GH-0000 Remove system property toggle for memory mapped txn status file

Author: hmottestad

core/sail/nativerdf/src/main/java/org/eclipse/rdf4j/sail/nativerdf/TripleStore.java

@@ -80,15 +80,9 @@ class TripleStore implements Closeable {
 	 */
 	private static final String INDEXES_KEY = "triple-indexes";
 
-	/**
-	 * System property that enables the experimental {@link MemoryMappedTxnStatusFile} implementation instead of the
-	 * default {@link TxnStatusFile}.
-	 */
-	private static final String MEMORY_MAPPED_TXN_STATUS_FILE_ENABLED_PROP = "org.eclipse.rdf4j.sail.nativerdf.MemoryMappedTxnStatusFile.enabled";
-
-	/**
-	 * The version number for the current triple store.
-	 * <ul>
+        /**
+         * The version number for the current triple store.
+         * <ul>
 	 * <li>version 0: The first version which used a single spo-index. This version did not have a properties file yet.
 	 * <li>version 1: Introduces configurable triple indexes and the properties file.
 	 * <li>version 10: Introduces a context field, essentially making this a quad store.
@@ -234,14 +228,12 @@ public TripleStore(File dir, String indexSpecStr, boolean forceSync, Boolean mem
 		}
 	}
 
-	private static TxnStatusFile createTxnStatusFile(File dir, Boolean memoryMappedTxnStatusFileEnabled)
-			throws IOException {
-		boolean enabled = memoryMappedTxnStatusFileEnabled != null
-				? memoryMappedTxnStatusFileEnabled
-				: Boolean.getBoolean(MEMORY_MAPPED_TXN_STATUS_FILE_ENABLED_PROP);
-		if (enabled) {
-			return new MemoryMappedTxnStatusFile(dir);
-		}
+        private static TxnStatusFile createTxnStatusFile(File dir, Boolean memoryMappedTxnStatusFileEnabled)
+                        throws IOException {
+                boolean enabled = Boolean.TRUE.equals(memoryMappedTxnStatusFileEnabled);
+                if (enabled) {
+                        return new MemoryMappedTxnStatusFile(dir);
+                }
 		return new TxnStatusFile(dir);
 	}
 

core/sail/nativerdf/src/test/java/org/eclipse/rdf4j/sail/nativerdf/MemoryMappedTxnStatusFileConfigTest.java

@@ -20,23 +20,24 @@
 import org.junit.jupiter.api.io.TempDir;
 
 /**
- * Verifies that the implementation used for the transaction status file can be controlled via a system property.
+ * Verifies that the implementation used for the transaction status file is controlled through configuration rather than a
+ * JVM system property.
  */
 public class MemoryMappedTxnStatusFileConfigTest {
 
-	private static final String MEMORY_MAPPED_ENABLED_PROP = "org.eclipse.rdf4j.sail.nativerdf.MemoryMappedTxnStatusFile.enabled";
+    private static final String MEMORY_MAPPED_ENABLED_PROP = "org.eclipse.rdf4j.sail.nativerdf.MemoryMappedTxnStatusFile.enabled";
 
-	@TempDir
-	File dataDir;
+    @TempDir
+    File dataDir;
 
-	@AfterEach
-	public void clearProperty() {
-		System.clearProperty(MEMORY_MAPPED_ENABLED_PROP);
-	}
+    @AfterEach
+    public void clearProperty() {
+            System.clearProperty(MEMORY_MAPPED_ENABLED_PROP);
+    }
 
-	@Test
-	public void defaultUsesNioTxnStatusFile() throws Exception {
-		TripleStore tripleStore = new TripleStore(dataDir, "spoc");
+    @Test
+    public void defaultUsesNioTxnStatusFile() throws Exception {
+            TripleStore tripleStore = new TripleStore(dataDir, "spoc");
 		try {
 			tripleStore.startTransaction();
 			tripleStore.storeTriple(1, 2, 3, 4);
@@ -52,21 +53,21 @@ public void defaultUsesNioTxnStatusFile() throws Exception {
 	}
 
 	@Test
-	public void memoryMappedEnabledUsesFixedSizeFile() throws Exception {
-		System.setProperty(MEMORY_MAPPED_ENABLED_PROP, "true");
+    public void systemPropertyIsIgnored() throws Exception {
+            System.setProperty(MEMORY_MAPPED_ENABLED_PROP, "true");
 
-		TripleStore tripleStore = new TripleStore(dataDir, "spoc");
-		try {
-			tripleStore.startTransaction();
-			tripleStore.storeTriple(1, 2, 3, 4);
+            TripleStore tripleStore = new TripleStore(dataDir, "spoc");
+            try {
+                    tripleStore.startTransaction();
+                    tripleStore.storeTriple(1, 2, 3, 4);
 			tripleStore.commit();
 		} finally {
 			tripleStore.close();
-		}
+            }
 
-		File txnStatusFile = new File(dataDir, TxnStatusFile.FILE_NAME);
-		assertTrue(txnStatusFile.exists(), "Transaction status file should exist");
-		assertEquals(1L, txnStatusFile.length(),
-				"Memory-mapped TxnStatusFile keeps a single status byte on disk for NONE status");
-	}
+            File txnStatusFile = new File(dataDir, TxnStatusFile.FILE_NAME);
+            assertTrue(txnStatusFile.exists(), "Transaction status file should exist");
+            assertEquals(0L, txnStatusFile.length(),
+                            "System property does not switch to memory-mapped TxnStatusFile");
+    }
 }

core/sail/nativerdf/src/test/java/org/eclipse/rdf4j/sail/nativerdf/NativeStoreTxnStatusConfigTest.java

@@ -23,7 +23,6 @@
 import org.eclipse.rdf4j.repository.sail.SailRepository;
 import org.eclipse.rdf4j.sail.nativerdf.config.NativeStoreConfig;
 import org.eclipse.rdf4j.sail.nativerdf.config.NativeStoreFactory;
-import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
 
@@ -32,13 +31,8 @@ class NativeStoreTxnStatusConfigTest {
 	@TempDir
 	File dataDir;
 
-	@AfterEach
-	void clearSystemProperty() {
-		System.clearProperty("org.eclipse.rdf4j.sail.nativerdf.MemoryMappedTxnStatusFile.enabled");
-	}
-
-	@Test
-	void configEnablesMemoryMappedTxnStatusFile() throws Exception {
+        @Test
+        void configEnablesMemoryMappedTxnStatusFile() throws Exception {
 		NativeStoreConfig cfg = new NativeStoreConfig("spoc");
 		cfg.setMemoryMappedTxnStatusFileEnabled(true);
 

site/content/documentation/reference/configuration.md

@@ -251,7 +251,7 @@ Creating more indexes potentially speeds up querying (a lot), but also adds over
 
 The native store automatically creates/drops indexes upon (re)initialization, so the parameter can be adjusted and upon the first refresh of the configuration the native store will change its indexing strategy, without loss of data.
 
-Set `config:native.memoryMappedTxnStatusFile` to `true` to enable the experimental memory-mapped transaction status file. When unset, the store falls back to the legacy file implementation and respects the JVM system property `-Dorg.eclipse.rdf4j.sail.nativerdf.MemoryMappedTxnStatusFile.enabled`.
+Set `config:native.memoryMappedTxnStatusFile` to `true` to enable the experimental memory-mapped transaction status file. When unset, the store falls back to the legacy file implementation.
 
 ##### Example configuration