Speed up Flyway by preventing it from doing classpath scanning

extensions/flyway/deployment/src/main/java/io/quarkus/flyway/FlywayProcessor.java

@@ -2,7 +2,6 @@
 
 import static io.quarkus.deployment.annotations.ExecutionTime.STATIC_INIT;
 
-import java.io.File;
 import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
@@ -41,6 +40,7 @@
 import io.quarkus.deployment.annotations.BuildStep;
 import io.quarkus.deployment.annotations.ExecutionTime;
 import io.quarkus.deployment.annotations.Record;
+import io.quarkus.deployment.builditem.BytecodeTransformerBuildItem;
 import io.quarkus.deployment.builditem.CapabilityBuildItem;
 import io.quarkus.deployment.builditem.FeatureBuildItem;
 import io.quarkus.deployment.builditem.ServiceStartBuildItem;
@@ -66,6 +66,13 @@ CapabilityBuildItem capability() {
         return new CapabilityBuildItem(Capabilities.FLYWAY);
     }
 
+    @BuildStep
+    void scannerTransformer(BuildProducer<BytecodeTransformerBuildItem> transformers) {
+        transformers
+                .produce(new BytecodeTransformerBuildItem(true, ScannerTransformer.FLYWAY_SCANNER_CLASS_NAME,
+                        new ScannerTransformer()));
+    }
+
     @Record(STATIC_INIT)
     @BuildStep
     void build(BuildProducer<FeatureBuildItem> featureProducer,
@@ -198,8 +205,9 @@ private Set<String> getApplicationMigrationsFromPath(final String location, fina
         try (final Stream<Path> pathStream = Files.walk(Paths.get(path.toURI()))) {
             return pathStream.filter(Files::isRegularFile)
                     .map(it -> Paths.get(location, it.getFileName().toString()).toString())
-                    .map(it -> it.replace(File.separatorChar, '/'))
-                    .peek(it -> LOGGER.debug("Discovered: " + it))
+                    // we don't want windows paths here since the paths are going to be used as classpath paths anyway
+                    .map(it -> it.replace('\\', '/'))
+                    .peek(it -> LOGGER.debugf("Discovered path: %s", it))
                     .collect(Collectors.toSet());
         }
     }

extensions/flyway/deployment/src/main/java/io/quarkus/flyway/ScannerTransformer.java

@@ -0,0 +1,121 @@
+package io.quarkus.flyway;
+
+import static org.objectweb.asm.Opcodes.ALOAD;
+import static org.objectweb.asm.Opcodes.ASTORE;
+import static org.objectweb.asm.Opcodes.DUP;
+import static org.objectweb.asm.Opcodes.GETFIELD;
+import static org.objectweb.asm.Opcodes.INVOKEINTERFACE;
+import static org.objectweb.asm.Opcodes.INVOKESPECIAL;
+import static org.objectweb.asm.Opcodes.NEW;
+import static org.objectweb.asm.Opcodes.POP;
+import static org.objectweb.asm.Opcodes.PUTFIELD;
+import static org.objectweb.asm.Opcodes.RETURN;
+
+import java.util.function.BiFunction;
+
+import org.flywaydb.core.internal.scanner.Scanner;
+import org.flywaydb.core.internal.scanner.classpath.ResourceAndClassScanner;
+import org.objectweb.asm.ClassVisitor;
+import org.objectweb.asm.MethodVisitor;
+
+import io.quarkus.flyway.runtime.QuarkusPathLocationScanner;
+import io.quarkus.gizmo.Gizmo;
+
+/**
+ * Transforms {@link Scanner} in a way to take advantage of our build time knowledge
+ * This should be removed completely if https://github.com/flyway/flyway/issues/2822
+ * is implemented
+ */
+class ScannerTransformer implements BiFunction<String, ClassVisitor, ClassVisitor> {
+
+    static final String FLYWAY_SCANNER_CLASS_NAME = Scanner.class.getName();
+    private static final String FLYWAY_SCANNER_INTERNAL_CLASS_NAME = FLYWAY_SCANNER_CLASS_NAME.replace('.', '/');
+
+    private static final String FLYWAY_RESOURCE_AND_CLASS_SCANNER_CLASS_NAME = ResourceAndClassScanner.class.getName();
+    private static final String FLYWAY_RESOURCE_AND_CLASS_SCANNER_INTERNAL_CLASS_NAME = FLYWAY_RESOURCE_AND_CLASS_SCANNER_CLASS_NAME
+            .replace('.', '/');
+
+    private static final String QUARKUS_RESOURCE_AND_CLASS_SCANNER_CLASS_NAME = QuarkusPathLocationScanner.class.getName();
+    private static final String QUARKUS_RESOURCE_AND_CLASS_SCANNER_INTERNAL_CLASS_NAME = QUARKUS_RESOURCE_AND_CLASS_SCANNER_CLASS_NAME
+            .replace('.', '/');
+
+    private static final String CTOR_METHOD_NAME = "<init>";
+
+    @Override
+    public ClassVisitor apply(String s, ClassVisitor cv) {
+        return new ScannerVisitor(cv);
+    }
+
+    private static final class ScannerVisitor extends ClassVisitor {
+
+        public ScannerVisitor(ClassVisitor cv) {
+            super(Gizmo.ASM_API_VERSION, cv);
+        }
+
+        @Override
+        public MethodVisitor visitMethod(int access, String name, String descriptor, String signature, String[] exceptions) {
+            MethodVisitor mv = super.visitMethod(access, name, descriptor, signature, exceptions);
+            if (name.equals(CTOR_METHOD_NAME)) {
+                return new ConstructorTransformer(mv);
+            }
+            return mv;
+        }
+
+        /**
+         * Replaces the constructor of the {@link Scanner} with:
+         *
+         * <pre>
+         * public ScannerSubstitutions(Class<?> implementedInterface, Collection<Location> locations, ClassLoader classLoader,
+         *         Charset encoding, ResourceNameCache resourceNameCache, LocationScannerCache locationScannerCache) {
+         *     ResourceAndClassScanner quarkusScanner = new QuarkusPathLocationScanner(locations);
+         *     resources.addAll(quarkusScanner.scanForResources());
+         *     classes.addAll(quarkusScanner.scanForClasses());
+         * }
+         * </pre>
+         */
+        private static class ConstructorTransformer extends MethodVisitor {
+
+            public ConstructorTransformer(MethodVisitor mv) {
+                super(Gizmo.ASM_API_VERSION, mv);
+            }
+
+            @Override
+            public void visitCode() {
+                super.visitVarInsn(ALOAD, 0);
+                super.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", CTOR_METHOD_NAME, "()V", false);
+                super.visitVarInsn(ALOAD, 0);
+                super.visitTypeInsn(NEW, "java/util/ArrayList");
+                super.visitInsn(DUP);
+                super.visitMethodInsn(INVOKESPECIAL, "java/util/ArrayList", CTOR_METHOD_NAME, "()V", false);
+                super.visitFieldInsn(PUTFIELD, FLYWAY_SCANNER_INTERNAL_CLASS_NAME, "resources", "Ljava/util/List;");
+                super.visitVarInsn(ALOAD, 0);
+                super.visitTypeInsn(NEW, "java/util/ArrayList");
+                super.visitInsn(DUP);
+                super.visitMethodInsn(INVOKESPECIAL, "java/util/ArrayList", CTOR_METHOD_NAME, "()V", false);
+                super.visitFieldInsn(PUTFIELD, FLYWAY_SCANNER_INTERNAL_CLASS_NAME, "classes", "Ljava/util/List;");
+                super.visitTypeInsn(NEW, QUARKUS_RESOURCE_AND_CLASS_SCANNER_INTERNAL_CLASS_NAME);
+                super.visitInsn(DUP);
+                super.visitVarInsn(ALOAD, 2);
+                super.visitMethodInsn(INVOKESPECIAL, QUARKUS_RESOURCE_AND_CLASS_SCANNER_INTERNAL_CLASS_NAME,
+                        CTOR_METHOD_NAME, "(Ljava/util/Collection;)V", false);
+                super.visitVarInsn(ASTORE, 7);
+                super.visitVarInsn(ALOAD, 0);
+                super.visitFieldInsn(GETFIELD, FLYWAY_SCANNER_INTERNAL_CLASS_NAME, "resources", "Ljava/util/List;");
+                super.visitVarInsn(ALOAD, 7);
+                super.visitMethodInsn(INVOKEINTERFACE, FLYWAY_RESOURCE_AND_CLASS_SCANNER_INTERNAL_CLASS_NAME,
+                        "scanForResources", "()Ljava/util/Collection;", true);
+                super.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "addAll", "(Ljava/util/Collection;)Z", true);
+                super.visitInsn(POP);
+                super.visitVarInsn(ALOAD, 0);
+                super.visitFieldInsn(GETFIELD, FLYWAY_SCANNER_INTERNAL_CLASS_NAME, "classes", "Ljava/util/List;");
+                super.visitVarInsn(ALOAD, 7);
+                super.visitMethodInsn(INVOKEINTERFACE, FLYWAY_RESOURCE_AND_CLASS_SCANNER_INTERNAL_CLASS_NAME,
+                        "scanForClasses", "()Ljava/util/Collection;", true);
+                super.visitMethodInsn(INVOKEINTERFACE, "java/util/List", "addAll", "(Ljava/util/Collection;)Z", true);
+                super.visitInsn(POP);
+                super.visitInsn(RETURN);
+                super.visitMaxs(3, 8);
+            }
+        }
+    }
+}

extensions/flyway/deployment/src/test/java/io/quarkus/flyway/test/FlywayExtensionMigrateAtStartNamedDataSourceTest.java

@@ -1,10 +1,12 @@
 package io.quarkus.flyway.test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import javax.inject.Inject;
 
 import org.flywaydb.core.Flyway;
+import org.flywaydb.core.api.MigrationInfo;
 import org.jboss.shrinkwrap.api.ShrinkWrap;
 import org.jboss.shrinkwrap.api.spec.JavaArchive;
 import org.junit.jupiter.api.DisplayName;
@@ -32,7 +34,12 @@ public class FlywayExtensionMigrateAtStartNamedDataSourceTest {
     @Test
     @DisplayName("Migrates at start for datasource named 'users' correctly")
     public void testFlywayConfigInjection() {
-        String currentVersion = flywayUsers.info().current().getVersion().toString();
+        MigrationInfo migrationInfo = flywayUsers.info().current();
+        assertNotNull(migrationInfo, "No Flyway migration was executed");
+
+        String currentVersion = migrationInfo
+                .getVersion()
+                .toString();
         // Expected to be 1.0.0 as migration runs at start
         assertEquals("1.0.0", currentVersion);
     }

extensions/flyway/deployment/src/test/java/io/quarkus/flyway/test/FlywayExtensionMigrateAtStartTest.java

@@ -1,10 +1,12 @@
 package io.quarkus.flyway.test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 
 import javax.inject.Inject;
 
 import org.flywaydb.core.Flyway;
+import org.flywaydb.core.api.MigrationInfo;
 import org.jboss.shrinkwrap.api.ShrinkWrap;
 import org.jboss.shrinkwrap.api.spec.JavaArchive;
 import org.junit.jupiter.api.DisplayName;
@@ -27,7 +29,12 @@ public class FlywayExtensionMigrateAtStartTest {
     @Test
     @DisplayName("Migrates at start correctly")
     public void testFlywayConfigInjection() {
-        String currentVersion = flyway.info().current().getVersion().toString();
+        MigrationInfo migrationInfo = flyway.info().current();
+        assertNotNull(migrationInfo, "No Flyway migration was executed");
+
+        String currentVersion = migrationInfo
+                .getVersion()
+                .toString();
         // Expected to be 1.0.0 as migration runs at start
         assertEquals("1.0.0", currentVersion);
     }

extensions/flyway/deployment/src/test/resources/migrate-at-start-config-named-datasource.properties

@@ -1,3 +1,5 @@
+quarkus.log.category."org.flywaydb.core".level=DEBUG
+quarkus.log.category."io.quarkus.flyway".level=DEBUG
 quarkus.datasource.users.db-kind=h2
 quarkus.datasource.users.username=sa
 quarkus.datasource.users.password=sa

extensions/flyway/runtime/src/main/java/io/quarkus/flyway/runtime/FlywayRecorder.java

@@ -7,18 +7,21 @@
 import javax.sql.DataSource;
 
 import org.flywaydb.core.Flyway;
+import org.jboss.logging.Logger;
 
 import io.quarkus.agroal.runtime.DataSources;
 import io.quarkus.arc.Arc;
-import io.quarkus.flyway.runtime.graal.QuarkusPathLocationScanner;
 import io.quarkus.runtime.annotations.Recorder;
 
 @Recorder
 public class FlywayRecorder {
 
+    private static final Logger log = Logger.getLogger(FlywayRecorder.class);
+
     private final List<FlywayContainer> flywayContainers = new ArrayList<>(2);
 
     public void setApplicationMigrationFiles(List<String> migrationFiles) {
+        log.debugv("Setting the following application migration files: {0}", migrationFiles);
         QuarkusPathLocationScanner.setApplicationMigrationFiles(migrationFiles);
     }
 

extensions/flyway/runtime/src/main/java/io/quarkus/flyway/runtime/graal/QuarkusPathLocationScanner.java → extensions/flyway/runtime/src/main/java/io/quarkus/flyway/runtime/QuarkusPathLocationScanner.java

@@ -1,4 +1,4 @@
-package io.quarkus.flyway.runtime.graal;
+package io.quarkus.flyway.runtime;
 
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
@@ -12,6 +12,11 @@
 import org.flywaydb.core.internal.scanner.classpath.ResourceAndClassScanner;
 import org.jboss.logging.Logger;
 
+/**
+ * This class is used in order to prevent Flyway from doing classpath scanning which is both slow
+ * and won't work in native mode
+ */
+@SuppressWarnings("rawtypes")
 public final class QuarkusPathLocationScanner implements ResourceAndClassScanner {
     private static final Logger LOGGER = Logger.getLogger(QuarkusPathLocationScanner.class);
     private static final String LOCATION_SEPARATOR = "/";
@@ -20,6 +25,8 @@ public final class QuarkusPathLocationScanner implements ResourceAndClassScanner
     private final Collection<LoadableResource> scannedResources;
 
     public QuarkusPathLocationScanner(Collection<Location> locations) {
+        LOGGER.debugv("Locations: {0}", locations);
+
         this.scannedResources = new ArrayList<>();
         ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
 
@@ -50,6 +57,9 @@ private boolean canHandleMigrationFile(Collection<Location> locations, String mi
 
             if (migrationFile.startsWith(locationPath)) {
                 return true;
+            } else {
+                LOGGER.debugf("Migration file '%s' will be ignored because it does not start with '%s'", migrationFile,
+                        locationPath);
             }
         }