refactor DefaultDittoHeadersValidator implementation to use failed co…

…mpletion stages everywhere instead of throwing exceptions Signed-off-by: Johannes Schneider <johannes.schneider@bosch.io>
eclipse-ditto · Aug 29, 2022 · 74c40c2 · 74c40c2
1 parent 156f17e
commit 74c40c2
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Showing 2 changed files with 24 additions and 21 deletions.
diff --git a/...ce/src/main/java/org/eclipse/ditto/edge/service/headers/DefaultDittoHeadersValidator.java b/...ce/src/main/java/org/eclipse/ditto/edge/service/headers/DefaultDittoHeadersValidator.java
@@ -46,26 +46,35 @@ public DefaultDittoHeadersValidator(final ActorSystem actorSystem, final Config
     @Override
     public CompletionStage<DittoHeaders> validate(DittoHeaders dittoHeaders) {
         checkNotNull(dittoHeaders, "dittoHeaders");
-        try {
-            validateAuthorizationContext(dittoHeaders);
-            if (dittoHeaders.isEntriesSizeGreaterThan(maxBytes)) {
-                throw DittoHeadersTooLargeException.newSizeLimitBuilder(maxBytes)
-                        .dittoHeaders(dittoHeaders)
-                        .build();
-            }
-            return CompletableFuture.completedStage(dittoHeaders);
-        } catch (DittoHeadersTooLargeException e) {
-            return CompletableFuture.failedStage(e);
+        return validateSize(dittoHeaders).thenCompose(this::validateAuthorizationContext);
+    }
+
+    /**
+     * Validates {@code dittoHeaders} against {@code maximum-size} defined in the extension configuration.
+     *
+     * @param dittoHeaders the headers to validate.
+     * @return a completion stage which completes successfully with the valid headers. Raises a
+     * {@link org.eclipse.ditto.base.model.exceptions.DittoHeadersTooLargeException} if {@code dittoHeaders} are not
+     * valid.
+     */
+    public CompletionStage<DittoHeaders> validateSize(final DittoHeaders dittoHeaders) {
+        if (dittoHeaders.isEntriesSizeGreaterThan(maxBytes)) {
+            return CompletableFuture.failedStage(DittoHeadersTooLargeException.newSizeLimitBuilder(maxBytes)
+                    .dittoHeaders(dittoHeaders)
+                    .build());
         }
+        return CompletableFuture.completedStage(dittoHeaders);
     }
 
-    private void validateAuthorizationContext(final DittoHeaders dittoHeaders) {
+    private CompletionStage<DittoHeaders> validateAuthorizationContext(final DittoHeaders dittoHeaders) {
         final int authSubjectsCount = dittoHeaders.getAuthorizationContext().getSize();
         if (authSubjectsCount > maxAuthSubjects) {
-            throw DittoHeadersTooLargeException.newAuthSubjectsLimitBuilder(authSubjectsCount, maxAuthSubjects)
-                    .dittoHeaders(dittoHeaders)
-                    .build();
+            return CompletableFuture.failedStage(
+                    DittoHeadersTooLargeException.newAuthSubjectsLimitBuilder(authSubjectsCount, maxAuthSubjects)
+                            .dittoHeaders(dittoHeaders)
+                            .build());
         }
+        return CompletableFuture.completedStage(dittoHeaders);
     }
 
     @Override

diff --git a/...rc/test/java/org/eclipse/ditto/edge/service/headers/DefaultDittoHeadersValidatorTest.java b/...rc/test/java/org/eclipse/ditto/edge/service/headers/DefaultDittoHeadersValidatorTest.java
@@ -28,7 +28,6 @@
 
 import akka.actor.ActorSystem;
 import akka.testkit.javadsl.TestKit;
-import com.typesafe.config.Config;
 import com.typesafe.config.ConfigFactory;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -41,14 +40,10 @@ public final class DefaultDittoHeadersValidatorTest {
 
     @Nullable
     private static ActorSystem actorSystem;
-    @Nullable
-    private static Config extensionConfig;
 
     @BeforeClass
     public static void init() {
         actorSystem = ActorSystem.create("AkkaTestSystem", ConfigFactory.load("test"));
-        extensionConfig = ScopedConfig.dittoExtension(actorSystem.settings().config())
-                .getConfig("ditto-headers-validator.extension-config");
     }
 
     @AfterClass
@@ -61,9 +56,8 @@ public static void tearDown() {
     @Test
     public void validationFailsForTooManyAuthSubjects() {
         assert actorSystem != null;
-        assert extensionConfig != null;
 
-        final var underTest = new DefaultDittoHeadersValidator(actorSystem, extensionConfig);
+        final var underTest = DittoHeadersValidator.get(actorSystem, ScopedConfig.dittoExtension(actorSystem.settings().config()));
 
         final var authorizationContext = AuthorizationContext.newInstance(
                 DittoAuthorizationContextType.PRE_AUTHENTICATED_HTTP,