Deprecated settings API for complete overhaul in 4.0

Renamed isReloadable to Dynamic and maid it an annotation instead

community/configuration/src/main/java/org/neo4j/configuration/Dynamic.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2002-2017 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.configuration;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Dynamic properties can be changed at runtime.
+ */
+@Retention( RetentionPolicy.RUNTIME )
+@Target( {ElementType.TYPE, ElementType.FIELD} )
+public @interface Dynamic
+{
+}

community/configuration/src/main/java/org/neo4j/configuration/LoadableConfig.java

@@ -75,6 +75,9 @@ default List<ConfigOptions> getConfigOptions()
 
                     final Internal internalAnnotation = f.getAnnotation( Internal.class );
                     setting.setInternal( internalAnnotation != null );
+
+                    final Dynamic dynamicAnnotation = f.getAnnotation( Dynamic.class );
+                    setting.setDynamic( dynamicAnnotation != null );
                 }
 
                 if ( publicSetting instanceof SettingGroup )

community/configuration/src/test/java/org/neo4j/configuration/LoadableConfigTest.java

@@ -29,48 +29,66 @@
 import org.neo4j.graphdb.config.BaseSetting;
 import org.neo4j.graphdb.config.Configuration;
 import org.neo4j.graphdb.config.Setting;
-import org.neo4j.helpers.collection.MapUtil;
+import org.neo4j.graphdb.config.SettingGroup;
 
 import static java.util.Collections.emptyMap;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.neo4j.helpers.collection.MapUtil.stringMap;
 
 public class LoadableConfigTest
 {
     @Test
     public void getConfigOptions() throws Exception
     {
-        Map<String,String> config = MapUtil.stringMap( "myInt", "123", "myString", "bah", "myOldString", "moo" );
+        Map<String,String> config = stringMap(
+                TestConfig.integer.name(), "123",
+                TestConfig.string.name(), "bah",
+                TestConfig.oldString.name(), "moo",
+                TestConfig.dynamic.name(), "foo" );
 
         TestConfig testSettings = new TestConfig();
 
         List<ConfigOptions> options = testSettings.getConfigOptions();
 
-        assertEquals( 3, options.size() );
-
-        assertEquals( 1, options.get( 0 ).settingGroup().values( emptyMap() ).get( "myInt" ) );
-        assertEquals( 123, options.get( 0 ).settingGroup().values( config ).get( "myInt" ) );
-        assertEquals( Optional.empty(), options.get( 0 ).settingGroup().description() );
-        assertFalse( options.get(0).settingGroup().deprecated() );
-        assertEquals( Optional.empty(), options.get( 0 ).settingGroup().replacement() );
-
-        assertEquals( "bob", options.get( 1 ).settingGroup().values( emptyMap() ).get( "myString" ) );
-        assertEquals( "bah", options.get( 1 ).settingGroup().values( config ).get( "myString" ) );
-        assertEquals( "A string setting", options.get( 1 ).settingGroup().description().get() );
-        assertFalse( options.get(1).settingGroup().deprecated() );
-        assertEquals( Optional.empty(), options.get( 1 ).settingGroup().replacement() );
-
-        assertEquals( "tim", options.get( 2 ).settingGroup().values( emptyMap() ).get( "myOldString" ) );
-        assertEquals( "moo", options.get( 2 ).settingGroup().values( config ).get( "myOldString" ) );
-        assertEquals( "A deprecated string setting", options.get( 2 ).settingGroup().description().get() );
-        assertTrue( options.get(2).settingGroup().deprecated() );
-        assertEquals( "myString", options.get( 2 ).settingGroup().replacement().get() );
+        assertEquals( 4, options.size() );
+
+        SettingGroup<?> integerSetting = options.get( 0 ).settingGroup();
+        assertEquals( 1, integerSetting.values( emptyMap() ).get( TestConfig.integer.name() ) );
+        assertEquals( 123, integerSetting.values( config ).get( TestConfig.integer.name() ) );
+        assertEquals( Optional.empty(), integerSetting.description() );
+        assertFalse( integerSetting.deprecated() );
+        assertFalse( integerSetting.dynamic() );
+        assertEquals( Optional.empty(), integerSetting.replacement() );
+
+        SettingGroup<?> stringSetting = options.get( 1 ).settingGroup();
+        assertEquals( "bob", stringSetting.values( emptyMap() ).get( TestConfig.string.name() ) );
+        assertEquals( "bah", stringSetting.values( config ).get( TestConfig.string.name() ) );
+        assertEquals( "A string setting", stringSetting.description().get() );
+        assertFalse( stringSetting.deprecated() );
+        assertFalse( stringSetting.dynamic() );
+        assertEquals( Optional.empty(), stringSetting.replacement() );
+
+        SettingGroup<?> oldStringSetting = options.get( 2 ).settingGroup();
+        assertEquals( "tim", oldStringSetting.values( emptyMap() ).get( TestConfig.oldString.name() ) );
+        assertEquals( "moo", oldStringSetting.values( config ).get( TestConfig.oldString.name() ) );
+        assertEquals( "A deprecated string setting", oldStringSetting.description().get() );
+        assertTrue( oldStringSetting.deprecated() );
+        assertFalse( oldStringSetting.dynamic() );
+        assertEquals( TestConfig.string.name(), oldStringSetting.replacement().get() );
+
+        SettingGroup<?> dynamicSetting = options.get( 3 ).settingGroup();
+        assertEquals( "defaultDynamic", dynamicSetting.values( emptyMap() ).get( TestConfig.dynamic.name() ) );
+        assertEquals( "foo", dynamicSetting.values( config ).get( TestConfig.dynamic.name() ) );
+        assertEquals( "A dynamic string setting", dynamicSetting.description().get() );
+        assertFalse( dynamicSetting.deprecated() );
+        assertTrue( dynamicSetting.dynamic() );
+        assertEquals( Optional.empty(), dynamicSetting.replacement() );
     }
 
     private static class TestConfig implements LoadableConfig
     {
-        @SuppressWarnings( "unused" )
         public static final Setting<Integer> integer = new BaseSetting<Integer>()
         {
             @Override
@@ -116,7 +134,6 @@ public Integer apply( Function<String,String> provider )
 
         };
 
-        @SuppressWarnings( "unused" )
         @Description( "A string setting" )
         public static final Setting<String> string = new StringSetting()
         {
@@ -156,7 +173,6 @@ public String from( Configuration configuration )
             }
         };
 
-        @SuppressWarnings( "unused" )
         @Description( "A deprecated string setting" )
         @Deprecated
         @ReplacedBy( "myString" )
@@ -232,16 +248,50 @@ public String from( Configuration configuration )
                 return configuration.get( this );
             }
         };
+
+        @Description( "A dynamic string setting" )
+        @Dynamic
+        public static final Setting<String> dynamic = new StringSetting()
+        {
+            @Override
+            public String apply( Function<String,String> provider )
+            {
+                String val = provider.apply( name() );
+                if ( val == null )
+                {
+                    val = getDefaultValue();
+                }
+                return val;
+            }
+
+            @Override
+            public String name()
+            {
+                return "myDynamicProperty";
+            }
+
+            @Override
+            public void withScope( Function<String,String> scopingRule )
+            {
+
+            }
+
+            @Override
+            public String getDefaultValue()
+            {
+                return "defaultDynamic";
+            }
+
+            @Override
+            public String from( Configuration configuration )
+            {
+                return configuration.get( this );
+            }
+        };
     }
 
     private abstract static class StringSetting extends BaseSetting<String>
     {
-        @Override
-        public boolean isReloadable()
-        {
-            return false;
-        }
-
         @Override
         public String valueDescription()
         {

community/graphdb-api/src/main/java/org/neo4j/graphdb/config/BaseSetting.java

@@ -24,12 +24,15 @@
 
 /**
  * All fields specified here are set via annotations when loaded
+ * @deprecated The settings API will be completely rewritten in 4.0
  */
+@Deprecated
 public abstract class BaseSetting<T> implements Setting<T>
 {
     private boolean deprecated;
     private String replacement;
     private boolean internal;
+    private boolean dynamic;
     private String documentedDefaultValue;
     private String description;
 
@@ -93,4 +96,21 @@ public String toString()
     {
         return valueDescription();
     }
+
+    /**
+     * Checks whether this setting is dynamic or not. Dynamic properties are allowed to be changed at runtime without
+     * restarting the server.
+     *
+     * @return {@code true} if this setting can be changed at runtime.
+     */
+    @Override
+    public boolean dynamic()
+    {
+        return dynamic;
+    }
+
+    public void setDynamic( boolean dynamic )
+    {
+        this.dynamic = dynamic;
+    }
 }

community/graphdb-api/src/main/java/org/neo4j/graphdb/config/Configuration.java

@@ -21,7 +21,9 @@
 
 /**
  * Provide the basic operation that one could perform on a set of configurations.
+ * @deprecated The settings API will be completely rewritten in 4.0
  */
+@Deprecated
 public interface Configuration
 {
     /**

community/graphdb-api/src/main/java/org/neo4j/graphdb/config/InvalidSettingException.java

@@ -21,7 +21,9 @@
 
 /**
  * Thrown when a configuration setting is, for one reason or another, invalid.
+ * @deprecated The settings API will be completely rewritten in 4.0
  */
+@Deprecated
 public class InvalidSettingException extends RuntimeException
 {
 

community/graphdb-api/src/main/java/org/neo4j/graphdb/config/ScopeAwareSetting.java

@@ -21,6 +21,10 @@
 
 import java.util.function.Function;
 
+/**
+ * @deprecated The settings API will be completely rewritten in 4.0
+ */
+@Deprecated
 public abstract class ScopeAwareSetting<T> extends BaseSetting<T>
 {
     private Function<String,String> scopingRule = Function.identity();

community/graphdb-api/src/main/java/org/neo4j/graphdb/config/Setting.java

@@ -33,12 +33,14 @@
 /**
  * Settings that can be provided in configurations are represented by instances of this interface, and are available
  * as static fields in various *Settings classes.
- *
+ * <p>
  * This interface is available only for use, not for implementing. Implementing this interface is not expected, and
  * backwards compatibility is not guaranteed for implementors.
  *
  * @param <T> type of value this setting will parse input string into and return.
+ * @deprecated The settings API will be completely rewritten in 4.0
  */
+@Deprecated
 public interface Setting<T> extends Function<Function<String,String>,T>, SettingValidator, SettingGroup<T>
 {
     /**
@@ -106,13 +108,8 @@ default List<Setting<T>> settings( Map<String,String> params )
      *
      * @return the parser function
      */
-    default Optional<Function<String, T>> getParser()
+    default Optional<Function<String,T>> getParser()
     {
         return Optional.empty();
     }
-
-    default boolean isReloadable()
-    {
-        return false;
-    }
 }

community/graphdb-api/src/main/java/org/neo4j/graphdb/config/SettingGroup.java

@@ -26,55 +26,60 @@
 /**
  * This interface represents a setting group. One example can be group defined by a common prefix, such as
  * `dbms.connector.*`. The important aspect is that config keys can only be known after a config has been parsed.
+ *
+ * @deprecated The settings API will be completely rewritten in 4.0
  */
+@Deprecated
 public interface SettingGroup<T> extends SettingValidator
 {
     /**
      * Apply this setting group to the config and return all of its configured keys and their corresponding values.
      *
-     * @param validConfig which can be examined
-     * @return the map of this group's configured keys and values
+     * @param validConfig which can be examined.
+     * @return the map of this group's configured keys and values.
      */
     Map<String,T> values( Map<String,String> validConfig );
 
     /**
-     * @return a list of the settings this group contains
+     * @return a list of the settings this group contains.
      */
     List<Setting<T>> settings( Map<String,String> params );
 
     /**
-     *
-     * @return true if this setting is deprecated, false otherwise
+     * @return {@code true} if this setting is deprecated, false otherwise.
      */
     boolean deprecated();
 
     /**
-     *
-     * @return the key of the setting which replaces this when its deprecated, empty if not depricated
+     * @return the key of the setting which replaces this when its deprecated, empty if not deprecated.
      */
     Optional<String> replacement();
 
     /**
-     *
-     * @return true if internal setting, false otherwise
+     * @return {@code true} if internal setting, false otherwise.
      */
     boolean internal();
 
     /**
-     *
-     * @return the documented default value if it needs special documentation, empty if default value is good as is
+     * @return the documented default value if it needs special documentation, empty if default value is good as is.
      */
     Optional<String> documentedDefaultValue();
 
     /**
-     *
      * @return description of which values are good
      */
     String valueDescription();
 
     /**
-     *
-     * @return description of setting, empty in case no description exists
+     * @return description of setting, empty in case no description exists.
      */
     Optional<String> description();
+
+    /**
+     * @return {@code true} if the setting can be changed at runtime.
+     */
+    default boolean dynamic()
+    {
+        return false;
+    }
 }

community/graphdb-api/src/main/java/org/neo4j/graphdb/config/SettingValidator.java

@@ -22,6 +22,10 @@
 import java.util.Map;
 import java.util.function.Consumer;
 
+/**
+ * @deprecated The settings API will be completely rewritten in 4.0
+ */
+@Deprecated
 public interface SettingValidator
 {
     /**