6490394: G1: Allow heap shrinking / memory unmapping after reclaiming regions during Remark
Reviewed-by: sjohanss, sangheki
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package jdk.internal.net.http;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpHeaders;
import jdk.internal.net.http.common.Log;
import jdk.internal.net.http.common.Utils;
class RedirectFilter implements HeaderFilter {
HttpRequestImpl request;
HttpClientImpl client;
HttpClient.Redirect policy;
String method;
MultiExchange<?> exchange;
static final int DEFAULT_MAX_REDIRECTS = 5;
URI uri;
/*
* NOT_MODIFIED status code results from a conditional GET where
* the server does not (must not) return a response body because
* the condition specified in the request disallows it
*/
static final int HTTP_NOT_MODIFIED = 304;
static final int max_redirects = Utils.getIntegerNetProperty(
"jdk.httpclient.redirects.retrylimit", DEFAULT_MAX_REDIRECTS
);
// A public no-arg constructor is required by FilterFactory
public RedirectFilter() {}
@Override
public synchronized void request(HttpRequestImpl r, MultiExchange<?> e) throws IOException {
this.request = r;
this.client = e.client();
this.policy = client.followRedirects();
this.method = r.method();
this.uri = r.uri();
this.exchange = e;
}
@Override
public synchronized HttpRequestImpl response(Response r) throws IOException {
return handleResponse(r);
}
private static String redirectedMethod(int statusCode, String orig) {
switch (statusCode) {
case 301:
case 302:
return orig.equals("POST") ? "GET" : orig;
case 303:
return "GET";
case 307:
case 308:
return orig;
default:
// unexpected but return orig
return orig;
}
}
/**
* Checks to see if a new request is needed and returns it.
* Null means response is ok to return to user.
*/
private HttpRequestImpl handleResponse(Response r) {
int rcode = r.statusCode();
if (rcode == 200 || policy == HttpClient.Redirect.NEVER) {
return null;
}
if (rcode == HTTP_NOT_MODIFIED)
return null;
if (rcode >= 300 && rcode <= 399) {
URI redir = getRedirectedURI(r.headers());
String newMethod = redirectedMethod(rcode, method);
Log.logTrace("response code: {0}, redirected URI: {1}", rcode, redir);
if (canRedirect(redir) && ++exchange.numberOfRedirects < max_redirects) {
Log.logTrace("redirect to: {0} with method: {1}", redir, newMethod);
return HttpRequestImpl.newInstanceForRedirection(redir, newMethod, request);
} else {
Log.logTrace("not redirecting");
return null;
}
}
return null;
}
private URI getRedirectedURI(HttpHeaders headers) {
URI redirectedURI;
redirectedURI = headers.firstValue("Location")
.map(URI::create)
.orElseThrow(() -> new UncheckedIOException(
new IOException("Invalid redirection")));
// redirect could be relative to original URL, but if not
// then redirect is used.
redirectedURI = uri.resolve(redirectedURI);
return redirectedURI;
}
private boolean canRedirect(URI redir) {
String newScheme = redir.getScheme();
String oldScheme = uri.getScheme();
switch (policy) {
case ALWAYS:
return true;
case NEVER:
return false;
case NORMAL:
return newScheme.equalsIgnoreCase(oldScheme)
|| newScheme.equalsIgnoreCase("https");
default:
throw new InternalError();
}
}
}