提交 662dd1fb 编写于 作者: X xuelei

4918870: Examine session cache implementation (sun.misc.Cache)

Summary: replace sun.misc.Cache with sun.security.util.Cache
Reviewed-by: weijun
上级 17f33b79
/*
* Copyright 1999-2007 Sun Microsystems, Inc. All Rights Reserved.
* Copyright 1999-2009 Sun Microsystems, Inc. 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
......@@ -41,88 +41,112 @@ import javax.net.ssl.SSLSessionBindingEvent;
import javax.net.ssl.SSLPeerUnverifiedException;
import javax.net.ssl.SSLSession;
import sun.misc.Cache;
import sun.security.util.Cache;
final class SSLSessionContextImpl implements SSLSessionContext
{
private Cache sessionCache = new Cache();
private Cache sessionHostPortCache = new Cache();
private int cacheLimit;
private long timeoutMillis;
final class SSLSessionContextImpl implements SSLSessionContext {
private Cache sessionCache; // session cache, session id as key
private Cache sessionHostPortCache; // session cache, "host:port" as key
private int cacheLimit; // the max cache size
private int timeout; // timeout in seconds
private static final Debug debug = Debug.getInstance("ssl");
// file private
SSLSessionContextImpl()
{
cacheLimit = getCacheLimit();
timeoutMillis = 86400000; // default, 24 hours
// package private
SSLSessionContextImpl() {
cacheLimit = getDefaultCacheLimit(); // default cache size
timeout = 86400; // default, 24 hours
// use soft reference
sessionCache = Cache.newSoftMemoryCache(cacheLimit, timeout);
sessionHostPortCache = Cache.newSoftMemoryCache(cacheLimit, timeout);
}
/**
* Returns the SSL session object associated with the
* specific session ID passed.
* Returns the <code>SSLSession</code> bound to the specified session id.
*/
public SSLSession getSession(byte[] id)
{
SSLSession sess = (SSLSession) sessionCache.get(
new SessionId(id));
return checkTimeValidity(sess);
public SSLSession getSession(byte[] sessionId) {
if (sessionId == null) {
throw new NullPointerException("session id cannot be null");
}
SSLSessionImpl sess =
(SSLSessionImpl)sessionCache.get(new SessionId(sessionId));
if (!isTimedout(sess)) {
return sess;
}
return null;
}
/**
* Returns an enumeration of the active SSL sessions.
*/
public Enumeration<byte[]> getIds() {
Vector<byte[]> v = new Vector<byte[]>(sessionCache.size());
SessionId sessId;
SessionCacheVisitor scVisitor = new SessionCacheVisitor();
sessionCache.accept(scVisitor);
for (Enumeration e = sessionCache.keys(); e.hasMoreElements(); ) {
sessId = (SessionId) e.nextElement();
if (!isTimedout((SSLSession)sessionCache.get(sessId)))
v.addElement(sessId.getId());
}
return v.elements();
return scVisitor.getSessionIds();
}
/**
* Sets the timeout limit for cached <code>SSLSession</code> objects
*
* Note that after reset the timeout, the cached session before
* should be timed within the shorter one of the old timeout and the
* new timeout.
*/
public void setSessionTimeout(int seconds)
throws IllegalArgumentException {
if (seconds < 0)
if (seconds < 0) {
throw new IllegalArgumentException();
timeoutMillis = seconds * 1000L;
}
if (timeout != seconds) {
sessionCache.setTimeout(seconds);
sessionHostPortCache.setTimeout(seconds);
timeout = seconds;
}
}
/**
* Gets the timeout limit for cached <code>SSLSession</code> objects
*/
public int getSessionTimeout() {
return (int) (timeoutMillis / 1000);
return timeout;
}
/**
* Sets the size of the cache used for storing
* <code>SSLSession</code> objects.
*/
public void setSessionCacheSize(int size)
throws IllegalArgumentException {
if (size < 0)
throw new IllegalArgumentException();
cacheLimit = size;
/**
* If cache size limit is reduced, when the cache is full to its
* previous limit, trim the cache before its contents
* are used.
*/
if ((cacheLimit != 0) && (sessionCache.size() > cacheLimit))
adjustCacheSizeTo(cacheLimit);
if (cacheLimit != size) {
sessionCache.setCapacity(size);
sessionHostPortCache.setCapacity(size);
cacheLimit = size;
}
}
/**
* Gets the size of the cache used for storing
* <code>SSLSession</code> objects.
*/
public int getSessionCacheSize() {
return cacheLimit;
}
// package-private method, used ONLY by ServerHandshaker
SSLSessionImpl get(byte[] id) {
return (SSLSessionImpl) getSession(id);
return (SSLSessionImpl)getSession(id);
}
/**
* Returns the SSL session object associated with the
* specific host name and port number passed.
*/
// package-private method, used ONLY by ClientHandshaker
SSLSessionImpl get(String hostname, int port) {
/*
* If no session caching info is available, we won't
......@@ -131,96 +155,51 @@ final class SSLSessionContextImpl implements SSLSessionContext
if (hostname == null && port == -1) {
return null;
}
SSLSession sess = (SSLSessionImpl) sessionHostPortCache
.get(getKey(hostname, port));
return (SSLSessionImpl) checkTimeValidity(sess);
SSLSessionImpl sess =
(SSLSessionImpl)sessionHostPortCache.get(getKey(hostname, port));
if (!isTimedout(sess)) {
return sess;
}
return null;
}
private String getKey(String hostname, int port) {
return (hostname + ":" + String.valueOf(port))
.toLowerCase();
return (hostname + ":" + String.valueOf(port)).toLowerCase();
}
// cache a SSLSession
//
// In SunJSSE implementation, a session is created while getting a
// client hello or a server hello message, and cached while the
// handshaking finished.
// Here we time the session from the time it cached instead of the
// time it created, which is a little longer than the expected. So
// please do check isTimedout() while getting entry from the cache.
void put(SSLSessionImpl s) {
// make space for the new session to be added
if ((cacheLimit != 0) && (sessionCache.size() >= cacheLimit))
adjustCacheSizeTo(cacheLimit - 1);
/*
* Can always add the session id.
*/
sessionCache.put(s.getSessionId(), s);
/*
* If no hostname/port info is available, don't add this one.
*/
// If no hostname/port info is available, don't add this one.
if ((s.getPeerHost() != null) && (s.getPeerPort() != -1)) {
sessionHostPortCache.put(
getKey(s.getPeerHost(), s.getPeerPort()), s);
}
s.setContext(this);
}
private void adjustCacheSizeTo(int targetSize) {
int cacheSize = sessionCache.size();
if (targetSize < 0)
return;
while (cacheSize > targetSize) {
SSLSessionImpl lru = null;
SSLSessionImpl s = null;
Enumeration e;
if (debug != null && Debug.isOn("sessioncache")) {
System.out.println("exceeded cache limit of " + cacheLimit);
}
/*
* Count the number of elements in the cache. The size() method
* does not reflect the cache entries that are no longer available,
* i.e entries that are garbage collected (the cache entries are
* held using soft references and are garbage collected when not
* in use).
*/
int count;
for (count = 0, e = sessionCache.elements();
e.hasMoreElements(); count++) {
try {
s = (SSLSessionImpl)e.nextElement();
} catch (NoSuchElementException nsee) {
break;
}
if (isTimedout(s)) {
lru = s;
break;
} else if ((lru == null) || (s.getLastAccessedTime()
< lru.getLastAccessedTime())) {
lru = s;
}
}
if ((lru != null) && (count > targetSize)) {
if (debug != null && Debug.isOn("sessioncache")) {
System.out.println("uncaching " + lru);
}
lru.invalidate();
count--; // element removed from the cache
}
cacheSize = count;
// package-private method, remove a cached SSLSession
void remove(SessionId key) {
SSLSessionImpl s = (SSLSessionImpl)sessionCache.get(key);
if (s != null) {
sessionCache.remove(key);
sessionHostPortCache.remove(
getKey(s.getPeerHost(), s.getPeerPort()));
}
}
// file private
void remove(SessionId key)
{
SSLSessionImpl s = (SSLSessionImpl) sessionCache.get(key);
sessionCache.remove(key);
sessionHostPortCache.remove(getKey(s.getPeerHost(),
s.getPeerPort()));
}
private int getCacheLimit() {
private int getDefaultCacheLimit() {
int cacheLimit = 0;
try {
String s = java.security.AccessController.doPrivileged(
......@@ -237,21 +216,40 @@ final class SSLSessionContextImpl implements SSLSessionContext
return (cacheLimit > 0) ? cacheLimit : 0;
}
SSLSession checkTimeValidity(SSLSession sess) {
if (isTimedout(sess)) {
sess.invalidate();
return null;
} else
return sess;
}
boolean isTimedout(SSLSession sess) {
if (timeoutMillis == 0)
if (timeout == 0) {
return false;
if ((sess != null) &&
((sess.getCreationTime() + timeoutMillis)
<= (System.currentTimeMillis())))
}
if ((sess != null) && ((sess.getCreationTime() + timeout * 1000L)
<= (System.currentTimeMillis()))) {
sess.invalidate();
return true;
}
return false;
}
final class SessionCacheVisitor
implements sun.security.util.Cache.CacheVisitor {
Vector<byte[]> ids = null;
// public void visit(java.util.Map<Object, Object> map) {}
public void visit(java.util.Map<Object, Object> map) {
ids = new Vector<byte[]>(map.size());
for (Object key : map.keySet()) {
SSLSessionImpl value = (SSLSessionImpl)map.get(key);
if (!isTimedout(value)) {
ids.addElement(((SessionId)key).getId());
}
}
}
public Enumeration<byte[]> getSessionIds() {
return ids != null ? ids.elements() :
new Vector<byte[]>().elements();
}
}
}
/*
* Copyright 2002-2006 Sun Microsystems, Inc. All Rights Reserved.
* Copyright 2002-2009 Sun Microsystems, Inc. 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
......@@ -100,6 +100,21 @@ public abstract class Cache {
*/
public abstract void remove(Object key);
/**
* Set the maximum size.
*/
public abstract void setCapacity(int size);
/**
* Set the timeout(in seconds).
*/
public abstract void setTimeout(int timeout);
/**
* accept a visitor
*/
public abstract void accept(CacheVisitor visitor);
/**
* Return a new memory cache with the specified maximum size, unlimited
* lifetime for entries, with the values held by SoftReferences.
......@@ -178,6 +193,10 @@ public abstract class Cache {
}
}
public interface CacheVisitor {
public void visit(Map<Object, Object> map);
}
}
class NullCache extends Cache {
......@@ -208,6 +227,18 @@ class NullCache extends Cache {
// empty
}
public void setCapacity(int size) {
// empty
}
public void setTimeout(int timeout) {
// empty
}
public void accept(CacheVisitor visitor) {
// empty
}
}
class MemoryCache extends Cache {
......@@ -218,8 +249,8 @@ class MemoryCache extends Cache {
private final static boolean DEBUG = false;
private final Map<Object, CacheEntry> cacheMap;
private final int maxSize;
private final int lifetime;
private int maxSize;
private long lifetime;
private final ReferenceQueue queue;
public MemoryCache(boolean soft, int maxSize) {
......@@ -328,7 +359,7 @@ class MemoryCache extends Cache {
oldEntry.invalidate();
return;
}
if (cacheMap.size() > maxSize) {
if (maxSize > 0 && cacheMap.size() > maxSize) {
expungeExpiredEntries();
if (cacheMap.size() > maxSize) { // still too large?
Iterator<CacheEntry> t = cacheMap.values().iterator();
......@@ -368,6 +399,55 @@ class MemoryCache extends Cache {
}
}
public synchronized void setCapacity(int size) {
expungeExpiredEntries();
if (size > 0 && cacheMap.size() > size) {
Iterator<CacheEntry> t = cacheMap.values().iterator();
for (int i = cacheMap.size() - size; i > 0; i--) {
CacheEntry lruEntry = t.next();
if (DEBUG) {
System.out.println("** capacity reset removal "
+ lruEntry.getKey() + " | " + lruEntry.getValue());
}
t.remove();
lruEntry.invalidate();
}
}
maxSize = size > 0 ? size : 0;
if (DEBUG) {
System.out.println("** capacity reset to " + size);
}
}
public synchronized void setTimeout(int timeout) {
emptyQueue();
lifetime = timeout > 0 ? timeout * 1000L : 0L;
if (DEBUG) {
System.out.println("** lifetime reset to " + timeout);
}
}
// it is a heavyweight method.
public synchronized void accept(CacheVisitor visitor) {
expungeExpiredEntries();
Map<Object, Object> cached = getCachedEntries();
visitor.visit(cached);
}
private Map<Object, Object> getCachedEntries() {
Map<Object,Object> kvmap = new HashMap<Object,Object>(cacheMap.size());
for (CacheEntry entry : cacheMap.values()) {
kvmap.put(entry.getKey(), entry.getValue());
}
return kvmap;
}
protected CacheEntry newEntry(Object key, Object value,
long expirationTime, ReferenceQueue queue) {
if (queue != null) {
......
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