Objects: simplify TombstoneMergingKvIterator

.github/workflows/server.yml

@@ -20,26 +20,21 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+        with:
+          submodules: 'recursive'
 
       - name: Install sudo for ACT
         run: apt-get update && apt-get install -y sudo
         if: env.ACT=='true'
 
-      - name: Install fuse and maven
+      - name: Install FUSE
-        run: sudo apt-get update && sudo apt-get install -y libfuse2
+        run: sudo apt-get update && sudo apt-get install -y libfuse2 libfuse3-dev libfuse3-3 fuse3
 
-      - name: Download maven
+      - name: User allow other for fuse
-        run: |
+        run: echo "user_allow_other" | sudo tee -a /etc/fuse.conf
-          cd "$HOME"
+      
-          mkdir maven-bin
+      - name: Dump fuse.conf
-          curl -s -L https://dlcdn.apache.org/maven/maven-3/3.9.9/binaries/apache-maven-3.9.9-bin.tar.gz | tar xvz --strip-components=1 -C maven-bin
+        run: cat /etc/fuse.conf
-          echo "$HOME"/maven-bin/bin >> $GITHUB_PATH
-
-      - name: Maven info
-        run: |
-          echo $GITHUB_PATH
-          echo $PATH
-          mvn -v
 
       - name: Set up JDK 21
         uses: actions/setup-java@v4
@@ -48,6 +43,9 @@ jobs:
           distribution: "zulu"
           cache: maven
 
+      - name: Build LazyFS
+        run: cd thirdparty/lazyfs/ && ./build.sh
+
       - name: Test with Maven
         run: cd dhfs-parent && mvn -T $(nproc) --batch-mode --update-snapshots package verify
 

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "thirdparty/lazyfs/lazyfs"]
+	path = thirdparty/lazyfs/lazyfs
+	url = git@github.com:dsrhaslab/lazyfs.git

dhfs-parent/dhfs-app/src/test/java/com/usatiuk/dhfs/integration/DhfsFusex3IT.java

@@ -35,13 +35,15 @@ public class DhfsFusex3IT {
     String c2uuid;
     String c3uuid;
 
+    Network network;
+
     // This calculation is somewhat racy, so keep it hardcoded for now
     long emptyFileCount = 9;
 
     @BeforeEach
     void setup(TestInfo testInfo) throws IOException, InterruptedException, TimeoutException {
         // TODO: Dedup
-        Network network = Network.newNetwork();
+        network = Network.newNetwork();
 
         container1 = new GenericContainer<>(DhfsImage.getInstance())
                 .withPrivilegedMode(true)
@@ -252,21 +254,22 @@ public class DhfsFusex3IT {
         await().atMost(45, TimeUnit.SECONDS).until(() -> "tesempty\n".equals(container3.execInContainer("/bin/sh", "-c", "cat /dhfs_test/fuse/testf").getStdout()));
 
         var client = DockerClientFactory.instance().client();
-        client.pauseContainerCmd(container1.getContainerId()).exec();
+        client.disconnectFromNetworkCmd().withContainerId(container1.getContainerId()).withNetworkId(network.getId()).exec();
-        client.pauseContainerCmd(container2.getContainerId()).exec();
+        client.disconnectFromNetworkCmd().withContainerId(container2.getContainerId()).withNetworkId(network.getId()).exec();
-        // Pauses needed as otherwise docker buffers some incoming packets
+        client.disconnectFromNetworkCmd().withContainerId(container3.getContainerId()).withNetworkId(network.getId()).exec();
+
         waitingConsumer3.waitUntil(frame -> frame.getUtf8String().contains("Lost connection to"), 60, TimeUnit.SECONDS, 2);
-        await().atMost(45, TimeUnit.SECONDS).until(() -> 0 == container3.execInContainer("/bin/sh", "-c", "echo test3 >> /dhfs_test/fuse/testf").getExitCode());
-        client.pauseContainerCmd(container3.getContainerId()).exec();
-        client.unpauseContainerCmd(container2.getContainerId()).exec();
         waitingConsumer2.waitUntil(frame -> frame.getUtf8String().contains("Lost connection to"), 60, TimeUnit.SECONDS, 2);
-        await().atMost(45, TimeUnit.SECONDS).until(() -> 0 == container2.execInContainer("/bin/sh", "-c", "echo test2 >> /dhfs_test/fuse/testf").getExitCode());
-        client.pauseContainerCmd(container2.getContainerId()).exec();
-        client.unpauseContainerCmd(container1.getContainerId()).exec();
         waitingConsumer1.waitUntil(frame -> frame.getUtf8String().contains("Lost connection to"), 60, TimeUnit.SECONDS, 2);
+
+        await().atMost(45, TimeUnit.SECONDS).until(() -> 0 == container3.execInContainer("/bin/sh", "-c", "echo test3 >> /dhfs_test/fuse/testf").getExitCode());
+        await().atMost(45, TimeUnit.SECONDS).until(() -> 0 == container2.execInContainer("/bin/sh", "-c", "echo test2 >> /dhfs_test/fuse/testf").getExitCode());
         await().atMost(45, TimeUnit.SECONDS).until(() -> 0 == container1.execInContainer("/bin/sh", "-c", "echo test1 >> /dhfs_test/fuse/testf").getExitCode());
-        client.unpauseContainerCmd(container2.getContainerId()).exec();
+
-        client.unpauseContainerCmd(container3.getContainerId()).exec();
+        client.connectToNetworkCmd().withContainerId(container1.getContainerId()).withNetworkId(network.getId()).exec();
+        client.connectToNetworkCmd().withContainerId(container2.getContainerId()).withNetworkId(network.getId()).exec();
+        client.connectToNetworkCmd().withContainerId(container3.getContainerId()).withNetworkId(network.getId()).exec();
+
         Log.warn("Waiting for connections");
         waitingConsumer1.waitUntil(frame -> frame.getUtf8String().contains("Connected"), 60, TimeUnit.SECONDS, 2);
         waitingConsumer2.waitUntil(frame -> frame.getUtf8String().contains("Connected"), 60, TimeUnit.SECONDS, 2);

dhfs-parent/dhfs-app/src/test/java/com/usatiuk/dhfs/integration/LazyFs.java

@@ -0,0 +1,177 @@
+package com.usatiuk.dhfs.integration;
+
+import io.quarkus.logging.Log;
+
+import java.io.*;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.TimeUnit;
+
+public class LazyFs {
+    private static final String lazyFsPath;
+
+    private final String dataRoot;
+    private final String lazyFsDataPath;
+    private final String name;
+    private final File tmpConfigFile;
+    private final File fifoPath;
+
+    static {
+        lazyFsPath = System.getProperty("lazyFsPath");
+        System.out.println("LazyFs Path: " + lazyFsPath);
+    }
+
+    public LazyFs(String name, String dataRoot, String lazyFsDataPath) {
+        this.name = name;
+        this.dataRoot = dataRoot;
+        this.lazyFsDataPath = lazyFsDataPath;
+
+        try {
+            tmpConfigFile = File.createTempFile("lazyfs", ".conf");
+            tmpConfigFile.deleteOnExit();
+
+            fifoPath = new File("/tmp/" + ThreadLocalRandom.current().nextLong() + ".faultsfifo");
+            fifoPath.deleteOnExit();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private Thread outputPiper;
+    private Process fs;
+
+    private String fifoPath() {
+        return fifoPath.getAbsolutePath();
+    }
+
+    public void start() {
+        var lfsPath = Path.of(lazyFsPath).resolve("build").resolve("lazyfs");
+        if (!lfsPath.toFile().isFile())
+            throw new IllegalStateException("LazyFs binary does not exist: " + lfsPath.toAbsolutePath());
+        if (!lfsPath.toFile().canExecute())
+            throw new IllegalStateException("LazyFs binary is not executable: " + lfsPath.toAbsolutePath());
+
+        try (var rwFile = new RandomAccessFile(tmpConfigFile, "rw");
+             var channel = rwFile.getChannel()) {
+            channel.truncate(0);
+            var config = "[faults]\n" +
+                    "fifo_path=\"" + fifoPath() + "\"\n" +
+                    "[cache]\n" +
+                    "apply_eviction=false\n" +
+                    "[cache.simple]\n" +
+                    "custom_size=\"1gb\"\n" +
+                    "blocks_per_page=1\n" +
+                    "[filesystem]\n" +
+                    "log_all_operations=false\n" +
+                    "logfile=\"\"";
+            rwFile.write(config.getBytes());
+            Log.info("LazyFs config: \n" + config);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+
+        var argList = new ArrayList<String>();
+
+        argList.add(lfsPath.toString());
+        argList.add(Path.of(dataRoot).toString());
+        argList.add("--config-path");
+        argList.add(tmpConfigFile.getAbsolutePath());
+        argList.add("-o");
+        argList.add("allow_other");
+        argList.add("-o");
+        argList.add("modules=subdir");
+        argList.add("-o");
+        argList.add("subdir=" + Path.of(lazyFsDataPath).toAbsolutePath().toString());
+        try {
+            Log.info("Starting LazyFs " + argList);
+            fs = Runtime.getRuntime().exec(argList.toArray(String[]::new));
+            Thread.sleep(1000);
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+
+        outputPiper = new Thread(() -> {
+            try {
+                try (BufferedReader input = new BufferedReader(new InputStreamReader(fs.getInputStream()))) {
+                    String line;
+
+                    while ((line = input.readLine()) != null) {
+                        System.out.println(line);
+                    }
+                }
+            } catch (Exception e) {
+                Log.info("Exception in LazyFs piper", e);
+            }
+        });
+        outputPiper.start();
+        outputPiper = new Thread(() -> {
+            try {
+                try (BufferedReader input = new BufferedReader(new InputStreamReader(fs.getErrorStream()))) {
+                    String line;
+
+                    while ((line = input.readLine()) != null) {
+                        System.out.println(line);
+                    }
+                }
+            } catch (Exception e) {
+                Log.info("Exception in LazyFs piper", e);
+            }
+        });
+        outputPiper.start();
+    }
+
+    public void crash() {
+        try {
+            var cmd = "echo \"lazyfs::crash::timing=after::op=write::from_rgx=*\" > " + fifoPath();
+            System.out.println("Running command: " + cmd);
+            Runtime.getRuntime().exec(new String[]{"/bin/sh", "-c", cmd});
+            stop();
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    public void stop() {
+        try {
+            if (fs == null) {
+                return;
+            }
+            Runtime.getRuntime().exec(new String[]{"/bin/sh", "-c", "fusermount3 -u " + dataRoot});
+            if (!fs.waitFor(1, TimeUnit.SECONDS))
+                throw new RuntimeException("LazyFs process did not stop in time");
+            fs = null;
+        } catch (Exception e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+//    Doesn't actually work?
+//
+//    public void crashop() {
+//        try {
+//            var cmd = "echo \"lazyfs::torn-op::file=" + Path.of(lazyFsDataPath).toAbsolutePath().toString() + "/objects/data.mdb::persist=1,3::parts=3::occurrence=5\" > /tmp/faults.fifo";
+//            System.out.println("Running command: " + cmd);
+//            Runtime.getRuntime().exec(new String[]{"/bin/sh", "-c", cmd});
+//            Thread.sleep(1000);
+//            Runtime.getRuntime().exec(new String[]{"/bin/sh", "-c", "fusermount3 -u " + dataRoot});
+//            Thread.sleep(1000);
+//        } catch (Exception e) {
+//            throw new RuntimeException(e);
+//        }
+//    }
+//
+//    public void crashseq() {
+//        try {
+//            var cmd = "echo \"lazyfs::torn-seq::op=write::file=" + Path.of(lazyFsDataPath).toAbsolutePath().toString() + "/objects/data.mdb::persist=1,4::occurrence=2\" > /tmp/faults.fifo";
+//            System.out.println("Running command: " + cmd);
+//            Runtime.getRuntime().exec(new String[]{"/bin/sh", "-c", cmd});
+//            Thread.sleep(1000);
+//            Runtime.getRuntime().exec(new String[]{"/bin/sh", "-c", "fusermount3 -u " + dataRoot});
+//            Thread.sleep(1000);
+//        } catch (Exception e) {
+//            throw new RuntimeException(e);
+//        }
+//    }
+}
+

dhfs-parent/dhfs-app/src/test/java/com/usatiuk/dhfs/integration/LazyFsIT.java

@@ -0,0 +1,199 @@
+package com.usatiuk.dhfs.integration;
+
+import com.github.dockerjava.api.model.Device;
+import com.usatiuk.dhfs.TestDataCleaner;
+import io.quarkus.logging.Log;
+import org.junit.jupiter.api.*;
+import org.slf4j.LoggerFactory;
+import org.testcontainers.DockerClientFactory;
+import org.testcontainers.containers.GenericContainer;
+import org.testcontainers.containers.Network;
+import org.testcontainers.containers.output.Slf4jLogConsumer;
+import org.testcontainers.containers.output.WaitingConsumer;
+import org.testcontainers.containers.wait.strategy.Wait;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.time.Duration;
+import java.util.Objects;
+import java.util.UUID;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import java.util.stream.Stream;
+
+import static org.awaitility.Awaitility.await;
+
+public class LazyFsIT {
+    GenericContainer<?> container1;
+    GenericContainer<?> container2;
+
+    WaitingConsumer waitingConsumer1;
+    WaitingConsumer waitingConsumer2;
+
+    String c1uuid;
+    String c2uuid;
+
+    File data1;
+    File data2;
+    File data1Lazy;
+
+    LazyFs lazyFs1;
+
+    @BeforeEach
+    void setup(TestInfo testInfo) throws IOException, InterruptedException, TimeoutException {
+        data1 = Files.createTempDirectory("dhfsdata").toFile();
+        data2 = Files.createTempDirectory("dhfsdata").toFile();
+        data1Lazy = Files.createTempDirectory("lazyfsroot").toFile();
+
+        Network network = Network.newNetwork();
+
+        lazyFs1 = new LazyFs(testInfo.getDisplayName(), data1.toString(), data1Lazy.toString());
+        lazyFs1.start();
+
+        container1 = new GenericContainer<>(DhfsImage.getInstance())
+                .withPrivilegedMode(true)
+                .withCreateContainerCmdModifier(cmd -> Objects.requireNonNull(cmd.getHostConfig()).withDevices(Device.parse("/dev/fuse")))
+                .waitingFor(Wait.forLogMessage(".*Listening.*", 1).withStartupTimeout(Duration.ofSeconds(60))).withNetwork(network)
+                .withFileSystemBind(data1.getAbsolutePath(), "/dhfs_test/data");
+        container2 = new GenericContainer<>(DhfsImage.getInstance())
+                .withPrivilegedMode(true)
+                .withCreateContainerCmdModifier(cmd -> Objects.requireNonNull(cmd.getHostConfig()).withDevices(Device.parse("/dev/fuse")))
+                .waitingFor(Wait.forLogMessage(".*Listening.*", 1).withStartupTimeout(Duration.ofSeconds(60))).withNetwork(network)
+                .withFileSystemBind(data2.getAbsolutePath(), "/dhfs_test/data");
+
+        Stream.of(container1, container2).parallel().forEach(GenericContainer::start);
+
+        waitingConsumer1 = new WaitingConsumer();
+        var loggingConsumer1 = new Slf4jLogConsumer(LoggerFactory.getLogger(LazyFsIT.class)).withPrefix("1-" + testInfo.getDisplayName());
+        container1.followOutput(loggingConsumer1.andThen(waitingConsumer1));
+        waitingConsumer2 = new WaitingConsumer();
+        var loggingConsumer2 = new Slf4jLogConsumer(LoggerFactory.getLogger(LazyFsIT.class)).withPrefix("2-" + testInfo.getDisplayName());
+        container2.followOutput(loggingConsumer2.andThen(waitingConsumer2));
+
+        c1uuid = container1.execInContainer("/bin/sh", "-c", "cat /dhfs_test/data/stuff/self_uuid").getStdout();
+        c2uuid = container2.execInContainer("/bin/sh", "-c", "cat /dhfs_test/data/stuff/self_uuid").getStdout();
+
+        Assertions.assertDoesNotThrow(() -> UUID.fromString(c1uuid));
+        Assertions.assertDoesNotThrow(() -> UUID.fromString(c2uuid));
+
+        waitingConsumer2.waitUntil(frame -> frame.getUtf8String().contains("New address"), 60, TimeUnit.SECONDS);
+        waitingConsumer1.waitUntil(frame -> frame.getUtf8String().contains("New address"), 60, TimeUnit.SECONDS);
+
+        var c1curl = container1.execInContainer("/bin/sh", "-c",
+                "curl --header \"Content-Type: application/json\" " +
+                        "  --request PUT " +
+                        "  --data '{\"uuid\":\"" + c2uuid + "\"}' " +
+                        "  http://localhost:8080/peers-manage/known-peers");
+
+        var c2curl = container2.execInContainer("/bin/sh", "-c",
+                "curl --header \"Content-Type: application/json\" " +
+                        "  --request PUT " +
+                        "  --data '{\"uuid\":\"" + c1uuid + "\"}' " +
+                        "  http://localhost:8080/peers-manage/known-peers");
+
+        waitingConsumer2.waitUntil(frame -> frame.getUtf8String().contains("Connected"), 60, TimeUnit.SECONDS);
+        waitingConsumer1.waitUntil(frame -> frame.getUtf8String().contains("Connected"), 60, TimeUnit.SECONDS);
+    }
+
+    @AfterEach
+    void stop() {
+        lazyFs1.stop();
+
+        Stream.of(container1, container2).parallel().forEach(GenericContainer::stop);
+        TestDataCleaner.purgeDirectory(data1);
+        TestDataCleaner.purgeDirectory(data1Lazy);
+        TestDataCleaner.purgeDirectory(data2);
+    }
+
+    @Test
+    void killTest(TestInfo testInfo) throws Exception {
+        var executor = Executors.newFixedThreadPool(2);
+        var barrier = new CyclicBarrier(2);
+        var ret1 = executor.submit(() -> {
+            try {
+                Log.info("Writing to container 1");
+                barrier.await();
+                container1.execInContainer("/bin/sh", "-c", "counter=0; while true; do counter=`expr $counter + 1`; echo $counter >> /dhfs_test/fuse/test1; done");
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        });
+        barrier.await();
+        Thread.sleep(1000);
+        Log.info("Killing");
+        lazyFs1.crash();
+
+        waitingConsumer1.waitUntil(frame -> frame.getUtf8String().contains("Caused by: org.lmdbjava"), 5, TimeUnit.SECONDS);
+        Thread.sleep(1000);
+        var client = DockerClientFactory.instance().client();
+        client.killContainerCmd(container1.getContainerId()).exec();
+        container1.stop();
+        waitingConsumer2.waitUntil(frame -> frame.getUtf8String().contains("Lost connection to"), 60, TimeUnit.SECONDS);
+        Log.info("Restart");
+        lazyFs1.start();
+        container1.start();
+        waitingConsumer1 = new WaitingConsumer();
+        var loggingConsumer1 = new Slf4jLogConsumer(LoggerFactory.getLogger(LazyFsIT.class)).withPrefix("1-" + testInfo.getDisplayName());
+        container1.followOutput(loggingConsumer1.andThen(waitingConsumer1));
+        waitingConsumer2.waitUntil(frame -> frame.getUtf8String().contains("Connected"), 60, TimeUnit.SECONDS);
+        waitingConsumer1.waitUntil(frame -> frame.getUtf8String().contains("Connected"), 60, TimeUnit.SECONDS);
+
+        await().atMost(45, TimeUnit.SECONDS).until(() -> {
+            Log.info("Listing consistency");
+            var ls1 = container1.execInContainer("/bin/sh", "-c", "ls /dhfs_test/fuse");
+            var cat1 = container1.execInContainer("/bin/sh", "-c", "cat /dhfs_test/fuse/*");
+            var ls2 = container2.execInContainer("/bin/sh", "-c", "ls /dhfs_test/fuse");
+            var cat2 = container2.execInContainer("/bin/sh", "-c", "cat /dhfs_test/fuse/*");
+            Log.info(ls1);
+            Log.info(cat1);
+            Log.info(ls2);
+            Log.info(cat2);
+
+            return ls1.equals(ls2) && cat1.equals(cat2);
+        });
+    }
+
+//    @Test
+//    void killTestDirs(TestInfo testInfo) throws Exception {
+//        var executor = Executors.newFixedThreadPool(2);
+//        var barrier = new CyclicBarrier(2);
+//        var ret1 = executor.submit(() -> {
+//            try {
+//                Log.info("Writing to container 1");
+//                barrier.await();
+//                container1.execInContainer("/bin/sh", "-c", "counter=0; while true; do counter=`expr $counter + 1`; echo $counter >> /dhfs_test/fuse/test$counter; done");
+//            } catch (Exception e) {
+//                throw new RuntimeException(e);
+//            }
+//        });
+//        barrier.await();
+//        Thread.sleep(10000);
+//        var client = DockerClientFactory.instance().client();
+//        client.killContainerCmd(container1.getContainerId()).exec();
+//        container1.stop();
+//        waitingConsumer2.waitUntil(frame -> frame.getUtf8String().contains("Lost connection to"), 60, TimeUnit.SECONDS);
+//        container1.start();
+//        waitingConsumer1 = new WaitingConsumer();
+//        var loggingConsumer1 = new Slf4jLogConsumer(LoggerFactory.getLogger(LazyFsIT.class)).withPrefix("1-" + testInfo.getDisplayName());
+//        container1.followOutput(loggingConsumer1.andThen(waitingConsumer1));
+//        waitingConsumer2.waitUntil(frame -> frame.getUtf8String().contains("Connected"), 60, TimeUnit.SECONDS);
+//        waitingConsumer1.waitUntil(frame -> frame.getUtf8String().contains("Connected"), 60, TimeUnit.SECONDS);
+//
+//        await().atMost(45, TimeUnit.SECONDS).until(() -> {
+//            Log.info("Listing consistency");
+//            var ls1 = container1.execInContainer("/bin/sh", "-c", "ls /dhfs_test/fuse");
+//            var cat1 = container1.execInContainer("/bin/sh", "-c", "cat /dhfs_test/fuse/*");
+//            var ls2 = container2.execInContainer("/bin/sh", "-c", "ls /dhfs_test/fuse");
+//            var cat2 = container2.execInContainer("/bin/sh", "-c", "cat /dhfs_test/fuse/*");
+//            Log.info(ls1);
+//            Log.info(cat1);
+//            Log.info(ls2);
+//            Log.info(cat2);
+//
+//            return ls1.equals(ls2) && cat1.equals(cat2);
+//        });
+//    }
+}

dhfs-parent/objects/src/main/java/com/usatiuk/objects/JDataVersionedWrapperSerializer.java

@@ -24,6 +24,8 @@ public class JDataVersionedWrapperSerializer implements ObjectSerializer<JDataVe
     public JDataVersionedWrapper deserialize(ByteString data) {
         var version = data.substring(0, Long.BYTES).asReadOnlyByteBuffer().getLong();
         var rawData = data.substring(Long.BYTES);
-        return new JDataVersionedWrapperLazy(version, rawData.size(), () -> dataSerializer.deserialize(rawData));
+        return new JDataVersionedWrapperLazy(version, rawData.size(),
+                () -> dataSerializer.deserialize(rawData)
+        );
     }
 }

dhfs-parent/objects/src/main/java/com/usatiuk/objects/iterators/TombstoneMergingKvIterator.java

@@ -1,21 +1,16 @@
 package com.usatiuk.objects.iterators;
 
 import io.quarkus.logging.Log;
-import org.apache.commons.lang3.tuple.Pair;
 
 import java.util.List;
 
-public class TombstoneMergingKvIterator<K extends Comparable<K>, V> implements CloseableKvIterator<K, V> {
+public abstract class TombstoneMergingKvIterator {
-    private final CloseableKvIterator<K, V> _backing;
+    public static <K extends Comparable<K>, V> CloseableKvIterator<K, V> of(String name, IteratorStart startType, K startKey, List<IterProdFn<K, MaybeTombstone<V>>> iterators) {
-    private final String _name;
+        return new PredicateKvIterator<K, MaybeTombstone<V>, V>(
-
+                new MergingKvIterator<K, MaybeTombstone<V>>(name + "-merging", startType, startKey, iterators),
-    public TombstoneMergingKvIterator(String name, IteratorStart startType, K startKey, List<IterProdFn<K, MaybeTombstone<V>>> iterators) {
-        _name = name;
-        _backing = new PredicateKvIterator<>(
-                new MergingKvIterator<>(name + "-merging", startType, startKey, iterators),
                 startType, startKey,
                 pair -> {
-                    Log.tracev("{0} - Processing pair {1}", _name, pair);
+                    Log.tracev("{0} - Processing pair {1}", name, pair);
                     if (pair instanceof Tombstone<V>) {
                         return null;
                     }
@@ -23,61 +18,7 @@ public class TombstoneMergingKvIterator<K extends Comparable<K>, V> implements C
                 });
     }
 
-    @SafeVarargs
+    public static <K extends Comparable<K>, V> CloseableKvIterator<K, V> of(String name, IteratorStart startType, K startKey, IterProdFn<K, MaybeTombstone<V>>... iterators) {
-    public TombstoneMergingKvIterator(String name, IteratorStart startType, K startKey, IterProdFn<K, MaybeTombstone<V>>... iterators) {
+        return of(name, startType, startKey, List.of(iterators));
-        this(name, startType, startKey, List.of(iterators));
-    }
-
-    @Override
-    public K peekNextKey() {
-        return _backing.peekNextKey();
-    }
-
-    @Override
-    public void skip() {
-        _backing.skip();
-    }
-
-    @Override
-    public K peekPrevKey() {
-        return _backing.peekPrevKey();
-    }
-
-    @Override
-    public Pair<K, V> prev() {
-        return _backing.prev();
-    }
-
-    @Override
-    public boolean hasPrev() {
-        return _backing.hasPrev();
-    }
-
-    @Override
-    public void skipPrev() {
-        _backing.skipPrev();
-    }
-
-    @Override
-    public void close() {
-        _backing.close();
-    }
-
-    @Override
-    public boolean hasNext() {
-        return _backing.hasNext();
-    }
-
-    @Override
-    public Pair<K, V> next() {
-        return _backing.next();
-    }
-
-    @Override
-    public String toString() {
-        return "TombstoneMergingKvIterator{" +
-                "_backing=" + _backing +
-                ", _name='" + _name + '\'' +
-                '}';
     }
 }

dhfs-parent/objects/src/main/java/com/usatiuk/objects/stores/CachingObjectPersistentStore.java

@@ -186,7 +186,7 @@ public class CachingObjectPersistentStore {
 
                     @Override
                     public CloseableKvIterator<JObjectKey, JDataVersionedWrapper> getIterator(IteratorStart start, JObjectKey key) {
-                        return new TombstoneMergingKvIterator<>("cache", start, key,
+                        return TombstoneMergingKvIterator.<JObjectKey, JDataVersionedWrapper>of("cache", start, key,
                                 (mS, mK) -> new NavigableMapKvIterator<JObjectKey, MaybeTombstone<JDataVersionedWrapper>>(_curCache.map(), mS, mK),
                                 (mS, mK) -> new CachingKvIterator(_backing.getIterator(start, key)));
                     }

dhfs-parent/objects/src/main/java/com/usatiuk/objects/stores/LmdbObjectPersistentStore.java

@@ -208,6 +208,7 @@ public class LmdbObjectPersistentStore implements ObjectPersistentStore {
         //        private final Exception _allocationStacktrace = new Exception();
         private final Exception _allocationStacktrace = null;
         private boolean _hasNext = false;
+        private JObjectKey _peekedNextKey = null;
 
         LmdbKvIterator(RefcountedCloseable<Txn<ByteBuffer>> txn, IteratorStart start, JObjectKey key) {
             _txn = txn;
@@ -277,24 +278,24 @@ public class LmdbObjectPersistentStore implements ObjectPersistentStore {
                 }
             }
 
-            var realGot = JObjectKey.fromByteBuffer(_cursor.key());
+//            var realGot = JObjectKey.fromByteBuffer(_cursor.key());
-            _cursor.key().flip();
+//            _cursor.key().flip();
-
+//
-            switch (start) {
+//            switch (start) {
-                case LT -> {
+//                case LT -> {
-//                    assert !_hasNext || realGot.compareTo(key) < 0;
+////                    assert !_hasNext || realGot.compareTo(key) < 0;
-                }
+//                }
-                case LE -> {
+//                case LE -> {
-//                    assert !_hasNext || realGot.compareTo(key) <= 0;
+////                    assert !_hasNext || realGot.compareTo(key) <= 0;
-                }
+//                }
-                case GT -> {
+//                case GT -> {
-                    assert !_hasNext || realGot.compareTo(key) > 0;
+//                    assert !_hasNext || realGot.compareTo(key) > 0;
-                }
+//                }
-                case GE -> {
+//                case GE -> {
-                    assert !_hasNext || realGot.compareTo(key) >= 0;
+//                    assert !_hasNext || realGot.compareTo(key) >= 0;
-                }
+//                }
-            }
+//            }
-            Log.tracev("got: {0}, hasNext: {1}", realGot, _hasNext);
+//            Log.tracev("got: {0}, hasNext: {1}", realGot, _hasNext);
         }
 
         @Override
@@ -323,6 +324,7 @@ public class LmdbObjectPersistentStore implements ObjectPersistentStore {
                 }
             }
             _goingForward = !_goingForward;
+            _peekedNextKey = null;
         }
 
         @Override
@@ -330,8 +332,12 @@ public class LmdbObjectPersistentStore implements ObjectPersistentStore {
             if (!_hasNext) {
                 throw new NoSuchElementException("No more elements");
             }
+            if (_peekedNextKey != null) {
+                return _peekedNextKey;
+            }
             var ret = JObjectKey.fromByteBuffer(_cursor.key());
             _cursor.key().flip();
+            _peekedNextKey = ret;
             return ret;
         }
 
@@ -341,6 +347,7 @@ public class LmdbObjectPersistentStore implements ObjectPersistentStore {
                 _hasNext = _cursor.next();
             else
                 _hasNext = _cursor.prev();
+            _peekedNextKey = null;
         }
 
         @Override
@@ -362,6 +369,7 @@ public class LmdbObjectPersistentStore implements ObjectPersistentStore {
             else
                 _hasNext = _cursor.prev();
             Log.tracev("Read: {0}, hasNext: {1}", ret, _hasNext);
+            _peekedNextKey = null;
             return ret;
         }
     }

dhfs-parent/objects/src/main/java/com/usatiuk/objects/stores/WritebackObjectPersistentStore.java

@@ -350,7 +350,7 @@ public class WritebackObjectPersistentStore {
 
                 @Override
                 public CloseableKvIterator<JObjectKey, JDataVersionedWrapper> getIterator(IteratorStart start, JObjectKey key) {
-                    return new TombstoneMergingKvIterator<JObjectKey, JDataVersionedWrapper>("writeback-ps", start, key,
+                    return  TombstoneMergingKvIterator.<JObjectKey, JDataVersionedWrapper>of("writeback-ps", start, key,
                             (tS, tK) -> new NavigableMapKvIterator<>(_pendingWrites, tS, tK),
                             (tS, tK) -> (CloseableKvIterator<JObjectKey, MaybeTombstone<JDataVersionedWrapper>>) (CloseableKvIterator<JObjectKey, ?>) _cache.getIterator(tS, tK));
                 }

dhfs-parent/objects/src/main/java/com/usatiuk/objects/transaction/TransactionFactoryImpl.java

@@ -161,7 +161,7 @@ public class TransactionFactoryImpl implements TransactionFactory {
         @Override
         public CloseableKvIterator<JObjectKey, JData> getIterator(IteratorStart start, JObjectKey key) {
             Log.tracev("Getting tx iterator with start={0}, key={1}", start, key);
-            return new ReadTrackingIterator(new TombstoneMergingKvIterator<>("tx", start, key,
+            return new ReadTrackingIterator(TombstoneMergingKvIterator.<JObjectKey, ReadTrackingInternalCrap>of("tx", start, key,
                     (tS, tK) -> new MappingKvIterator<>(new NavigableMapKvIterator<>(_writes, tS, tK),
                             t -> switch (t) {
                                 case TxRecord.TxObjectRecordWrite<?> write ->
@@ -175,6 +175,11 @@ public class TransactionFactoryImpl implements TransactionFactory {
 
         @Override
         public void put(JData obj) {
+            var read = _readSet.get(obj.key());
+            if (read != null && (read.data().map(JDataVersionedWrapper::data).orElse(null) == obj)) {
+                return;
+            }
+
             _writes.put(obj.key(), new TxRecord.TxObjectRecordWrite<>(obj));
             _newWrites.put(obj.key(), new TxRecord.TxObjectRecordWrite<>(obj));
         }

dhfs-parent/pom.xml

@@ -144,6 +144,7 @@
                         </native.image.path>
                         <java.util.logging.manager>org.jboss.logmanager.LogManager</java.util.logging.manager>
                         <buildDirectory>${project.build.directory}</buildDirectory>
+                        <lazyFsPath>${project.basedir}/../../thirdparty/lazyfs/lazyfs/lazyfs</lazyFsPath>
                         <nativeLibsDirectory>${dhfs.native-libs-dir}</nativeLibsDirectory>
                         <maven.home>${maven.home}</maven.home>
                     </systemPropertyVariables>

dhfs-parent/sync-base/src/main/java/com/usatiuk/dhfs/repository/invalidation/DeferredInvalidationQueueService.java

@@ -36,7 +36,11 @@ public class DeferredInvalidationQueueService implements PeerConnectedEventListe
         Log.info("Initializing with root " + dataRoot);
         if (Paths.get(dataRoot).resolve(dataFileName).toFile().exists()) {
             Log.info("Reading invalidation queue");
-            _persistentData = SerializationHelper.deserialize(Files.readAllBytes(Paths.get(dataRoot).resolve(dataFileName)));
+            try {
+                _persistentData = SerializationHelper.deserialize(Files.readAllBytes(Paths.get(dataRoot).resolve(dataFileName)));
+            } catch (Exception e) {
+                Log.error("Error reading invalidation queue", e);
+            }
         }
     }
 

thirdparty/lazyfs/build.sh

@@ -0,0 +1,9 @@
+# apt install g++ cmake libfuse3-dev libfuse3-3 fuse3
+
+export CMAKE_BUILD_PARALLEL_LEVEL="$(nproc)"
+
+cd lazyfs
+
+cd libs/libpcache && ./build.sh && cd -
+
+cd lazyfs && ./build.sh && cd -