io.trino.gateway.proxyserver.ProxyHandler Maven / Gradle / Ivy

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/*
 * 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.trino.gateway.proxyserver;

import com.google.common.collect.ImmutableList;
import io.airlift.log.Logger;
import jakarta.servlet.http.Cookie;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;
import org.eclipse.jetty.client.api.Request;
import org.eclipse.jetty.http.HttpHeader;
import org.eclipse.jetty.util.Callback;

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.Charset;
import java.util.Arrays;
import java.util.Enumeration;
import java.util.List;
import java.util.zip.GZIPInputStream;

/* Order of control => rewriteTarget, preConnectionHook, postConnectionHook. */
public class ProxyHandler
{
    private static final Logger log = Logger.get(ProxyHandler.class);

    protected String rewriteTarget(HttpServletRequest request)
    {
        // Dont override this unless absolutely needed.
        return null;
    }

    /**
     * Request interceptor.
     */
    public void preConnectionHook(HttpServletRequest request, Request proxyRequest)
    {
        // you may override it.
    }

    /**
     * Response interceptor default.
     */
    protected void postConnectionHook(
            HttpServletRequest request,
            HttpServletResponse response,
            byte[] buffer,
            int offset,
            int length,
            Callback callback)
    {
        try {
            response.getOutputStream().write(buffer, offset, length);
            callback.succeeded();
        }
        catch (Throwable var9) {
            callback.failed(var9);
        }
    }

    protected void debugLogHeaders(HttpServletRequest request)
    {
        if (log.isDebugEnabled()) {
            log.debug("-------HttpServletRequest headers---------");
            Enumeration headers = request.getHeaderNames();
            while (headers.hasMoreElements()) {
                String header = headers.nextElement();
                log.debug(header + "->" + request.getHeader(header));
            }
        }
    }

    protected boolean isGZipEncoding(HttpServletResponse response)
    {
        String contentEncoding = response.getHeader(HttpHeader.CONTENT_ENCODING.toString());
        return contentEncoding != null && contentEncoding.toLowerCase().contains("gzip");
    }

    protected String plainTextFromGz(byte[] compressed)
            throws IOException
    {
        final StringBuilder outStr = new StringBuilder();
        if ((compressed == null) || (compressed.length == 0)) {
            return "";
        }
        if (isCompressed(compressed)) {
            final GZIPInputStream gis = new GZIPInputStream(new ByteArrayInputStream(compressed));
            final BufferedReader bufferedReader =
                    new BufferedReader(new InputStreamReader(gis, Charset.defaultCharset()));
            String line;
            while ((line = bufferedReader.readLine()) != null) {
                outStr.append(line);
            }
            gis.close();
        }
        else {
            outStr.append(Arrays.toString(compressed));
        }
        return outStr.toString();
    }

    protected boolean isCompressed(final byte[] compressed)
    {
        return (compressed[0] == (byte) GZIPInputStream.GZIP_MAGIC)
                && (compressed[1] == (byte) (GZIPInputStream.GZIP_MAGIC >> 8));
    }

    public List generateDeleteCookieList(HttpServletRequest clientRequest)
    {
        return ImmutableList.of();
    }
}