for #1172, avoid load spi multiple times to cause gc

apache · Sep 27, 2018 · 3cb9d37 · 3cb9d37
1 parent c85f382
commit 3cb9d37
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Showing 4 changed files with 80 additions and 14 deletions.
diff --git a/sharding-core/src/main/java/io/shardingsphere/spi/NewInstanceServiceLoader.java b/sharding-core/src/main/java/io/shardingsphere/spi/NewInstanceServiceLoader.java
@@ -0,0 +1,55 @@
+package io.shardingsphere.spi;
+
+import io.shardingsphere.core.exception.ShardingException;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+
+import java.util.Collection;
+import java.util.LinkedList;
+import java.util.ServiceLoader;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * SPI service loader for new instance for every call.
+ *
+ * @author zhangliang
+ * @param <T> type of class
+ */
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public final class NewInstanceServiceLoader<T> {
+
+    private final Collection<Class<T>> serviceClasses = new CopyOnWriteArrayList<>();
+
+    /**
+     * Creates a new service class loader for the given service type.
+     * 
+     * @param service service type
+     * @param <T> type of service
+     * @return new service class loader
+     */
+    @SuppressWarnings("unchecked")
+    public static synchronized <T> NewInstanceServiceLoader<T> load(final Class<T> service) {
+        NewInstanceServiceLoader result = new NewInstanceServiceLoader();
+        for (T each : ServiceLoader.load(service)) {
+            result.serviceClasses.add(each.getClass());
+        }
+        return result;
+    }
+
+    /**
+     * New service instances.
+     * 
+     * @return service instances
+     */
+    public Collection<T> newServiceInstances() {
+        Collection<T> result = new LinkedList<>();
+        for (Class<T> each : serviceClasses) {
+            try {
+                result.add(each.newInstance());
+            } catch (final ReflectiveOperationException ex) {
+                throw new ShardingException(ex);
+            }
+        }
+        return result;
+    }
+}
diff --git a/sharding-core/src/main/java/io/shardingsphere/spi/executor/SPISQLExecutionHook.java b/sharding-core/src/main/java/io/shardingsphere/spi/executor/SPISQLExecutionHook.java
@@ -19,8 +19,9 @@
 
 import io.shardingsphere.core.metadata.datasource.DataSourceMetaData;
 import io.shardingsphere.core.routing.RouteUnit;
+import io.shardingsphere.spi.NewInstanceServiceLoader;
 
-import java.util.ServiceLoader;
+import java.util.Collection;
 
 /**
  * SQL Execution hook for SPI.
@@ -29,25 +30,27 @@
  */
 public final class SPISQLExecutionHook implements SQLExecutionHook {
 
-    private final ServiceLoader<SQLExecutionHook> serviceLoader = ServiceLoader.load(SQLExecutionHook.class);
+    private static final NewInstanceServiceLoader<SQLExecutionHook> SERVICE_LOADER = NewInstanceServiceLoader.load(SQLExecutionHook.class);
+
+    private final Collection<SQLExecutionHook> sqlExecutionHooks = SERVICE_LOADER.newServiceInstances();
 
     @Override
     public void start(final RouteUnit routeUnit, final DataSourceMetaData dataSourceMetaData, final boolean isTrunkThread) {
-        for (SQLExecutionHook each : serviceLoader) {
+        for (SQLExecutionHook each : sqlExecutionHooks) {
             each.start(routeUnit, dataSourceMetaData, isTrunkThread);
         }
     }
 
     @Override
     public void finishSuccess() {
-        for (SQLExecutionHook each : serviceLoader) {
+        for (SQLExecutionHook each : sqlExecutionHooks) {
             each.finishSuccess();
         }
     }
 
     @Override
     public void finishFailure(final Exception cause) {
-        for (SQLExecutionHook each : serviceLoader) {
+        for (SQLExecutionHook each : sqlExecutionHooks) {
             each.finishFailure(cause);
         }
     }

diff --git a/sharding-core/src/main/java/io/shardingsphere/spi/parsing/SPIParsingHook.java b/sharding-core/src/main/java/io/shardingsphere/spi/parsing/SPIParsingHook.java
@@ -17,7 +17,9 @@
 
 package io.shardingsphere.spi.parsing;
 
-import java.util.ServiceLoader;
+import io.shardingsphere.spi.NewInstanceServiceLoader;
+
+import java.util.Collection;
 
 /**
  * Parsing hook for SPI.
@@ -26,25 +28,27 @@
  */
 public final class SPIParsingHook implements ParsingHook {
 
-    private final ServiceLoader<ParsingHook> serviceLoader = ServiceLoader.load(ParsingHook.class);
+    private static final NewInstanceServiceLoader<ParsingHook> SERVICE_LOADER = NewInstanceServiceLoader.load(ParsingHook.class);
+
+    private final Collection<ParsingHook> parsingHooks = SERVICE_LOADER.newServiceInstances();
 
     @Override
     public void start(final String sql) {
-        for (ParsingHook each : serviceLoader) {
+        for (ParsingHook each : parsingHooks) {
             each.start(sql);
         }
     }
 
     @Override
     public void finishSuccess() {
-        for (ParsingHook each : serviceLoader) {
+        for (ParsingHook each : parsingHooks) {
             each.finishSuccess();
         }
     }
 
     @Override
     public void finishFailure(final Exception cause) {
-        for (ParsingHook each : serviceLoader) {
+        for (ParsingHook each : parsingHooks) {
             each.finishFailure(cause);
         }
     }

diff --git a/sharding-core/src/main/java/io/shardingsphere/spi/root/SPIRootInvokeHook.java b/sharding-core/src/main/java/io/shardingsphere/spi/root/SPIRootInvokeHook.java
@@ -17,7 +17,9 @@
 
 package io.shardingsphere.spi.root;
 
-import java.util.ServiceLoader;
+import io.shardingsphere.spi.NewInstanceServiceLoader;
+
+import java.util.Collection;
 
 /**
  * Root invoke hook for SPI.
@@ -26,18 +28,20 @@
  */
 public final class SPIRootInvokeHook implements RootInvokeHook {
 
-    private final ServiceLoader<RootInvokeHook> serviceLoader = ServiceLoader.load(RootInvokeHook.class);
+    private static final NewInstanceServiceLoader<RootInvokeHook> SERVICE_LOADER = NewInstanceServiceLoader.load(RootInvokeHook.class);
+
+    private final Collection<RootInvokeHook> rootInvokeHooks = SERVICE_LOADER.newServiceInstances();
 
     @Override
     public void start() {
-        for (RootInvokeHook each : serviceLoader) {
+        for (RootInvokeHook each : rootInvokeHooks) {
             each.start();
         }
     }
 
     @Override
     public void finish(final int connectionCount) {
-        for (RootInvokeHook each : serviceLoader) {
+        for (RootInvokeHook each : rootInvokeHooks) {
             each.finish(connectionCount);
         }
     }