hbase-rest/src/main/java/org/apache/hadoop/hbase/rest/TableScanResource.java

   1 /*
   2  *
   3  * Licensed to the Apache Software Foundation (ASF) under one
   4  * or more contributor license agreements.  See the NOTICE file
   5  * distributed with this work for additional information
   6  * regarding copyright ownership.  The ASF licenses this file
   7  * to you under the Apache License, Version 2.0 (the
   8  * "License"); you may not use this file except in compliance
   9  * with the License.  You may obtain a copy of the License at
  10  *
  11  *     http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  */
  19 package org.apache.hadoop.hbase.rest;
  20
  21 import java.io.IOException;
  22 import java.util.ArrayList;
  23 import java.util.Iterator;
  24 import java.util.List;
  25
  26 import javax.ws.rs.GET;
  27 import javax.ws.rs.HeaderParam;
  28 import javax.ws.rs.Produces;
  29 import javax.ws.rs.core.Context;
  30 import javax.ws.rs.core.Response;
  31 import javax.ws.rs.core.Response.ResponseBuilder;
  32 import javax.ws.rs.core.StreamingOutput;
  33 import javax.ws.rs.core.UriInfo;
  34 import javax.xml.bind.annotation.XmlAccessType;
  35 import javax.xml.bind.annotation.XmlAccessorType;
  36 import javax.xml.bind.annotation.XmlElement;
  37 import javax.xml.bind.annotation.XmlRootElement;
  38
  39 import org.apache.hadoop.hbase.Cell;
  40 import org.apache.hadoop.hbase.CellUtil;
  41 import org.apache.hadoop.hbase.client.Result;
  42 import org.apache.hadoop.hbase.client.ResultScanner;
  43 import org.apache.hadoop.hbase.rest.model.CellModel;
  44 import org.apache.hadoop.hbase.rest.model.RowModel;
  45 import org.apache.yetus.audience.InterfaceAudience;
  46 import org.slf4j.Logger;
  47 import org.slf4j.LoggerFactory;
  48
  49 import com.fasterxml.jackson.annotation.JsonIgnore;
  50 import com.fasterxml.jackson.annotation.JsonProperty;
  51
  52 @InterfaceAudience.Private
  53 public class TableScanResource  extends ResourceBase {
  54   private static final Logger LOG = LoggerFactory.getLogger(TableScanResource.class);
  55
  56   TableResource tableResource;
  57   ResultScanner results;
  58   int userRequestedLimit;
  59
  60   public TableScanResource(ResultScanner scanner, int userRequestedLimit) throws IOException {
  61     super();
  62     this.results = scanner;
  63     this.userRequestedLimit = userRequestedLimit;
  64   }
  65
  66   @GET
  67   @Produces({ Constants.MIMETYPE_XML, Constants.MIMETYPE_JSON })
  68   public CellSetModelStream get(final @Context UriInfo uriInfo) {
  69     if (LOG.isTraceEnabled()) {
  70       LOG.trace("GET " + uriInfo.getAbsolutePath());
  71     }
  72     servlet.getMetrics().incrementRequests(1);
  73     final int rowsToSend = userRequestedLimit;
  74     servlet.getMetrics().incrementSucessfulScanRequests(1);
  75     final Iterator<Result> itr = results.iterator();
  76     return new CellSetModelStream(new ArrayList<RowModel>() {
  77       @Override
  78       public Iterator<RowModel> iterator() {
  79         return new Iterator<RowModel>() {
  80           int count = rowsToSend;
  81
  82           @Override
  83           public boolean hasNext() {
  84             return count > 0 && itr.hasNext();
  85           }
  86
  87           @Override
  88           public RowModel next() {
  89             Result rs = itr.next();
  90             if ((rs == null) || (count <= 0)) {
  91               return null;
  92             }
  93             byte[] rowKey = rs.getRow();
  94             RowModel rModel = new RowModel(rowKey);
  95             List<Cell> kvs = rs.listCells();
  96             for (Cell kv : kvs) {
  97               rModel.addCell(new CellModel(CellUtil.cloneFamily(kv), CellUtil.cloneQualifier(kv),
  98                   kv.getTimestamp(), CellUtil.cloneValue(kv)));
  99             }
 100             count--;
 101             if (count == 0) {
 102               results.close();
 103             }
 104             return rModel;
 105           }
 106         };
 107       }
 108     });
 109   }
 110
 111   @GET
 112   @Produces({ Constants.MIMETYPE_PROTOBUF, Constants.MIMETYPE_PROTOBUF_IETF })
 113   public Response getProtobuf(
 114       final @Context UriInfo uriInfo,
 115       final @HeaderParam("Accept") String contentType) {
 116     if (LOG.isTraceEnabled()) {
 117       LOG.trace("GET " + uriInfo.getAbsolutePath() + " as " +
 118               MIMETYPE_BINARY);
 119     }
 120     servlet.getMetrics().incrementRequests(1);
 121     try {
 122       int fetchSize = this.servlet.getConfiguration().getInt(Constants.SCAN_FETCH_SIZE, 10);
 123       StreamingOutput stream = new ProtobufStreamingOutput(this.results, contentType,
 124           userRequestedLimit, fetchSize);
 125       servlet.getMetrics().incrementSucessfulScanRequests(1);
 126       ResponseBuilder response = Response.ok(stream);
 127       response.header("content-type", contentType);
 128       return response.build();
 129     } catch (Exception exp) {
 130       servlet.getMetrics().incrementFailedScanRequests(1);
 131       processException(exp);
 132       LOG.warn(exp.toString(), exp);
 133       return null;
 134     }
 135   }
 136
 137   @XmlRootElement(name = "CellSet")
 138   @XmlAccessorType(XmlAccessType.FIELD)
 139   public static class CellSetModelStream {
 140     // JAXB needs an arraylist for streaming
 141     @XmlElement(name = "Row")
 142     @JsonIgnore
 143     private ArrayList<RowModel> Row;
 144
 145     public CellSetModelStream() {
 146     }
 147
 148     public CellSetModelStream(final ArrayList<RowModel> rowList) {
 149       this.Row = rowList;
 150     }
 151
 152     // jackson needs an iterator for streaming
 153     @JsonProperty("Row")
 154     public Iterator<RowModel> getIterator() {
 155       return Row.iterator();
 156     }
 157   }
 158 }