/*
* Copyright 2013 Rackspace
*
* 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.rackspacecloud.blueflood.outputs.handlers;
import com.codahale.metrics.Meter;
import com.codahale.metrics.Timer;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;
import com.rackspacecloud.blueflood.exceptions.InvalidRequestException;
import com.rackspacecloud.blueflood.exceptions.SerializationException;
import com.rackspacecloud.blueflood.http.HTTPRequestWithDecodedQueryParams;
import com.rackspacecloud.blueflood.http.HttpRequestHandler;
import com.rackspacecloud.blueflood.http.HttpResponder;
import com.rackspacecloud.blueflood.io.Constants;
import com.rackspacecloud.blueflood.outputs.serializers.JSONHistogramOutputSerializer;
import com.rackspacecloud.blueflood.outputs.utils.PlotRequestParser;
import com.rackspacecloud.blueflood.rollup.Granularity;
import com.rackspacecloud.blueflood.types.Resolution;
import com.rackspacecloud.blueflood.outputs.utils.RollupsQueryParams;
import com.rackspacecloud.blueflood.utils.Metrics;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.http.*;
import org.json.simple.JSONObject;
import java.io.IOException;
public class HttpHistogramQueryHandler extends RollupHandler implements HttpRequestHandler {
private final JSONHistogramOutputSerializer serializer;
private final Gson gson; // thread-safe
private final JsonParser parser; // thread-safe
private static final Timer histFetchTimer = Metrics.timer(HttpRollupsQueryHandler.class,
"Handle HTTP request for histograms");
private static final Meter histByPointsMeter = Metrics.meter(RollupHandler.class, "Get histograms by points",
"BF-API");
private static final Meter histByGranularityMeter = Metrics.meter(RollupHandler.class, "Get histograms by gran",
"BF-API");
public HttpHistogramQueryHandler() {
this.gson = new GsonBuilder().setPrettyPrinting().serializeNulls().create();
this.parser = new JsonParser();
this.serializer = new JSONHistogramOutputSerializer();
}
private JSONObject GetHistogramByPoints(String tenantId,
String metric,
long from,
long to,
int points) throws IOException, SerializationException {
histByPointsMeter.mark();
Granularity g = Granularity.granularityFromPointsInInterval(from, to, points);
return serializer.transformHistogram(getHistogramsByGranularity(tenantId, metric, from, to, g));
}
private JSONObject GetHistogramByResolution(String tenantId,
String metric,
long from,
long to,
Resolution resolution) throws IOException, SerializationException {
histByGranularityMeter.mark();
if (resolution == null || resolution == Resolution.FULL) {
resolution = Resolution.MIN5;
}
Granularity g = Granularity.granularities()[resolution.getValue()];
return serializer.transformHistogram(getHistogramsByGranularity(tenantId, metric, from, to, g));
}
@Override
public void handle(ChannelHandlerContext ctx, HttpRequest request) {
final String tenantId = request.getHeader("tenantId");
final String metricName = request.getHeader("metricName");
if (!(request instanceof HTTPRequestWithDecodedQueryParams)) {
sendResponse(ctx, request, "Missing query params: from, to, points",
HttpResponseStatus.BAD_REQUEST);
return;
}
HTTPRequestWithDecodedQueryParams requestWithParams = (HTTPRequestWithDecodedQueryParams) request;
final Timer.Context histFetchTimerContext = histFetchTimer.time();
try {
RollupsQueryParams params = PlotRequestParser.parseParams(requestWithParams.getQueryParams());
JSONObject metricData;
if (params.isGetByPoints()) {
metricData = GetHistogramByPoints(tenantId, metricName, params.getRange().getStart(),
params.getRange().getStop(), params.getPoints());
} else if (params.isGetByResolution()) {
metricData = GetHistogramByResolution(tenantId, metricName, params.getRange().getStart(),
params.getRange().getStop(), params.getResolution());
} else {
throw new InvalidRequestException("Invalid rollups query. Neither points nor resolution specified.");
}
final JsonElement element = parser.parse(metricData.toString());
final String jsonStringRep = gson.toJson(element);
sendResponse(ctx, request, jsonStringRep, HttpResponseStatus.OK);
} catch (InvalidRequestException e) {
sendResponse(ctx, request, e.getMessage(), HttpResponseStatus.BAD_REQUEST);
} catch (SerializationException e) {
sendResponse(ctx, request, e.getMessage(), HttpResponseStatus.INTERNAL_SERVER_ERROR);
} catch (Exception e) {
sendResponse(ctx, request, e.getMessage(), HttpResponseStatus.INTERNAL_SERVER_ERROR);
} finally {
histFetchTimerContext.stop();
}
}
private void sendResponse(ChannelHandlerContext channel, HttpRequest request, String messageBody,
HttpResponseStatus status) {
HttpResponse response = new DefaultHttpResponse(HttpVersion.HTTP_1_1, status);
if (messageBody != null && !messageBody.isEmpty()) {
response.setContent(ChannelBuffers.copiedBuffer(messageBody, Constants.DEFAULT_CHARSET));
}
HttpResponder.respond(channel, request, response);
}
}