Stage 1 (wip)

src/main/java/ru/vk/itmo/test/elenakhodosova/HttpServerImpl.java

@@ -0,0 +1,86 @@
+package ru.vk.itmo.test.elenakhodosova;
+
+import one.nio.http.*;
+import one.nio.server.AcceptorConfig;
+import ru.vk.itmo.ServiceConfig;
+import ru.vk.itmo.dao.BaseEntry;
+import ru.vk.itmo.dao.Entry;
+import ru.vk.itmo.test.elenakhodosova.dao.ReferenceDao;
+
+import java.io.IOException;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+
+public class HttpServerImpl extends HttpServer {
+
+    private final ReferenceDao dao;
+
+    public HttpServerImpl(ServiceConfig config, ReferenceDao dao) throws IOException {
+        super(createServerConfig(config));
+        this.dao = dao;
+    }
+
+    private static HttpServerConfig createServerConfig(ServiceConfig serviceConfig) {
+        HttpServerConfig httpServerConfig = new HttpServerConfig();
+        AcceptorConfig acceptorConfig = new AcceptorConfig();
+        acceptorConfig.port = serviceConfig.selfPort();
+        acceptorConfig.reusePort = true;
+
+        httpServerConfig.acceptors = new AcceptorConfig[]{acceptorConfig};
+        httpServerConfig.closeSessions = true;
+        return httpServerConfig;
+    }
+
+    @Path("/v0/entity")
+    @RequestMethod(Request.METHOD_GET)
+    public Response getEntity(@Param(value = "id", required = true) String id) {
+        if (isParamIncorrect(id)) return new Response(Response.BAD_REQUEST, Response.EMPTY);
+        Entry<MemorySegment> value = dao.get(MemorySegment.ofArray(id.toCharArray()));
+        return value == null ? new Response(Response.NOT_FOUND, Response.EMPTY)
+                : Response.ok(value.value().toArray(ValueLayout.JAVA_BYTE));
+    }
+
+    @Path("/v0/entity")
+    @RequestMethod(Request.METHOD_PUT)
+    public Response putEntity(@Param(value = "id", required = true) String id, Request request) {
+        byte[] value = request.getBody();
+        if (isParamIncorrect(id)) return new Response(Response.BAD_REQUEST, Response.EMPTY);
+        dao.upsert(new BaseEntry<>(
+                MemorySegment.ofArray(id.toCharArray()),
+                MemorySegment.ofArray(value)));
+        return new Response(Response.CREATED, Response.EMPTY);
+    }
+
+    @Path("/v0/entity")
+    @RequestMethod(Request.METHOD_DELETE)
+    public Response deleteEntity(@Param(value = "id", required = true) String id) {
+        if (isParamIncorrect(id)) return new Response(Response.BAD_REQUEST, Response.EMPTY);
+        dao.upsert(new BaseEntry<>(MemorySegment.ofArray(id.toCharArray()), null));
+        return new Response(Response.ACCEPTED, Response.EMPTY);
+    }
+
+    @Path("/v0/entity")
+    public Response methodNotSupported() {
+        return new Response(Response.METHOD_NOT_ALLOWED, Response.EMPTY);
+    }
+
+    @Override
+    public void handleDefault(Request request, HttpSession session) throws IOException {
+        Response badRequest = new Response(Response.BAD_REQUEST, Response.EMPTY);
+        session.sendResponse(badRequest);
+    }
+
+    @Override
+    public synchronized void stop() {
+        try {
+            dao.close();
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        super.stop();
+    }
+
+    private boolean isParamIncorrect(String param) {
+        return param == null || param.isEmpty();
+    }
+}

src/main/java/ru/vk/itmo/test/elenakhodosova/Server.java

@@ -0,0 +1,26 @@
+package ru.vk.itmo.test.elenakhodosova;
+
+import ru.vk.itmo.ServiceConfig;
+import ru.vk.itmo.dao.Config;
+import ru.vk.itmo.test.elenakhodosova.dao.ReferenceDao;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.util.List;
+
+public class Server {
+    public static final long FLUSH_THRESHOLD_BYTES = 4 * 1024 * 1024;
+    public static void main(String[] args) throws IOException {
+         ReferenceDao dao;
+         ServiceConfig config = new ServiceConfig(
+                8080,
+                "http://localhost",
+                List.of("http://localhost"),
+                Files.createTempDirectory(".")
+        );
+
+        dao = new ReferenceDao(new Config(config.workingDir(), FLUSH_THRESHOLD_BYTES));
+        HttpServerImpl server = new HttpServerImpl(config, dao);
+        server.start();
+    }
+}

src/main/java/ru/vk/itmo/test/elenakhodosova/ServiceImpl.java

@@ -0,0 +1,48 @@
+package ru.vk.itmo.test.elenakhodosova;
+
+import ru.vk.itmo.Service;
+import ru.vk.itmo.ServiceConfig;
+import ru.vk.itmo.dao.Config;
+import ru.vk.itmo.test.ServiceFactory;
+import ru.vk.itmo.test.elenakhodosova.dao.ReferenceDao;
+
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+
+
+public class ServiceImpl implements Service {
+
+    private HttpServerImpl server;
+    private ReferenceDao dao;
+    private final ServiceConfig config;
+    public static final long FLUSH_THRESHOLD_BYTES = 4 * 1024 * 1024;
+
+    public ServiceImpl(ServiceConfig config) {
+        this.config = config;
+
+    }
+
+    @Override
+    public CompletableFuture<Void> start() throws IOException {
+        dao = new ReferenceDao(new Config(config.workingDir(), FLUSH_THRESHOLD_BYTES));
+        this.server = new HttpServerImpl(config, dao);
+        server.start();
+        return CompletableFuture.completedFuture(null);
+    }
+
+    @Override
+    public CompletableFuture<Void> stop() throws IOException {
+        server.stop();
+        dao.close();
+        return CompletableFuture.completedFuture(null);
+    }
+
+    @ServiceFactory(stage = 1)
+    public static class Factory implements ServiceFactory.Factory {
+
+        @Override
+        public Service create(ServiceConfig config) {
+            return new ServiceImpl(config);
+        }
+    }
+}

src/main/java/ru/vk/itmo/test/elenakhodosova/dao/ByteArraySegment.java

@@ -0,0 +1,48 @@
+package ru.vk.itmo.test.elenakhodosova.dao;
+
+import java.io.IOException;
+import java.lang.foreign.MemorySegment;
+import java.nio.ByteBuffer;
+
+/**
+ * Growable buffer with {@link ByteBuffer} and {@link MemorySegment} interface.
+ *
+ * @author incubos
+ */
+final class ByteArraySegment {
+    private byte[] array;
+    private MemorySegment segment;
+
+    ByteArraySegment(final int capacity) {
+        this.array = new byte[capacity];
+        this.segment = MemorySegment.ofArray(array);
+    }
+
+    void withArray(final ArrayConsumer consumer) throws IOException {
+        consumer.process(array);
+    }
+
+    MemorySegment segment() {
+        return segment;
+    }
+
+    void ensureCapacity(final long size) {
+        if (size > Integer.MAX_VALUE) {
+            throw new IllegalArgumentException("Too big!");
+        }
+
+        final int capacity = (int) size;
+        if (array.length >= capacity) {
+            return;
+        }
+
+        // Grow to the nearest bigger power of 2
+        final int newSize = Integer.highestOneBit(capacity) << 1;
+        array = new byte[newSize];
+        segment = MemorySegment.ofArray(array);
+    }
+
+    interface ArrayConsumer {
+        void process(byte[] array) throws IOException;
+    }
+}

src/main/java/ru/vk/itmo/test/elenakhodosova/dao/LiveFilteringIterator.java

@@ -0,0 +1,52 @@
+package ru.vk.itmo.test.elenakhodosova.dao;
+
+import ru.vk.itmo.dao.Entry;
+
+import java.lang.foreign.MemorySegment;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ * Filters non tombstone {@link Entry}s.
+ *
+ * @author incubos
+ */
+final class LiveFilteringIterator implements Iterator<Entry<MemorySegment>> {
+    private final Iterator<Entry<MemorySegment>> delegate;
+    private Entry<MemorySegment> next;
+
+    LiveFilteringIterator(final Iterator<Entry<MemorySegment>> delegate) {
+        this.delegate = delegate;
+        skipTombstones();
+    }
+
+    private void skipTombstones() {
+        while (delegate.hasNext()) {
+            final Entry<MemorySegment> entry = delegate.next();
+            if (entry.value() != null) {
+                this.next = entry;
+                break;
+            }
+        }
+    }
+
+    @Override
+    public boolean hasNext() {
+        return next != null;
+    }
+
+    @Override
+    public Entry<MemorySegment> next() {
+        if (!hasNext()) {
+            throw new NoSuchElementException();
+        }
+
+        // Consume
+        final Entry<MemorySegment> result = next;
+        next = null;
+
+        skipTombstones();
+
+        return result;
+    }
+}

src/main/java/ru/vk/itmo/test/elenakhodosova/dao/MemTable.java

@@ -0,0 +1,49 @@
+package ru.vk.itmo.test.elenakhodosova.dao;
+
+import ru.vk.itmo.dao.Entry;
+
+import java.lang.foreign.MemorySegment;
+import java.util.Iterator;
+import java.util.NavigableMap;
+import java.util.concurrent.ConcurrentSkipListMap;
+
+/**
+ * Memory table.
+ *
+ * @author incubos
+ */
+final class MemTable {
+    private final NavigableMap<MemorySegment, Entry<MemorySegment>> map =
+            new ConcurrentSkipListMap<>(
+                    MemorySegmentComparator.INSTANCE);
+
+    boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+    Iterator<Entry<MemorySegment>> get(
+            final MemorySegment from,
+            final MemorySegment to) {
+        if (from == null && to == null) {
+            // All
+            return map.values().iterator();
+        } else if (from == null) {
+            // Head
+            return map.headMap(to).values().iterator();
+        } else if (to == null) {
+            // Tail
+            return map.tailMap(from).values().iterator();
+        } else {
+            // Slice
+            return map.subMap(from, to).values().iterator();
+        }
+    }
+
+    Entry<MemorySegment> get(final MemorySegment key) {
+        return map.get(key);
+    }
+
+    Entry<MemorySegment> upsert(final Entry<MemorySegment> entry) {
+        return map.put(entry.key(), entry);
+    }
+}