/**
* Copyright (c) 2012-2014, s3auth.com
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met: 1) Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer. 2) Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution. 3) Neither the name of the s3auth.com nor
* the names of its contributors may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.s3auth.hosts;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.model.ListVersionsRequest;
import com.amazonaws.services.s3.model.S3VersionSummary;
import com.amazonaws.services.s3.model.VersionListing;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableSet;
import com.jcabi.aspects.Immutable;
import com.jcabi.aspects.Loggable;
import com.jcabi.xml.XMLDocument;
import com.jcabi.xml.XSL;
import com.jcabi.xml.XSLDocument;
import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.util.Collection;
import java.util.Date;
import java.util.zip.CRC32;
import javax.validation.constraints.NotNull;
import javax.ws.rs.core.HttpHeaders;
import lombok.EqualsAndHashCode;
import lombok.ToString;
import org.apache.commons.io.Charsets;
import org.xembly.Directives;
import org.xembly.ImpossibleModificationException;
import org.xembly.Xembler;
/**
* XML S3 Object Version Listing.
* @author Carlos Miranda (miranda.cma@gmail.com)
* @version $Id$
*/
@Immutable
@ToString
@EqualsAndHashCode(of = "content")
@Loggable(Loggable.DEBUG)
final class ObjectVersionListing implements Resource {
/**
* The STYLESHEET used for transforming the output.
*/
private static final XSL STYLESHEET = XSLDocument.make(
ObjectVersionListing.class.getResourceAsStream("versions.xsl")
);
/**
* Byte representation of XML data.
*/
private final transient byte[] content;
/**
* Public constructor.
* @param client Amazon S3 client
* @param bucket Bucket name
* @param key The S3 object key
*/
ObjectVersionListing(@NotNull final AmazonS3 client,
@NotNull final String bucket, @NotNull final String key) {
VersionListing listing = client.listVersions(
new ListVersionsRequest().withPrefix(key).withBucketName(bucket)
);
final ImmutableList.Builder<S3VersionSummary> versions =
ImmutableList.builder();
versions.addAll(listing.getVersionSummaries());
while (listing.isTruncated()) {
listing = client.listNextBatchOfVersions(listing);
versions.addAll(listing.getVersionSummaries());
}
// @checkstyle LineLength (2 lines)
final Directives dirs = new Directives()
.add("versions").attr("object", key);
for (final S3VersionSummary version : versions.build()) {
dirs.add("version")
.attr("key", version.getKey())
.set(version.getVersionId()).up();
}
try {
this.content = ObjectVersionListing.STYLESHEET.transform(
new XMLDocument(new Xembler(dirs).xml())
).toString().getBytes(Charsets.UTF_8);
} catch (final ImpossibleModificationException ex) {
throw new IllegalStateException(
"Unable to generate version listing", ex
);
}
}
@Override
public int status() {
return HttpURLConnection.HTTP_OK;
}
@Override
public long writeTo(final OutputStream stream) throws IOException {
stream.write(this.content);
return (long) this.content.length;
}
@Override
public Collection<String> headers() throws IOException {
final ImmutableSet.Builder<String> headers = ImmutableSet.builder();
headers.add(
ObjectVersionListing.header(
HttpHeaders.CONTENT_TYPE,
this.contentType()
)
);
headers.add(
ObjectVersionListing.header(
HttpHeaders.CONTENT_LENGTH,
String.valueOf(this.content.length)
)
);
return headers.build();
}
@Override
public String etag() {
final CRC32 crc = new CRC32();
crc.update(this.content);
return Long.toHexString(crc.getValue());
}
@Override
public Date lastModified() {
return new Date();
}
@Override
public String contentType() {
return "application/xhtml+xml";
}
@Override
public void close() {
// nothing to do
}
/**
* Create a HTTP header from name and value.
* @param name Name of the header
* @param value The value
* @return Full HTTP header string
*/
@NotNull
private static String header(@NotNull final String name,
@NotNull final String value) {
return String.format("%s: %s", name, value);
}
}