com.addthis.hydra.query.web.DetailedStatusHandler.java Source code

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Here is the source code for com.addthis.hydra.query.web.DetailedStatusHandler.java

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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 com.addthis.hydra.query.web;

import java.nio.CharBuffer;

import com.addthis.codec.CodecJSON;
import com.addthis.hydra.query.tracker.QueryEntry;
import com.addthis.hydra.query.tracker.QueryEntryInfo;
import com.addthis.maljson.JSONObject;

import org.apache.commons.io.output.StringBuilderWriter;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.http.DefaultHttpContent;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.HttpContent;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.LastHttpContent;
import io.netty.util.CharsetUtil;
import io.netty.util.concurrent.DefaultPromise;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.FutureListener;
import io.netty.util.concurrent.Promise;

public class DetailedStatusHandler implements FutureListener<QueryEntryInfo> {

    private final StringBuilderWriter writer;
    private final HttpResponse response;
    private final ChannelHandlerContext ctx;
    private final FullHttpRequest request;
    private final QueryEntry queryEntry;

    public DetailedStatusHandler(StringBuilderWriter writer, HttpResponse response, ChannelHandlerContext ctx,
            FullHttpRequest request, QueryEntry queryEntry) {
        this.writer = writer;
        this.response = response;
        this.ctx = ctx;
        this.request = request;
        this.queryEntry = queryEntry;
    }

    public void handle() {
        if (queryEntry != null) {
            Promise<QueryEntryInfo> promise = new DefaultPromise<>(ctx.executor());
            promise.addListener(this);
            queryEntry.getDetailedQueryEntryInfo(promise);
        } else {
            onFailure(new RuntimeException("query entry unexpectedly null"));
        }
    }

    private void onSuccess(QueryEntryInfo queryEntryInfo) throws Exception {
        JSONObject entryJSON = CodecJSON.encodeJSON(queryEntryInfo);
        writer.write(entryJSON.toString());
        ByteBuf textResponse = ByteBufUtil.encodeString(ctx.alloc(), CharBuffer.wrap(writer.getBuilder()),
                CharsetUtil.UTF_8);
        HttpContent content = new DefaultHttpContent(textResponse);
        response.headers().set(HttpHeaders.Names.CONTENT_LENGTH, textResponse.readableBytes());
        if (HttpHeaders.isKeepAlive(request)) {
            response.headers().set(HttpHeaders.Names.CONNECTION, HttpHeaders.Values.KEEP_ALIVE);
        }
        ctx.write(response);
        ctx.write(content);
        ChannelFuture lastContentFuture = ctx.writeAndFlush(LastHttpContent.EMPTY_LAST_CONTENT);
        if (!HttpHeaders.isKeepAlive(request)) {
            lastContentFuture.addListener(ChannelFutureListener.CLOSE);
        }
    }

    private void onFailure(Throwable cause) {
        if (ctx.channel().isActive()) {
            HttpUtils.sendError(ctx, new HttpResponseStatus(500, cause.getMessage()));
        }
    }

    @Override
    public void operationComplete(Future<QueryEntryInfo> future) throws Exception {
        if (future.isSuccess()) {
            onSuccess(future.get());
        } else {
            onFailure(future.cause());
        }
    }
}