ZOOKEEPER-1843. Oddity in ByteBufferInputStream skip (Bill Havanki via michim)

git-svn-id: https://svn.apache.org/repos/asf/zookeeper/trunk@1590298 13f79535-47bb-0310-9956-ffa450edef68

CHANGES.txt

@@ -626,6 +626,8 @@ BUGFIXES:
   ZOOKEEPER-1673. Zookeeper don't support cidr in expression in ACL with ip
   scheme (Craig Condit via michim)
 
+  ZOOKEEPER-1843. Oddity in ByteBufferInputStream skip (Bill Havanki via michim)
+
 IMPROVEMENTS:
 
   ZOOKEEPER-1170. Fix compiler (eclipse) warnings: unused imports,

src/java/main/org/apache/zookeeper/server/ByteBufferInputStream.java

@@ -64,10 +64,10 @@ public class ByteBufferInputStream extends InputStream {
 
     @Override
     public long skip(long n) throws IOException {
-        long newPos = bb.position() + n;
-        if (newPos > bb.remaining()) {
-            n = bb.remaining();
+        if (n < 0L) {
+            return 0;
         }
+        n = Math.min(n, bb.remaining());
         bb.position(bb.position() + (int) n);
         return n;
     }

src/java/test/org/apache/zookeeper/server/ByteBufferInputStreamTest.java

@@ -0,0 +1,143 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.zookeeper.server;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.util.Arrays;
+import org.apache.zookeeper.ZKTestCase;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class ByteBufferInputStreamTest extends ZKTestCase {
+    private static final byte[] DATA_BYTES_0 =
+        "Apache ZooKeeper".getBytes(Charset.forName("UTF-8"));
+
+    private static byte[] DATA_BYTES;
+    @BeforeClass public static void setUpClass() {
+        int len = DATA_BYTES_0.length + 2;
+        DATA_BYTES = new byte[len];
+        System.arraycopy(DATA_BYTES_0, 0, DATA_BYTES, 0, DATA_BYTES_0.length);
+        DATA_BYTES[len - 2] = (byte) 0x0;
+        DATA_BYTES[len - 1] = (byte) 0xff;
+    }
+
+    private ByteBuffer bb;
+    private ByteBufferInputStream in;
+    private byte[] bs;
+    @Before public void setUp() throws Exception {
+        bb = ByteBuffer.wrap(DATA_BYTES);
+        in = new ByteBufferInputStream(bb);
+        bs = new byte[] { (byte) 1, (byte) 2, (byte) 3, (byte) 4 };
+    }
+
+    @Test public void testRead() throws Exception {
+        for (int i = 0; i < DATA_BYTES.length; i++) {
+            int b = in.read();
+            assertEquals(DATA_BYTES[i], (byte) b);
+        }
+        assertEquals(-1, in.read());
+    }
+    @Test public void testReadArrayOffsetLength() throws Exception {
+        assertEquals(1, in.read(bs, 2, 1));
+        byte[] expected =
+            new byte[] { (byte) 1, (byte) 2, DATA_BYTES[0], (byte) 4 };
+        assertArrayEquals(expected, bs);
+    }
+    @Test(expected=IndexOutOfBoundsException.class)
+    public void testReadArrayOffsetLength_LengthTooLarge() throws Exception {
+        in.read(bs, 2, 3);
+    }
+    @Test public void testReadArrayOffsetLength_HitEndOfStream()
+        throws Exception {
+        for (int i = 0; i < DATA_BYTES.length - 1; i++) {
+            in.read();
+        }
+        assertEquals(1, in.read(bs, 2, 2));
+        byte[] expected =
+            new byte[] { (byte) 1, (byte) 2, DATA_BYTES[DATA_BYTES.length - 1],
+                (byte) 4 };
+        assertArrayEquals(expected, bs);
+    }
+    @Test public void testReadArrayOffsetLength_AtEndOfStream()
+        throws Exception {
+        for (int i = 0; i < DATA_BYTES.length; i++) {
+            in.read();
+        }
+        byte[] expected = Arrays.copyOf(bs, bs.length);
+        assertEquals(-1, in.read(bs, 2, 2));
+        assertArrayEquals(expected, bs);
+    }
+    @Test public void testReadArrayOffsetLength_0Length() throws Exception {
+        byte[] expected = Arrays.copyOf(bs, bs.length);
+        assertEquals(0, in.read(bs, 2, 0));
+        assertArrayEquals(expected, bs);
+    }
+    @Test public void testReadArray() throws Exception {
+        byte[] expected = Arrays.copyOf(DATA_BYTES, 4);
+        assertEquals(4, in.read(bs));
+        assertArrayEquals(expected, bs);
+    }
+
+    @Test public void testSkip() throws Exception {
+        in.read();
+        assertEquals(2L, in.skip(2L));
+        assertEquals(DATA_BYTES[3], in.read());
+        assertEquals(DATA_BYTES[4], in.read());
+    }
+    @Test public void testSkip2() throws Exception {
+        for (int i = 0; i < DATA_BYTES.length / 2; i++) {
+            in.read();
+        }
+        long skipAmount = DATA_BYTES.length / 4;
+        assertEquals(skipAmount, in.skip(skipAmount));
+        int idx = DATA_BYTES.length / 2 + (int) skipAmount;
+        assertEquals(DATA_BYTES[idx++], in.read());
+        assertEquals(DATA_BYTES[idx++], in.read());
+    }
+    @Test public void testNegativeSkip() throws Exception {
+        in.read();
+        assertEquals(0L, in.skip(-2L));
+        assertEquals(DATA_BYTES[1], in.read());
+        assertEquals(DATA_BYTES[2], in.read());
+    }
+    @Test public void testSkip_HitEnd() throws Exception {
+        for (int i = 0; i < DATA_BYTES.length  - 1; i++) {
+            in.read();
+        }
+        assertEquals(1L, in.skip(2L));
+        assertEquals(-1, in.read());
+    }
+    @Test public void testSkip_AtEnd() throws Exception {
+        for (int i = 0; i < DATA_BYTES.length; i++) {
+            in.read();
+        }
+        assertEquals(0L, in.skip(2L));
+        assertEquals(-1, in.read());
+    }
+
+    @Test public void testAvailable() throws Exception {
+        for (int i = DATA_BYTES.length; i > 0; i--) {
+            assertEquals(i, in.available());
+            in.read();
+        }
+        assertEquals(0, in.available());
+    }
+}