/*
* JBoss, Home of Professional Open Source.
* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed 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 io.undertow.server.handlers.resource;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.nio.ByteBuffer;
import java.nio.file.Path;
import java.util.Date;
import java.util.List;
import io.undertow.UndertowLogger;
import io.undertow.io.IoCallback;
import io.undertow.io.Sender;
import io.undertow.server.HttpServerExchange;
import io.undertow.server.handlers.cache.DirectBufferCache;
import io.undertow.server.handlers.cache.LimitedBufferSlicePool;
import io.undertow.server.handlers.cache.ResponseCachingSender;
import io.undertow.util.DateUtils;
import io.undertow.util.ETag;
import io.undertow.util.MimeMappings;
/**
* @author Stuart Douglas
*/
public class CachedResource implements Resource, RangeAwareResource {
private final CacheKey cacheKey;
private final CachingResourceManager cachingResourceManager;
private final Resource underlyingResource;
private final boolean directory;
private final Date lastModifiedDate;
private final String lastModifiedDateString;
private final ETag eTag;
private final String name;
private volatile long nextMaxAgeCheck;
public CachedResource(final CachingResourceManager cachingResourceManager, final Resource underlyingResource, final String path) {
this.cachingResourceManager = cachingResourceManager;
this.underlyingResource = underlyingResource;
this.directory = underlyingResource.isDirectory();
this.lastModifiedDate = underlyingResource.getLastModified();
if (lastModifiedDate != null) {
this.lastModifiedDateString = DateUtils.toDateString(lastModifiedDate);
} else {
this.lastModifiedDateString = null;
}
this.eTag = underlyingResource.getETag();
this.name = underlyingResource.getName();
this.cacheKey = new CacheKey(cachingResourceManager, underlyingResource.getCacheKey());
if (cachingResourceManager.getMaxAge() > 0) {
nextMaxAgeCheck = System.currentTimeMillis() + cachingResourceManager.getMaxAge();
} else {
nextMaxAgeCheck = -1;
}
}
@Override
public String getPath() {
return underlyingResource.getPath();
}
@Override
public Date getLastModified() {
return lastModifiedDate;
}
@Override
public String getLastModifiedString() {
return lastModifiedDateString;
}
@Override
public ETag getETag() {
return eTag;
}
@Override
public String getName() {
return name;
}
@Override
public boolean isDirectory() {
return directory;
}
@Override
public List<Resource> list() {
return underlyingResource.list();
}
@Override
public String getContentType(final MimeMappings mimeMappings) {
return underlyingResource.getContentType(mimeMappings);
}
public void invalidate() {
final DirectBufferCache dataCache = cachingResourceManager.getDataCache();
if(dataCache != null) {
dataCache.remove(cacheKey);
}
}
public boolean checkStillValid() {
if (nextMaxAgeCheck > 0) {
long time = System.currentTimeMillis();
if (time > nextMaxAgeCheck) {
nextMaxAgeCheck = time + cachingResourceManager.getMaxAge();
if (!underlyingResource.getLastModified().equals(lastModifiedDate)) {
return false;
}
}
}
return true;
}
@Override
public void serve(final Sender sender, final HttpServerExchange exchange, final IoCallback completionCallback) {
final DirectBufferCache dataCache = cachingResourceManager.getDataCache();
if(dataCache == null) {
underlyingResource.serve(sender, exchange, completionCallback);
return;
}
final DirectBufferCache.CacheEntry existing = dataCache.get(cacheKey);
final Long length = getContentLength();
//if it is not eligible to be served from the cache
if (length == null || length > cachingResourceManager.getMaxFileSize()) {
underlyingResource.serve(sender, exchange, completionCallback);
return;
}
//it is not cached yet, install a wrapper to grab the data
if (existing == null || !existing.enabled() || !existing.reference()) {
Sender newSender = sender;
final DirectBufferCache.CacheEntry entry;
if (existing == null) {
entry = dataCache.add(cacheKey, length.intValue(), cachingResourceManager.getMaxAge());
} else {
entry = existing;
}
if (entry != null && entry.buffers().length != 0 && entry.claimEnable()) {
if (entry.reference()) {
newSender = new ResponseCachingSender(sender, entry, length);
} else {
entry.disable();
}
}
underlyingResource.serve(newSender, exchange, completionCallback);
} else {
UndertowLogger.REQUEST_LOGGER.tracef("Serving resource %s from the buffer cache to %s", name, exchange);
//serve straight from the cache
ByteBuffer[] buffers;
boolean ok = false;
try {
LimitedBufferSlicePool.PooledByteBuffer[] pooled = existing.buffers();
buffers = new ByteBuffer[pooled.length];
for (int i = 0; i < buffers.length; i++) {
// Keep position from mutating
buffers[i] = pooled[i].getBuffer().duplicate();
}
ok = true;
} finally {
if (!ok) {
existing.dereference();
}
}
sender.send(buffers, new DereferenceCallback(existing, completionCallback));
}
}
@Override
public Long getContentLength() {
//we always use the underlying size unless the data is cached in the buffer cache
//to prevent a mis-match between size on disk and cached size
final DirectBufferCache dataCache = cachingResourceManager.getDataCache();
if(dataCache == null) {
return underlyingResource.getContentLength();
}
final DirectBufferCache.CacheEntry existing = dataCache.get(cacheKey);
if(existing == null || !existing.enabled()) {
return underlyingResource.getContentLength();
}
//we only return the
return (long)existing.size();
}
@Override
public String getCacheKey() {
return cacheKey.cacheKey;
}
@Override
public File getFile() {
return underlyingResource.getFile();
}
@Override
public Path getFilePath() {
return underlyingResource.getFilePath();
}
@Override
public File getResourceManagerRoot() {
return underlyingResource.getResourceManagerRoot();
}
@Override
public Path getResourceManagerRootPath() {
return underlyingResource.getResourceManagerRootPath();
}
@Override
public URL getUrl() {
return underlyingResource.getUrl();
}
@Override
public void serveRange(Sender sender, HttpServerExchange exchange, long start, long end, IoCallback completionCallback) {
final DirectBufferCache dataCache = cachingResourceManager.getDataCache();
if(dataCache == null) {
((RangeAwareResource)underlyingResource).serveRange(sender, exchange, start, end, completionCallback);
return;
}
final DirectBufferCache.CacheEntry existing = dataCache.get(cacheKey);
final Long length = getContentLength();
//if it is not eligible to be served from the cache
if (length == null || length > cachingResourceManager.getMaxFileSize()) {
underlyingResource.serve(sender, exchange, completionCallback);
return;
}
//it is not cached yet, just serve it directly
if (existing == null || !existing.enabled() || !existing.reference()) {
//it is not cached yet, install a wrapper to grab the data
((RangeAwareResource)underlyingResource).serveRange(sender, exchange, start, end, completionCallback);
} else {
//serve straight from the cache
ByteBuffer[] buffers;
boolean ok = false;
try {
LimitedBufferSlicePool.PooledByteBuffer[] pooled = existing.buffers();
buffers = new ByteBuffer[pooled.length];
for (int i = 0; i < buffers.length; i++) {
// Keep position from mutating
buffers[i] = pooled[i].getBuffer().duplicate();
}
ok = true;
} finally {
if (!ok) {
existing.dereference();
}
}
if(start > 0) {
long startDec = start;
long endCount = 0;
//handle the start of the range
for(ByteBuffer b : buffers) {
if(endCount == end) {
b.limit(b.position());
continue;
} else if(endCount + b.remaining() < end) {
endCount += b.remaining();
} else {
b.limit((int) (b.position() + (end - endCount)));
endCount = end;
}
if(b.remaining() >= startDec) {
startDec = 0;
b.position((int) (b.position() + startDec));
} else {
startDec -= b.remaining();
b.position(b.limit());
}
}
}
sender.send(buffers, new DereferenceCallback(existing, completionCallback));
}
}
@Override
public boolean isRangeSupported() {
//we can only handle range requests if the underlying resource supports it
//even if we have the resource in the cache it may disappear before we try and serve it
return underlyingResource instanceof RangeAwareResource && ((RangeAwareResource) underlyingResource).isRangeSupported();
}
private static class DereferenceCallback implements IoCallback {
private final DirectBufferCache.CacheEntry entry;
private final IoCallback callback;
DereferenceCallback(DirectBufferCache.CacheEntry entry, final IoCallback callback) {
this.entry = entry;
this.callback = callback;
}
@Override
public void onComplete(final HttpServerExchange exchange, final Sender sender) {
try {
entry.dereference();
} finally {
callback.onComplete(exchange, sender);
}
}
@Override
public void onException(final HttpServerExchange exchange, final Sender sender, final IOException exception) {
UndertowLogger.REQUEST_IO_LOGGER.ioException(exception);
try {
entry.dereference();
} finally {
callback.onException(exchange, sender, exception);
}
}
}
static final class CacheKey {
final CachingResourceManager manager;
final String cacheKey;
CacheKey(CachingResourceManager manager, String cacheKey) {
this.manager = manager;
this.cacheKey = cacheKey;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
CacheKey cacheKey1 = (CacheKey) o;
if (cacheKey != null ? !cacheKey.equals(cacheKey1.cacheKey) : cacheKey1.cacheKey != null) return false;
if (manager != null ? !manager.equals(cacheKey1.manager) : cacheKey1.manager != null) return false;
return true;
}
@Override
public int hashCode() {
int result = manager != null ? manager.hashCode() : 0;
result = 31 * result + (cacheKey != null ? cacheKey.hashCode() : 0);
return result;
}
}
}