content: /*
   * 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.
   */
  package org.apache.bookkeeper.server.http.service;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  import static java.nio.charset.StandardCharsets.US_ASCII;
  
  import com.google.common.collect.Maps;
  import java.util.Iterator;
  import java.util.Map;
  import org.apache.bookkeeper.client.BookKeeperAdmin;
  import org.apache.bookkeeper.client.LedgerEntry;
  import org.apache.bookkeeper.common.util.JsonUtil;
  import org.apache.bookkeeper.conf.ServerConfiguration;
  import org.apache.bookkeeper.http.HttpServer;
  import org.apache.bookkeeper.http.service.HttpEndpointService;
  import org.apache.bookkeeper.http.service.HttpServiceRequest;
  import org.apache.bookkeeper.http.service.HttpServiceResponse;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * HttpEndpointService that handle Bookkeeper read ledger entry related http request.
   *
   * <p>The GET method will print all entry content of wanted entry.
   * User should set wanted "ledger_id", and can choose only print out wanted entry
   * by set parameter "start_entry_id", "end_entry_id" and "page".
   */
  public class ReadLedgerEntryService implements HttpEndpointService {
  
      static final Logger LOG = LoggerFactory.getLogger(ReadLedgerEntryService.class);
  
      protected ServerConfiguration conf;
      protected BookKeeperAdmin bka;
  
      public ReadLedgerEntryService(ServerConfiguration conf, BookKeeperAdmin bka) {
          checkNotNull(conf);
          this.conf = conf;
          this.bka = bka;
      }
  
      static final Long ENTRIES_PER_PAE = 1000L;
  
      @Override
      public HttpServiceResponse handle(HttpServiceRequest request) throws Exception {
          HttpServiceResponse response = new HttpServiceResponse();
          Map<String, String> params = request.getParams();
  
          if (HttpServer.Method.GET == request.getMethod() && (params != null) && params.containsKey("ledger_id")) {
              Long ledgerId = Long.parseLong(params.get("ledger_id"));
              Long startEntryId = 0L;
              Long endEntryId = -1L;
              if (params.containsKey("start_entry_id")) {
                  startEntryId = Long.parseLong(params.get("start_entry_id"));
              }
              if (params.containsKey("end_entry_id")) {
                  endEntryId = Long.parseLong(params.get("end_entry_id"));
              }
  
              // output <entryid: entry_content>
              Map<String, String> output = Maps.newHashMap();
  
              // Page index should start from 1;
              Integer pageIndex = params.containsKey("page") ? Integer.parseInt(params.get("page")) : -1;
              if (pageIndex > 0) {
                  // start and end ledger index for wanted page.
                  Long startIndexInPage = (pageIndex - 1) * ENTRIES_PER_PAE;
                  Long endIndexInPage = startIndexInPage + ENTRIES_PER_PAE - 1;
  
                  if ((startEntryId == 0L) || (startEntryId < startIndexInPage)) {
                      startEntryId = startIndexInPage;
                  }
                  if ((endEntryId == -1L) || (endEntryId > endIndexInPage)) {
                      endEntryId = endIndexInPage;
                  }
                  output.put("Entries for page: ", pageIndex.toString());
              }
  
              if (endEntryId != -1L && startEntryId > endEntryId) {
                  response.setCode(HttpServer.StatusCode.INTERNAL_ERROR);
                  response.setBody("parameter for start_entry_id: " + startEntryId
                      + " and end_entry_id: " + endEntryId + " conflict with page=" + pageIndex);
                  return response;
              }
  
              Iterator<LedgerEntry> entries = bka.readEntries(ledgerId, startEntryId, endEntryId).iterator();
              while (entries.hasNext()) {
                  LedgerEntry entry = entries.next();
                  output.put(Long.valueOf(entry.getEntryId()).toString(), new String(entry.getEntry(), US_ASCII));
              }
  
              String jsonResponse = JsonUtil.toJson(output);
              if (LOG.isDebugEnabled()) {
                  LOG.debug("output body:" + jsonResponse);
              }
              response.setBody(jsonResponse);
              response.setCode(HttpServer.StatusCode.OK);
              return response;
          } else {
              response.setCode(HttpServer.StatusCode.NOT_FOUND);
              response.setBody("Not found method. Should be GET method, with ledger_id provided");
              return response;
          }
      }
  }
  