Add support for caching of configuration values. (#7608)

src/main/java/net/minecraftforge/common/ForgeConfigSpec.java

@@ -42,6 +42,7 @@ import java.util.stream.Collectors;
 
 import javax.annotation.Nonnull;
 
+import com.google.common.annotations.VisibleForTesting;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.logging.log4j.LogManager;
 
@@ -90,6 +91,7 @@ public class ForgeConfigSpec extends UnmodifiableConfigWrapper<UnmodifiableConfi
                 ((FileConfig) config).save();
             }
         }
+        this.afterReload();
     }
 
     public boolean isCorrecting() {
@@ -108,6 +110,22 @@ public class ForgeConfigSpec extends UnmodifiableConfigWrapper<UnmodifiableConfi
         return this.values;
     }
 
+    public void afterReload() {
+        this.resetCaches(getValues().valueMap().values());
+    }
+
+    private void resetCaches(final Iterable<Object> configValues) {
+        configValues.forEach(value -> {
+            if (value instanceof ConfigValue) {
+                final ConfigValue<?> configValue = (ConfigValue<?>) value;
+                configValue.clearCache();
+            } else if (value instanceof Config) {
+                final Config innerConfig = (Config) value;
+                this.resetCaches(innerConfig.valueMap().values());
+            }
+        });
+    }
+
     public void save()
     {
         Preconditions.checkNotNull(childConfig, "Cannot save config value without assigned Config object present");
@@ -690,10 +708,15 @@ public class ForgeConfigSpec extends UnmodifiableConfigWrapper<UnmodifiableConfi
 
     public static class ConfigValue<T>
     {
+        @VisibleForTesting
+        static boolean USE_CACHES = true;
+
         private final Builder parent;
         private final List<String> path;
         private final Supplier<T> defaultSupplier;
 
+        private T cachedValue = null;
+
         private ForgeConfigSpec spec;
 
         ConfigValue(Builder parent, List<String> path, Supplier<T> defaultSupplier)
@@ -714,7 +737,13 @@ public class ForgeConfigSpec extends UnmodifiableConfigWrapper<UnmodifiableConfi
             Preconditions.checkNotNull(spec, "Cannot get config value before spec is built");
             if (spec.childConfig == null)
                 return defaultSupplier.get();
-            return getRaw(spec.childConfig, path, defaultSupplier);
+
+            if (USE_CACHES && cachedValue == null)
+                cachedValue = getRaw(spec.childConfig, path, defaultSupplier);
+            else if (!USE_CACHES)
+                return getRaw(spec.childConfig, path, defaultSupplier);
+
+            return cachedValue;
         }
 
         protected T getRaw(Config config, List<String> path, Supplier<T> defaultSupplier)
@@ -739,6 +768,11 @@ public class ForgeConfigSpec extends UnmodifiableConfigWrapper<UnmodifiableConfi
             Preconditions.checkNotNull(spec, "Cannot set config value before spec is built");
             Preconditions.checkNotNull(spec.childConfig, "Cannot set config value without assigned Config object present");
             spec.childConfig.set(path, value);
+            this.cachedValue = value;
+        }
+
+        public void clearCache() {
+            this.cachedValue = null;
         }
     }
 

src/main/java/net/minecraftforge/fml/config/ConfigFileTypeHandler.java

@@ -156,6 +156,7 @@ public class ConfigFileTypeHandler {
                     throw new ConfigLoadingException(modConfig, ex);
                 }
                 LOGGER.debug(CONFIG, "Config file {} changed, sending notifies", this.modConfig.getFileName());
+                this.modConfig.getSpec().afterReload();
                 this.modConfig.fireEvent(new ModConfig.Reloading(this.modConfig));
             }
         }