Convert between byte[] and String[] efficiently

compiler/tests/org/jetbrains/jet/descriptors/serialization/JavaProtoBufUtilTest.java

@@ -17,6 +17,7 @@
 package org.jetbrains.jet.descriptors.serialization;
 
 import com.intellij.testFramework.UsefulTestCase;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.Random;
 
@@ -25,29 +26,48 @@ import static org.jetbrains.jet.descriptors.serialization.JavaProtoBufUtil.encod
 import static org.junit.Assert.assertArrayEquals;
 
 public class JavaProtoBufUtilTest extends UsefulTestCase {
-    private static final int[] LENGTHS = new int[] {0, 1, 2, 3, 7, 10, 100, 1000, 32000, 33000, 65000, 65534, 65535, 65536, 65537,
-            100000, 131074, 239017, 314159, 1000000};
+    private static final int[] BIG_LENGTHS = new int[]
+            {1000, 32000, 33000, 65000, 65534, 65535, 65536, 65537, 100000, 131074, 239017, 314159, 1000000};
 
-    private static void doTest(int randSeed, int length) {
+    private static void doTest(int randSeed, int length) throws Exception {
         byte[] a = new byte[length];
         new Random(randSeed).nextBytes(a);
 
-        String message = "Failed randSeed = " + randSeed + ", length = " + length;
-
         String[] b = encodeBytes(a);
+        for (String string : b) {
+            assertStringConformsToJVMS(string);
+        }
+
         byte[] c = decodeBytes(b);
+        String message = "Failed randSeed = " + randSeed + ", length = " + length;
         assertArrayEquals(message, a, c);
 
         String[] d = encodeBytes(c);
-        assertArrayEquals(message, d, b);
+        assertArrayEquals(message, b, d);
 
         byte[] e = decodeBytes(d);
         assertArrayEquals(message, a, e);
+
     }
 
-    public void testEncodeDecode() {
-        for (int randSeed = 1; randSeed <= 3; randSeed++) {
-            for (int length : LENGTHS) {
+    private static void assertStringConformsToJVMS(@NotNull String string) {
+        int effectiveLength = string.length();
+        for (char c : string.toCharArray()) {
+            if (c == 0x0) effectiveLength++;
+        }
+        assertTrue(String.format("String exceeds maximum allowed length in a class file: %d > 65535", effectiveLength),
+                   effectiveLength <= 65535);
+    }
+
+    public void testEncodeDecode() throws Exception {
+        for (int length = 0; length <= 100; length++) {
+            for (int randSeed = 1; randSeed <= 100; randSeed++) {
+                doTest(randSeed, length);
+            }
+        }
+
+        for (int length : BIG_LENGTHS) {
+            for (int randSeed = 1; randSeed <= 3; randSeed++) {
                 doTest(randSeed, length);
             }
         }