feat: support incremental configuration synchronization client

CHANGES.md

@@ -11,6 +11,7 @@ Apollo Java 2.4.0
 * [Add more observability in apollo config client](https://github.com/apolloconfig/apollo-java/pull/74)
 * [Feature Support Kubernetes ConfigMap cache for Apollo java, golang client](https://github.com/apolloconfig/apollo-java/pull/79)
 * [Feature support pulling configuration information from multiple AppIds](https://github.com/apolloconfig/apollo-java/pull/70)
+* [Feature support incremental configuration synchronization client](https://github.com/apolloconfig/apollo-java/pull/90)
 
 
 ------------------

apollo-client/src/main/java/com/ctrip/framework/apollo/internals/RemoteConfigRepository.java

@@ -23,7 +23,10 @@
 import com.ctrip.framework.apollo.core.ConfigConsts;
 import com.ctrip.framework.apollo.core.dto.ApolloConfig;
 import com.ctrip.framework.apollo.core.dto.ApolloNotificationMessages;
+import com.ctrip.framework.apollo.core.dto.ConfigurationChange;
 import com.ctrip.framework.apollo.core.dto.ServiceDTO;
+import com.ctrip.framework.apollo.core.enums.ConfigSyncType;
+import com.ctrip.framework.apollo.core.enums.ConfigurationChangeType;
 import com.ctrip.framework.apollo.core.schedule.ExponentialSchedulePolicy;
 import com.ctrip.framework.apollo.core.schedule.SchedulePolicy;
 import com.ctrip.framework.apollo.core.signature.Signature;
@@ -49,6 +52,7 @@
 import com.google.common.util.concurrent.RateLimiter;
 import com.google.gson.Gson;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
@@ -255,6 +259,24 @@ private ApolloConfig loadApolloConfig() {
 
           ApolloConfig result = response.getBody();
 
+          if (result != null) {
+            ConfigSyncType configSyncType = ConfigSyncType.fromString(result.getConfigSyncType());
+
+            if (configSyncType == ConfigSyncType.INCREMENTAL_SYNC) {
+              ApolloConfig previousConfig = m_configCache.get();
+              Map<String, String> previousConfigurations =
+                  (previousConfig != null) ? previousConfig.getConfigurations() : null;
+              result.setConfigurations(
+                  mergeConfigurations(previousConfigurations, result.getConfigurationChanges()));
+            } else if (configSyncType == ConfigSyncType.UNKNOWN) {
+              String message = String.format(
+                  "Apollo Config Sync type invalid - configSyncType: %s",
+                  result.getConfigSyncType());
+              throw new ApolloConfigException(message, exception);
+            }
+
+          }
+
           logger.debug("Loaded config for {}: {}", m_namespace, result);
 
           return result;
@@ -269,7 +291,7 @@ private ApolloConfig loadApolloConfig() {
             statusCodeException = new ApolloConfigStatusCodeException(ex.getStatusCode(),
                 message);
             Tracer.logEvent(APOLLO_CLIENT_NAMESPACE_NOT_FOUND,m_namespace);
-            
+
           }
           Tracer.logEvent(APOLLO_CONFIG_EXCEPTION, ExceptionUtil.getDetailMessage(statusCodeException));
           transaction.setStatus(statusCodeException);
@@ -363,4 +385,34 @@ private List<ServiceDTO> getConfigServices() {
 
     return services;
   }
+
+  Map<String, String> mergeConfigurations(Map<String, String> previousConfigurations,
+      List<ConfigurationChange> configurationChanges) {
+    Map<String, String> newConfigurations = new HashMap<>();
+
+    if (previousConfigurations != null) {
+      newConfigurations = Maps.newHashMap(previousConfigurations);
+    }
+
+    if (configurationChanges == null) {
+      return newConfigurations;
+    }
+
+    for (ConfigurationChange change : configurationChanges) {
+      switch (ConfigurationChangeType.fromString(change.getConfigurationChangeType())) {
+        case ADDED:
+        case MODIFIED:
+          newConfigurations.put(change.getKey(), change.getNewValue());
+          break;
+        case DELETED:
+          newConfigurations.remove(change.getKey());
+          break;
+        default:
+          //do nothing
+          break;
+      }
+    }
+
+    return newConfigurations;
+  }
 }

apollo-client/src/test/java/com/ctrip/framework/apollo/internals/RemoteConfigRepositoryTest.java

@@ -34,7 +34,9 @@
 import com.ctrip.framework.apollo.core.dto.ApolloConfig;
 import com.ctrip.framework.apollo.core.dto.ApolloConfigNotification;
 import com.ctrip.framework.apollo.core.dto.ApolloNotificationMessages;
+import com.ctrip.framework.apollo.core.dto.ConfigurationChange;
 import com.ctrip.framework.apollo.core.dto.ServiceDTO;
+import com.ctrip.framework.apollo.core.enums.ConfigSyncType;
 import com.ctrip.framework.apollo.core.signature.Signature;
 import com.ctrip.framework.apollo.enums.ConfigSourceType;
 import com.ctrip.framework.apollo.exceptions.ApolloConfigException;
@@ -53,6 +55,7 @@
 import com.google.common.util.concurrent.SettableFuture;
 import com.google.gson.Gson;
 import java.lang.reflect.Type;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
@@ -154,6 +157,141 @@ public void testLoadConfig() throws Exception {
     assertEquals(ConfigSourceType.REMOTE, remoteConfigRepository.getSourceType());
   }
 
+  @Test
+  public void testLoadConfigWithIncrementalSync() throws Exception {
+
+    String someKey = "someKey";
+    String someValue = "someValue";
+    String someKey1 = "someKey1";
+    String someValue1 = "someKey1";
+    Map<String, String> configurations = Maps.newHashMap();
+    configurations.put(someKey, someValue);
+    configurations.put(someKey1, someValue1);
+    ApolloConfig someApolloConfig = assembleApolloConfig(configurations);
+
+    when(someResponse.getStatusCode()).thenReturn(200);
+    when(someResponse.getBody()).thenReturn(someApolloConfig);
+
+    RemoteConfigRepository remoteConfigRepository = new RemoteConfigRepository(someAppId,
+        someNamespace);
+
+    remoteConfigRepository.sync();
+
+    List<ConfigurationChange> configurationChanges = new ArrayList<>();
+    String someNewValue = "someNewValue";
+    configurationChanges.add(new ConfigurationChange(someKey, someNewValue, "MODIFIED"));
+    configurationChanges.add(new ConfigurationChange(someKey1, null, "DELETED"));
+    String someKey2 = "someKey2";
+    String someValue2 = "someValue2";
+    configurationChanges.add(new ConfigurationChange(someKey2, someValue2, "ADDED"));
+    ApolloConfig someApolloConfigWithIncrementalSync = assembleApolloConfigWithIncrementalSync(
+        configurationChanges);
+
+    when(someResponse.getStatusCode()).thenReturn(200);
+    when(someResponse.getBody()).thenReturn(someApolloConfigWithIncrementalSync);
+
+    remoteConfigRepository.sync();
+
+    Properties config = remoteConfigRepository.getConfig();
+
+    assertEquals(2, config.size());
+    assertEquals("someNewValue", config.getProperty("someKey"));
+    assertEquals("someValue2", config.getProperty("someKey2"));
+    assertEquals(ConfigSourceType.REMOTE, remoteConfigRepository.getSourceType());
+    remoteConfigLongPollService.stopLongPollingRefresh();
+  }
+
+  @Test
+  public void testMergeConfigurations() throws Exception {
+    String key1 = "key1";
+    String value1 = "value1";
+    String anotherValue1 = "anotherValue1";
+
+    String key3 = "key3";
+    String value3 = "value3";
+    Map<String, String> previousConfigurations = ImmutableMap.of(key1, value1, key3, value3);
+
+    List<ConfigurationChange> configurationChanges = new ArrayList<>();
+    configurationChanges.add(new ConfigurationChange(key1, anotherValue1, "MODIFIED"));
+    String key2 = "key2";
+    String value2 = "value2";
+    configurationChanges.add(new ConfigurationChange(key2, value2, "ADDED"));
+    configurationChanges.add(new ConfigurationChange(key3, null, "DELETED"));
+
+    RemoteConfigRepository remoteConfigRepository = new RemoteConfigRepository(someAppId,
+        someNamespace);
+    Map<String, String> result = remoteConfigRepository.mergeConfigurations(previousConfigurations,
+        configurationChanges);
+
+    assertEquals(2, result.size());
+    assertEquals(anotherValue1, result.get(key1));
+    assertEquals(value2, result.get(key2));
+  }
+
+  @Test
+  public void testMergeConfigurationWithPreviousConfigurationsIsNULL() throws Exception {
+    String key1 = "key1";
+    String value1 = "value1";
+
+    String key3 = "key3";
+    String value3 = "value3";
+
+    Map<String, String> previousConfigurations = ImmutableMap.of(key1, value1, key3, value3);
+
+    RemoteConfigRepository remoteConfigRepository = new RemoteConfigRepository(someAppId,
+        someNamespace);
+    Map<String, String> result = remoteConfigRepository.mergeConfigurations(previousConfigurations,
+        null);
+
+    assertEquals(2, result.size());
+    assertEquals(value1, result.get(key1));
+    assertEquals(value3, result.get(key3));
+  }
+
+  @Test
+  public void testMergeConfigurationWithChangesIsNULL() throws Exception {
+    String key1 = "key1";
+    String value1 = "value1";
+    String anotherValue1 = "anotherValue1";
+
+    String key3 = "key3";
+    String value3 = "value3";
+
+    List<ConfigurationChange> configurationChanges = new ArrayList<>();
+    configurationChanges.add(new ConfigurationChange(key1, anotherValue1, "MODIFIED"));
+    String key2 = "key2";
+    String value2 = "value2";
+    configurationChanges.add(new ConfigurationChange(key2, value2, "ADDED"));
+    configurationChanges.add(new ConfigurationChange(key3, null, "DELETED"));
+
+    RemoteConfigRepository remoteConfigRepository = new RemoteConfigRepository(someAppId,
+        someNamespace);
+    Map<String, String> result = remoteConfigRepository.mergeConfigurations(null,
+        configurationChanges);
+
+    assertEquals(2, result.size());
+    assertEquals(anotherValue1, result.get(key1));
+    assertEquals(value2, result.get(key2));
+  }
+
+  @Test(expected = ApolloConfigException.class)
+  public void testGetRemoteConfigWithUnknownSync() throws Exception {
+
+    ApolloConfig someApolloConfigWithUnknownSync = assembleApolloConfigWithUnknownSync(
+        new ArrayList<>());
+
+    when(someResponse.getStatusCode()).thenReturn(200);
+    when(someResponse.getBody()).thenReturn(someApolloConfigWithUnknownSync);
+
+    RemoteConfigRepository remoteConfigRepository = new RemoteConfigRepository(someAppId,
+        someNamespace);
+
+    //must stop the long polling before exception occurred
+    remoteConfigLongPollService.stopLongPollingRefresh();
+
+    remoteConfigRepository.getConfig();
+  }
+
   @Test
   public void testLoadConfigWithOrderedProperties() throws Exception {
     String someKey = "someKey";
@@ -371,6 +509,32 @@ private ApolloConfig assembleApolloConfig(Map<String, String> configurations) {
     return apolloConfig;
   }
 
+  private ApolloConfig assembleApolloConfigWithIncrementalSync(
+      List<ConfigurationChange> configurationChanges) {
+    String someAppId = "appId";
+    String someClusterName = "cluster";
+    String someReleaseKey = "1";
+    ApolloConfig apolloConfig =
+        new ApolloConfig(someAppId, someClusterName, someNamespace, someReleaseKey);
+
+    apolloConfig.setConfigSyncType(ConfigSyncType.INCREMENTAL_SYNC.getValue());
+    apolloConfig.setConfigurationChanges(configurationChanges);
+    return apolloConfig;
+  }
+
+  private ApolloConfig assembleApolloConfigWithUnknownSync(
+      List<ConfigurationChange> configurationChanges) {
+    String someAppId = "appId";
+    String someClusterName = "cluster";
+    String someReleaseKey = "1";
+    ApolloConfig apolloConfig =
+        new ApolloConfig(someAppId, someClusterName, someNamespace, someReleaseKey);
+
+    apolloConfig.setConfigSyncType(ConfigSyncType.UNKNOWN.getValue());
+    apolloConfig.setConfigurationChanges(configurationChanges);
+    return apolloConfig;
+  }
+
   public static class MockConfigUtil extends ConfigUtil {
 
     @Override

apollo-core/src/main/java/com/ctrip/framework/apollo/core/dto/ApolloConfig.java

@@ -16,6 +16,8 @@
  */
 package com.ctrip.framework.apollo.core.dto;
 
+
+import java.util.List;
 import java.util.Map;
 
 /**
@@ -33,6 +35,10 @@ public class ApolloConfig {
 
   private String releaseKey;
 
+  private String configSyncType;
+
+  private List<ConfigurationChange> configurationChanges;
+
   public ApolloConfig() {
   }
 
@@ -62,6 +68,14 @@ public String getReleaseKey() {
     return releaseKey;
   }
 
+  public String getConfigSyncType() {
+    return configSyncType;
+  }
+
+  public List<ConfigurationChange> getConfigurationChanges() {
+    return configurationChanges;
+  }
+
   public Map<String, String> getConfigurations() {
     return configurations;
   }
@@ -82,10 +96,18 @@ public void setReleaseKey(String releaseKey) {
     this.releaseKey = releaseKey;
   }
 
+  public void setConfigSyncType(String configSyncType) {
+    this.configSyncType = configSyncType;
+  }
+
   public void setConfigurations(Map<String, String> configurations) {
     this.configurations = configurations;
   }
 
+  public void setConfigurationChanges(List<ConfigurationChange> configurationChanges) {
+    this.configurationChanges = configurationChanges;
+  }
+
   @Override
   public String toString() {
     final StringBuilder sb = new StringBuilder("ApolloConfig{");