Allow updating child fields

src/main/java/com/yelp/nrtsearch/server/field/AtomFieldDef.java

@@ -43,7 +43,24 @@ public class AtomFieldDef extends TextBaseFieldDef
 
   public AtomFieldDef(
       String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
-    super(name, requestField, context);
+    this(name, requestField, context, null);
+  }
+
+  /**
+   * Constructor for creating an instance of this field based on a previous instance. This is used
+   * when updating field properties.
+   *
+   * @param name name of the field
+   * @param requestField the field definition from the request
+   * @param context context for creating the field definition
+   * @param previousField the previous instance of this field definition, or null if there is none
+   */
+  protected AtomFieldDef(
+      String name,
+      Field requestField,
+      FieldDefCreator.FieldDefCreatorContext context,
+      AtomFieldDef previousField) {
+    super(name, requestField, context, previousField);
   }
 
   @Override
@@ -59,6 +76,12 @@ public String getType() {
     return "ATOM";
   }
 
+  @Override
+  public FieldDef createUpdatedFieldDef(
+      String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
+    return new AtomFieldDef(name, requestField, context, this);
+  }
+
   @Override
   public Object parseLastValue(String value) {
     return new BytesRef(value);

src/main/java/com/yelp/nrtsearch/server/field/BooleanFieldDef.java

@@ -39,7 +39,24 @@
 public class BooleanFieldDef extends IndexableFieldDef<Boolean> implements TermQueryable {
   protected BooleanFieldDef(
       String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
-    super(name, requestField, context, Boolean.class);
+    this(name, requestField, context, null);
+  }
+
+  /**
+   * Constructor for creating an instance of this field based on a previous instance. This is used
+   * when updating field properties.
+   *
+   * @param name name of the field
+   * @param requestField the field definition from the request
+   * @param context context for creating the field definition
+   * @param previousField the previous instance of this field definition, or null if there is none
+   */
+  protected BooleanFieldDef(
+      String name,
+      Field requestField,
+      FieldDefCreator.FieldDefCreatorContext context,
+      BooleanFieldDef previousField) {
+    super(name, requestField, context, Boolean.class, previousField);
   }
 
   @Override
@@ -138,6 +155,12 @@ public String getType() {
     return "BOOLEAN";
   }
 
+  @Override
+  public FieldDef createUpdatedFieldDef(
+      String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
+    return new BooleanFieldDef(name, requestField, context, this);
+  }
+
   @Override
   public Query getTermQueryFromBooleanValue(boolean booleanValue) {
     verifySearchable("Term query");

src/main/java/com/yelp/nrtsearch/server/field/ContextSuggestFieldDef.java

@@ -41,7 +41,24 @@ public class ContextSuggestFieldDef extends IndexableFieldDef<Void> {
    */
   protected ContextSuggestFieldDef(
       String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
-    super(name, requestField, context, Void.class);
+    this(name, requestField, context, null);
+  }
+
+  /**
+   * Constructor for creating an instance of this field based on a previous instance. This is used
+   * when updating field properties.
+   *
+   * @param name name of the field
+   * @param requestField the field definition from the request
+   * @param context context for creating the field definition
+   * @param previousField the previous instance of this field definition, or null if there is none
+   */
+  protected ContextSuggestFieldDef(
+      String name,
+      Field requestField,
+      FieldDefCreator.FieldDefCreatorContext context,
+      ContextSuggestFieldDef previousField) {
+    super(name, requestField, context, Void.class, previousField);
     this.indexAnalyzer = this.parseIndexAnalyzer(requestField);
     this.searchAnalyzer = this.parseSearchAnalyzer(requestField);
     this.postingsFormat =
@@ -64,6 +81,12 @@ public String getType() {
     return "CONTEXT_SUGGEST";
   }
 
+  @Override
+  public FieldDef createUpdatedFieldDef(
+      String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
+    return new ContextSuggestFieldDef(name, requestField, context, this);
+  }
+
   @Override
   public void parseDocumentField(
       Document document, List<String> fieldValues, List<List<String>> facetHierarchyPaths) {

src/main/java/com/yelp/nrtsearch/server/field/DateTimeFieldDef.java

@@ -82,7 +82,24 @@ private static DateTimeFormatter createDateTimeFormatter(String dateTimeFormat)
 
   public DateTimeFieldDef(
       String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
-    super(name, requestField, context, Instant.class);
+    this(name, requestField, context, null);
+  }
+
+  /**
+   * Constructor for creating an instance of this field based on a previous instance. This is used
+   * when updating field properties.
+   *
+   * @param name name of the field
+   * @param requestField the field definition from the request
+   * @param context context for creating the field definition
+   * @param previousField the previous instance of this field definition, or null if there is none
+   */
+  protected DateTimeFieldDef(
+      String name,
+      Field requestField,
+      FieldDefCreator.FieldDefCreatorContext context,
+      DateTimeFieldDef previousField) {
+    super(name, requestField, context, Instant.class, previousField);
     dateTimeFormat = requestField.getDateTimeFormat();
     dateTimeFormatter = createDateTimeFormatter(dateTimeFormat);
   }
@@ -369,6 +386,12 @@ public String getType() {
     return "DATE_TIME";
   }
 
+  @Override
+  public FieldDef createUpdatedFieldDef(
+      String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
+    return new DateTimeFieldDef(name, requestField, context, this);
+  }
+
   /**
    * Get the format used to parse date time string.
    *

src/main/java/com/yelp/nrtsearch/server/field/DoubleFieldDef.java

@@ -39,7 +39,24 @@ public class DoubleFieldDef extends NumberFieldDef<Double> {
 
   public DoubleFieldDef(
       String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
-    super(name, requestField, DOUBLE_PARSER, context, Double.class);
+    this(name, requestField, context, null);
+  }
+
+  /**
+   * Constructor for creating an instance of this field based on a previous instance. This is used
+   * when updating field properties.
+   *
+   * @param name name of the field
+   * @param requestField the field definition from the request
+   * @param context context for creating the field definition
+   * @param previousField the previous instance of this field definition, or null if there is none
+   */
+  protected DoubleFieldDef(
+      String name,
+      Field requestField,
+      FieldDefCreator.FieldDefCreatorContext context,
+      DoubleFieldDef previousField) {
+    super(name, requestField, DOUBLE_PARSER, context, Double.class, previousField);
   }
 
   @Override
@@ -101,6 +118,12 @@ public String getType() {
     return "DOUBLE";
   }
 
+  @Override
+  public FieldDef createUpdatedFieldDef(
+      String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
+    return new DoubleFieldDef(name, requestField, context, this);
+  }
+
   @Override
   public Query getRangeQuery(RangeQuery rangeQuery) {
     verifySearchableOrDocValues("Range query");

src/main/java/com/yelp/nrtsearch/server/field/FieldDef.java

@@ -15,6 +15,7 @@
  */
 package com.yelp.nrtsearch.server.field;
 
+import com.yelp.nrtsearch.server.grpc.Field;
 import java.io.Closeable;
 
 /** Base class for all field definition types. */
@@ -35,6 +36,22 @@ public String getName() {
     return name;
   }
 
+  /**
+   * Create a new instance of the current {@link FieldDef} that is updated to use the provided
+   * request field definition. This method must not modify the current instance, but instead return
+   * a new instance with the updated properties.
+   *
+   * @param name name of the field
+   * @param requestField the field definition from the request
+   * @param context context for creating the field definition
+   * @return a new instance of the field definition with updated properties
+   */
+  public FieldDef createUpdatedFieldDef(
+      String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
+    throw new UnsupportedOperationException(
+        String.format("Field %s does not support update", this.getName()));
+  }
+
   /** Get String representation of the field type. */
   public abstract String getType();
 

src/main/java/com/yelp/nrtsearch/server/field/FieldDefCreator.java

@@ -97,6 +97,29 @@ public FieldDef createFieldDef(String name, Field field, FieldDefCreatorContext
     return provider.get(name, field, context);
   }
 
+  /**
+   * Create a new {@link FieldDef} instance based on a previous {@link FieldDef}. This is typically
+   * used when updating a field definition in the index.
+   *
+   * @param name name of the field
+   * @param field grpc request field definition
+   * @param previousFieldDef previous field definition, or null if there is none
+   * @param context context for creating the field definition
+   * @return new field definition instance
+   */
+  public FieldDef createFieldDefFromPrevious(
+      String name, Field field, FieldDef previousFieldDef, FieldDefCreatorContext context) {
+    if (previousFieldDef == null) {
+      return createFieldDef(name, field, context);
+    }
+    FieldDef updatedFieldDef = previousFieldDef.createUpdatedFieldDef(name, field, context);
+    if (updatedFieldDef == null) {
+      throw new IllegalArgumentException(
+          "FieldDef " + previousFieldDef.getName() + " cannot be updated");
+    }
+    return updatedFieldDef;
+  }
+
   /**
    * Create a new {@link FieldDefCreatorContext} instance.
    *

src/main/java/com/yelp/nrtsearch/server/field/FloatFieldDef.java

@@ -39,7 +39,24 @@ public class FloatFieldDef extends NumberFieldDef<Float> {
 
   public FloatFieldDef(
       String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
-    super(name, requestField, FLOAT_PARSER, context, Float.class);
+    this(name, requestField, context, null);
+  }
+
+  /**
+   * Constructor for creating an instance of this field based on a previous instance. This is used
+   * when updating field properties.
+   *
+   * @param name name of the field
+   * @param requestField the field definition from the request
+   * @param context context for creating the field definition
+   * @param previousField the previous instance of this field definition, or null if there is none
+   */
+  protected FloatFieldDef(
+      String name,
+      Field requestField,
+      FieldDefCreator.FieldDefCreatorContext context,
+      FloatFieldDef previousField) {
+    super(name, requestField, FLOAT_PARSER, context, Float.class, previousField);
   }
 
   @Override
@@ -99,6 +116,12 @@ public String getType() {
     return "FLOAT";
   }
 
+  @Override
+  public FieldDef createUpdatedFieldDef(
+      String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
+    return new FloatFieldDef(name, requestField, context, this);
+  }
+
   @Override
   public Query getRangeQuery(RangeQuery rangeQuery) {
     verifySearchableOrDocValues("Range query");

src/main/java/com/yelp/nrtsearch/server/field/IdFieldDef.java

@@ -43,7 +43,24 @@ public class IdFieldDef extends IndexableFieldDef<String> implements TermQueryab
 
   protected IdFieldDef(
       String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
-    super(name, requestField, context, String.class);
+    this(name, requestField, context, null);
+  }
+
+  /**
+   * Constructor for creating an instance of this field based on a previous instance. This is used
+   * when updating field properties.
+   *
+   * @param name name of the field
+   * @param requestField the field definition from the request
+   * @param context context for creating the field definition
+   * @param previousField the previous instance of this field definition, or null if there is none
+   */
+  protected IdFieldDef(
+      String name,
+      Field requestField,
+      FieldDefCreator.FieldDefCreatorContext context,
+      IdFieldDef previousField) {
+    super(name, requestField, context, String.class, previousField);
   }
 
   /**
@@ -142,6 +159,12 @@ public String getType() {
     return "_ID";
   }
 
+  @Override
+  public FieldDef createUpdatedFieldDef(
+      String name, Field requestField, FieldDefCreator.FieldDefCreatorContext context) {
+    return new IdFieldDef(name, requestField, context, this);
+  }
+
   /**
    * Construct a Term with the given field and value to identify the document to be added or updated
    *