PersistentMap can store data in multiple nodes

block-storage/src/test/java/org/lucares/pdb/blockstorage/intsequence/VariableByteEncoderTest.java

@@ -81,4 +81,29 @@ public class VariableByteEncoderTest {
 		final LongList decodedValues = VariableByteEncoder.decode(buffer);
 		Assert.assertEquals(decodedValues, originalValues);
 	}
+
+	@DataProvider
+	public Object[][] providerNededBytes() {
+		return new Object[][] { //
+				{ 0, 1 }, //
+				{ -10, 1 }, //
+				{ 10, 1 }, //
+				{ -63, 1 }, //
+				{ 63, 1 }, //
+				{ -64, 2 }, //
+				{ 64, 2 }, //
+				{ -8191, 2 }, //
+				{ 8191, 2 }, //
+				{ -8192, 3 }, //
+				{ 8192, 3 }, //
+		};
+	}
+
+	@Test(dataProvider = "providerNededBytes")
+	public void testNeededBytes(final long value, final int expectedNeededBytes) {
+
+		final int neededBytes = VariableByteEncoder.neededBytes(value);
+		final byte[] encoded = VariableByteEncoder.encode(value);
+		Assert.assertEquals(encoded.length, neededBytes);
+	}
 }

block-storage/src/test/java/org/lucares/pdb/map/PersistentMapTest.java

@@ -3,6 +3,8 @@ package org.lucares.pdb.map;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.UUID;
 
 import org.lucares.pdb.diskstorage.DiskStorage;
 import org.lucares.utils.file.FileUtils;
@@ -38,9 +40,51 @@ public class PersistentMapTest {
 			Assert.assertNull(map.getAsString(key));
 
 			Assert.assertNull(map.put(key, value));
-			final String actualValue = map.getAsString(key);
 
-			Assert.assertEquals(actualValue, value);
+			Assert.assertEquals(map.getAsString(key), value);
 		}
 	}
+
+	public void testManyValues() throws Exception {
+		final Path file = dataDirectory.resolve("map.db");
+		final var insertedValues = new HashMap<String, String>();
+
+		try (final DiskStorage ds = new DiskStorage(file)) {
+			final PersistentMap map = new PersistentMap(ds);
+
+			for (int i = 0; i < 100; i++) {
+
+				final String key = UUID.randomUUID().toString() + "__" + i;
+				final String value = "long value to waste some bytes " + i;
+				Assert.assertNull(map.getAsString(key));
+
+				Assert.assertNull(map.put(key, value));
+
+				insertedValues.put(key, value);
+
+				for (final var entry : insertedValues.entrySet()) {
+					final String actualValue = map.getAsString(entry.getKey());
+					Assert.assertEquals(actualValue, entry.getValue(),
+							"value for key " + entry.getKey() + " in the " + i + "th iteration");
+				}
+			}
+		}
+
+		try (final DiskStorage ds = new DiskStorage(file)) {
+			final PersistentMap map = new PersistentMap(ds);
+			map.visitPreOrder((nodeEntry, depth) -> {
+				if (nodeEntry.isInnerNode()) {
+					System.out.println("    ".repeat(depth) + nodeEntry);
+				}
+			});
+
+			for (final var entry : insertedValues.entrySet()) {
+				final String actualValue = map.getAsString(entry.getKey());
+				Assert.assertEquals(actualValue, entry.getValue(),
+						"value for key " + entry.getKey() + " after all iterations");
+			}
+
+		}
+	}
+
 }