Thread Safety + More

1. Removed Mockito because it wasn't used.
2. Normalized formatting across files.
3. Normalized the use of `final` across files.
4. Improve thread safety in `EmbeddedPostgres` by making `lockChannel` and `lock` final instead of volatile.
5. Switched from `MD5` to `SHA-512` in `EmbeddedPostgres` for the digest.

Author: SmushyTaco

build.gradle.kts

@@ -19,7 +19,6 @@ val commonsCompressVersion = providers.gradleProperty("commons_compress_version"
 val flywayVersion = providers.gradleProperty("flyway_version")
 val junitVersion = providers.gradleProperty("junit_version")
 val liquibaseVersion = providers.gradleProperty("liquibase_version")
-val mockitoVersion = providers.gradleProperty("mockito_version")
 val postgresqlVersion = providers.gradleProperty("postgresql_version")
 val slf4jVersion = providers.gradleProperty("slf4j_version")
 val xzVersion = providers.gradleProperty("xz_version")
@@ -33,7 +32,6 @@ version = projectVersion.get()
 
 repositories { mavenCentral() }
 
-val mockitoAgent by configurations.creating
 dependencies {
     dokkaPlugin("org.jetbrains.dokka:kotlin-as-java-plugin:${dokkaVersion.get()}")
 
@@ -55,9 +53,6 @@ dependencies {
     testImplementation("org.liquibase:liquibase-core:${liquibaseVersion.get()}")
     testImplementation(platform("org.junit:junit-bom:${junitVersion.get()}"))
     testImplementation("org.junit.jupiter:junit-jupiter")
-    testImplementation("org.mockito:mockito-core:${mockitoVersion.get()}")
-
-    mockitoAgent("org.mockito:mockito-core:${mockitoVersion.get()}") { isTransitive = false }
 
     testRuntimeOnly("org.junit.platform:junit-platform-launcher")
     testRuntimeOnly("org.slf4j:slf4j-simple:${slf4jVersion.get()}")
@@ -69,12 +64,6 @@ java {
     withSourcesJar()
     withJavadocJar()
 }
-abstract class MockitoAgentArgs @Inject constructor(objects: ObjectFactory) : CommandLineArgumentProvider {
-    @get:InputFiles
-    @get:PathSensitive(PathSensitivity.RELATIVE)
-    val agentFiles: ConfigurableFileCollection = objects.fileCollection()
-    override fun asArguments(): Iterable<String> = agentFiles.files.map { "-javaagent:${it.absolutePath}" }
-}
 tasks {
     withType<JavaCompile>().configureEach {
         options.encoding = "UTF-8"
@@ -85,8 +74,6 @@ tasks {
     withType<JavaExec>().configureEach { defaultCharacterEncoding = "UTF-8" }
     withType<Javadoc>().configureEach { options.encoding = "UTF-8" }
     withType<Test>().configureEach {
-        val provider = objects.newInstance(MockitoAgentArgs::class.java).apply { agentFiles.from(mockitoAgent) }
-        jvmArgumentProviders.add(provider)
         defaultCharacterEncoding = "UTF-8"
         useJUnitPlatform()
     }

gradle.properties

@@ -23,8 +23,6 @@ flyway_version = 11.16.0
 junit_version = 6.0.1
 # Check this on https://central.sonatype.com/artifact/org.liquibase/liquibase-core/
 liquibase_version = 5.0.1
-# Check this on https://central.sonatype.com/artifact/org.mockito/mockito-core/
-mockito_version = 5.20.0
 # Check this on https://central.sonatype.com/artifact/org.postgresql/postgresql/
 postgresql_version = 42.7.8
 # Check this on https://central.sonatype.com/artifact/org.slf4j/slf4j-api/

src/main/java/com/smushytaco/postgres/embedded/ConnectionInfo.java

@@ -35,7 +35,6 @@
  * @param properties additional connection properties (maybe empty)
  */
 public record ConnectionInfo(String dbName, int port, String user, Map<String, String> properties) {
-
     /**
      * Creates a {@link ConnectionInfo} without any additional connection properties.
      *

src/main/java/com/smushytaco/postgres/embedded/DatabaseConnectionPreparer.java

@@ -29,10 +29,9 @@
  * at the {@link javax.sql.DataSource} level.
  */
 public interface DatabaseConnectionPreparer extends DatabasePreparer {
-
     @Override
-    default void prepare(DataSource ds) throws SQLException {
-        try (Connection c = ds.getConnection()) {
+    default void prepare(final DataSource ds) throws SQLException {
+        try (final Connection c = ds.getConnection()) {
             prepare(c);
         }
     }
@@ -47,5 +46,5 @@ default void prepare(DataSource ds) throws SQLException {
      * @param conn an active JDBC connection to the target database
      * @throws SQLException if an error occurs while preparing the database
      */
-    void prepare(Connection conn) throws SQLException;
+    void prepare(final Connection conn) throws SQLException;
 }

src/main/java/com/smushytaco/postgres/embedded/DatabasePreparer.java

@@ -41,5 +41,5 @@ public interface DatabasePreparer {
      * @param ds the {@link DataSource} representing the target database
      * @throws SQLException if a database access error occurs during preparation
      */
-    void prepare(DataSource ds) throws SQLException;
+    void prepare(final DataSource ds) throws SQLException;
 }

src/main/java/com/smushytaco/postgres/embedded/DefaultPostgresBinaryResolver.java

@@ -42,7 +42,6 @@
  * It also includes fallback behavior for unsupported or emulated architectures.
  */
 public class DefaultPostgresBinaryResolver implements PgBinaryResolver {
-
     private static final Logger logger = LoggerFactory.getLogger(DefaultPostgresBinaryResolver.class);
 
     /**
@@ -56,15 +55,14 @@ public class DefaultPostgresBinaryResolver implements PgBinaryResolver {
     private DefaultPostgresBinaryResolver() {}
 
     @Override
-    public InputStream getPgBinary(String system, String machineHardware) throws IOException {
-        String architecture = ArchUtils.normalize(machineHardware);
-        String distribution = LinuxUtils.getDistributionName();
+    public InputStream getPgBinary(final String system, final String machineHardware) throws IOException {
+        final String architecture = ArchUtils.normalize(machineHardware);
+        final String distribution = LinuxUtils.getDistributionName();
 
-        if (logger.isInfoEnabled())
-            logger.info("Detected distribution: '{}'", Optional.ofNullable(distribution).orElse("Unknown"));
+        if (logger.isInfoEnabled()) logger.info("Detected distribution: '{}'", Optional.ofNullable(distribution).orElse("Unknown"));
 
         if (distribution != null) {
-            Resource resource = findPgBinary(normalize(format("postgres-%s-%s-%s.txz", system, architecture, distribution)));
+            final Resource resource = findPgBinary(normalize(format("postgres-%s-%s-%s.txz", system, architecture, distribution)));
             if (resource != null) {
                 logger.info("Distribution specific postgres binaries found: '{}'", resource.getFilename());
                 return resource.getInputStream();
@@ -97,45 +95,38 @@ public InputStream getPgBinary(String system, String machineHardware) throws IOE
         throw new IllegalStateException("Missing embedded postgres binaries");
     }
 
-    private static Resource findPgBinary(String resourceLocation) throws IOException {
+    private static Resource findPgBinary(final String resourceLocation) throws IOException {
         logger.trace("Searching for postgres binaries - location: '{}'", resourceLocation);
-        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
-        List<URL> urls = Collections.list(classLoader.getResources(resourceLocation));
+        final ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+        final List<URL> urls = Collections.list(classLoader.getResources(resourceLocation));
 
         if (urls.size() > 1) {
             logger.error("Detected multiple binaries of the same architecture: '{}'", urls);
             throw new IllegalStateException("Duplicate embedded postgres binaries");
         }
-        if (urls.size() == 1) {
-            return new Resource(urls.getFirst());
-        }
+        if (urls.size() == 1) return new Resource(urls.getFirst());
 
         return null;
     }
 
-    private static String normalize(String input) {
-        if (input == null || input.isBlank()) {
-            return input;
-        }
+    private static String normalize(final String input) {
+        if (input == null || input.isBlank()) return input;
         return input.replace(' ', '_').toLowerCase(Locale.ROOT);
     }
 
     private record Resource(URL url) {
-
         public String getFilename() {
-            String path = URLDecoder.decode(url.getPath(), StandardCharsets.UTF_8);
-            int slash = path.lastIndexOf('/');
+            final String path = URLDecoder.decode(url.getPath(), StandardCharsets.UTF_8);
+            final int slash = path.lastIndexOf('/');
             return (slash != -1) ? path.substring(slash + 1) : path;
         }
 
         public InputStream getInputStream() throws IOException {
-            URLConnection con = this.url.openConnection();
+            final URLConnection con = this.url.openConnection();
             try {
                 return con.getInputStream();
-            } catch (IOException ex) {
-                if (con instanceof HttpURLConnection httpURLConnection) {
-                    httpURLConnection.disconnect();
-                }
+            } catch (final IOException ex) {
+                if (con instanceof final HttpURLConnection httpURLConnection) httpURLConnection.disconnect();
                 throw ex;
             }
         }