GIRAPH-1075: UnsafeByteArrayOutputStream silently writes long UTFs in…

…correctly

Summary: UnsafeByteArrayOutputStream.writeUTF was copied from DataOutputStream, but part which checks the length was missed out. When we try to write long strings they serialize without an issue, but when we try to deserialize them we get a wrong value back and don't read the same number of bytes. Make it fail like DataOutputStream instead.

Test Plan: Added a test

Differential Revision: https://reviews.facebook.net/D59817

giraph-core/src/main/java/org/apache/giraph/utils/UnsafeByteArrayOutputStream.java

@@ -19,6 +19,7 @@
 
 import java.io.IOException;
 import java.io.OutputStream;
+import java.io.UTFDataFormatException;
 import java.lang.reflect.Field;
 import java.util.Arrays;
 
@@ -289,6 +290,10 @@ public void writeUTF(String s) throws IOException {
       }
     }
 
+    if (utflen > 65535)
+      throw new UTFDataFormatException(
+          "encoded string too long: " + utflen + " bytes");
+
     ensureSize(utflen + SIZE_OF_SHORT);
     writeShort(utflen);
 

giraph-core/src/test/java/org/apache/giraph/utils/TestUnsafeByteArrayOutputStream.java

@@ -17,9 +17,11 @@
  */
 package org.apache.giraph.utils;
 
+import org.junit.Assert;
 import org.junit.Test;
 
 import java.io.IOException;
+import java.io.UTFDataFormatException;
 
 import static org.junit.Assert.assertEquals;
 
@@ -70,21 +72,42 @@ public void testWriteChars() throws IOException {
 
     @Test
     public void testWriteUTF() throws IOException {
-        UnsafeByteArrayOutputStream os = new UnsafeByteArrayOutputStream();
-        int length = os.getByteArray().length;
-
         StringBuilder sb = new StringBuilder();
-        for (int i = 0; i < length; i++) {
+        for (int i = 0; i < 20; i++) {
             sb.append("\u06ea");
         }
 
         String s = sb.toString();
-        os.writeUTF(s);
 
-        UnsafeByteArrayInputStream is = new UnsafeByteArrayInputStream(os.getByteArray());
+        assertEquals(s, writeAndReadUTF(s));
+    }
 
-        assertEquals(s, is.readUTF());
+    @Test
+    public void testWriteLongUTF() throws IOException {
+        int maxLength = 65535;
+        StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < maxLength; i++) {
+            sb.append("a");
+        }
 
+        String s = sb.toString();
+
+        assertEquals(s, writeAndReadUTF(s));
+
+        s = sb.append("a").toString();
+        try {
+            writeAndReadUTF(s);
+            throw new IllegalStateException("Exception expected");
+        } catch (Exception e) {
+            Assert.assertTrue(e instanceof UTFDataFormatException);
+        }
+    }
+
+    private String writeAndReadUTF(String s) throws IOException {
+        UnsafeByteArrayOutputStream os = new UnsafeByteArrayOutputStream();
+        os.writeUTF(s);
         os.close();
+        UnsafeByteArrayInputStream is = new UnsafeByteArrayInputStream(os.getByteArray());
+        return is.readUTF();
     }
 }