Fix JDK bug for concatenated GZIP streams

src/main/java/io/airlift/compress/gzip/JdkGzipHadoopInputStream.java

@@ -15,10 +15,12 @@
 
 import io.airlift.compress.hadoop.HadoopInputStream;
 
+import java.io.BufferedInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.zip.GZIPInputStream;
 
+import static java.lang.Math.max;
 import static java.util.Objects.requireNonNull;
 
 class JdkGzipHadoopInputStream
@@ -30,7 +32,7 @@ class JdkGzipHadoopInputStream
     public JdkGzipHadoopInputStream(InputStream input, int bufferSize)
             throws IOException
     {
-        this.input = new GZIPInputStream(requireNonNull(input, "input is null"), bufferSize);
+        this.input = new GZIPInputStream(new GzipBufferedInputStream(input, bufferSize), bufferSize);
     }
 
     @Override
@@ -63,4 +65,22 @@ public void close()
     {
         input.close();
     }
+
+    // workaround for https://bugs.openjdk.org/browse/JDK-8081450
+    private static class GzipBufferedInputStream
+            extends BufferedInputStream
+    {
+        public GzipBufferedInputStream(InputStream input, int bufferSize)
+        {
+            super(requireNonNull(input, "input is null"), bufferSize);
+        }
+
+        @Override
+        public int available()
+                throws IOException
+        {
+            // GZIPInputStream thinks the stream is complete if this returns zero
+            return max(1, super.available());
+        }
+    }
 }

src/test/java/io/airlift/compress/gzip/TestJdkGzipHadoopInputStream.java

@@ -0,0 +1,53 @@
+/*
+ * Licensed 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 io.airlift.compress.gzip;
+
+import com.google.common.io.ByteStreams;
+import org.testng.annotations.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.SequenceInputStream;
+import java.util.zip.GZIPOutputStream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class TestJdkGzipHadoopInputStream
+{
+    @Test
+    public void testGzipInputStreamBug()
+            throws IOException
+    {
+        byte[] part1 = zip("hello ".getBytes());
+        byte[] part2 = zip("world".getBytes());
+
+        InputStream compressed = new SequenceInputStream(new ByteArrayInputStream(part1), new ByteArrayInputStream(part2));
+        byte[] data = ByteStreams.toByteArray(new JdkGzipHadoopStreams().createInputStream(compressed));
+
+        assertThat(data).isEqualTo("hello world".getBytes());
+    }
+
+    private static byte[] zip(byte[] data)
+            throws IOException
+    {
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        try (OutputStream gzipOut = new GZIPOutputStream(out)) {
+            gzipOut.write(data);
+        }
+        return out.toByteArray();
+    }
+}