update source to Ceph Pacific 16.2.2

[ceph.git] / ceph / src / rocksdb / java / src / main / java / org / rocksdb / util / ByteUtil.java

diff --git a/ceph/src/rocksdb/java/src/main/java/org/rocksdb/util/ByteUtil.java b/ceph/src/rocksdb/java/src/main/java/org/rocksdb/util/ByteUtil.java
new file mode 100644 (file)
index 0000000..9014fcb
--- /dev/null
+++ b/ceph/src/rocksdb/java/src/main/java/org/rocksdb/util/ByteUtil.java
@@ -0,0 +1,46 @@
+package org.rocksdb.util;
+
+import java.nio.ByteBuffer;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+public class ByteUtil {
+
+  /**
+   * Convert a String to a UTF-8 byte array.
+   *
+   * @param str the string
+   *
+   * @return the byte array.
+   */
+  public static byte[] bytes(final String str) {
+    return str.getBytes(UTF_8);
+  }
+
+  /**
+   * Compares the first {@code count} bytes of two areas of memory.  Returns
+   * zero if they are the same, a value less than zero if {@code x} is
+   * lexically less than {@code y}, or a value greater than zero if {@code x}
+   * is lexically greater than {@code y}.  Note that lexical order is determined
+   * as if comparing unsigned char arrays.
+   *
+   * Similar to <a href="https://github.com/gcc-mirror/gcc/blob/master/libiberty/memcmp.c">memcmp.c</a>.
+   *
+   * @param x the first value to compare with
+   * @param y the second value to compare against
+   * @param count the number of bytes to compare
+   *
+   * @return the result of the comparison
+   */
+  public static int memcmp(final ByteBuffer x, final ByteBuffer y,
+                            final int count) {
+    for (int idx = 0; idx < count; idx++) {
+      final int aa = x.get(idx) & 0xff;
+      final int bb = y.get(idx) & 0xff;
+      if (aa != bb) {
+        return aa - bb;
+      }
+    }
+    return 0;
+  }
+}