/*
* ====================================================================
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
*/
package org.apache.hc.client5.http.cache;
import java.io.Serializable;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import org.apache.hc.client5.http.utils.DateUtils;
import org.apache.hc.core5.annotation.Contract;
import org.apache.hc.core5.annotation.ThreadingBehavior;
import org.apache.hc.core5.http.Header;
import org.apache.hc.core5.http.HttpHeaders;
import org.apache.hc.core5.http.HttpStatus;
import org.apache.hc.core5.http.MessageHeaders;
import org.apache.hc.core5.http.ProtocolException;
import org.apache.hc.core5.http.message.HeaderGroup;
import org.apache.hc.core5.util.Args;
/**
* Structure used to store an {@link org.apache.hc.core5.http.HttpResponse} in a cache.
* Some entries can optionally depend on system resources that may require
* explicit deallocation. In such a case {@link #getResource()} should return
* a non null instance of {@link Resource} that must be deallocated by calling
* {@link Resource#dispose()} method when no longer used.
*
* @since 4.1
*/
@Contract(threading = ThreadingBehavior.IMMUTABLE)
public class HttpCacheEntry implements MessageHeaders, Serializable {
private static final long serialVersionUID = -6300496422359477413L;
private static final String REQUEST_METHOD_HEADER_NAME = "Hc-Request-Method";
private final Date requestDate;
private final Date responseDate;
private final int status;
private final HeaderGroup responseHeaders;
private final Resource resource;
private final Map<String,String> variantMap;
private final Date date;
/**
* Create a new {@link HttpCacheEntry} with variants.
* @param requestDate
* Date/time when the request was made (Used for age
* calculations)
* @param responseDate
* Date/time that the response came back (Used for age
* calculations)
* @param status
* HTTP status from origin response
* @param responseHeaders
* Header[] from original HTTP Response
* @param resource representing origin response body
* @param variantMap describing cache entries that are variants
* of this parent entry; this maps a "variant key" (derived
* from the varying request headers) to a "cache key" (where
* in the cache storage the particular variant is located)
*/
public HttpCacheEntry(
final Date requestDate,
final Date responseDate,
final int status,
final Header[] responseHeaders,
final Resource resource,
final Map<String,String> variantMap) {
super();
Args.notNull(requestDate, "Request date");
Args.notNull(responseDate, "Response date");
Args.check(status >= HttpStatus.SC_SUCCESS, "Status code");
Args.notNull(responseHeaders, "Response headers");
this.requestDate = requestDate;
this.responseDate = responseDate;
this.status = status;
this.responseHeaders = new HeaderGroup();
this.responseHeaders.setHeaders(responseHeaders);
this.resource = resource;
this.variantMap = variantMap != null ? new HashMap<>(variantMap) : null;
this.date = parseDate();
}
/**
* Create a new {@link HttpCacheEntry}.
*
* @param requestDate
* Date/time when the request was made (Used for age
* calculations)
* @param responseDate
* Date/time that the response came back (Used for age
* calculations)
* @param status
* HTTP status from origin response
* @param responseHeaders
* Header[] from original HTTP Response
* @param resource representing origin response body
*/
public HttpCacheEntry(final Date requestDate, final Date responseDate, final int status,
final Header[] responseHeaders, final Resource resource) {
this(requestDate, responseDate, status, responseHeaders, resource, new HashMap<String,String>());
}
/**
* Find the "Date" response header and parse it into a java.util.Date
* @return the Date value of the header or null if the header is not present
*/
private Date parseDate() {
final Header dateHdr = getFirstHeader(HttpHeaders.DATE);
if (dateHdr == null) {
return null;
}
return DateUtils.parseDate(dateHdr.getValue());
}
/**
* Returns the status from the origin {@link org.apache.hc.core5.http.HttpResponse}.
*/
public int getStatus() {
return this.status;
}
/**
* Returns the time the associated origin request was initiated by the
* caching module.
* @return {@link Date}
*/
public Date getRequestDate() {
return requestDate;
}
/**
* Returns the time the origin response was received by the caching module.
* @return {@link Date}
*/
public Date getResponseDate() {
return responseDate;
}
/**
* Returns all the headers that were on the origin response.
*/
@Override
public Header[] getAllHeaders() {
final HeaderGroup filteredHeaders = new HeaderGroup();
for (final Iterator<Header> iterator = responseHeaders.headerIterator(); iterator.hasNext();) {
final Header header = iterator.next();
if (!REQUEST_METHOD_HEADER_NAME.equals(header.getName())) {
filteredHeaders.addHeader(header);
}
}
return filteredHeaders.getAllHeaders();
}
/**
* Returns the first header from the origin response with the given
* name.
*/
@Override
public Header getFirstHeader(final String name) {
if (REQUEST_METHOD_HEADER_NAME.equalsIgnoreCase(name)) {
return null;
}
return responseHeaders.getFirstHeader(name);
}
/**
* @since 5.0
*/
@Override
public Header getLastHeader(final String name) {
return responseHeaders.getLastHeader(name);
}
/**
* Gets all the headers with the given name that were on the origin
* response.
*/
@Override
public Header[] getHeaders(final String name) {
if (REQUEST_METHOD_HEADER_NAME.equalsIgnoreCase(name)) {
return new Header[0];
}
return responseHeaders.getHeaders(name);
}
/**
* @since 5.0
*/
@Override
public boolean containsHeader(final String name) {
return responseHeaders.containsHeader(name);
}
/**
* @since 5.0
*/
@Override
public int containsHeaders(final String name) {
return responseHeaders.containsHeaders(name);
}
/**
* @since 5.0
*/
@Override
public Header getSingleHeader(final String name) throws ProtocolException {
return responseHeaders.getSingleHeader(name);
}
/**
* @since 5.0
*/
@Override
public Iterator<Header> headerIterator() {
return responseHeaders.headerIterator();
}
/**
* @since 5.0
*/
@Override
public Iterator<Header> headerIterator(final String name) {
return responseHeaders.headerIterator(name);
}
/**
* Gets the Date value of the "Date" header or null if the header is missing or cannot be
* parsed.
*
* @since 4.3
*/
public Date getDate() {
return date;
}
/**
* Returns the {@link Resource} containing the origin response body.
*/
public Resource getResource() {
return this.resource;
}
/**
* Indicates whether the origin response indicated the associated
* resource had variants (i.e. that the Vary header was set on the
* origin response).
* @return {@code true} if this cached response was a variant
*/
public boolean hasVariants() {
return getFirstHeader(HeaderConstants.VARY) != null;
}
/**
* Returns an index about where in the cache different variants for
* a given resource are stored. This maps "variant keys" to "cache keys",
* where the variant key is derived from the varying request headers,
* and the cache key is the location in the
* {@link HttpCacheStorage} where that
* particular variant is stored. The first variant returned is used as
* the "parent" entry to hold this index of the other variants.
*/
public Map<String, String> getVariantMap() {
return Collections.unmodifiableMap(variantMap);
}
/**
* Returns the HTTP request method that was used to create the cached
* response entry.
*
* @since 4.4
*/
public String getRequestMethod() {
final Header requestMethodHeader = responseHeaders.getFirstHeader(REQUEST_METHOD_HEADER_NAME);
if (requestMethodHeader != null) {
return requestMethodHeader.getValue();
}
return HeaderConstants.GET_METHOD;
}
/**
* Provides a string representation of this instance suitable for
* human consumption.
*/
@Override
public String toString() {
return "[request date=" + this.requestDate + "; response date=" + this.responseDate
+ "; status=" + this.status + "]";
}
}