Added javadocs for PropertiesRegistry

Author: artem-v

metrics/src/main/java/io/scalecube/metrics/PropertiesRegistry.java

@@ -11,6 +11,10 @@
 import org.agrona.concurrent.status.CountersManager;
 import org.agrona.concurrent.status.CountersReader;
 
+/**
+ * Registry for storing typed properties as Agrona counters. Supports setting properties of any
+ * primitive type and retrieving them via {@link CountersReader}.
+ */
 public class PropertiesRegistry {
 
   public static final int PROPERTY_COUNTER_TYPE_ID = 2;
@@ -20,12 +24,24 @@ public class PropertiesRegistry {
   private final ThreadLocal<CounterAllocator> counterAllocatorHolder;
   private final Map<String, AtomicCounter> counters = new ConcurrentHashMap<>();
 
+  /**
+   * Creates new registry backed by given {@link CountersManager}.
+   *
+   * @param countersManager countersManager
+   */
   public PropertiesRegistry(CountersManager countersManager) {
     this.countersManager = countersManager;
     this.counterAllocatorHolder =
         ThreadLocal.withInitial(() -> new CounterAllocator(this.countersManager));
   }
 
+  /**
+   * Stores or updates property. If property does not exist, new counter is allocated, otherwise,
+   * counter is updated with the new value.
+   *
+   * @param name property name
+   * @param value property value
+   */
   public void put(String name, Object value) {
     Objects.requireNonNull(name, "name");
     Objects.requireNonNull(value, "value");
@@ -45,41 +61,105 @@ public void put(String name, Object value) {
         });
   }
 
+  /**
+   * Retrieves {@link Byte} property.
+   *
+   * @param countersReader countersReader
+   * @param name property name
+   * @return property value, or {@code null} if not found
+   */
   public static Byte getByteProperty(CountersReader countersReader, String name) {
     return getProperty(countersReader, name, Byte::parseByte);
   }
 
+  /**
+   * Retrieves {@link Short} property.
+   *
+   * @param countersReader countersReader
+   * @param name property name
+   * @return property value, or {@code null} if not found
+   */
   public static Short getShortProperty(CountersReader countersReader, String name) {
     return getProperty(countersReader, name, Short::parseShort);
   }
 
+  /**
+   * Retrieves {@link Integer} property.
+   *
+   * @param countersReader countersReader
+   * @param name property name
+   * @return property value, or {@code null} if not found
+   */
   public static Integer getIntProperty(CountersReader countersReader, String name) {
     return getProperty(countersReader, name, Integer::parseInt);
   }
 
+  /**
+   * Retrieves {@link Long} property.
+   *
+   * @param countersReader countersReader
+   * @param name property name
+   * @return property value, or {@code null} if not found
+   */
   public static Long getLongProperty(CountersReader countersReader, String name) {
     return getProperty(countersReader, name, Long::parseLong);
   }
 
+  /**
+   * Retrieves {@link Double} property.
+   *
+   * @param countersReader countersReader
+   * @param name property name
+   * @return property value, or {@code null} if not found
+   */
   public static Double getDoubleProperty(CountersReader countersReader, String name) {
     return getProperty(countersReader, name, Double::parseDouble);
   }
 
+  /**
+   * Retrieves enum property.
+   *
+   * @param countersReader countersReader
+   * @param name property name
+   * @return property value, or {@code null} if not found
+   */
   public static <T extends Enum<T>> T getEnumProperty(
       CountersReader countersReader, String name, Function<String, T> enumFunc) {
     return getProperty(countersReader, name, enumFunc);
   }
 
+  /**
+   * Retrieves {@link String} property.
+   *
+   * @param countersReader countersReader
+   * @param name property name
+   * @return property value, or {@code null} if not found
+   */
   public static String getProperty(CountersReader countersReader, String name) {
     return getProperty(countersReader, name, s -> s);
   }
 
+  /**
+   * Retrieves property from and converts it using provided function.
+   *
+   * @param countersReader countersReader
+   * @param name property name
+   * @param converter function to convert string value
+   * @param <T> result type
+   * @return converted property value, or {@code null} if not found
+   */
   public static <T> T getProperty(
       CountersReader countersReader, String name, Function<String, T> converter) {
     final var counter = CounterDescriptor.findFirstCounter(countersReader, byPropertyName(name));
     return counter != null ? converter.apply(counter.label().split("=")[1]) : null;
   }
 
+  /**
+   * Returns predicate that matches counters of property type, and with given property name.
+   *
+   * @param name property name
+   * @return predicate for filtering property counters by property name
+   */
   public static Predicate<CounterDescriptor> byPropertyName(String name) {
     return byType(PropertiesRegistry.PROPERTY_COUNTER_TYPE_ID)
         .and(descriptor -> name.equals(descriptor.label().split("=")[0]));