[#804] improvement: Optimize CRC calculation of ByteBuffer (#805)

### What changes were proposed in this pull request?
1. remove unnecessary methods
2. Optimize crc method

### Why are the changes needed?

Fix: #804

### Does this PR introduce _any_ user-facing change?
No.

### How was this patch tested?
New ut

common/src/main/java/org/apache/uniffle/common/util/ChecksumUtils.java

@@ -40,14 +40,20 @@ public static long getCrc32(byte[] buf, int offset, int length) {
     return crc32.getValue();
   }
 
-  // you may need to flip at first
   public static long getCrc32(ByteBuffer byteBuffer) {
-    if (byteBuffer.hasArray()) {
-      return getCrc32(byteBuffer.array(), byteBuffer.arrayOffset() + byteBuffer.position(), byteBuffer.remaining());
-    } else {
-      byte[] byteArray = new byte[byteBuffer.remaining()];
-      byteBuffer.get(byteArray);
-      return getCrc32(byteArray);
+    return getCrc32(byteBuffer, byteBuffer.position(), byteBuffer.limit() - byteBuffer.position());
+  }
+
+  public static long getCrc32(ByteBuffer byteBuffer, int offset, int length) {
+    CRC32 crc32 = new CRC32();
+    ByteBuffer crcBuffer = byteBuffer.duplicate();
+    crcBuffer.position(offset);
+    for (int i = 0; i < length; ) {
+      int len = Math.min(LENGTH_PER_CRC, length - i);
+      crcBuffer.limit(crcBuffer.position() + len);
+      crc32.update(crcBuffer);
+      i += len;
     }
+    return crc32.getValue();
   }
 }

common/src/test/java/org/apache/uniffle/common/util/ChecksumUtilsTest.java

@@ -76,7 +76,6 @@ public void crc32TestWithByteBuff() throws Exception {
     buffer.flip();
     long expectedChecksum = ChecksumUtils.getCrc32(data);
     assertEquals(expectedChecksum, ChecksumUtils.getCrc32(buffer));
-    assertEquals(length, buffer.position());
 
     // test heap ByteBuffer
     path = Paths.get(file.getAbsolutePath());
@@ -89,4 +88,29 @@ public void crc32TestWithByteBuff() throws Exception {
     assertEquals(expectedChecksum, ChecksumUtils.getCrc32(buffer));
 
   }
+
+  @Test
+  public void crc32ByteBufferTest() throws Exception {
+    int length = 32 * 1024 * 1024;
+    byte[] data = new byte[length];
+    Random random = new Random();
+    random.nextBytes(data);
+    long expectCrc = ChecksumUtils.getCrc32(data);
+    ByteBuffer originBuffer = ByteBuffer.allocateDirect(length);
+    originBuffer.put(data);
+    originBuffer.flip();
+    assertEquals(expectCrc, ChecksumUtils.getCrc32(ByteBuffer.wrap(data)));
+    ByteBuffer directBuffer = ByteBuffer.allocateDirect(length);
+    directBuffer.put(data);
+    directBuffer.flip();
+    assertEquals(expectCrc, ChecksumUtils.getCrc32(directBuffer));
+    assertEquals(originBuffer, directBuffer);
+    int offset = random.nextInt(15);
+    ByteBuffer directOffsetBuffer = ByteBuffer.allocateDirect(length + offset);
+    byte[] dataOffset = new byte[offset];
+    random.nextBytes(dataOffset);
+    directOffsetBuffer.put(dataOffset);
+    directOffsetBuffer.put(data);
+    assertEquals(expectCrc, ChecksumUtils.getCrc32(directOffsetBuffer, offset, length));
+  }
 }

storage/src/main/java/org/apache/uniffle/storage/handler/impl/HdfsFileWriter.java

@@ -21,7 +21,6 @@
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.nio.ByteBuffer;
-import java.util.List;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataOutputStream;
@@ -31,10 +30,8 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import org.apache.uniffle.common.util.ChecksumUtils;
 import org.apache.uniffle.storage.api.FileWriter;
 import org.apache.uniffle.storage.common.FileBasedShuffleSegment;
-import org.apache.uniffle.storage.util.ShuffleStorageUtils;
 
 public class HdfsFileWriter implements FileWriter, Closeable {
 
@@ -103,30 +100,6 @@ public void writeIndex(FileBasedShuffleSegment segment) throws IOException {
     fsDataOutputStream.writeLong(segment.getTaskAttemptId());
   }
 
-  // index file header is PartitionNum | [(PartitionId | PartitionFileLength | PartitionDataFileLength), ] | CRC
-  public void writeHeader(List<Integer> partitionList,
-      List<Long> indexFileSizeList,
-      List<Long> dataFileSizeList) throws IOException {
-    ByteBuffer headerContentBuf = ByteBuffer.allocate(
-        (int)ShuffleStorageUtils.getIndexFileHeaderLen(partitionList.size()) - ShuffleStorageUtils.getHeaderCrcLen());
-    fsDataOutputStream.writeInt(partitionList.size());
-    headerContentBuf.putInt(partitionList.size());
-    for (int i = 0; i < partitionList.size(); i++) {
-      fsDataOutputStream.writeInt(partitionList.get(i));
-      fsDataOutputStream.writeLong(indexFileSizeList.get(i));
-      fsDataOutputStream.writeLong(dataFileSizeList.get(i));
-      headerContentBuf.putInt(partitionList.get(i));
-      headerContentBuf.putLong(indexFileSizeList.get(i));
-      headerContentBuf.putLong(dataFileSizeList.get(i));
-    }
-    headerContentBuf.flip();
-    fsDataOutputStream.writeLong(ChecksumUtils.getCrc32(headerContentBuf));
-    long len = ShuffleStorageUtils.getIndexFileHeaderLen(partitionList.size());
-    if (fsDataOutputStream.getPos() != len) {
-      throw new IOException("Fail to write index header");
-    }
-  }
-
   public long nextOffset() {
     return nextOffset;
   }

storage/src/main/java/org/apache/uniffle/storage/util/ShuffleStorageUtils.java

@@ -56,15 +56,6 @@ public static String generateIndexFileName(String fileNamePrefix) {
     return fileNamePrefix + Constants.SHUFFLE_INDEX_FILE_SUFFIX;
   }
 
-  public static String generateAbsoluteFilePrefix(String base, String key, int partition, String id) {
-    return String.join(
-        HDFS_PATH_SEPARATOR,
-        base,
-        key,
-        String.join(HDFS_DIRNAME_SEPARATOR, String.valueOf(partition), String.valueOf(partition)),
-        id);
-  }
-
   public static List<DataFileSegment> mergeSegments(
       String path, List<FileBasedShuffleSegment> segments, int readBufferSize) {
     List<DataFileSegment> dataFileSegments = Lists.newArrayList();
@@ -207,10 +198,6 @@ public static long getIndexFileHeaderLen(int partitionNum) {
     return 4 + (4 + 8 + 8) * (long) partitionNum + 8;
   }
 
-  public static int getHeaderCrcLen() {
-    return 8;
-  }
-
   public static long uploadFile(File file, HdfsFileWriter writer, int bufferSize) throws IOException {
     try (FileInputStream inputStream = new FileInputStream(file)) {
       return writer.copy(inputStream, bufferSize);