/*
* Copyright 2010 Manuel Carrasco Moñino. (manolo at apache/org)
* http://code.google.com/p/gwtupload
*
* 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 gwtupload.server.gae;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.Serializable;
import java.io.UnsupportedEncodingException;
import java.util.Collections;
import java.util.HashMap;
import javax.cache.Cache;
import javax.cache.CacheManager;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileItemHeaders;
import com.google.appengine.api.memcache.stdimpl.GCacheFactory;
/**
* <p>
* This factory stores the data of FileItems in server's cache.
* </p>
*
* This class in useful in App-engine where writing to file-system is not supported.
* Cache has a limit of 1024KB per object, so this class stores long files in multiple
* cache records.
*
* Some time ago GAE had the limitation a request size is limited to 512 KB.
* It seems it has changed and now it is possible larger sizes.
*
* @author Manolo Carrasco Moñino
*
*/
public class MemCacheFileItemFactory implements FileItemFactory, Serializable {
/**
* An OutputStream that saves received data in memory.
*
* When the close method is called, it invokes the save method of the object
* which is using this.
*
*/
public static class CacheableByteArrayOutputStream extends OutputStream implements Serializable {
private static final long serialVersionUID = 1L;
Saveable<CacheableByteArrayOutputStream> saveable;
private byte[] buff;
private int read = 0;
private int size = 0;
public CacheableByteArrayOutputStream(Saveable<CacheableByteArrayOutputStream> object, int size) {
saveable = object;
buff = new byte[size];
}
@Override
public void close() throws IOException {
saveable.save(this);
}
public byte[] get() {
return buff;
}
public int read(byte[] ret) {
int i = 0;
for (; i < ret.length && read < size; i++, read++) {
ret[i] = buff[read];
}
return i;
}
public void reset() {
size = 0;
}
public int size() {
return size;
}
@Override
public void write(int b) throws IOException {
buff[size++] = (byte) b;
}
}
/**
* FileItem class which stores file data in cache.
*/
public class CacheableFileItem implements FileItem, Saveable<CacheableByteArrayOutputStream> {
private static final long serialVersionUID = 1L;
String ctype;
CacheableByteArrayOutputStream data = null;
String fname;
int rSize;
boolean formfield;
String name;
int size = 0;
public CacheableFileItem(String fieldName, String contentType, boolean isFormField, String fileName, int requestSize) {
ctype = contentType;
fname = fieldName;
name = fileName;
formfield = isFormField;
rSize = requestSize;
data = new CacheableByteArrayOutputStream(this, rSize);
}
public void delete() {
if (data != null) {
data.reset();
} else {
try {
Cache cache = CacheManager.getInstance().getCacheFactory().createCache(Collections.emptyMap());
String key = fname;
while (cache.remove(key) != null) {
key += "X";
}
} catch (Exception e) { }
data = new CacheableByteArrayOutputStream(this, rSize);
}
}
public byte[] get() {
return getData();
}
public String getContentType() {
return ctype;
}
public String getFieldName() {
return fname;
}
public InputStream getInputStream() throws IOException {
return new MemCacheInputStream(fname);
}
public String getName() {
return name;
}
public OutputStream getOutputStream() throws IOException {
return data;
}
public long getSize() {
return size;
}
public String getString() {
return getData().toString();
}
public String getString(String arg0) throws UnsupportedEncodingException {
return new String(get(), arg0);
}
public boolean isFormField() {
return formfield;
}
public boolean isInMemory() {
return data != null;
}
@SuppressWarnings({ "unchecked", "serial" })
public void save(CacheableByteArrayOutputStream o) {
if (data != null) {
try {
Cache cache = CacheManager.getInstance().getCacheFactory().createCache(new HashMap() { {
put(GCacheFactory.EXPIRATION_DELTA, 3600);
}});
size = data.size();
int storedBytes = 0;
String sufix = "";
while(storedBytes < size) {
byte[] buff = new byte[Math.min(MEMCACHE_LIMIT, size - storedBytes)];
storedBytes += data.read(buff);
cache.put(fname + sufix, buff);
sufix += "X";
}
data = null;
} catch (Exception e) {
e.printStackTrace();
}
}
}
public void setFieldName(String arg0) {
fname = arg0;
}
public void setFormField(boolean arg0) {
formfield = arg0;
}
public void write(File arg0) throws Exception {
throw new UnsupportedOperationException(this.getClass().getName() + " doesn't support write to files");
}
private byte[] getData() {
if (data == null) {
try {
Cache cache = CacheManager.getInstance().getCacheFactory().createCache(Collections.emptyMap());
int pos = 0;
byte[] pData = new byte[size];
byte[] cacheBuf = null;
String suffix = "";
while ((cacheBuf = (byte[]) cache.get(fname + suffix)) != null) {
System.arraycopy(cacheBuf, 0, pData, pos, cacheBuf.length);
pos += cacheBuf.length;
suffix += "X";
}
return pData;
} catch (Exception e) {
e.printStackTrace();
return null;
}
} else {
return data.get();
}
}
public FileItemHeaders getHeaders() {
return null;
}
public void setHeaders(FileItemHeaders headers) {
}
}
/**
*/
public class MemCacheInputStream extends InputStream {
ByteArrayInputStream is;
String key;
private Cache cache = null;
public MemCacheInputStream(String key) {
this.key = key;
try {
cache = CacheManager.getInstance().getCacheFactory().createCache(Collections.emptyMap());
} catch (Exception e) {
}
}
public int read() throws IOException {
if (is == null || is.available() <= 0) {
try {
byte[] data = (byte[]) cache.get(key);
if (data != null) {
is = new ByteArrayInputStream(data);
key += "X";
}
} catch (Exception e) {
}
}
if (is != null) {
return is.read();
}
return -1;
}
}
/**
* Interface for objects that has can be saved.
*
* @param <T>
*/
public interface Saveable<T> {
void save(T o);
}
// Max request size in App-engine
public static final int DEFAULT_REQUEST_SIZE = 3 * 1024 * 1024 - 1024;
static final int MEMCACHE_LIMIT = 1023 * 1024;
private static final long serialVersionUID = 1L;
private int requestSize = 0;
public MemCacheFileItemFactory() {
this(DEFAULT_REQUEST_SIZE);
}
public MemCacheFileItemFactory(int requestSize) {
this.requestSize = requestSize;
}
public FileItem createItem(String fieldName, String contentType, boolean isFormField, String fileName) {
return new CacheableFileItem(fieldName, contentType, isFormField, fileName, requestSize);
}
}