Support custom map creators in GenericBuilder, resolve #62

The core_android patches still need to be fixed in order for the project to build correctly.

core/src/main/java/com/electronwill/nightconfig/core/AbstractConfig.java

@@ -73,11 +73,7 @@ public AbstractConfig(UnmodifiableConfig toCopy, Supplier<Map<String, Object>> m
 	}
 
 	protected static <T> Supplier<Map<String, T>> getDefaultMapCreator(boolean concurrent) {
-		if (Config.isInsertionOrderPreserved()) {
-			return concurrent ? ()->Collections.synchronizedMap(new LinkedHashMap<>()) : LinkedHashMap::new;
-			// TODO find or make a ConcurrentMap that preserves the insertion order
-		}
-		return concurrent ? ConcurrentHashMap::new : HashMap::new;
+		return Config.getDefaultMapCreator(concurrent);
 	}
 
 	protected static <T> Supplier<Map<String, T>> getWildcardMapCreator(Supplier<Map<String, Object>> mapCreator) {

core/src/main/java/com/electronwill/nightconfig/core/Config.java

@@ -1,6 +1,8 @@
 package com.electronwill.nightconfig.core;
 
 import java.util.*;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 import java.util.function.Supplier;
 
 import static com.electronwill.nightconfig.core.utils.StringUtils.split;
@@ -241,7 +243,7 @@ default void update(List<String> path, Object value) {
 	static Config of(ConfigFormat<? extends Config> format) {
 		return new SimpleConfig(format, false);
 	}
-	
+
 	/**
 	 * Creates a Config backed by a certain kind of map, given by a supplier.
 	 *
@@ -327,7 +329,7 @@ static Config wrap(Map<String, Object> map, ConfigFormat<?> format) {
 	static Config copy(UnmodifiableConfig config) {
 		return new SimpleConfig(config, config.configFormat(), false);
 	}
-	
+
 	/**
 	 * Creates a new Config with the content of the given config. The returned config will have
 	 * the same format as the copied config, and be backed by the given supplier.
@@ -355,14 +357,14 @@ static Config copy(UnmodifiableConfig config, Supplier<Map<String, Object>> mapC
 	static Config copy(UnmodifiableConfig config, ConfigFormat<?> format) {
 		return new SimpleConfig(config, format, false);
 	}
-	
+
 	/**
 	 * Creates a new Config with the content of the given config.
 	 * The returned config will be backed by the given map supplier.
 	 *
 	 * If you wish all your configs to preserve insertion order, please have a look at the more
 	 * practical setting {@link #setInsertionOrderPreserved(boolean)}.
-	 * 
+	 *
 	 * @see #of(Supplier, ConfigFormat)
 	 *
 	 * @param config the config to copy
@@ -426,4 +428,31 @@ static boolean isInsertionOrderPreserved() {
 	static void setInsertionOrderPreserved(boolean orderPreserved) {
 		System.setProperty("nightconfig.preserveInsertionOrder", orderPreserved ? "true" : "false");
 	}
+
+	/**
+	 * Returns a map supplier that fulfills the given requirements.
+	 *
+	 * @param concurrent true to make the maps thread-safe
+	 * @param insertionOrderPreserved true to make the maps preserve the insertion order of values
+	 * @return a map supplier corresponding to the given settings
+	 */
+	static <T> Supplier<Map<String, T>> getDefaultMapCreator(boolean concurrent, boolean insertionOrderPreserved) {
+		if (insertionOrderPreserved) {
+			return concurrent ? ()->Collections.synchronizedMap(new LinkedHashMap<>()) : LinkedHashMap::new;
+			// TODO find or make a ConcurrentMap that preserves the insertion order
+		}
+		return concurrent ? ConcurrentHashMap::new : HashMap::new;
+	}
+
+	/**
+	 * Returns a map supplier that fullfills the given requirements. It preserves
+	 * (or not) the insertion order of its values according to
+	 * {@link Config#isInsertionOrderPreserved()}.
+	 *
+	 * @param concurrent true to make the maps thread-safe
+	 * @return a map supplier corresponding to the given settings
+	 */
+	static <T> Supplier<Map<String, T>> getDefaultMapCreator(boolean concurrent) {
+		return getDefaultMapCreator(concurrent, Config.isInsertionOrderPreserved());
+	}
 }

core/src/main/java/com/electronwill/nightconfig/core/ConfigFormat.java

@@ -8,11 +8,13 @@
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Map;
+import java.util.function.Supplier;
 
 /**
  * A configuration format, that can parse, create and write some types of configurations.
  *
- * @param <C>the type of configurations createdby this format
+ * @param <C>the type of configurations created by this format
  * @author TheElectronWill
  */
 public interface ConfigFormat<C extends Config> {
@@ -29,14 +31,27 @@ public interface ConfigFormat<C extends Config> {
 	/**
 	 * @return a config of this format
 	 */
-	C createConfig();
+	default C createConfig() {
+		return createConfig(Config.getDefaultMapCreator(false));
+	}
 
 	/**
 	 * Creates a config of this format. The returned config is guaranteed to be thread-safe.
 	 *
 	 * @return a concurrent config of this format
 	 */
-	C createConcurrentConfig();
+	default C createConcurrentConfig() {
+		return createConfig(Config.getDefaultMapCreator(true));
+	}
+
+	/**
+	 * Creates a config that uses the given map supplier for all its levels (top
+	 * level and subconfigs).
+	 *
+	 * @param mapCreator the map supplier for the config
+	 * @return a config of this format with the given map creator
+	 */
+	C createConfig(Supplier<Map<String, Object>> mapCreator);
 
 	/**
 	 * Checks if this format supports CommentedConfigs. Note that supporting CommentedConfigs

core/src/main/java/com/electronwill/nightconfig/core/InMemoryCommentedFormat.java

@@ -3,7 +3,9 @@
 import com.electronwill.nightconfig.core.io.ConfigParser;
 import com.electronwill.nightconfig.core.io.ConfigWriter;
 
+import java.util.Map;
 import java.util.function.Predicate;
+import java.util.function.Supplier;
 
 /**
  * The commented version of {@link InMemoryFormat}
@@ -45,13 +47,8 @@ public ConfigParser<CommentedConfig> createParser() {
 	}
 
 	@Override
-	public CommentedConfig createConfig() {
-		return CommentedConfig.of(this);
-	}
-
-	@Override
-	public CommentedConfig createConcurrentConfig() {
-		return CommentedConfig.ofConcurrent(this);
+	public CommentedConfig createConfig(Supplier<Map<String, Object>> mapCreator) {
+		return CommentedConfig.of(mapCreator, this);
 	}
 
 	@Override

core/src/main/java/com/electronwill/nightconfig/core/InMemoryFormat.java

@@ -4,7 +4,9 @@
 import com.electronwill.nightconfig.core.io.ConfigWriter;
 
 import java.util.Collection;
+import java.util.Map;
 import java.util.function.Predicate;
+import java.util.function.Supplier;
 
 /**
  * A ConfigFormat that is only in memory. Its method {@link #isInMemory()} returns always true.
@@ -60,13 +62,8 @@ public ConfigParser<Config> createParser() {
 	}
 
 	@Override
-	public Config createConfig() {
-		return Config.of(this);
-	}
-
-	@Override
-	public Config createConcurrentConfig() {
-		return Config.ofConcurrent(this);
+	public Config createConfig(Supplier<Map<String, Object>> mapCreator) {
+		return Config.of(mapCreator, this);
 	}
 
 	@Override

core/src/main/java/com/electronwill/nightconfig/core/conversion/ConvertedFormat.java

@@ -5,7 +5,9 @@
 import com.electronwill.nightconfig.core.io.ConfigParser;
 import com.electronwill.nightconfig.core.io.ConfigWriter;
 
+import java.util.Map;
 import java.util.function.Predicate;
+import java.util.function.Supplier;
 
 /**
  * @author TheElectronWill
@@ -39,6 +41,11 @@ public C createConcurrentConfig() {
 		return initialFormat.createConcurrentConfig();
 	}
 
+	@Override
+	public C createConfig(Supplier<Map<String, Object>> mapCreator) {
+		return initialFormat.createConfig(mapCreator);
+	}
+
 	@Override
 	public boolean supportsComments() {
 		return initialFormat.supportsComments();

core/src/main/java/com/electronwill/nightconfig/core/file/GenericBuilder.java

@@ -11,6 +11,8 @@
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.Map;
+import java.util.function.Supplier;
 
 /**
  * A generic FileConfig/CommentedFileConfig/someOtherFileConfig builder. The default settings are:
@@ -24,6 +26,8 @@
  * <li>Not autosaved - change it with {@link #autosave()}</li>
  * <li>Not autoreloaded - change it with {@link #autoreload()}</li>
  * <li>Not thread-safe - change it with {@link #concurrent()}</li>
+ * <li>Values' insertion order preserved if {@link Config#isInsertionOrderPreserved()}
+ * returns true when the builder is constructed.</li>
  * </ul>
  *
  * @author TheElectronWill
@@ -38,7 +42,9 @@ public abstract class GenericBuilder<Base extends Config, Result extends FileCon
 	protected WritingMode writingMode = WritingMode.REPLACE;
 	protected ParsingMode parsingMode = ParsingMode.REPLACE;
 	protected FileNotFoundAction nefAction = FileNotFoundAction.CREATE_EMPTY;
-	protected boolean sync = false, autosave = false, autoreload = false;
+	protected boolean sync = false, autosave = false, autoreload = false, concurrent = false;
+	protected boolean insertionOrder = Config.isInsertionOrderPreserved();
+	protected Supplier<Map<String, Object>> mapCreator = null;
 
 	GenericBuilder(Path file, ConfigFormat<? extends Base> format) {
 		this.file = file;
@@ -173,6 +179,33 @@ public GenericBuilder<Base, Result> concurrent() {
 		if (config == null) {
 			config = format.createConcurrentConfig();
 		}
+		concurrent = true;
+		return this;
+	}
+
+	/**
+	 * Makes the configuration preserve the insertion order of its values.
+	 *
+	 * @return this builder
+	 */
+	public GenericBuilder<Base, Result> preserveInsertionOrder() {
+		insertionOrder = true;
+		return this;
+	}
+
+	/**
+	 * Uses a specific Supplier to create the backing maps (one for the top level
+	 * and one for each sub-configuration) of the configuration.
+	 * <p><br>
+	 * <b>Warning :</b> if {@link #autoreload()} is called, the map creator
+	 * must return thread-safe maps, because the autoreloading system will modify
+	 * the configuration from another thread.
+	 *
+	 * @param s the map supplier to use
+	 * @return this builder
+	 */
+	public GenericBuilder<Base, Result> backingMapCreator(Supplier<Map<String,Object>> s) {
+		mapCreator = s;
 		return this;
 	}
 
@@ -219,8 +252,11 @@ public Result build() {
 	protected abstract Result buildNormal(FileConfig chain);
 
 	protected final Base getConfig() {
-		if (config == null) {// concurrent() has not been called
-			config = format.createConfig();
+		if (config == null) {
+			if (mapCreator == null) {
+				mapCreator = Config.getDefaultMapCreator(concurrent, insertionOrder);
+			}
+			config = format.createConfig(mapCreator);
 		}
 		return config;
 	}

hocon/src/main/java/com/electronwill/nightconfig/hocon/HoconFormat.java

@@ -6,6 +6,9 @@
 import com.electronwill.nightconfig.core.io.ConfigParser;
 import com.electronwill.nightconfig.core.io.ConfigWriter;
 
+import java.util.Map;
+import java.util.function.Supplier;
+
 /**
  * Represents the Hocon config format.
  *
@@ -28,6 +31,13 @@ public static CommentedConfig newConfig() {
 		return INSTANCE.createConfig();
 	}
 
+	/**
+	 * @return a new config with the given map creator
+	 */
+	public static CommentedConfig newConfig(Supplier<Map<String, Object>> s) {
+		return INSTANCE.createConfig(s);
+	}
+
 	/**
 	 * @return a new thread-safe config with the hocon format
 	 */
@@ -53,13 +63,8 @@ public ConfigParser<CommentedConfig> createParser() {
 	}
 
 	@Override
-	public CommentedConfig createConfig() {
-		return CommentedConfig.of(this);
-	}
-
-	@Override
-	public CommentedConfig createConcurrentConfig() {
-		return CommentedConfig.ofConcurrent(this);
+	public CommentedConfig createConfig(Supplier<Map<String, Object>> mapCreator) {
+		return CommentedConfig.of(mapCreator, this);
 	}
 
 	@Override

json/src/main/java/com/electronwill/nightconfig/json/JsonFormat.java

@@ -9,6 +9,8 @@
 
 import java.io.IOException;
 import java.io.Writer;
+import java.util.Map;
+import java.util.function.Supplier;
 
 /**
  * @author TheElectronWill
@@ -93,6 +95,13 @@ public static Config newConfig() {
 		return FANCY.createConfig();
 	}
 
+	/**
+	 * @return a new config with the given map creator
+	 */
+	public static Config newConfig(Supplier<Map<String, Object>> s) {
+		return FANCY.createConfig(s);
+	}
+
 	/**
 	 * @return a new thread-safe config with the format {@link JsonFormat#fancyInstance()}.
 	 */
@@ -113,13 +122,8 @@ private JsonFormat() {}
 	public abstract ConfigParser<Config> createParser();
 
 	@Override
-	public Config createConfig() {
-		return Config.of(this);
-	}
-
-	@Override
-	public Config createConcurrentConfig() {
-		return Config.ofConcurrent(this);
+	public Config createConfig(Supplier<Map<String, Object>> mapCreator) {
+		return Config.of(mapCreator, this);
 	}
 
 	@Override