From 87d87b04e6eb6f42c8998d7ddfdf60767a6e04e1 Mon Sep 17 00:00:00 2001
From: Tsz-wo Sze <szetszwo@apache.org>
Date: Fri, 17 Aug 2012 01:42:35 +0000
Subject: [PATCH] HDFS-3788. ByteRangeInputStream should not expect HTTP
 Content-Length header when chunked transfer-encoding is used.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1374122 13f79535-47bb-0310-9956-ffa450edef68
---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt   |  3 +
 .../hadoop/hdfs/ByteRangeInputStream.java     | 69 ++++++++++++++-----
 2 files changed, 55 insertions(+), 17 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index ba0de405eb..95de3d3ab3 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -625,6 +625,9 @@ Branch-2 ( Unreleased changes )
     HDFS-3808. fuse_dfs: postpone libhdfs intialization until after fork.
     (Colin Patrick McCabe via atm)
 
+    HDFS-3788. ByteRangeInputStream should not expect HTTP Content-Length header
+    when chunked transfer-encoding is used.  (szetszwo)
+
   BREAKDOWN OF HDFS-3042 SUBTASKS
 
     HDFS-2185. HDFS portion of ZK-based FailoverController (todd)
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/ByteRangeInputStream.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/ByteRangeInputStream.java
index e745714c9b..6bc192f345 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/ByteRangeInputStream.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/ByteRangeInputStream.java
@@ -22,12 +22,15 @@
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 import java.net.URL;
+import java.util.List;
+import java.util.Map;
+import java.util.StringTokenizer;
 
 import org.apache.commons.io.input.BoundedInputStream;
 import org.apache.hadoop.fs.FSInputStream;
-import org.apache.hadoop.hdfs.server.namenode.StreamFile;
 
 import com.google.common.annotations.VisibleForTesting;
+import com.google.common.net.HttpHeaders;
 
 /**
  * To support HTTP byte streams, a new connection to an HTTP server needs to be
@@ -70,7 +73,7 @@ enum StreamStatus {
   protected URLOpener resolvedURL;
   protected long startPos = 0;
   protected long currentPos = 0;
-  protected long filelength;
+  protected Long fileLength = null;
 
   StreamStatus status = StreamStatus.SEEK;
 
@@ -114,28 +117,60 @@ protected InputStream openInputStream() throws IOException {
     final URLOpener opener = resolved? resolvedURL: originalURL;
 
     final HttpURLConnection connection = opener.connect(startPos, resolved);
-    final String cl = connection.getHeaderField(StreamFile.CONTENT_LENGTH);
-    if (cl == null) {
-      throw new IOException(StreamFile.CONTENT_LENGTH+" header is missing");
-    }
-    final long streamlength = Long.parseLong(cl);
-    filelength = startPos + streamlength;
-    // Java has a bug with >2GB request streams.  It won't bounds check
-    // the reads so the transfer blocks until the server times out
-    InputStream is =
-        new BoundedInputStream(connection.getInputStream(), streamlength);
-
     resolvedURL.setURL(getResolvedUrl(connection));
-    
-    return is;
+
+    InputStream in = connection.getInputStream();
+    final Map<String, List<String>> headers = connection.getHeaderFields();
+    if (isChunkedTransferEncoding(headers)) {
+      // file length is not known
+      fileLength = null;
+    } else {
+      // for non-chunked transfer-encoding, get content-length
+      final String cl = connection.getHeaderField(HttpHeaders.CONTENT_LENGTH);
+      if (cl == null) {
+        throw new IOException(HttpHeaders.CONTENT_LENGTH + " is missing: "
+            + headers);
+      }
+      final long streamlength = Long.parseLong(cl);
+      fileLength = startPos + streamlength;
+
+      // Java has a bug with >2GB request streams.  It won't bounds check
+      // the reads so the transfer blocks until the server times out
+      in = new BoundedInputStream(in, streamlength);
+    }
+
+    return in;
   }
   
+  private static boolean isChunkedTransferEncoding(
+      final Map<String, List<String>> headers) {
+    return contains(headers, HttpHeaders.TRANSFER_ENCODING, "chunked")
+        || contains(headers, HttpHeaders.TE, "chunked");
+  }
+
+  /** Does the HTTP header map contain the given key, value pair? */
+  private static boolean contains(final Map<String, List<String>> headers,
+      final String key, final String value) {
+    final List<String> values = headers.get(key);
+    if (values != null) {
+      for(String v : values) {
+        for(final StringTokenizer t = new StringTokenizer(v, ",");
+            t.hasMoreTokens(); ) {
+          if (value.equalsIgnoreCase(t.nextToken())) {
+            return true;
+          }
+        }
+      }
+    }
+    return false;
+  }
+
   private int update(final int n) throws IOException {
     if (n != -1) {
       currentPos += n;
-    } else if (currentPos < filelength) {
+    } else if (fileLength != null && currentPos < fileLength) {
       throw new IOException("Got EOF but currentPos = " + currentPos
-          + " < filelength = " + filelength);
+          + " < filelength = " + fileLength);
     }
     return n;
   }