Use wrapped gzipinputstream from twitter

2 files changed, 38 insertions, 2 deletions

diff --git a/src/io/StreamImpl.java b/src/io/StreamImpl.java
index b6be055..6d6ba64 100644
--- a/src/io/StreamImpl.java
+++ b/src/io/StreamImpl.java
@@ -11,7 +11,6 @@ import java.util.HashSet;
 import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
-import java.util.zip.GZIPInputStream;
 import mining.Stream;
 import org.apache.commons.io.Charsets;
 import org.apache.commons.lang.StringUtils;
@@ -20,6 +19,7 @@ import org.json.JSONObject;
 import org.json.JSONTokener;
 import provider.ExceptionListener;
 import provider.ResultListener;
+import support.StreamingGZIPInputStream;
 
 /**
  * Provides access to Twitter stream data. Data is processed in a separate
@@ -188,7 +188,7 @@ public class StreamImpl implements Stream {
          */
         private InputStream wrapGzip(InputStream is) throws IOException {
             if ("gzip".equals(connection.getContentEncoding())) {
-                return new GZIPInputStream(is);
+                return new StreamingGZIPInputStream(is);
             }
             return is;
         }
diff --git a/src/support/StreamingGZIPInputStream.java b/src/support/StreamingGZIPInputStream.java
new file mode 100644
index 0000000..036df5f
--- /dev/null
+++ b/src/support/StreamingGZIPInputStream.java
@@ -0,0 +1,36 @@
+package support;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.zip.GZIPInputStream;
+
+/**
+ * Implementation that immediately returns uncompressed data available from an
+ * input stream. Adapted from
+ * https://dev.twitter.com/docs/streaming-apis/processing.
+ */
+public class StreamingGZIPInputStream extends GZIPInputStream {
+
+    private final InputStream wrapped;
+
+    public StreamingGZIPInputStream(InputStream is) throws IOException {
+        super(is);
+        wrapped = is;
+    }
+
+    /**
+     * Overrides behavior of GZIPInputStream which assumes we have all the data
+     * available which is not true for streaming. We instead rely on the
+     * underlying stream to tell us how much data is available.
+     *
+     * Programs should not count on this method to return the actual number of
+     * bytes that could be read without blocking.
+     *
+     * @return whatever the wrapped InputStream returns.
+     * @exception IOException if an I/O error occurs.
+     */
+    @Override
+    public int available() throws IOException {
+        return wrapped.available();
+    }
+}