Тузиков Александр, ИТМО DWS, Stage 6

src/main/java/ru/vk/itmo/test/tuzikovalexandr/Constants.java

@@ -4,6 +4,7 @@
 import one.nio.http.Response;
 
 import java.net.HttpURLConnection;
+import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.util.Set;
 
@@ -30,6 +31,18 @@ public final class Constants {
     public static final String HTTP_TIMESTAMP_HEADER = "X-Timestamp";
     public static final String NIO_TIMESTAMP_HEADER = "x-timestamp:";
     public static final String HTTP_TERMINATION_HEADER = "X-Termination";
+    public static final String RANGE_REQUEST = "/v0/entities?start=";
+    public static final String ID_REQUEST = "/v0/entity?id=";
+    public static final byte[] CRLF = "\r\n".getBytes(StandardCharsets.UTF_8);
+    public static final byte[] LAST_STRING = "0\r\n\r\n".getBytes(StandardCharsets.UTF_8);
+    public static final byte[] NEW_LINE = "\n".getBytes(StandardCharsets.UTF_8);
+    public static final byte[] HEADER =
+            """
+                    HTTP/1.1 200 OK\r
+                    Content-Type: text/plain\r
+                    Transfer-Encoding: chunked\r
+                    \r
+                    """.getBytes(StandardCharsets.UTF_8);
 
     private Constants() {
     }

src/main/java/ru/vk/itmo/test/tuzikovalexandr/RequestHandler.java

@@ -10,6 +10,7 @@
 import java.lang.foreign.MemorySegment;
 import java.lang.foreign.ValueLayout;
 import java.nio.charset.StandardCharsets;
+import java.util.Iterator;
 
 public class RequestHandler {
     private final Dao dao;
@@ -84,4 +85,11 @@ private Response sendResponseWithTimestamp(String resultCode, byte[] body, long
     private MemorySegment fromString(String data) {
         return data == null ? null : MemorySegment.ofArray(data.getBytes(StandardCharsets.UTF_8));
     }
+
+    public Iterator<EntryWithTimestamp<MemorySegment>> getEntries(String start, String end) {
+        MemorySegment startVal = fromString(start);
+        MemorySegment endVal = end != null ? fromString(end) : null;
+
+        return dao.get(startVal, endVal);
+    }
 }

src/main/java/ru/vk/itmo/test/tuzikovalexandr/ServerImpl.java

@@ -11,15 +11,18 @@
 import org.slf4j.LoggerFactory;
 import ru.vk.itmo.ServiceConfig;
 import ru.vk.itmo.test.tuzikovalexandr.dao.Dao;
+import ru.vk.itmo.test.tuzikovalexandr.dao.EntryWithTimestamp;
 
 import java.io.IOException;
+import java.lang.foreign.MemorySegment;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -78,7 +81,16 @@ public void handleDefault(Request request, HttpSession session) throws IOExcepti
     @Override
     public void handleRequest(Request request, HttpSession session) throws IOException {
         try {
-            if (!request.getURI().startsWith("/v0/entity?id=") || !Constants.METHODS.contains(request.getMethod())) {
+            if (request.getURI().startsWith(Constants.RANGE_REQUEST)) {
+                String paramStart = request.getParameter("start=");
+                String paramEnd = request.getParameter("end=");
+
+                rangeRequest(session, paramStart, paramEnd);
+                return;
+            }
+
+            if (!request.getURI().startsWith(Constants.ID_REQUEST)
+                    || !Constants.METHODS.contains(request.getMethod())) {
                 handleDefault(request, session);
                 return;
             }
@@ -109,6 +121,25 @@ public void handleRequest(Request request, HttpSession session) throws IOExcepti
         }
     }
 
+    private void rangeRequest(HttpSession session, String start, String end) {
+        if (start == null || start.isBlank()) {
+            sendResponse(session, new Response(Response.BAD_REQUEST, Response.EMPTY));
+            return;
+        }
+
+        executorService.execute(() -> {
+            try {
+                Iterator<EntryWithTimestamp<MemorySegment>> entries = requestHandler.getEntries(start, end);
+
+                final StreamResponse streamResponse = new StreamResponse(Response.OK, entries);
+                streamResponse.stream(session);
+            } catch (IOException e) {
+                log.error("Exception while sending close connection", e);
+                session.scheduleClose();
+            }
+        });
+    }
+
     private void processingRequest(Request request, HttpSession session, long processingStartTime,
                                    String paramId, int from, int ack) throws IOException {
         if (System.currentTimeMillis() - processingStartTime > Constants.REQUEST_TIMEOUT) {

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

@@ -48,7 +48,7 @@ public synchronized CompletableFuture<Void> stop() throws IOException {
         return CompletableFuture.completedFuture(null);
     }
 
-    @ServiceFactory(stage = 5)
+    @ServiceFactory(stage = 6)
     public static class Factory implements ServiceFactory.Factory {
 
         @Override

src/main/java/ru/vk/itmo/test/tuzikovalexandr/StreamResponse.java

@@ -0,0 +1,74 @@
+package ru.vk.itmo.test.tuzikovalexandr;
+
+import one.nio.http.Response;
+import one.nio.net.Session;
+import ru.vk.itmo.test.tuzikovalexandr.dao.EntryWithTimestamp;
+
+import java.io.IOException;
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.Iterator;
+
+public class StreamResponse extends Response {
+    private final Iterator<EntryWithTimestamp<MemorySegment>> entries;
+
+    public StreamResponse(String resultCode, Iterator<EntryWithTimestamp<MemorySegment>> entries) {
+        super(resultCode);
+        this.entries = entries;
+    }
+
+    public void stream(Session session) throws IOException {
+        session.write(Constants.HEADER, 0, Constants.HEADER.length);
+
+        processWrite(session);
+        session.scheduleClose();
+    }
+
+    private void next(Session session, MemorySegment key, MemorySegment value) throws IOException {
+        byte[] keyInBytes = toByteArray(key);
+        byte[] valueInBytes = toByteArray(value);
+
+        byte[] entrySize = Integer.toHexString(keyInBytes.length + valueInBytes.length + Constants.NEW_LINE.length)
+                .getBytes(StandardCharsets.UTF_8);
+
+        byte[] resultValue = new byte[keyInBytes.length + valueInBytes.length + Constants.NEW_LINE.length
+                + Constants.CRLF.length * 2 + entrySize.length];
+
+        ByteBuffer target = ByteBuffer.wrap(resultValue);
+        target.put(entrySize);
+        target.put(Constants.CRLF);
+        target.put(keyInBytes);
+        target.put(Constants.NEW_LINE);
+        target.put(valueInBytes);
+        target.put(Constants.CRLF);
+
+        session.write(target.array(), 0, target.array().length);
+    }
+
+    private void processWrite(Session session) throws IOException {
+        while (entries.hasNext()) {
+            EntryWithTimestamp<MemorySegment> entry = entries.next();
+
+            next(session, entry.key(), entry.value());
+        }
+        session.write(Constants.LAST_STRING, 0, Constants.LAST_STRING.length);
+    }
+
+    private <T> byte[] toByteArray(T segment) {
+        if (segment == null) {
+            throw new IllegalArgumentException();
+        }
+
+        if (segment instanceof MemorySegment) {
+            return ((MemorySegment) segment).toArray(ValueLayout.JAVA_BYTE);
+        }
+
+        if (segment instanceof String) {
+            return ((String) segment).getBytes(StandardCharsets.UTF_8);
+        }
+
+        return new byte[0];
+    }
+}