubleDefault<R>> doubleBuilder() {
+            return DoubleBuilder.create(wrap(new DoubleDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain string type without custom properties. This is equivalent to:
+         * <pre>
+         * stringBuilder().endString();
+         * </pre>
+         */
+        public final StringDefault<R> stringType() {
+            return stringBuilder().endString();
+        }
+
+        /**
+         * Build a string type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #stringType()}.
+         */
+        public final StringBldr<StringDefault<R>> stringBuilder() {
+            return StringBldr.create(wrap(new StringDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain bytes type without custom properties. This is equivalent to:
+         * <pre>
+         * bytesBuilder().endBytes();
+         * </pre>
+         */
+        public final BytesDefault<R> bytesType() {
+            return bytesBuilder().endBytes();
+        }
+
+        /**
+         * Build a bytes type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #bytesType()}.
+         */
+        public final BytesBuilder<BytesDefault<R>> bytesBuilder() {
+            return BytesBuilder.create(wrap(new BytesDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain null type without custom properties. This is equivalent to:
+         * <pre>
+         * nullBuilder().endNull();
+         * </pre>
+         */
+        public final NullDefault<R> nullType() {
+            return nullBuilder().endNull();
+        }
+
+        /**
+         * Build a null type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #nullType()}.
+         */
+        public final NullBuilder<NullDefault<R>> nullBuilder() {
+            return NullBuilder.create(wrap(new NullDefault<R>(bldr)), names);
+        }
+
+        /** Build an Avro map type **/
+        public final MapBuilder<MapDefault<R>> map() {
+            return MapBuilder.create(wrap(new MapDefault<R>(bldr)), names);
+        }
+
+        /** Build an Avro array type **/
+        public final ArrayBuilder<ArrayDefault<R>> array() {
+            return ArrayBuilder.create(wrap(new ArrayDefault<R>(bldr)), names);
+        }
+
+        /** Build an Avro enum type. **/
+        public final EnumBuilder<EnumDefault<R>> enumeration(String name) {
+            return EnumBuilder.create(wrap(new EnumDefault<R>(bldr)), names, name);
+        }
+
+        private <C> Completion<C> wrap(
+                Completion<C> completion) {
+            if (wrapper != null) {
+                return wrapper.wrap(completion);
+            }
+            return completion;
+        }
+    }
+
+    /** FieldTypeBuilder adds {@link #unionOf()}, {@link #nullable()}, and {@link #optional()}
+     * to BaseFieldTypeBuilder. **/
+    public static final class FieldTypeBuilder<R> extends BaseFieldTypeBuilder<R> {
+        private FieldTypeBuilder(FieldBuilder<R> bldr) {
+            super(bldr, null);
+        }
+
+        /** Build an Avro union schema type. **/
+        public UnionFieldTypeBuilder<R> unionOf() {
+            return new UnionFieldTypeBuilder<R>(bldr);
+        }
+
+        /**
+         * A shortcut for building a union of a type and null, with an optional default
+         * value of the non-null type.
+         * <p/>
+         * For example, the two code snippets below are equivalent:
+         * <pre>nullable().booleanType().booleanDefault(true)</pre>
+         * <pre>unionOf().booleanType().and().nullType().endUnion().booleanDefault(true)</pre>
+         **/
+        public BaseFieldTypeBuilder<R> nullable() {
+            return new BaseFieldTypeBuilder<R>(bldr, new NullableCompletionWrapper());
+        }
+
+        /**
+         * A shortcut for building a union of null and a type, with a null default.
+         * <p/>
+         * For example, the two code snippets below are equivalent:
+         * <pre>optional().booleanType()</pre>
+         * <pre>unionOf().nullType().and().booleanType().endUnion().nullDefault()</pre>
+         */
+        public BaseTypeBuilder<FieldAssembler<R>> optional() {
+            return new BaseTypeBuilder<FieldAssembler<R>>(
+                    new OptionalCompletion<R>(bldr), names);
+        }
+    }
+
+    /** Builder for a union field.  The first type in the union corresponds
+     * to the possible default value type.
+     */
+    public static final class UnionFieldTypeBuilder<R> {
+        private final FieldBuilder<R> bldr;
+        private final NameContext names;
+
+        private UnionFieldTypeBuilder(FieldBuilder<R> bldr) {
+            this.bldr = bldr;
+            this.names = bldr.names();
+        }
+
+        /**
+         * A plain boolean type without custom properties. This is equivalent to:
+         * <pre>
+         * booleanBuilder().endBoolean();
+         * </pre>
+         */
+        public UnionAccumulator<BooleanDefault<R>> booleanType() {
+            return booleanBuilder().endBoolean();
+        }
+
+        /**
+         * Build a boolean type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #booleanType()}.
+         */
+        public BooleanBuilder<UnionAccumulator<BooleanDefault<R>>> booleanBuilder() {
+            return BooleanBuilder.create(completion(new BooleanDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain int type without custom properties. This is equivalent to:
+         * <pre>
+         * intBuilder().endInt();
+         * </pre>
+         */
+        public UnionAccumulator<IntDefault<R>> intType() {
+            return intBuilder().endInt();
+        }
+
+        /**
+         * Build an int type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #intType()}.
+         */
+        public IntBuilder<UnionAccumulator<IntDefault<R>>> intBuilder() {
+            return IntBuilder.create(completion(new IntDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain long type without custom properties. This is equivalent to:
+         * <pre>
+         * longBuilder().endLong();
+         * </pre>
+         */
+        public UnionAccumulator<LongDefault<R>> longType() {
+            return longBuilder().endLong();
+        }
+
+        /**
+         * Build a long type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #longType()}.
+         */
+        public LongBuilder<UnionAccumulator<LongDefault<R>>> longBuilder() {
+            return LongBuilder.create(completion(new LongDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain float type without custom properties. This is equivalent to:
+         * <pre>
+         * floatBuilder().endFloat();
+         * </pre>
+         */
+        public UnionAccumulator<FloatDefault<R>> floatType() {
+            return floatBuilder().endFloat();
+        }
+
+        /**
+         * Build a float type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #floatType()}.
+         */
+        public FloatBuilder<UnionAccumulator<FloatDefault<R>>> floatBuilder() {
+            return FloatBuilder.create(completion(new FloatDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain double type without custom properties. This is equivalent to:
+         * <pre>
+         * doubleBuilder().endDouble();
+         * </pre>
+         */
+        public UnionAccumulator<DoubleDefault<R>> doubleType() {
+            return doubleBuilder().endDouble();
+        }
+
+        /**
+         * Build a double type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #doubleType()}.
+         */
+        public DoubleBuilder<UnionAccumulator<DoubleDefault<R>>> doubleBuilder() {
+            return DoubleBuilder.create(completion(new DoubleDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain string type without custom properties. This is equivalent to:
+         * <pre>
+         * stringBuilder().endString();
+         * </pre>
+         */
+        public UnionAccumulator<StringDefault<R>> stringType() {
+            return stringBuilder().endString();
+        }
+
+        /**
+         * Build a string type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #stringType()}.
+         */
+        public StringBldr<UnionAccumulator<StringDefault<R>>> stringBuilder() {
+            return StringBldr.create(completion(new StringDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain bytes type without custom properties. This is equivalent to:
+         * <pre>
+         * bytesBuilder().endBytes();
+         * </pre>
+         */
+        public UnionAccumulator<BytesDefault<R>> bytesType() {
+            return bytesBuilder().endBytes();
+        }
+
+        /**
+         * Build a bytes type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #bytesType()}.
+         */
+        public BytesBuilder<UnionAccumulator<BytesDefault<R>>> bytesBuilder() {
+            return BytesBuilder.create(completion(new BytesDefault<R>(bldr)), names);
+        }
+
+        /**
+         * A plain null type without custom properties. This is equivalent to:
+         * <pre>
+         * nullBuilder().endNull();
+         * </pre>
+         */
+        public UnionAccumulator<NullDefault<R>> nullType() {
+            return nullBuilder().endNull();
+        }
+
+        /**
+         * Build a null type that can set custom properties. If custom properties
+         * are not needed it is simpler to use {@link #nullType()}.
+         */
+        public NullBuilder<UnionAccumulator<NullDefault<R>>> nullBuilder() {
+            return NullBuilder.create(completion(new NullDefault<R>(bldr)), names);
+        }
+
+        /** Build an Avro map type **/
+        public MapBuilder<UnionAccumulator<MapDefault<R>>> map() {
+            return MapBuilder.create(completion(new MapDefault<R>(bldr)), names);
+        }
+
+        /** Build an Avro array type **/
+        public ArrayBuilder<UnionAccumulator<ArrayDefault<R>>> array() {
+            return ArrayBuilder.create(completion(new ArrayDefault<R>(bldr)), names);
+        }
+
+        /** Build an Avro enum type. **/
+        public EnumBuilder<UnionAccumulator<EnumDefault<R>>> enumeration(String name) {
+            return EnumBuilder.create(completion(new EnumDefault<R>(bldr)), names, name);
+        }
+
+        private <C> UnionCompletion<C> completion(Completion<C> context) {
+            return new UnionCompletion<C>(context, names, new ArrayList<Schema>());
+        }
+    }
+
+    public final static class FieldAssembler<R> {
+        private final List<Field> fields = new ArrayList<Field>();
+        private final Completion<R> context;
+        private final NameContext names;
+        private final Schema record;
+
+        private FieldAssembler(Completion<R> context, NameContext names, Schema record) {
+            this.context = context;
+            this.names = names;
+            this.record = record;
+        }
+
+        /**
+         * Add a field with the given name.
+         * @return A {@link FieldBuilder} for the given name.
+         */
+        public FieldBuilder<R> name(String fieldName) {
+            return new FieldBuilder<R>(this, names, fieldName);
+        }
+
+        /**
+         * Shortcut for creating a boolean field with the given name and no default.
+         * <p/>This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().booleanType().noDefault()
+         * </pre>
+         */
+        public FieldAssembler<R> requiredBoolean(String fieldName) {
+            return name(fieldName).type().booleanType().noDefault();
+        }
+
+        /**
+         * Shortcut for creating an optional boolean field: a union of null and
+         * boolean with null default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().optional().booleanType()
+         * </pre>
+         */
+        public FieldAssembler<R> optionalBoolean(String fieldName) {
+            return name(fieldName).type().optional().booleanType();
+        }
+
+        /**
+         * Shortcut for creating a nullable boolean field: a union of boolean and
+         * null with an boolean default.
+         * <p/>
+         * This is equivalent to:
+         *
+         * <pre>
+         * name(fieldName).type().nullable().booleanType().booleanDefault(defaultVal)
+         * </pre>
+         */
+        public FieldAssembler<R> nullableBoolean(String fieldName, boolean defaultVal) {
+            return name(fieldName)
+                    .type().nullable().booleanType().booleanDefault(defaultVal);
+        }
+
+        /**
+         * Shortcut for creating an int field with the given name and no default.
+         * <p/>This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().intType().noDefault()
+         * </pre>
+         */
+        public FieldAssembler<R> requiredInt(String fieldName) {
+            return name(fieldName).type().intType().noDefault();
+        }
+
+        /**
+         * Shortcut for creating an optional int field: a union of null and int
+         * with null default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().optional().intType()
+         * </pre>
+         */
+        public FieldAssembler<R> optionalInt(String fieldName) {
+            return name(fieldName).type().optional().intType();
+        }
+
+        /**
+         * Shortcut for creating a nullable int field: a union of int and null
+         * with an int default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().nullable().intType().intDefault(defaultVal)
+         * </pre>
+         */
+        public FieldAssembler<R> nullableInt(String fieldName, int defaultVal) {
+            return name(fieldName).type().nullable().intType().intDefault(defaultVal);
+        }
+
+        /**
+         * Shortcut for creating a long field with the given name and no default.
+         * <p/>This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().longType().noDefault()
+         * </pre>
+         */
+        public FieldAssembler<R> requiredLong(String fieldName) {
+            return name(fieldName).type().longType().noDefault();
+        }
+
+        /**
+         * Shortcut for creating an optional long field: a union of null and long
+         * with null default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().optional().longType()
+         * </pre>
+         */
+        public FieldAssembler<R> optionalLong(String fieldName) {
+            return name(fieldName).type().optional().longType();
+        }
+
+        /**
+         * Shortcut for creating a nullable long field: a union of long and null
+         * with a long default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().nullable().longType().longDefault(defaultVal)
+         * </pre>
+         */
+        public FieldAssembler<R> nullableLong(String fieldName, long defaultVal) {
+            return name(fieldName).type().nullable().longType().longDefault(defaultVal);
+        }
+
+        /**
+         * Shortcut for creating a float field with the given name and no default.
+         * <p/>This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().floatType().noDefault()
+         * </pre>
+         */
+        public FieldAssembler<R> requiredFloat(String fieldName) {
+            return name(fieldName).type().floatType().noDefault();
+        }
+
+        /**
+         * Shortcut for creating an optional float field: a union of null and float
+         * with null default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().optional().floatType()
+         * </pre>
+         */
+        public FieldAssembler<R> optionalFloat(String fieldName) {
+            return name(fieldName).type().optional().floatType();
+        }
+
+        /**
+         * Shortcut for creating a nullable float field: a union of float and null
+         * with a float default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().nullable().floatType().floatDefault(defaultVal)
+         * </pre>
+         */
+        public FieldAssembler<R> nullableFloat(String fieldName, float defaultVal) {
+            return name(fieldName).type().nullable().floatType().floatDefault(defaultVal);
+        }
+
+        /**
+         * Shortcut for creating a double field with the given name and no default.
+         * <p/>This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().doubleType().noDefault()
+         * </pre>
+         */
+        public FieldAssembler<R> requiredDouble(String fieldName) {
+            return name(fieldName).type().doubleType().noDefault();
+        }
+
+        /**
+         * Shortcut for creating an optional double field: a union of null and double
+         * with null default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().optional().doubleType()
+         * </pre>
+         */
+        public FieldAssembler<R> optionalDouble(String fieldName) {
+            return name(fieldName).type().optional().doubleType();
+        }
+
+        /**
+         * Shortcut for creating a nullable double field: a union of double and null
+         * with a double default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().nullable().doubleType().doubleDefault(defaultVal)
+         * </pre>
+         */
+        public FieldAssembler<R> nullableDouble(String fieldName, double defaultVal) {
+            return name(fieldName).type().nullable().doubleType().doubleDefault(defaultVal);
+        }
+
+        /**
+         * Shortcut for creating a string field with the given name and no default.
+         * <p/>This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().stringType().noDefault()
+         * </pre>
+         */
+        public FieldAssembler<R> requiredString(String fieldName) {
+            return name(fieldName).type().stringType().noDefault();
+        }
+
+        /**
+         * Shortcut for creating an optional string field: a union of null and string
+         * with null default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().optional().stringType()
+         * </pre>
+         */
+        public FieldAssembler<R> optionalString(String fieldName) {
+            return name(fieldName).type().optional().stringType();
+        }
+
+        /**
+         * Shortcut for creating a nullable string field: a union of string and null
+         * with a string default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().nullable().stringType().stringDefault(defaultVal)
+         * </pre>
+         */
+        public FieldAssembler<R> nullableString(String fieldName, String defaultVal) {
+            return name(fieldName).type().nullable().stringType().stringDefault(defaultVal);
+        }
+
+        /**
+         * Shortcut for creating a bytes field with the given name and no default.
+         * <p/>This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().bytesType().noDefault()
+         * </pre>
+         */
+        public FieldAssembler<R> requiredBytes(String fieldName) {
+            return name(fieldName).type().bytesType().noDefault();
+        }
+
+        /**
+         * Shortcut for creating an optional bytes field: a union of null and bytes
+         * with null default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().optional().bytesType()
+         * </pre>
+         */
+        public FieldAssembler<R> optionalBytes(String fieldName) {
+            return name(fieldName).type().optional().bytesType();
+        }
+
+        /**
+         * Shortcut for creating a nullable bytes field: a union of bytes and null
+         * with a bytes default.<p/>
+         * This is equivalent to:
+         * <pre>
+         *   name(fieldName).type().nullable().bytesType().bytesDefault(defaultVal)
+         * </pre>
+         */
+        public FieldAssembler<R> nullableBytes(String fieldName, byte[] defaultVal) {
+            return name(fieldName).type().nullable().bytesType().bytesDefault(defaultVal);
+        }
+
+        /**
+         * End adding fields to this record, returning control
+         * to the context that this record builder was created in.
+         */
+        public R endRecord() {
+            record.setFields(fields);
+            return context.complete(record);
+        }
+
+        private FieldAssembler<R> addField(Field field) {
+            fields.add(field);
+            return this;
+        }
+
+    }
+
+    /**
+     * Builds a Field in the context of a {@link FieldAssembler}.
+     *
+     * Usage is to first configure any of the optional parameters and then to call one
+     * of the type methods to complete the field.  For example
+     * <pre>
+     *   .namespace("org.apache.example").orderDecending().type()
+     * </pre>
+     * Optional parameters for a field are namespace, doc, order, and aliases.
+     */
+    public final static class FieldBuilder<R> extends
+            NamedBuilder<FieldBuilder<R>> {
+        private final FieldAssembler<R> fields;
+        private Schema.Field.Order order = Schema.Field.Order.ASCENDING;
+
+        private FieldBuilder(FieldAssembler<R> fields, NameContext names, String name) {
+            super(names, name);
+            this.fields = fields;
+        }
+
+        /** Set this field to have ascending order.  Ascending is the default **/
+        public FieldBuilder<R> orderAscending() {
+            order = Schema.Field.Order.ASCENDING;
+            return self();
+        }
+
+        /** Set this field to have decending order.  Decending is the default **/
+        public FieldBuilder<R> orderDescending() {
+            order = Schema.Field.Order.DESCENDING;
+            return self();
+        }
+
+        /** Set this field to ignore order.  **/
+        public FieldBuilder<R> orderIgnore() {
+            order = Schema.Field.Order.IGNORE;
+            return self();
+        }
+
+        /**
+         * Final step in configuring this field, finalizing name, namespace, alias,
+         * and order.
+         * @return A builder for the field's type and default value.
+         */
+        public FieldTypeBuilder<R> type() {
+            return new FieldTypeBuilder<R>(this);
+        }
+
+        /**
+         * Final step in configuring this field, finalizing name, namespace, alias,
+         * and order.  Sets the field's type to the provided schema, returns a
+         * {@link GenericDefault}.
+         */
+        public GenericDefault<R> type(Schema type) {
+            return new GenericDefault<R>(this, type);
+        }
+
+        /**
+         * Final step in configuring this field, finalizing name, namespace, alias,
+         * and order. Sets the field's type to the schema by name reference.
+         * <p/>
+         * The name must correspond with a named schema that has already been
+         * created in the context of this builder. The name may be a fully qualified
+         * name, or a short name. If it is a short name, the namespace context of
+         * this builder will be used.
+         * <p/>
+         * The name and namespace context rules are the same as the Avro schema JSON
+         * specification.
+         */
+        public GenericDefault<R> type(String name) {
+            return type(name, null);
+        }
+
+        /**
+         * Final step in configuring this field, finalizing name, namespace, alias,
+         * and order. Sets the field's type to the schema by name reference.
+         * <p/>
+         * The name must correspond with a named schema that has already been
+         * created in the context of this builder. The name may be a fully qualified
+         * name, or a short name. If it is a full name, the namespace is ignored. If
+         * it is a short name, the namespace provided is used. If the namespace
+         * provided is null, the namespace context of this builder will be used.
+         * <p/>
+         * The name and namespace context rules are the same as the Avro schema JSON
+         * specification.
+         */
+        public GenericDefault<R> type(String name, String namespace) {
+            Schema schema = names().get(name, namespace);
+            return type(schema);
+        }
+
+        private FieldAssembler<R> completeField(Schema schema) {
+            return completeField(schema, null);
+        }
+
+        private FieldAssembler<R> completeField(Schema schema, Object defaultVal) {
+            Field field = new Field(name(), schema, doc(), defaultVal, order);
+            addPropsTo(field);
+            addAliasesTo(field);
+            return fields.addField(field);
+        }
+
+        @Override
+        protected FieldBuilder<R> self() {
+            return this;
+        }
+    }
+
+    /** Abstract base class for field defaults. **/
+    public static abstract class FieldDefault<R, S extends FieldDefault<R, S>> extends Completion<S> {
+        private final FieldBuilder<R> field;
+        private Schema schema;
+
+        FieldDefault(FieldBuilder<R> field) {
+            this.field = field;
+        }
+
+        /** Completes this field with no default value **/
+        public final FieldAssembler<R> noDefault() {
+            return field.completeField(schema);
+        }
+
+        private FieldAssembler<R> usingDefault(Object defaultVal) {
+            return field.completeField(schema, defaultVal);
+        }
+
+        @Override
+        final S complete(Schema schema) {
+            this.schema = schema;
+            return self();
+        }
+
+        abstract S self();
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class BooleanDefault<R> extends FieldDefault<R, BooleanDefault<R>> {
+        private BooleanDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided **/
+        public final FieldAssembler<R> booleanDefault(boolean defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final BooleanDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class IntDefault<R> extends FieldDefault<R, IntDefault<R>> {
+        private IntDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided **/
+        public final FieldAssembler<R> intDefault(int defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final IntDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class LongDefault<R> extends FieldDefault<R, LongDefault<R>> {
+        private LongDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided **/
+        public final FieldAssembler<R> longDefault(long defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final LongDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class FloatDefault<R> extends FieldDefault<R, FloatDefault<R>> {
+        private FloatDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided **/
+        public final FieldAssembler<R> floatDefault(float defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final FloatDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class DoubleDefault<R> extends FieldDefault<R, DoubleDefault<R>> {
+        private DoubleDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided **/
+        public final FieldAssembler<R> doubleDefault(double defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final DoubleDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class StringDefault<R> extends FieldDefault<R, StringDefault<R>> {
+        private StringDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided. Cannot be null. **/
+        public final FieldAssembler<R> stringDefault(String defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final StringDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class BytesDefault<R> extends FieldDefault<R, BytesDefault<R>> {
+        private BytesDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided, cannot be null **/
+        public final FieldAssembler<R> bytesDefault(byte[] defaultVal) {
+            return super.usingDefault(ByteBuffer.wrap(defaultVal));
+        }
+
+        /** Completes this field with the default value provided, cannot be null **/
+        public final FieldAssembler<R> bytesDefault(ByteBuffer defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        /** Completes this field with the default value provided, cannot be null.
+         * The string is interpreted as a byte[], with each character code point
+         * value equalling the byte value, as in the Avro spec JSON default. **/
+        public final FieldAssembler<R> bytesDefault(String defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final BytesDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class NullDefault<R> extends FieldDefault<R, NullDefault<R>> {
+        private NullDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with a default value of null **/
+        public final FieldAssembler<R> nullDefault() {
+            return super.usingDefault(null);
+        }
+
+        @Override
+        final NullDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class MapDefault<R> extends FieldDefault<R, MapDefault<R>> {
+        private MapDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided, cannot be null **/
+        public final <K, V> FieldAssembler<R> mapDefault(Map<K, V> defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final MapDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class ArrayDefault<R> extends FieldDefault<R, ArrayDefault<R>> {
+        private ArrayDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided, cannot be null **/
+        public final <V> FieldAssembler<R> arrayDefault(List<V> defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final ArrayDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class FixedDefault<R> extends FieldDefault<R, FixedDefault<R>> {
+        private FixedDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided, cannot be null **/
+        public final FieldAssembler<R> fixedDefault(byte[] defaultVal) {
+            return super.usingDefault(ByteBuffer.wrap(defaultVal));
+        }
+
+        /** Completes this field with the default value provided, cannot be null **/
+        public final FieldAssembler<R> fixedDefault(ByteBuffer defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        /** Completes this field with the default value provided, cannot be null.
+         * The string is interpreted as a byte[], with each character code point
+         * value equalling the byte value, as in the Avro spec JSON default. **/
+        public final FieldAssembler<R> fixedDefault(String defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final FixedDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class EnumDefault<R> extends FieldDefault<R, EnumDefault<R>> {
+        private EnumDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        /** Completes this field with the default value provided, cannot be null **/
+        public final FieldAssembler<R> enumDefault(String defaultVal) {
+            return super.usingDefault(defaultVal);
+        }
+
+        @Override
+        final EnumDefault<R> self() {
+            return this;
+        }
+    }
+
+    /** Choose whether to use a default value for the field or not. **/
+    public static class RecordDefault<R> extends FieldDefault<R, RecordDefault<R>> {
+        private RecordDefault(FieldBuilder<R> field) {
+            super(field);
+        }
+
+        @Override
+        final RecordDefault<R> self() {
+            return this;
+        }
+    }
+
+    public final static class GenericDefault<R> {
+        private final FieldBuilder<R> field;
+        private final Schema schema;
+
+        private GenericDefault(FieldBuilder<R> field, Schema schema) {
+            this.field = field;
+            this.schema = schema;
+        }
+
+        /** Do not use a default value for this field. **/
+        public FieldAssembler<R> noDefault() {
+            return field.completeField(schema);
+        }
+
+        /** Completes this field with the default value provided.
+         * The value must conform to the schema of the field. **/
+        public FieldAssembler<R> withDefault(Object defaultVal) {
+            return field.completeField(schema, defaultVal);
+        }
+    }
+
+    /**
+     * Completion<R> is for internal builder use, all subclasses are private.
+     *
+     * Completion is an object that takes a Schema and returns some result.
+     */
+    private abstract static class Completion<R> {
+        abstract R complete(Schema schema);
+    }
+
+    private static class SchemaCompletion extends Completion<Schema> {
+        @Override
+        protected Schema complete(Schema schema) {
+            return schema;
+        }
+    }
+
+    private static final Schema NULL_SCHEMA = Schema.create(Schema.Type.NULL);
+
+    private static class NullableCompletion<R> extends Completion<R> {
+        private final Completion<R> context;
+
+        private NullableCompletion(Completion<R> context) {
+            this.context = context;
+        }
+
+        @Override
+        protected R complete(Schema schema) {
+            // wrap the schema as a union of the schema and null
+            Schema nullable = Schema.createUnion(Arrays.asList(schema, NULL_SCHEMA));
+            return context.complete(nullable);
+        }
+    }
+
+    private static class OptionalCompletion<R> extends Completion<FieldAssembler<R>> {
+        private final FieldBuilder<R> bldr;
+
+        public OptionalCompletion(FieldBuilder<R> bldr) {
+            this.bldr = bldr;
+        }
+
+        @Override
+        protected FieldAssembler<R> complete(Schema schema) {
+            // wrap the schema as a union of null and the schema
+            Schema optional = Schema.createUnion(Arrays.asList(NULL_SCHEMA, schema));
+            return bldr.completeField(optional, (Object) null);
+        }
+    }
+
+    private abstract static class CompletionWrapper {
+        abstract <R> Completion<R> wrap(Completion<R> completion);
+    }
+
+    private static final class NullableCompletionWrapper extends CompletionWrapper {
+        @Override
+        <R> Completion<R> wrap(Completion<R> completion) {
+            return new NullableCompletion<R>(completion);
+        }
+    }
+
+    private static abstract class NestedCompletion<R> extends Completion<R> {
+        private final Completion<R> context;
+        private final PropBuilder<?> assembler;
+
+        private NestedCompletion(PropBuilder<?> assembler, Completion<R> context) {
+            this.context = context;
+            this.assembler = assembler;
+        }
+
+        @Override
+        protected final R complete(Schema schema) {
+            Schema outer = outerSchema(schema);
+            assembler.addPropsTo(outer);
+            return context.complete(outer);
+        }
+
+        protected abstract Schema outerSchema(Schema inner);
+    }
+
+    private static class MapCompletion<R> extends NestedCompletion<R> {
+        private MapCompletion(MapBuilder<R> assembler, Completion<R> context) {
+            super(assembler, context);
+        }
+
+        @Override
+        protected Schema outerSchema(Schema inner) {
+            return Schema.createMap(inner);
+        }
+    }
+
+    private static class ArrayCompletion<R> extends NestedCompletion<R> {
+        private ArrayCompletion(ArrayBuilder<R> assembler, Completion<R> context) {
+            super(assembler, context);
+        }
+
+        @Override
+        protected Schema outerSchema(Schema inner) {
+            return Schema.createArray(inner);
+        }
+    }
+
+    private static class UnionCompletion<R> extends
+            Completion<UnionAccumulator<R>> {
+        private final Completion<R> context;
+        private final NameContext names;
+        private final List<Schema> schemas;
+
+        private UnionCompletion(Completion<R> context, NameContext names, List<Schema> schemas) {
+            this.context = context;
+            this.names = names;
+            this.schemas = schemas;
+        }
+
+        @Override
+        protected UnionAccumulator<R> complete(Schema schema) {
+            List<Schema> updated = new ArrayList<Schema>(this.schemas);
+            updated.add(schema);
+            return new UnionAccumulator<R>(context, names, updated);
+        }
+    }
+
+    /** Accumulates all of the types in a union.  Add an additional type with
+     * {@link #and()}.  Complete the union with {@link #endUnion()}
+     */
+    public static final class UnionAccumulator<R> {
+        private final Completion<R> context;
+        private final NameContext names;
+        private final List<Schema> schemas;
+
+        private UnionAccumulator(Completion<R> context, NameContext names, List<Schema> schemas) {
+            this.context = context;
+            this.names = names;
+            this.schemas = schemas;
+        }
+
+        /** Add an additional type to this union **/
+        public BaseTypeBuilder<UnionAccumulator<R>> and() {
+            return new UnionBuilder<R>(context, names, schemas);
+        }
+
+        /** Complete this union **/
+        public R endUnion() {
+            Schema schema = Schema.createUnion(schemas);
+            return context.complete(schema);
+        }
+    }
+
+    private static void checkRequired(Object reference, String errorMessage) {
+        if (reference == null) {
+            throw new NullPointerException(errorMessage);
+        }
+    }
+}

http://git-wip-us.apache.org/repos/asf/kafka/blob/f6acfb08/copycat/data/src/main/java/org/apache/kafka/copycat/data/SchemaParseException.java
----------------------------------------------------------------------
diff --git a/copycat/data/src/main/java/org/apache/kafka/copycat/data/SchemaParseException.java b/copycat/data/src/main/java/org/apache/kafka/copycat/data/SchemaParseException.java
new file mode 100644
index 0000000..0982791
--- /dev/null
+++ b/copycat/data/src/main/java/org/apache/kafka/copycat/data/SchemaParseException.java
@@ -0,0 +1,32 @@
+/**
+ * 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.
+ **/
+
+
+
+package org.apache.kafka.copycat.data;
+
+/** Thrown for errors parsing schemas and protocols. */
+public class SchemaParseException extends DataRuntimeException {
+    public SchemaParseException(Throwable cause) {
+        super(cause);
+    }
+
+    public SchemaParseException(String message) {
+        super(message);
+    }
+}
+


Mime
View raw message