Fix Incremental long crc32c (#1010)

apache · Jan 2, 2018 · 1358200 · 1358200
1 parent 87b9d4a
commit 1358200
Show file tree

Hide file tree

Showing 2 changed files with 25 additions and 4 deletions.
diff --git a/pulsar-checksum/src/main/java/com/scurrilous/circe/crc/ReflectedLongCrc.java b/pulsar-checksum/src/main/java/com/scurrilous/circe/crc/ReflectedLongCrc.java
@@ -35,9 +35,13 @@ final class ReflectedLongCrc extends AbstractLongCrc {
         }
     }
 
+    @Override
+    protected long initial() {
+        return reflect(super.initial());
+    }
+
     @Override
     protected long resumeRaw(long crc, byte[] input, int index, int length) {
-        crc = reflect(crc);
         for (int i = 0; i < length; ++i)
             crc = table[(int) (crc ^ input[index + i]) & 0xff] ^ (crc >>> 8);
         return crc;

diff --git a/pulsar-checksum/src/test/java/com/scurrilous/circe/crc/CRCTest.java b/pulsar-checksum/src/test/java/com/scurrilous/circe/crc/CRCTest.java
@@ -26,6 +26,7 @@
 import static com.scurrilous.circe.params.CrcParameters.CRC64_XZ;
 import static org.testng.Assert.assertEquals;
 
+import com.scurrilous.circe.IncrementalLongHash;
 import java.nio.charset.Charset;
 
 import org.testng.annotations.Test;
@@ -163,12 +164,12 @@ public void testCRC64_XZ() {
     }
 
     @Test
-    public void testCRC32CIncremental() {
+    public void testCRC32CIncrementalInt() {
         // reflected
-        testIncremental(PROVIDER.getIncrementalInt(CRC32C));
+        testIncrementalInt(PROVIDER.getIncrementalInt(CRC32C));
     }
 
-    private void testIncremental(IncrementalIntHash hash) {
+    private void testIncrementalInt(IncrementalIntHash hash) {
         final String data = "data";
         final String combined = data + data;
 
@@ -177,4 +178,20 @@ private void testIncremental(IncrementalIntHash hash) {
         final int incrementalChecksum = hash.resume(dataChecksum, data.getBytes(ASCII));
         assertEquals(combinedChecksum, incrementalChecksum);
     }
+
+    @Test
+    public void testCRC32CIncrementalLong() {
+        // reflected
+        testIncrementalLong(PROVIDER.getIncrementalLong(CRC32C));
+    }
+
+    private void testIncrementalLong(IncrementalLongHash hash) {
+        final String data = "data";
+        final String combined = data + data;
+
+        final long dataChecksum = hash.calculate(data.getBytes(ASCII));
+        final long combinedChecksum = hash.calculate(combined.getBytes(ASCII));
+        final long incrementalChecksum = hash.resume(dataChecksum, data.getBytes(ASCII));
+        assertEquals(combinedChecksum, incrementalChecksum);
+    }
 }