refactor local config repository strategy to load config first from upstream if possible

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

@@ -49,6 +49,10 @@ public class LocalFileConfigRepository extends AbstractConfigRepository
    * @param namespace the namespace
    */
   public LocalFileConfigRepository(String namespace) {
+    this(namespace, null);
+  }
+
+  public LocalFileConfigRepository(String namespace, ConfigRepository upstream) {
     m_namespace = namespace;
     m_container = ContainerLoader.getDefaultContainer();
     try {
@@ -57,13 +61,17 @@ public class LocalFileConfigRepository extends AbstractConfigRepository
       Cat.logError(ex);
       throw new ApolloConfigException("Unable to load component!", ex);
     }
-    this.setLocalCacheDir(findLocalCacheDir());
+    this.setLocalCacheDir(findLocalCacheDir(), false);
+    this.setUpstreamRepository(upstream);
+    this.trySync();
   }
 
-  void setLocalCacheDir(File baseDir) {
+  void setLocalCacheDir(File baseDir, boolean syncImmediately) {
     m_baseDir = baseDir;
     this.checkLocalConfigCacheDir(m_baseDir);
-    this.trySync();
+    if (syncImmediately) {
+      this.trySync();
+    }
   }
 
   private File findLocalCacheDir() {
@@ -95,6 +103,9 @@ public class LocalFileConfigRepository extends AbstractConfigRepository
 
   @Override
   public void setUpstreamRepository(ConfigRepository upstreamConfigRepository) {
+    if (upstreamConfigRepository == null) {
+      return;
+    }
     //clear previous listener
     if (m_upstream != null) {
       m_upstream.removeChangeListener(this);
@@ -118,7 +129,7 @@ public class LocalFileConfigRepository extends AbstractConfigRepository
   @Override
   protected void sync() {
     //sync with upstream immediately
-   boolean syncFromUpstreamResultSuccess = trySyncFromUpstream();
+    boolean syncFromUpstreamResultSuccess = trySyncFromUpstream();
 
     if (syncFromUpstreamResultSuccess) {
       return;
@@ -252,7 +263,8 @@ public class LocalFileConfigRepository extends AbstractConfigRepository
     } catch (IOException ex) {
       ApolloConfigException exception =
           new ApolloConfigException(
-              String.format("Create local config directory %s failed", baseDir.getAbsolutePath()), ex);
+              String.format("Create local config directory %s failed", baseDir.getAbsolutePath()),
+              ex);
       Cat.logError(exception);
       transaction.setStatus(exception);
       logger.warn(

apollo-client/src/main/java/com/ctrip/framework/apollo/spi/DefaultConfigFactory.java

@@ -46,16 +46,13 @@ public class DefaultConfigFactory implements ConfigFactory {
   }
 
   LocalFileConfigRepository createLocalConfigRepository(String namespace) {
-    LocalFileConfigRepository localFileConfigRepository =
-        new LocalFileConfigRepository(namespace);
     if (m_configUtil.isInLocalMode()) {
       logger.warn(
           "==== Apollo is in local mode! Won't pull configs from remote server for namespace {} ! ====",
           namespace);
-    } else {
-      localFileConfigRepository.setUpstreamRepository(createRemoteConfigRepository(namespace));
+      return new LocalFileConfigRepository(namespace);
     }
-    return localFileConfigRepository;
+    return new LocalFileConfigRepository(namespace, createRemoteConfigRepository(namespace));
   }
 
   RemoteConfigRepository createRemoteConfigRepository(String namespace) {

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

@@ -33,7 +33,7 @@ import static org.mockito.Mockito.when;
 public class LocalFileConfigRepositoryTest extends ComponentTestCase {
   private File someBaseDir;
   private String someNamespace;
-  private ConfigRepository fallbackRepo;
+  private ConfigRepository upstreamRepo;
   private Properties someProperties;
   private static String someAppId = "someApp";
   private static String someCluster = "someCluster";
@@ -51,8 +51,8 @@ public class LocalFileConfigRepositoryTest extends ComponentTestCase {
     defaultKey = "defaultKey";
     defaultValue = "defaultValue";
     someProperties.setProperty(defaultKey, defaultValue);
-    fallbackRepo = mock(ConfigRepository.class);
-    when(fallbackRepo.getConfig()).thenReturn(someProperties);
+    upstreamRepo = mock(ConfigRepository.class);
+    when(upstreamRepo.getConfig()).thenReturn(someProperties);
 
     defineComponent(ConfigUtil.class, MockConfigUtil.class);
   }
@@ -93,7 +93,7 @@ public class LocalFileConfigRepositoryTest extends ComponentTestCase {
     createLocalCachePropertyFile(someProperties);
 
     LocalFileConfigRepository localRepo = new LocalFileConfigRepository(someNamespace);
-    localRepo.setLocalCacheDir(someBaseDir);
+    localRepo.setLocalCacheDir(someBaseDir, true);
     Properties properties = localRepo.getConfig();
 
     assertEquals(someValue, properties.getProperty(someKey));
@@ -108,11 +108,8 @@ public class LocalFileConfigRepositoryTest extends ComponentTestCase {
 
     Files.write(defaultKey + "=" + someValue, file, Charsets.UTF_8);
 
-    LocalFileConfigRepository localRepo = new LocalFileConfigRepository(someNamespace);
-    localRepo.setLocalCacheDir(someBaseDir);
-
-    //when fallback is set, it will try to sync from it
-    localRepo.setUpstreamRepository(fallbackRepo);
+    LocalFileConfigRepository localRepo = new LocalFileConfigRepository(someNamespace, upstreamRepo);
+    localRepo.setLocalCacheDir(someBaseDir, true);
 
     Properties properties = localRepo.getConfig();
 
@@ -123,10 +120,8 @@ public class LocalFileConfigRepositoryTest extends ComponentTestCase {
   public void testLoadConfigWithNoLocalFile() throws Exception {
     LocalFileConfigRepository
         localFileConfigRepository =
-        new LocalFileConfigRepository(someNamespace);
-    localFileConfigRepository.setLocalCacheDir(someBaseDir);
-
-    localFileConfigRepository.setUpstreamRepository(fallbackRepo);
+        new LocalFileConfigRepository(someNamespace, upstreamRepo);
+    localFileConfigRepository.setLocalCacheDir(someBaseDir, true);
 
     Properties result = localFileConfigRepository.getConfig();
 
@@ -138,17 +133,15 @@ public class LocalFileConfigRepositoryTest extends ComponentTestCase {
   @Test
   public void testLoadConfigWithNoLocalFileMultipleTimes() throws Exception {
     LocalFileConfigRepository localRepo =
-        new LocalFileConfigRepository(someNamespace);
-    localRepo.setLocalCacheDir(someBaseDir);
-
-    localRepo.setUpstreamRepository(fallbackRepo);
+        new LocalFileConfigRepository(someNamespace, upstreamRepo);
+    localRepo.setLocalCacheDir(someBaseDir, true);
 
     Properties someProperties = localRepo.getConfig();
 
     LocalFileConfigRepository
         anotherLocalRepoWithNoFallback =
         new LocalFileConfigRepository(someNamespace);
-    anotherLocalRepoWithNoFallback.setLocalCacheDir(someBaseDir);
+    anotherLocalRepoWithNoFallback.setLocalCacheDir(someBaseDir, true);
 
     Properties anotherProperties = anotherLocalRepoWithNoFallback.getConfig();
 
@@ -163,9 +156,8 @@ public class LocalFileConfigRepositoryTest extends ComponentTestCase {
     RepositoryChangeListener someListener = mock(RepositoryChangeListener.class);
 
     LocalFileConfigRepository localFileConfigRepository =
-        new LocalFileConfigRepository(someNamespace);
-    localFileConfigRepository.setLocalCacheDir(someBaseDir);
-    localFileConfigRepository.setUpstreamRepository(fallbackRepo);
+        new LocalFileConfigRepository(someNamespace, upstreamRepo);
+    localFileConfigRepository.setLocalCacheDir(someBaseDir, true);
     localFileConfigRepository.addChangeListener(someListener);
 
     localFileConfigRepository.getConfig();