/**
* 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.hadoop.hdfs.server.datanode;
import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.URLEncoder;
import java.security.PrivilegedExceptionAction;
import java.util.Date;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspWriter;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FsShell;
import org.apache.hadoop.hdfs.DFSClient;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
import org.apache.hadoop.hdfs.protocol.DirectoryListing;
import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
import org.apache.hadoop.hdfs.protocol.LocatedBlock;
import org.apache.hadoop.hdfs.security.BlockAccessToken;
import org.apache.hadoop.hdfs.server.common.JspHelper;
import org.apache.hadoop.net.NetUtils;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.util.StringUtils;
@InterfaceAudience.Private
public class DatanodeJspHelper {
private static final DataNode datanode = DataNode.getDataNode();
private static DFSClient getDFSClient(final UserGroupInformation user,
final InetSocketAddress addr,
final Configuration conf
) throws IOException,
InterruptedException {
return
user.doAs(new PrivilegedExceptionAction<DFSClient>() {
public DFSClient run() throws IOException {
return new DFSClient(addr, conf);
}
});
}
/**
* Get the default chunk size.
* @param conf the configuration
* @return the number of bytes to chunk in
*/
private static int getDefaultChunkSize(Configuration conf) {
return conf.getInt("dfs.default.chunk.view.size", 32 * 1024);
}
static void generateDirectoryStructure(JspWriter out,
HttpServletRequest req,
HttpServletResponse resp,
Configuration conf
) throws IOException,
InterruptedException {
final String dir = JspHelper.validatePath(req.getParameter("dir"));
if (dir == null) {
out.print("Invalid input");
return;
}
String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
UserGroupInformation ugi = JspHelper.getUGI(req, conf);
String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
int namenodeInfoPort = -1;
if (namenodeInfoPortStr != null)
namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);
DFSClient dfs = getDFSClient(ugi, datanode.getNameNodeAddr(), conf);
String target = dir;
final HdfsFileStatus targetStatus = dfs.getFileInfo(target);
if (targetStatus == null) { // not exists
out.print("<h3>File or directory : " + target + " does not exist</h3>");
JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, target);
} else {
if (!targetStatus.isDir()) { // a file
List<LocatedBlock> blocks = dfs.getNamenode().getBlockLocations(dir, 0, 1)
.getLocatedBlocks();
LocatedBlock firstBlock = null;
DatanodeInfo[] locations = null;
if (blocks.size() > 0) {
firstBlock = blocks.get(0);
locations = firstBlock.getLocations();
}
if (locations == null || locations.length == 0) {
out.print("Empty file");
} else {
DatanodeInfo chosenNode = JspHelper.bestNode(firstBlock);
String fqdn = InetAddress.getByName(chosenNode.getHost())
.getCanonicalHostName();
String datanodeAddr = chosenNode.getName();
int datanodePort = Integer.parseInt(datanodeAddr.substring(
datanodeAddr.indexOf(':') + 1, datanodeAddr.length()));
String redirectLocation = "http://" + fqdn + ":"
+ chosenNode.getInfoPort() + "/browseBlock.jsp?blockId="
+ firstBlock.getBlock().getBlockId() + "&blockSize="
+ firstBlock.getBlock().getNumBytes() + "&genstamp="
+ firstBlock.getBlock().getGenerationStamp() + "&filename="
+ URLEncoder.encode(dir, "UTF-8") + "&datanodePort="
+ datanodePort + "&namenodeInfoPort=" + namenodeInfoPort
+ JspHelper.SET_DELEGATION + tokenString;
resp.sendRedirect(redirectLocation);
}
return;
}
// directory
// generate a table and dump the info
String[] headings = { "Name", "Type", "Size", "Replication",
"Block Size", "Modification Time", "Permission", "Owner", "Group" };
out.print("<h3>Contents of directory ");
JspHelper.printPathWithLinks(dir, out, namenodeInfoPort, tokenString);
out.print("</h3><hr>");
JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, dir);
out.print("<hr>");
File f = new File(dir);
String parent;
if ((parent = f.getParent()) != null)
out.print("<a href=\"" + req.getRequestURL() + "?dir=" + parent
+ "&namenodeInfoPort=" + namenodeInfoPort
+ JspHelper.SET_DELEGATION + tokenString
+ "\">Go to parent directory</a><br>");
DirectoryListing thisListing =
dfs.listPaths(target, HdfsFileStatus.EMPTY_NAME);
if (thisListing == null || thisListing.getPartialListing().length == 0) {
out.print("Empty directory");
} else {
JspHelper.addTableHeader(out);
int row = 0;
JspHelper.addTableRow(out, headings, row++);
String cols[] = new String[headings.length];
do {
HdfsFileStatus[] files = thisListing.getPartialListing();
for (int i = 0; i < files.length; i++) {
String localFileName = files[i].getLocalName();
// Get the location of the first block of the file
if (!files[i].isDir()) {
cols[1] = "file";
cols[2] = StringUtils.byteDesc(files[i].getLen());
cols[3] = Short.toString(files[i].getReplication());
cols[4] = StringUtils.byteDesc(files[i].getBlockSize());
} else {
cols[1] = "dir";
cols[2] = "";
cols[3] = "";
cols[4] = "";
}
String datanodeUrl = req.getRequestURL() + "?dir="
+ URLEncoder.encode(files[i].getFullName(target), "UTF-8")
+ "&namenodeInfoPort=" + namenodeInfoPort
+ JspHelper.SET_DELEGATION + tokenString;
cols[0] = "<a href=\"" + datanodeUrl + "\">"
+ localFileName + "</a>";
cols[5] = FsShell.dateForm.format(new Date((files[i]
.getModificationTime())));
cols[6] = files[i].getPermission().toString();
cols[7] = files[i].getOwner();
cols[8] = files[i].getGroup();
JspHelper.addTableRow(out, cols, row++);
}
if (!thisListing.hasMore()) {
break;
}
thisListing = dfs.listPaths(target, thisListing.getLastName());
} while (thisListing != null);
JspHelper.addTableFooter(out);
}
}
String namenodeHost = datanode.getNameNodeAddr().getHostName();
out.print("<br><a href=\"http://"
+ InetAddress.getByName(namenodeHost).getCanonicalHostName() + ":"
+ namenodeInfoPort + "/dfshealth.jsp\">Go back to DFS home</a>");
dfs.close();
}
static void generateFileDetails(JspWriter out,
HttpServletRequest req,
Configuration conf
) throws IOException,
InterruptedException {
long startOffset = 0;
int datanodePort;
final Long blockId = JspHelper.validateLong(req.getParameter("blockId"));
if (blockId == null) {
out.print("Invalid input (blockId absent)");
return;
}
String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
UserGroupInformation ugi = JspHelper.getUGI(req, conf);
String datanodePortStr = req.getParameter("datanodePort");
if (datanodePortStr == null) {
out.print("Invalid input (datanodePort absent)");
return;
}
datanodePort = Integer.parseInt(datanodePortStr);
String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
int namenodeInfoPort = -1;
if (namenodeInfoPortStr != null)
namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);
final int chunkSizeToView = JspHelper.string2ChunkSizeToView(
req.getParameter("chunkSizeToView"), getDefaultChunkSize(conf));
String startOffsetStr = req.getParameter("startOffset");
if (startOffsetStr == null || Long.parseLong(startOffsetStr) < 0)
startOffset = 0;
else
startOffset = Long.parseLong(startOffsetStr);
final String filename=JspHelper.validatePath(req.getParameter("filename"));
if (filename == null) {
out.print("Invalid input");
return;
}
String blockSizeStr = req.getParameter("blockSize");
long blockSize = 0;
if (blockSizeStr == null || blockSizeStr.length() == 0) {
out.print("Invalid input");
return;
}
blockSize = Long.parseLong(blockSizeStr);
final DFSClient dfs = getDFSClient(ugi, datanode.getNameNodeAddr(), conf);
List<LocatedBlock> blocks = dfs.getNamenode().getBlockLocations(filename, 0,
Long.MAX_VALUE).getLocatedBlocks();
// Add the various links for looking at the file contents
// URL for downloading the full file
String downloadUrl = "http://" + req.getServerName() + ":"
+ req.getServerPort() + "/streamFile?" + "filename="
+ URLEncoder.encode(filename, "UTF-8")
+ JspHelper.SET_DELEGATION + tokenString;
out.print("<a name=\"viewOptions\"></a>");
out.print("<a href=\"" + downloadUrl + "\">Download this file</a><br>");
DatanodeInfo chosenNode;
// URL for TAIL
LocatedBlock lastBlk = blocks.get(blocks.size() - 1);
try {
chosenNode = JspHelper.bestNode(lastBlk);
} catch (IOException e) {
out.print(e.toString());
dfs.close();
return;
}
String fqdn = InetAddress.getByName(chosenNode.getHost())
.getCanonicalHostName();
String tailUrl = "http://" + fqdn + ":" + chosenNode.getInfoPort()
+ "/tail.jsp?filename=" + URLEncoder.encode(filename, "UTF-8")
+ "&namenodeInfoPort=" + namenodeInfoPort
+ "&chunkSizeToView=" + chunkSizeToView
+ JspHelper.SET_DELEGATION + tokenString
+ "&referrer=" + URLEncoder.encode(
req.getRequestURL() + "?" + req.getQueryString(), "UTF-8");
out.print("<a href=\"" + tailUrl + "\">Tail this file</a><br>");
out.print("<form action=\"/browseBlock.jsp\" method=GET>");
out.print("<b>Chunk size to view (in bytes, up to file's DFS block size): </b>");
out.print("<input type=\"hidden\" name=\"blockId\" value=\"" + blockId
+ "\">");
out.print("<input type=\"hidden\" name=\"blockSize\" value=\"" + blockSize
+ "\">");
out.print("<input type=\"hidden\" name=\"startOffset\" value=\""
+ startOffset + "\">");
out.print("<input type=\"hidden\" name=\"filename\" value=\"" + filename
+ "\">");
out.print("<input type=\"hidden\" name=\"datanodePort\" value=\""
+ datanodePort + "\">");
out.print("<input type=\"hidden\" name=\"namenodeInfoPort\" value=\""
+ namenodeInfoPort + "\">");
out.print("<input type=\"text\" name=\"chunkSizeToView\" value="
+ chunkSizeToView + " size=10 maxlength=10>");
out.print(" <input type=\"submit\" name=\"submit\" value=\"Refresh\">");
out.print("</form>");
out.print("<hr>");
out.print("<a name=\"blockDetails\"></a>");
out.print("<B>Total number of blocks: " + blocks.size() + "</B><br>");
// generate a table and dump the info
out.println("\n<table>");
String namenodeHost = datanode.getNameNodeAddr().getHostName();
String namenodeHostName = InetAddress.getByName(namenodeHost).getCanonicalHostName();
for (LocatedBlock cur : blocks) {
out.print("<tr>");
final String blockidstring = Long.toString(cur.getBlock().getBlockId());
blockSize = cur.getBlock().getNumBytes();
out.print("<td>" + blockidstring + ":</td>");
DatanodeInfo[] locs = cur.getLocations();
for (int j = 0; j < locs.length; j++) {
String datanodeAddr = locs[j].getName();
datanodePort = Integer.parseInt(datanodeAddr.substring(datanodeAddr
.indexOf(':') + 1, datanodeAddr.length()));
fqdn = InetAddress.getByName(locs[j].getHost()).getCanonicalHostName();
String blockUrl = "http://" + fqdn + ":" + locs[j].getInfoPort()
+ "/browseBlock.jsp?blockId=" + blockidstring
+ "&blockSize=" + blockSize
+ "&filename=" + URLEncoder.encode(filename, "UTF-8")
+ "&datanodePort=" + datanodePort
+ "&genstamp=" + cur.getBlock().getGenerationStamp()
+ "&namenodeInfoPort=" + namenodeInfoPort
+ "&chunkSizeToView=" + chunkSizeToView
+ JspHelper.SET_DELEGATION + tokenString;
String blockInfoUrl = "http://" + namenodeHostName + ":"
+ namenodeInfoPort
+ "/block_info_xml.jsp?blockId=" + blockidstring;
out.print("<td> </td><td><a href=\"" + blockUrl + "\">"
+ datanodeAddr + "</a></td><td>"
+ "<a href=\"" + blockInfoUrl + "\">View Block Info</a></td>");
}
out.println("</tr>");
}
out.println("</table>");
out.print("<hr>");
out.print("<br><a href=\"http://"
+ InetAddress.getByName(namenodeHost).getCanonicalHostName() + ":"
+ namenodeInfoPort + "/dfshealth.jsp\">Go back to DFS home</a>");
dfs.close();
}
static void generateFileChunks(JspWriter out, HttpServletRequest req,
Configuration conf
) throws IOException,
InterruptedException {
long startOffset = 0;
int datanodePort = 0;
String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
UserGroupInformation ugi = JspHelper.getUGI(req, conf);
int namenodeInfoPort = -1;
if (namenodeInfoPortStr != null)
namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);
final String filename = JspHelper
.validatePath(req.getParameter("filename"));
if (filename == null) {
out.print("Invalid input (filename absent)");
return;
}
final Long blockId = JspHelper.validateLong(req.getParameter("blockId"));
if (blockId == null) {
out.print("Invalid input (blockId absent)");
return;
}
final DFSClient dfs = getDFSClient(ugi, datanode.getNameNodeAddr(), conf);
BlockAccessToken accessToken = BlockAccessToken.DUMMY_TOKEN;
if (conf.getBoolean(
DFSConfigKeys.DFS_BLOCK_ACCESS_TOKEN_ENABLE_KEY,
DFSConfigKeys.DFS_BLOCK_ACCESS_TOKEN_ENABLE_DEFAULT)) {
List<LocatedBlock> blks = dfs.getNamenode().getBlockLocations(filename, 0,
Long.MAX_VALUE).getLocatedBlocks();
if (blks == null || blks.size() == 0) {
out.print("Can't locate file blocks");
dfs.close();
return;
}
for (int i = 0; i < blks.size(); i++) {
if (blks.get(i).getBlock().getBlockId() == blockId) {
accessToken = blks.get(i).getAccessToken();
break;
}
}
}
final Long genStamp = JspHelper.validateLong(req.getParameter("genstamp"));
if (genStamp == null) {
out.print("Invalid input (genstamp absent)");
return;
}
String blockSizeStr;
long blockSize = 0;
blockSizeStr = req.getParameter("blockSize");
if (blockSizeStr == null) {
out.print("Invalid input (blockSize absent)");
return;
}
blockSize = Long.parseLong(blockSizeStr);
final int chunkSizeToView = JspHelper.string2ChunkSizeToView(req
.getParameter("chunkSizeToView"), getDefaultChunkSize(conf));
String startOffsetStr = req.getParameter("startOffset");
if (startOffsetStr == null || Long.parseLong(startOffsetStr) < 0)
startOffset = 0;
else
startOffset = Long.parseLong(startOffsetStr);
String datanodePortStr = req.getParameter("datanodePort");
if (datanodePortStr == null) {
out.print("Invalid input (datanodePort absent)");
return;
}
datanodePort = Integer.parseInt(datanodePortStr);
out.print("<h3>File: ");
JspHelper.printPathWithLinks(filename, out, namenodeInfoPort,
tokenString);
out.print("</h3><hr>");
String parent = new File(filename).getParent();
JspHelper.printGotoForm(out, namenodeInfoPort, tokenString, parent);
out.print("<hr>");
out.print("<a href=\"http://"
+ req.getServerName() + ":" + req.getServerPort()
+ "/browseDirectory.jsp?dir=" + URLEncoder.encode(parent, "UTF-8")
+ "&namenodeInfoPort=" + namenodeInfoPort
+ JspHelper.SET_DELEGATION + tokenString
+ "\"><i>Go back to dir listing</i></a><br>");
out.print("<a href=\"#viewOptions\">Advanced view/download options</a><br>");
out.print("<hr>");
// Determine the prev & next blocks
long nextStartOffset = 0;
long nextBlockSize = 0;
String nextBlockIdStr = null;
String nextGenStamp = null;
String nextHost = req.getServerName();
int nextPort = req.getServerPort();
int nextDatanodePort = datanodePort;
// determine data for the next link
if (startOffset + chunkSizeToView >= blockSize) {
// we have to go to the next block from this point onwards
List<LocatedBlock> blocks = dfs.getNamenode().getBlockLocations(filename, 0,
Long.MAX_VALUE).getLocatedBlocks();
for (int i = 0; i < blocks.size(); i++) {
if (blocks.get(i).getBlock().getBlockId() == blockId) {
if (i != blocks.size() - 1) {
LocatedBlock nextBlock = blocks.get(i + 1);
nextBlockIdStr = Long.toString(nextBlock.getBlock().getBlockId());
nextGenStamp = Long.toString(nextBlock.getBlock()
.getGenerationStamp());
nextStartOffset = 0;
nextBlockSize = nextBlock.getBlock().getNumBytes();
DatanodeInfo d = JspHelper.bestNode(nextBlock);
String datanodeAddr = d.getName();
nextDatanodePort = Integer.parseInt(datanodeAddr.substring(
datanodeAddr.indexOf(':') + 1, datanodeAddr.length()));
nextHost = InetAddress.getByName(d.getHost())
.getCanonicalHostName();
nextPort = d.getInfoPort();
}
}
}
} else {
// we are in the same block
nextBlockIdStr = blockId.toString();
nextStartOffset = startOffset + chunkSizeToView;
nextBlockSize = blockSize;
nextGenStamp = genStamp.toString();
}
String nextUrl = null;
if (nextBlockIdStr != null) {
nextUrl = "http://" + nextHost + ":" + nextPort
+ "/browseBlock.jsp?blockId=" + nextBlockIdStr
+ "&blockSize=" + nextBlockSize
+ "&startOffset=" + nextStartOffset
+ "&genstamp=" + nextGenStamp
+ "&filename=" + URLEncoder.encode(filename, "UTF-8")
+ "&chunkSizeToView=" + chunkSizeToView
+ "&datanodePort=" + nextDatanodePort
+ "&namenodeInfoPort=" + namenodeInfoPort
+ JspHelper.SET_DELEGATION + tokenString;
out.print("<a href=\"" + nextUrl + "\">View Next chunk</a> ");
}
// determine data for the prev link
String prevBlockIdStr = null;
String prevGenStamp = null;
long prevStartOffset = 0;
long prevBlockSize = 0;
String prevHost = req.getServerName();
int prevPort = req.getServerPort();
int prevDatanodePort = datanodePort;
if (startOffset == 0) {
List<LocatedBlock> blocks = dfs.getNamenode().getBlockLocations(filename, 0,
Long.MAX_VALUE).getLocatedBlocks();
for (int i = 0; i < blocks.size(); i++) {
if (blocks.get(i).getBlock().getBlockId() == blockId) {
if (i != 0) {
LocatedBlock prevBlock = blocks.get(i - 1);
prevBlockIdStr = Long.toString(prevBlock.getBlock().getBlockId());
prevGenStamp = Long.toString(prevBlock.getBlock()
.getGenerationStamp());
prevStartOffset = prevBlock.getBlock().getNumBytes()
- chunkSizeToView;
if (prevStartOffset < 0)
prevStartOffset = 0;
prevBlockSize = prevBlock.getBlock().getNumBytes();
DatanodeInfo d = JspHelper.bestNode(prevBlock);
String datanodeAddr = d.getName();
prevDatanodePort = Integer.parseInt(datanodeAddr.substring(
datanodeAddr.indexOf(':') + 1, datanodeAddr.length()));
prevHost = InetAddress.getByName(d.getHost())
.getCanonicalHostName();
prevPort = d.getInfoPort();
}
}
}
} else {
// we are in the same block
prevBlockIdStr = blockId.toString();
prevStartOffset = startOffset - chunkSizeToView;
if (prevStartOffset < 0)
prevStartOffset = 0;
prevBlockSize = blockSize;
prevGenStamp = genStamp.toString();
}
String prevUrl = null;
if (prevBlockIdStr != null) {
prevUrl = "http://" + prevHost + ":" + prevPort
+ "/browseBlock.jsp?blockId=" + prevBlockIdStr
+ "&blockSize=" + prevBlockSize
+ "&startOffset=" + prevStartOffset
+ "&filename=" + URLEncoder.encode(filename, "UTF-8")
+ "&chunkSizeToView=" + chunkSizeToView
+ "&genstamp=" + prevGenStamp
+ "&datanodePort=" + prevDatanodePort
+ "&namenodeInfoPort=" + namenodeInfoPort
+ JspHelper.SET_DELEGATION + tokenString;
out.print("<a href=\"" + prevUrl + "\">View Prev chunk</a> ");
}
out.print("<hr>");
out.print("<textarea cols=\"100\" rows=\"25\" wrap=\"virtual\" style=\"width:100%\" READONLY>");
try {
JspHelper.streamBlockInAscii(new InetSocketAddress(req.getServerName(),
datanodePort), blockId, accessToken, genStamp, blockSize,
startOffset, chunkSizeToView, out, conf);
} catch (Exception e) {
out.print(e);
}
out.print("</textarea>");
dfs.close();
}
static void generateFileChunksForTail(JspWriter out, HttpServletRequest req,
Configuration conf
) throws IOException,
InterruptedException {
final String referrer = JspHelper.validateURL(req.getParameter("referrer"));
boolean noLink = false;
if (referrer == null) {
noLink = true;
}
final String filename = JspHelper
.validatePath(req.getParameter("filename"));
if (filename == null) {
out.print("Invalid input (file name absent)");
return;
}
String tokenString = req.getParameter(JspHelper.DELEGATION_PARAMETER_NAME);
UserGroupInformation ugi = JspHelper.getUGI(req, conf);
String namenodeInfoPortStr = req.getParameter("namenodeInfoPort");
int namenodeInfoPort = -1;
if (namenodeInfoPortStr != null)
namenodeInfoPort = Integer.parseInt(namenodeInfoPortStr);
final int chunkSizeToView = JspHelper.string2ChunkSizeToView(req
.getParameter("chunkSizeToView"), getDefaultChunkSize(conf));
if (!noLink) {
out.print("<h3>Tail of File: ");
JspHelper.printPathWithLinks(filename, out, namenodeInfoPort,
tokenString);
out.print("</h3><hr>");
out.print("<a href=\"" + referrer + "\">Go Back to File View</a><hr>");
} else {
out.print("<h3>" + filename + "</h3>");
}
out.print("<b>Chunk size to view (in bytes, up to file's DFS block size): </b>");
out.print("<input type=\"text\" name=\"chunkSizeToView\" value="
+ chunkSizeToView + " size=10 maxlength=10>");
out.print(" <input type=\"submit\" name=\"submit\" value=\"Refresh\"><hr>");
out.print("<input type=\"hidden\" name=\"filename\" value=\"" + filename
+ "\">");
out.print("<input type=\"hidden\" name=\"namenodeInfoPort\" value=\""
+ namenodeInfoPort + "\">");
if (!noLink)
out.print("<input type=\"hidden\" name=\"referrer\" value=\"" + referrer
+ "\">");
// fetch the block from the datanode that has the last block for this file
final DFSClient dfs = getDFSClient(ugi, datanode.getNameNodeAddr(), conf);
List<LocatedBlock> blocks = dfs.getNamenode().getBlockLocations(filename, 0,
Long.MAX_VALUE).getLocatedBlocks();
if (blocks == null || blocks.size() == 0) {
out.print("No datanodes contain blocks of file " + filename);
dfs.close();
return;
}
LocatedBlock lastBlk = blocks.get(blocks.size() - 1);
long blockSize = lastBlk.getBlock().getNumBytes();
long blockId = lastBlk.getBlock().getBlockId();
BlockAccessToken accessToken = lastBlk.getAccessToken();
long genStamp = lastBlk.getBlock().getGenerationStamp();
DatanodeInfo chosenNode;
try {
chosenNode = JspHelper.bestNode(lastBlk);
} catch (IOException e) {
out.print(e.toString());
dfs.close();
return;
}
InetSocketAddress addr = NetUtils.createSocketAddr(chosenNode.getName());
// view the last chunkSizeToView bytes while Tailing
final long startOffset = blockSize >= chunkSizeToView ? blockSize
- chunkSizeToView : 0;
out.print("<textarea cols=\"100\" rows=\"25\" wrap=\"virtual\" style=\"width:100%\" READONLY>");
JspHelper.streamBlockInAscii(addr, blockId, accessToken, genStamp,
blockSize, startOffset, chunkSizeToView, out, conf);
out.print("</textarea>");
dfs.close();
}
}