feat: load config in parallel way

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ConfigWatcher.java

@@ -17,7 +17,7 @@
 package org.springframework.cloud.zookeeper.config;
 
 import java.io.Closeable;
-import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.util.HashMap;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -124,7 +124,7 @@ public String getEventDesc(TreeCacheEvent event) {
 		out.append(", path=").append(event.getData().getPath());
 		byte[] data = event.getData().getData();
 		if (data != null && data.length > 0) {
-			out.append(", data=").append(new String(data, Charset.forName("UTF-8")));
+			out.append(", data=").append(new String(data, StandardCharsets.UTF_8));
 		}
 		return out.toString();
 	}

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigDataLoader.java

@@ -42,12 +42,13 @@ public ZookeeperConfigDataLoader(DeferredLogFactory logFactory) {
 	public ConfigData load(ConfigDataLoaderContext context, ZookeeperConfigDataResource resource) {
 		try {
 			CuratorFramework curator = context.getBootstrapContext().get(CuratorFramework.class);
-			if (curator == null) {
+			ZookeeperConfigProperties properties = context.getBootstrapContext().get(ZookeeperConfigProperties.class);
+			if (curator == null || properties == null) {
 				// this can happen if certain conditions are met
 				return null;
 			}
-			ZookeeperPropertySource propertySource = new ZookeeperPropertySource(resource.getContext(),
-					curator);
+			ZookeeperPropertySource propertySource = new ZookeeperPropertySource(resource.getContext(), curator,
+					properties);
 			List<ZookeeperPropertySource> propertySources = Collections.singletonList(propertySource);
 
 			return new ConfigData(propertySources, source -> {

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigDataLocationResolver.java

@@ -87,7 +87,7 @@ public List<ZookeeperConfigDataResource> resolveProfileSpecific(ConfigDataLocati
 
 		// create locations
 		ZookeeperConfigProperties properties = loadConfigProperties(context);
-		context.getBootstrapContext().register(ZookeeperConfigProperties.class, InstanceSupplier.of(properties));
+		context.getBootstrapContext().registerIfAbsent(ZookeeperConfigProperties.class, InstanceSupplier.of(properties));
 
 		ZookeeperPropertySources sources = new ZookeeperPropertySources(properties, log);
 

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperConfigProperties.java

@@ -62,6 +62,11 @@ public class ZookeeperConfigProperties {
 	 */
 	private boolean failFast = true;
 
+	/**
+	 * get config in parallel way.
+	 */
+	private boolean parallel = false;
+
 	public boolean isEnabled() {
 		return this.enabled;
 	}
@@ -112,6 +117,14 @@ public void setFailFast(boolean failFast) {
 		this.failFast = failFast;
 	}
 
+	public boolean isParallel() {
+		return parallel;
+	}
+
+	public void setParallel(boolean parallel) {
+		this.parallel = parallel;
+	}
+
 	@Override
 	public String toString() {
 		return new ToStringCreator(this)
@@ -121,6 +134,7 @@ public String toString() {
 				.append("defaultContext", defaultContext)
 				.append("profileSeparator", profileSeparator)
 				.append("failFast", failFast)
+				.append("parallel", parallel)
 				.toString();
 
 	}

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySource.java

@@ -16,11 +16,12 @@
 
 package org.springframework.cloud.zookeeper.config;
 
-import java.nio.charset.Charset;
-import java.util.LinkedHashMap;
+import java.nio.charset.StandardCharsets;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.stream.Stream;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -40,10 +41,14 @@ public class ZookeeperPropertySource extends AbstractZookeeperPropertySource {
 
 	private static final Log log = LogFactory.getLog(ZookeeperPropertySource.class);
 
-	private Map<String, String> properties = new LinkedHashMap<>();
+	private final ZookeeperConfigProperties zookeeperConfigProperties;
 
-	public ZookeeperPropertySource(String context, CuratorFramework source) {
+	private Map<String, String> properties = new ConcurrentHashMap<>(256);
+
+	public ZookeeperPropertySource(String context, CuratorFramework source,
+			ZookeeperConfigProperties zookeeperConfigProperties) {
 		super(context, source);
+		this.zookeeperConfigProperties = zookeeperConfigProperties;
 		findProperties(this.getContext(), null);
 	}
 
@@ -86,9 +91,20 @@ private void findProperties(String path, List<String> children) {
 			if (children == null || children.isEmpty()) {
 				return;
 			}
-			for (String child : children) {
+
+			Stream<String> childrenStream = children.stream();
+			if (zookeeperConfigProperties.isParallel() && this.getContext().equals(path)) {
+				childrenStream = children.parallelStream();
+			}
+			childrenStream.forEach(child -> {
 				String childPath = path + "/" + child;
-				List<String> childPathChildren = getChildren(childPath);
+				List<String> childPathChildren = null;
+				try {
+					childPathChildren = getChildren(childPath);
+				}
+				catch (Exception e) {
+					ReflectionUtils.rethrowRuntimeException(e);
+				}
 
 				byte[] bytes = getPropertyBytes(childPath);
 				if (bytes == null || bytes.length == 0) {
@@ -97,13 +113,13 @@ private void findProperties(String path, List<String> children) {
 					}
 				}
 				else {
-					registerKeyValue(childPath,
-							new String(bytes, Charset.forName("UTF-8")));
+					registerKeyValue(childPath, new String(bytes, StandardCharsets.UTF_8));
 				}
 
 				// Check children even if we have found a value for the current znode
 				findProperties(childPath, childPathChildren);
-			}
+			});
+
 			log.trace("leaving findProperties for path: " + path);
 		}
 		catch (Exception exception) {

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySourceLocator.java

@@ -107,16 +107,4 @@ public PropertySource<?> locate(Environment environment) {
 	@PreDestroy
 	public void destroy() {
 	}
-
-	private PropertySource<CuratorFramework> create(String context) {
-		return new ZookeeperPropertySource(context, this.curator);
-	}
-
-	private void addProfiles(List<String> contexts, String baseContext,
-			List<String> profiles) {
-		for (String profile : profiles) {
-			contexts.add(baseContext + this.properties.getProfileSeparator() + profile);
-		}
-	}
-
 }

spring-cloud-zookeeper-config/src/main/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySources.java

@@ -75,7 +75,7 @@ private void addProfiles(List<Context> contexts, String baseContext, List<String
 
 	public ZookeeperPropertySource createPropertySource(String context, boolean optional, CuratorFramework curator) {
 		try {
-			return new ZookeeperPropertySource(context, curator);
+			return new ZookeeperPropertySource(context, curator, this.properties);
 			// TODO: howto call close when /refresh
 		}
 		catch (Exception e) {

spring-cloud-zookeeper-config/src/test/java/org/springframework/cloud/zookeeper/config/ZookeeperPropertySourceTests.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2015-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.zookeeper.config;
+
+import java.lang.reflect.Field;
+import java.util.Map;
+import java.util.UUID;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.curator.framework.CuratorFramework;
+import org.apache.curator.framework.CuratorFrameworkFactory;
+import org.apache.curator.retry.RetryOneTime;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.springframework.cloud.zookeeper.test.ZookeeperTestingServer;
+import org.springframework.util.ReflectionUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * {@link org.springframework.core.env.PropertySource} that stores properties
+ * from Zookeeper inside a map. Properties are loaded upon class initialization.
+ *
+ * @author lemonJ
+ * @since 1.0.0
+ */
+public class ZookeeperPropertySourceTests {
+
+	private static final Log log = LogFactory.getLog(ZookeeperPropertySourceTests.class);
+
+	public static final String PREFIX = "test__config__";
+
+	public static final String ROOT = "/" + PREFIX + UUID.randomUUID();
+
+	private ZookeeperTestingServer testingServer;
+
+	private CuratorFramework curator;
+
+	@Before
+	public void setup() throws Exception {
+		this.testingServer = new ZookeeperTestingServer();
+		testingServer.start();
+		String connectString = "localhost:" + testingServer.getPort();
+		this.curator = CuratorFrameworkFactory.builder().retryPolicy(new RetryOneTime(500)).connectString(connectString)
+				.build();
+		this.curator.start();
+	}
+
+	@Test
+	public void loadConfigInParallel() throws Exception {
+		for (int i = 0; i < 1000; i++) {
+			String path = ROOT + "/" + i;
+			this.curator.create().creatingParentsIfNeeded().forPath(path);
+			this.curator.setData().forPath(path, "testPropValUpdate".getBytes());
+		}
+
+		ZookeeperConfigProperties properties = new ZookeeperConfigProperties();
+		properties.setParallel(true);
+		ZookeeperPropertySource parallelPropertySource = new ZookeeperPropertySource(ROOT, curator, properties);
+
+		properties.setParallel(false);
+		ZookeeperPropertySource serialPropertySource = new ZookeeperPropertySource(ROOT, curator, properties);
+
+		Field propertiesField = ZookeeperPropertySource.class.getDeclaredField("properties");
+		propertiesField.setAccessible(true);
+		Map<String, String> serialPropertyMap = (Map<String, String>) ReflectionUtils.getField(propertiesField,
+				serialPropertySource);
+		Map<String, String> parallelPropertyMap = (Map<String, String>) ReflectionUtils.getField(propertiesField,
+				parallelPropertySource);
+		assertThat(parallelPropertyMap).as("parallelPropertyMap").containsAllEntriesOf(serialPropertyMap);
+	}
+}