Пелогейко Макар, ИТМО DWS, Stage 4

src/main/java/ru/vk/itmo/test/pelogeikomakar/Convertor.java

@@ -0,0 +1,63 @@
+package ru.vk.itmo.test.pelogeikomakar;
+
+import ru.vk.itmo.dao.BaseEntry;
+import ru.vk.itmo.dao.Entry;
+
+import java.lang.foreign.MemorySegment;
+import java.lang.foreign.ValueLayout;
+import java.nio.charset.StandardCharsets;
+
+public final class Convertor {
+
+    private Convertor() {
+        throw new UnsupportedOperationException("cannot be instantiated");
+    }
+
+    public static byte[] addLongToArray(long l, byte[] given) {
+        int gLength = 0;
+        if (given != null) {
+            gLength = given.length;
+        }
+        byte[] result = new byte[Long.BYTES + gLength];
+        for (int i = 0; i < Long.BYTES; ++i) {
+            result[i] = (byte)(l & 0xFF);
+            l >>= Byte.SIZE;
+        }
+
+        if (given != null) {
+            System.arraycopy(given, 0, result, 8, given.length);
+        } else {
+            result[Long.BYTES - 1] = (byte)(result[Long.BYTES - 1] | 0x80);
+        }
+
+        return result;
+    }
+
+    public static long getTimeStamp(MemorySegment segment) {
+        long time = segment.get(ValueLayout.JAVA_LONG_UNALIGNED, 0);
+
+        if (((time >> (Byte.SIZE * 7)) & 0x80) != 0) {
+            time &= ~(1L << 63);
+        }
+        return time;
+    }
+
+    public static boolean isValNull(MemorySegment segment) {
+        long time = segment.get(ValueLayout.JAVA_LONG_UNALIGNED, 0);
+        return ((time >> (Byte.SIZE * 7)) & 0x80) != 0;
+    }
+
+    public static MemorySegment stringToMemorySegment(String str) {
+        return MemorySegment.ofArray(str.getBytes(StandardCharsets.UTF_8));
+    }
+
+    public static Entry<MemorySegment> requestToEntry(String key, byte[] value, long timeStamp) {
+        byte[] storedValue = addLongToArray(timeStamp, value);
+        return new BaseEntry<>(stringToMemorySegment(key), MemorySegment.ofArray(storedValue));
+    }
+
+    public static byte[] getValueNotNullAsBytes(MemorySegment segment) {
+        return segment.asSlice(Long.BYTES).toArray(ValueLayout.JAVA_BYTE);
+    }
+
+}