1 files changed, 62 insertions, 0 deletions
diff --git a/keystore/java/android/security/ArrayUtils.java b/keystore/java/android/security/ArrayUtils.java
new file mode 100644
index 0000000..2047d3f
--- /dev/null
+++ b/keystore/java/android/security/ArrayUtils.java
@@ -0,0 +1,62 @@
+package android.security;
+
+import libcore.util.EmptyArray;
+
+/**
+ * @hide
+ */
+abstract class ArrayUtils {
+    private ArrayUtils() {}
+
+    public static String[] nullToEmpty(String[] array) {
+        return (array != null) ? array : EmptyArray.STRING;
+    }
+
+    public static String[] cloneIfNotEmpty(String[] array) {
+        return ((array != null) && (array.length > 0)) ? array.clone() : array;
+    }
+
+    public static byte[] concat(byte[] arr1, byte[] arr2) {
+        return concat(arr1, 0, (arr1 != null) ? arr1.length : 0,
+                arr2, 0, (arr2 != null) ? arr2.length : 0);
+    }
+
+    public static byte[] concat(byte[] arr1, int offset1, int len1, byte[] arr2, int offset2,
+            int len2) {
+        if (len1 == 0) {
+            return subarray(arr2, offset2, len2);
+        } else if (len2 == 0) {
+            return subarray(arr1, offset1, len1);
+        } else {
+            byte[] result = new byte[len1 + len2];
+            System.arraycopy(arr1, offset1, result, 0, len1);
+            System.arraycopy(arr2, offset2, result, len1, len2);
+            return result;
+        }
+    }
+
+    public static byte[] subarray(byte[] arr, int offset, int len) {
+        if (len == 0) {
+            return EmptyArray.BYTE;
+        }
+        if ((offset == 0) && (len == arr.length)) {
+            return arr;
+        }
+        byte[] result = new byte[len];
+        System.arraycopy(arr, offset, result, 0, len);
+        return result;
+    }
+
+    public static int[] concat(int[] arr1, int[] arr2) {
+        if ((arr1 == null) || (arr1.length == 0)) {
+            return arr2;
+        } else if ((arr2 == null) || (arr2.length == 0)) {
+            return arr1;
+        } else {
+            int[] result = new int[arr1.length + arr2.length];
+            System.arraycopy(arr1, 0, result, 0, arr1.length);
+            System.arraycopy(arr2, 0, result, arr1.length, arr2.length);
+            return result;
+        }
+    }
+}