Fixes #258 - fixed/improved snapshotAutoUpdater

pom.xml

@@ -8,7 +8,7 @@
 	<groupId>com.github.switcherapi</groupId>
 	<artifactId>switcher-client</artifactId>
 	<packaging>jar</packaging>
-	<version>2.0.4</version>
+	<version>2.0.5-SNAPSHOT</version>
 
 	<name>Switcher Client</name>
 	<description>Switcher Client SDK for working with Switcher API</description>

src/main/java/com/github/switcherapi/client/SnapshotCallback.java

@@ -0,0 +1,31 @@
+package com.github.switcherapi.client;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public class SnapshotCallback {
+
+    private static final Logger logger = LogManager.getLogger(SnapshotCallback.class);
+
+    /**
+     * Callback method that will be invoked when the snapshot is updated
+     *
+     * @param version of the new snapshot
+     */
+    public void onSnapshotUpdate(long version) {
+        if (logger.isDebugEnabled()) {
+            logger.debug(String.format("Snapshot updated: %s", version));
+        }
+    }
+
+    /**
+     * Callback method that will be invoked when the snapshot update fails
+     *
+     * @param e Exception
+     */
+    public void onSnapshotUpdateError(Exception e) {
+        if (logger.isDebugEnabled()) {
+            logger.debug(String.format("Failed to update snapshot: %s", e.getMessage()));
+        }
+    }
+}

src/main/java/com/github/switcherapi/client/SwitcherContext.java

@@ -1,7 +1,5 @@
 package com.github.switcherapi.client;
 
-import com.github.switcherapi.client.exception.SwitcherKeyNotFoundException;
-import com.github.switcherapi.client.exception.SwitchersValidationException;
 import com.github.switcherapi.client.model.ContextKey;
 import com.github.switcherapi.client.model.Switcher;
 
@@ -37,20 +35,14 @@ public static void loadProperties() {
 	}
 
 	/**
-	 * Initialize Switcher Client
+	 * {@link SwitcherContextBase#initializeClient()}
 	 */
 	public static void initializeClient() {
 		SwitcherContextBase.initializeClient();
 	}
 
 	/**
-	 * Return a ready-to-use Switcher that will invoke the criteria configured into the Switcher API or Snapshot
-	 * 
-	 * @param key name of the key created
-	 * @param keepEntries when true it will return a cached Switcher with all parameters used before
-	 * 
-	 * @return a ready to use Switcher
-	 * @throws SwitcherKeyNotFoundException in case the key was not properly loaded
+	 * {@link SwitcherContextBase#getSwitcher(String, boolean)}
 	 */
 	public static Switcher getSwitcher(String key, boolean keepEntries) {
 		return SwitcherContextBase.getSwitcher(key, keepEntries);
@@ -67,19 +59,14 @@ public static Switcher getSwitcher(String key) {
 	}
 
 	/**
-	 * Validate and update local snapshot file.<br>
-	 * It requires offline mode or SwitcherContextParam.SNAPSHOT_LOCATION configured
-	 * 
-	 * @return true if validation was performed
+	 * {@link SwitcherContextBase#validateSnapshot()}
 	 */
 	public static boolean validateSnapshot() {
 		return SwitcherContextBase.validateSnapshot();
 	}
 
 	/**
-	 * Executes smoke test against the API to verify if all Switchers are properly configured
-	 * 
-	 * @throws SwitchersValidationException when one or more Switcher Key is not found
+	 * {@link SwitcherContextBase#checkSwitchers()}
 	 */
 	public static void checkSwitchers() {
 		SwitcherContextBase.checkSwitchers();
@@ -95,29 +82,21 @@ public static long getSnapshotVersion() {
 	}
 
 	/**
-	 * Retrieve string context parameter based on contextKey
-	 * 
-	 * @param contextKey to be retrieved
-	 * @return Value configured for the context parameter
+	 * {@link SwitcherContextBase#contextStr(ContextKey)}
 	 */
 	public static String contextStr(ContextKey contextKey) {
 		return SwitcherContextBase.contextStr(contextKey);
 	}
 
 	/**
-	 * Retrieve boolean context parameter based on contextKey
-	 * 
-	 * @param contextKey to be retrieved
-	 * @return Value configured for the context parameter
+	 * {@link SwitcherContextBase#contextBol(ContextKey)}
 	 */
 	public static boolean contextBol(ContextKey contextKey) {
 		return SwitcherContextBase.contextBol(contextKey);
 	}
 
 	/**
-	 * Fluent builder to configure the Switcher Context
-	 * 
-	 * @param builder specification to be applied
+	 * {@link SwitcherContextBase#configure(ContextBuilder)}
 	 */
 	public static void configure(ContextBuilder builder) {
 		SwitcherContextBase.configure(builder);

src/main/java/com/github/switcherapi/client/SwitcherContextBase.java

@@ -116,7 +116,7 @@ public static void initializeClient() {
 		}
 
 		loadSwitchers();
-		scheduleSnapshotAutoUpdate();
+		scheduleSnapshotAutoUpdate(switcherProperties.getSnapshotAutoUpdateInterval(), null);
 		ContextBuilder.preConfigure(switcherProperties);
 	}
 
@@ -163,15 +163,28 @@ private static void loadSwitchers() {
 	}
 
 	/**
-	 * Configure worker for Scheduled Snapshot Auto Update based on the interval provided at
-	 * the configuration "switcher.snapshot.updateinterval"
+	 * Schedule a task to update the snapshot automatically.<br>
+	 * The task will be executed in a single thread executor service.
+	 *
+	 * @param intervalValue to be used for the update (e.g. 5s, 1m, 1h, 1d)
+	 * @param callback to be invoked when the snapshot is updated or when an error occurs
 	 */
-	private static void scheduleSnapshotAutoUpdate() {
-		if (StringUtils.isBlank(switcherProperties.getSnapshotAutoUpdateInterval()))
+	public static void scheduleSnapshotAutoUpdate(String intervalValue, SnapshotCallback callback) {
+		if (StringUtils.isBlank(intervalValue))
 			return;
 
-		final long interval = SwitcherUtils.getMillis(switcherProperties.getSnapshotAutoUpdateInterval());
-		final Runnable runnableSnapshotValidate = SwitcherContextBase::validateSnapshot;
+		final long interval = SwitcherUtils.getMillis(intervalValue);
+		final SnapshotCallback callbackFinal = Optional.ofNullable(callback).orElse(new SnapshotCallback());
+		final Runnable runnableSnapshotValidate = () -> {
+			try {
+				if (validateSnapshot()) {
+					callbackFinal.onSnapshotUpdate(instance.getSnapshotVersion());
+				}
+			} catch (Exception e) {
+				logger.error(e.getMessage());
+				callbackFinal.onSnapshotUpdateError(e);
+			}
+		};
 
 		initExecutorService();
 		scheduledExecutorService.scheduleAtFixedRate(runnableSnapshotValidate, 0, interval, TimeUnit.MILLISECONDS);
@@ -223,20 +236,17 @@ public static Switcher getSwitcher(String key) {
 	}
 
 	/**
-	 * Validate and update local snapshot file.<br>
-	 * It requires offline mode or SwitcherContextParam.SNAPSHOT_LOCATION configured
+	 * Validate if the snapshot version is the same as the one in the API.<br>
+	 * If the version is different, it will update the snapshot in memory.
 	 * 
-	 * @return true if validation was performed
+	 * @return true if snapshot was updated
 	 */
 	public static boolean validateSnapshot() {
-		if (switcherProperties.isSnapshotSkipValidation()) {
+		if (switcherProperties.isSnapshotSkipValidation() || instance.checkSnapshotVersion()) {
 			return false;
 		}
-
-		if (!instance.checkSnapshotVersion()) {
-			instance.updateSnapshot();
-		}
-
+
+		instance.updateSnapshot();
 		return true;
 	}
 

src/test/java/com/github/switcherapi/client/SwitcherApiMockTest.java

@@ -253,7 +253,7 @@ void shouldValidateAndNotUpdateSnapshot() {
 
 		assertDoesNotThrow(() -> {
 			Switchers.initializeClient();
-			assertTrue(Switchers.validateSnapshot());
+			assertFalse(Switchers.validateSnapshot());
 		});
 	}
 

src/test/java/com/github/switcherapi/client/SwitcherSnapshotAutoUpdateTest.java

@@ -227,4 +227,34 @@ void shouldUpdateSnapshot_online_inMemory() {
 		assertEquals(2, Switchers.getSnapshotVersion());
 	}
 
+	@Test
+	@Order(5)
+	void shouldNotKillThread_whenAPI_wentOffline() {
+		//given
+		givenResponse(generateMockAuth()); //auth
+		givenResponse(generateSnapshotResponse("default_outdated.json")); //graphql
+
+		//that
+		Switchers.configure(ContextBuilder.builder()
+				.url(String.format("http://localhost:%s", mockBackEnd.getPort()))
+				.snapshotLocation(null)
+				.environment("generated_mock_default_6")
+				.offlineMode(true)
+				.snapshotAutoLoad(true)
+				.snapshotAutoUpdateInterval("1s"));
+
+		Switchers.initializeClient();
+		assertEquals(1, Switchers.getSnapshotVersion());
+
+		CountDownHelper.wait(1);
+
+		//given - API is online again
+		givenResponse(generateCheckSnapshotVersionResponse(Boolean.toString(false))); //criteria/snapshot_check
+		givenResponse(generateSnapshotResponse("default.json")); //graphql
+
+		//test
+		CountDownHelper.wait(2);
+		assertEquals(2, Switchers.getSnapshotVersion());
+	}
+
 }