/*
* Copyright (c) 2004, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.jvmstat.perfdata.monitor.protocol.local;
import java.io.File;
import java.io.FilenameFilter;
import jdk.internal.vm.VMSupport;
/**
* Class to provide translations from the local Vm Identifier
* name space into the file system name space and vice-versa.
* <p>
* Provides a factory for creating a File object to the backing
* store file for instrumentation shared memory region for a JVM
* identified by its Local Java Virtual Machine Identifier, or
* <em>lvmid</em>.
*
* @author Brian Doherty
* @since 1.5
* @see java.io.File
*/
public class PerfDataFile {
private PerfDataFile() { };
/**
* The name of the of the system dependent temporary directory
*/
public static final String tmpDirName;
/**
* The file name prefix for PerfData shared memory files.
* <p>
* This prefix must be kept in sync with the prefix used by the JVM.
*/
public static final String dirNamePrefix = "hsperfdata_";
/**
* The directory name pattern for the user directories.
*/
public static final String userDirNamePattern = "hsperfdata_\\S*";
/**
* The file name pattern for PerfData shared memory files.
* <p>
* This pattern must be kept in synch with the file name pattern
* used by the 1.4.2 and later HotSpot JVM.
*/
public static final String fileNamePattern = "^[0-9]+$";
/**
* The file name pattern for 1.4.1 PerfData shared memory files.
* <p>
* This pattern must be kept in synch with the file name pattern
* used by the 1.4.1 HotSpot JVM.
*/
public static final String tmpFileNamePattern =
"^hsperfdata_[0-9]+(_[1-2]+)?$";
/**
* Get a File object for the instrumentation backing store file
* for the JVM identified by the given local Vm Identifier.
* <p>
* This method looks for the most up to date backing store file for
* the given {@code lvmid}. It will search all the user specific
* directories in the temporary directory for the host operating
* system, which may be influenced by platform specific environment
* variables.
*
* @param lvmid the local Java Virtual Machine Identifier for the target
* @return File - a File object to the backing store file for the named
* shared memory region of the target JVM.
* @see java.io.File
* @see #getTempDirectory()
*/
public static File getFile(int lvmid) {
if (lvmid == 0) {
/*
* lvmid == 0 is used to indicate the current Java Virtual Machine.
* If the SDK provided an API to get a unique Java Virtual Machine
* identifier, then a filename could be constructed with that
* identifier. In absence of such an api, return null.
*/
return null;
}
/*
* iterate over all files in all directories in tmpDirName that
* match the file name patterns.
*/
File tmpDir = new File(tmpDirName);
String[] files = tmpDir.list(new FilenameFilter() {
public boolean accept(File dir, String name) {
if (!name.startsWith(dirNamePrefix)) {
return false;
}
File candidate = new File(dir, name);
return ((candidate.isDirectory() || candidate.isFile())
&& candidate.canRead());
}
});
long newestTime = 0;
File newest = null;
for (int i = 0; i < files.length; i++) {
File f = new File(tmpDirName + files[i]);
File candidate = null;
if (f.exists() && f.isDirectory()) {
/*
* found a directory matching the name patterns. This
* is a 1.4.2 hsperfdata_<user> directory. Check for
* file named <lvmid> in that directory
*/
String name = Integer.toString(lvmid);
candidate = new File(f.getName(), name);
} else if (f.exists() && f.isFile()) {
/*
* found a file matching the name patterns. This
* is a 1.4.1 hsperfdata_<lvmid> file.
*/
candidate = f;
} else {
// unexpected - let conditional below filter this one out
candidate = f;
}
if (candidate.exists() && candidate.isFile()
&& candidate.canRead()) {
long modTime = candidate.lastModified();
if (modTime >= newestTime) {
newestTime = modTime;
newest = candidate;
}
}
}
return newest;
}
/**
* Return the File object for the backing store file for the specified Java
* Virtual Machine.
* <p>
* This method looks for the most up to date backing store file for
* the JVM identified by the given user name and lvmid. The directory
* searched is the temporary directory for the host operating system,
* which may be influenced by environment variables.
*
* @param user the user name
* @param lvmid the local Java Virtual Machine Identifier for the target
* @return File - a File object to the backing store file for the named
* shared memory region of the target JVM.
* @see java.io.File
* @see #getTempDirectory()
*/
public static File getFile(String user, int lvmid) {
if (lvmid == 0) {
/*
* lvmid == 0 is used to indicate the current Java Virtual Machine.
* If the SDK provided an API to get a unique Java Virtual Machine
* identifier, then a filename could be constructed with that
* identifier. In absence of such an api, return null.
*/
return null;
}
// first try for 1.4.2 and later JVMs
String basename = getTempDirectory(user) + Integer.toString(lvmid);
File f = new File(basename);
if (f.exists() && f.isFile() && f.canRead()) {
return f;
}
// No hit on 1.4.2 JVMs, try 1.4.1 files
long newestTime = 0;
File newest = null;
for (int i = 0; i < 2; i++) {
if (i == 0) {
basename = getTempDirectory() + Integer.toString(lvmid);
} else {
basename = getTempDirectory() + Integer.toString(lvmid)
+ Integer.toString(i);
}
f = new File(basename);
if (f.exists() && f.isFile() && f.canRead()) {
long modTime = f.lastModified();
if (modTime >= newestTime) {
newestTime = modTime;
newest = f;
}
}
}
return newest;
}
/**
* Method to extract a local Java Virtual Machine Identifier from the
* file name of the given File object.
*
* @param file A File object representing the name of a
* shared memory region for a target JVM
* @return int - the local Java Virtual Machine Identifier for the target
* associated with the file
* @throws java.lang.IllegalArgumentException Thrown if the file name
* does not conform to the expected pattern
*/
public static int getLocalVmId(File file) {
try {
// try 1.4.2 and later format first
return Integer.parseInt(file.getName());
} catch (NumberFormatException e) { }
// now try the 1.4.1 format
String name = file.getName();
if (name.startsWith(dirNamePrefix)) {
int first = name.indexOf('_');
int last = name.lastIndexOf('_');
try {
if (first == last) {
return Integer.parseInt(name.substring(first + 1));
} else {
return Integer.parseInt(name.substring(first + 1, last));
}
} catch (NumberFormatException e) { }
}
throw new IllegalArgumentException("file name does not match pattern");
}
/**
* Return the name of the temporary directory being searched for
* HotSpot PerfData backing store files.
* <p>
* This method generally returns the value of the java.io.tmpdir
* property. However, on some platforms it may return a different
* directory, as the JVM implementation may store the PerfData backing
* store files in a different directory for performance reasons.
*
* @return String - the name of the temporary directory.
*/
public static String getTempDirectory() {
return tmpDirName;
}
/**
* Return the name of the temporary directory to be searched
* for HotSpot PerfData backing store files for a given user.
* <p>
* This method generally returns the name of a subdirectory of
* the directory indicated in the java.io.tmpdir property. However,
* on some platforms it may return a different directory, as the
* JVM implementation may store the PerfData backing store files
* in a different directory for performance reasons.
*
* @return String - the name of the temporary directory.
*/
public static String getTempDirectory(String user) {
return tmpDirName + dirNamePrefix + user + File.separator;
}
static {
/*
* For this to work, the target VM and this code need to use
* the same directory. Instead of guessing which directory the
* VM is using, we will ask.
*/
String tmpdir = VMSupport.getVMTemporaryDirectory();
/*
* Assure that the string returned has a trailing File.separator
* character. This check was added because the Linux implementation
* changed such that the java.io.tmpdir string no longer terminates
* with a File.separator character.
*/
if (tmpdir.lastIndexOf(File.separator) != (tmpdir.length()-1)) {
tmpdir = tmpdir + File.separator;
}
tmpDirName = tmpdir;
}
}