Add offset parameter to DataUtils.getFletcher32()

h2/src/main/org/h2/mvstore/Chunk.java

@@ -259,7 +259,7 @@ public class Chunk {
         DataUtils.appendMap(buff, "block", block);
         DataUtils.appendMap(buff, "version", version);
         byte[] bytes = buff.toString().getBytes(StandardCharsets.ISO_8859_1);
-        int checksum = DataUtils.getFletcher32(bytes, bytes.length);
+        int checksum = DataUtils.getFletcher32(bytes, 0, bytes.length);
         DataUtils.appendMap(buff, "fletcher", checksum);
         while (buff.length() < Chunk.FOOTER_LENGTH - 1) {
             buff.append(' ');

h2/src/main/org/h2/mvstore/DataUtils.java

@@ -695,7 +695,7 @@ public final class DataUtils {
                 DataUtils.parseMapValue(buff, s, i + 1, size);
                 int check = (int) Long.parseLong(buff.toString(), 16);
                 bytes = s.getBytes(StandardCharsets.ISO_8859_1);
-                if (check == DataUtils.getFletcher32(bytes, startKey - 1)) {
+                if (check == DataUtils.getFletcher32(bytes, 0, startKey - 1)) {
                     return map;
                 }
                 // Corrupted map
@@ -759,22 +759,23 @@ public final class DataUtils {
      * Calculate the Fletcher32 checksum.
      *
      * @param bytes the bytes
+     * @param offset initial offset
      * @param length the message length (if odd, 0 is appended)
      * @return the checksum
      */
-    public static int getFletcher32(byte[] bytes, int length) {
+    public static int getFletcher32(byte[] bytes, int offset, int length) {
         int s1 = 0xffff, s2 = 0xffff;
-        int i = 0, evenLength = length & ~1;
-        while (i < evenLength) {
+        int i = offset, len = offset + (length & ~1);
+        while (i < len) {
             // reduce after 360 words (each word is two bytes)
-            for (int end = Math.min(i + 720, evenLength); i < end;) {
+            for (int end = Math.min(i + 720, len); i < end;) {
                 int x = ((bytes[i++] & 0xff) << 8) | (bytes[i++] & 0xff);
                 s2 += s1 += x;
             }
             s1 = (s1 & 0xffff) + (s1 >>> 16);
             s2 = (s2 & 0xffff) + (s2 >>> 16);
         }
-        if (i < length) {
+        if ((length & 1) != 0) {
             // odd length: append 0
             int x = (bytes[i] & 0xff) << 8;
             s2 += s1 += x;

h2/src/main/org/h2/mvstore/MVStore.java

@@ -818,7 +818,7 @@ public final class MVStore {
         }
         DataUtils.appendMap(buff, storeHeader);
         byte[] bytes = buff.toString().getBytes(StandardCharsets.ISO_8859_1);
-        int checksum = DataUtils.getFletcher32(bytes, bytes.length);
+        int checksum = DataUtils.getFletcher32(bytes, 0, bytes.length);
         DataUtils.appendMap(buff, "fletcher", checksum);
         buff.append("\n");
         bytes = buff.toString().getBytes(StandardCharsets.ISO_8859_1);

h2/src/test/org/h2/test/store/TestDataUtils.java

@@ -54,24 +54,24 @@ public class TestDataUtils extends TestBase {
     private void testFletcher() {
         byte[] data = new byte[10000];
         for (int i = 0; i < 10000; i += 1000) {
-            assertEquals(-1, DataUtils.getFletcher32(data, i));
+            assertEquals(-1, DataUtils.getFletcher32(data, 0, i));
         }
         Arrays.fill(data, (byte) 255);
         for (int i = 0; i < 10000; i += 1000) {
-            assertEquals(-1, DataUtils.getFletcher32(data, i));
+            assertEquals(-1, DataUtils.getFletcher32(data, 0, i));
         }
         for (int i = 0; i < 1000; i++) {
             for (int j = 0; j < 255; j++) {
                 Arrays.fill(data, 0, i, (byte) j);
                 data[i] = 0;
-                int a = DataUtils.getFletcher32(data, i);
+                int a = DataUtils.getFletcher32(data, 0, i);
                 if (i % 2 == 1) {
                     // add length: same as appending a 0
-                    int b = DataUtils.getFletcher32(data, i + 1);
+                    int b = DataUtils.getFletcher32(data, 0, i + 1);
                     assertEquals(a, b);
                 }
                 data[i] = 10;
-                int c = DataUtils.getFletcher32(data, i);
+                int c = DataUtils.getFletcher32(data, 0, i);
                 assertEquals(a, c);
             }
         }
@@ -79,16 +79,18 @@ public class TestDataUtils extends TestBase {
         for (int i = 1; i < 255; i++) {
             Arrays.fill(data, (byte) i);
             for (int j = 0; j < 10; j += 2) {
-                int x = DataUtils.getFletcher32(data, j);
+                int x = DataUtils.getFletcher32(data, 0, j);
                 assertTrue(x != last);
                 last = x;
             }
         }
         Arrays.fill(data, (byte) 10);
         assertEquals(0x1e1e1414,
-                DataUtils.getFletcher32(data, 10000));
+                DataUtils.getFletcher32(data, 0, 10000));
         assertEquals(0x1e3fa7ed,
-                DataUtils.getFletcher32("Fletcher32".getBytes(), 10));
+                DataUtils.getFletcher32("Fletcher32".getBytes(), 0, 10));
+        assertEquals(0x1e3fa7ed,
+                DataUtils.getFletcher32("XFletcher32".getBytes(), 1, 10));
     }
 
     private void testMap() {

h2/src/tools/org/h2/dev/fs/ArchiveToolStore.java

@@ -525,7 +525,7 @@ public class ArchiveToolStore {
         }
         key[0] = cs;
         key[1] = bucket;
-        key[2] = DataUtils.getFletcher32(buff, buff.length);
+        key[2] = DataUtils.getFletcher32(buff, 0, buff.length);
         return key;
     }