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1   /*
2    * Copyright 2010 The Apache Software Foundation
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *     http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing, software
15   * distributed under the License is distributed on an "AS IS" BASIS,
16   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
17   * See the License for the specific language governing permissions and
18   * limitations under the License.
19   */
20  
21  package org.apache.hadoop.hbase.client;
22  
23  import org.apache.hadoop.hbase.HConstants;
24  import org.apache.hadoop.hbase.KeyValue;
25  import org.apache.hadoop.hbase.util.Bytes;
26  import org.apache.hadoop.io.Writable;
27  
28  import java.io.DataInput;
29  import java.io.DataOutput;
30  import java.io.IOException;
31  import java.util.ArrayList;
32  import java.util.List;
33  import java.util.Map;
34  
35  /**
36   * Used to perform Delete operations on a single row.
37   * <p>
38   * To delete an entire row, instantiate a Delete object with the row
39   * to delete.  To further define the scope of what to delete, perform
40   * additional methods as outlined below.
41   * <p>
42   * To delete specific families, execute {@link #deleteFamily(byte[]) deleteFamily}
43   * for each family to delete.
44   * <p>
45   * To delete multiple versions of specific columns, execute
46   * {@link #deleteColumns(byte[], byte[]) deleteColumns}
47   * for each column to delete.
48   * <p>
49   * To delete specific versions of specific columns, execute
50   * {@link #deleteColumn(byte[], byte[], long) deleteColumn}
51   * for each column version to delete.
52   * <p>
53   * Specifying timestamps, deleteFamily and deleteColumns will delete all
54   * versions with a timestamp less than or equal to that passed.  If no
55   * timestamp is specified, an entry is added with a timestamp of 'now'
56   * where 'now' is the servers's System.currentTimeMillis().
57   * Specifying a timestamp to the deleteColumn method will
58   * delete versions only with a timestamp equal to that specified.
59   * If no timestamp is passed to deleteColumn, internally, it figures the
60   * most recent cell's timestamp and adds a delete at that timestamp; i.e.
61   * it deletes the most recently added cell.
62   * <p>The timestamp passed to the constructor is used ONLY for delete of
63   * rows.  For anything less -- a deleteColumn, deleteColumns or
64   * deleteFamily -- then you need to use the method overrides that take a
65   * timestamp.  The constructor timestamp is not referenced.
66   */
67  public class Delete extends Mutation
68    implements Writable, Comparable<Row> {
69    private static final byte DELETE_VERSION = (byte)3;
70  
71    /** Constructor for Writable.  DO NOT USE */
72    public Delete() {
73      this((byte [])null);
74    }
75  
76    /**
77     * Create a Delete operation for the specified row.
78     * <p>
79     * If no further operations are done, this will delete everything
80     * associated with the specified row (all versions of all columns in all
81     * families).
82     * @param row row key
83     */
84    public Delete(byte [] row) {
85      this(row, HConstants.LATEST_TIMESTAMP);
86    }
87  
88    /**
89     * Create a Delete operation for the specified row and timestamp.<p>
90     *
91     * If no further operations are done, this will delete all columns in all
92     * families of the specified row with a timestamp less than or equal to the
93     * specified timestamp.<p>
94     *
95     * This timestamp is ONLY used for a delete row operation.  If specifying
96     * families or columns, you must specify each timestamp individually.
97     * @param row row key
98     * @param timestamp maximum version timestamp (only for delete row)
99     */
100   public Delete(byte [] row, long timestamp) {
101     this.row = row;
102     this.ts = timestamp;
103   }
104 
105   /**
106    * Create a Delete operation for the specified row and timestamp, using
107    * an optional row lock.<p>
108    *
109    * If no further operations are done, this will delete all columns in all
110    * families of the specified row with a timestamp less than or equal to the
111    * specified timestamp.<p>
112    *
113    * This timestamp is ONLY used for a delete row operation.  If specifying
114    * families or columns, you must specify each timestamp individually.
115    * @param row row key
116    * @param timestamp maximum version timestamp (only for delete row)
117    * @param rowLock previously acquired row lock, or null
118    * @deprecated {@link RowLock} is deprecated, use {@link #Delete(byte[], long)}.
119    */
120   public Delete(byte [] row, long timestamp, RowLock rowLock) {
121     this.row = row;
122     this.ts = timestamp;
123     if (rowLock != null) {
124     	this.lockId = rowLock.getLockId();
125     }
126   }
127 
128   /**
129    * @param d Delete to clone.
130    */
131   public Delete(final Delete d) {
132     this.row = d.getRow();
133     this.ts = d.getTimeStamp();
134     this.lockId = d.getLockId();
135     this.familyMap.putAll(d.getFamilyMap());
136     this.writeToWAL = d.writeToWAL;
137   }
138 
139   /**
140    * Advanced use only. Add an existing delete marker to this Delete object.
141    * @param kv An existing 'delete' tpye KeyValue - can be family, column, or point delete
142    * @return this for invocation chaining
143    * @throws IOException
144    */
145   public Delete addDeleteMarker(KeyValue kv) throws IOException {
146     if (!(kv.isDelete() || kv.isDeleteColumnOrFamily())) {
147       throw new IOException("The recently added KeyValue is not of type "
148           + "delete. Rowkey: " + Bytes.toStringBinary(this.row));
149     }
150     if (!kv.matchingRow(row)) {
151       throw new IOException("The row in the recently added KeyValue "
152           + Bytes.toStringBinary(kv.getRow()) + " doesn't match the original one "
153           + Bytes.toStringBinary(this.row));
154     }
155     byte [] family = kv.getFamily();
156     List<KeyValue> list = familyMap.get(family);
157     if (list == null) {
158       list = new ArrayList<KeyValue>();
159     }
160     list.add(kv);
161     familyMap.put(family, list);
162     return this;
163   }
164 
165   /**
166    * Delete all versions of all columns of the specified family.
167    * <p>
168    * Overrides previous calls to deleteColumn and deleteColumns for the
169    * specified family.
170    * @param family family name
171    * @return this for invocation chaining
172    */
173   public Delete deleteFamily(byte [] family) {
174     this.deleteFamily(family, HConstants.LATEST_TIMESTAMP);
175     return this;
176   }
177 
178   /**
179    * Delete all columns of the specified family with a timestamp less than
180    * or equal to the specified timestamp.
181    * <p>
182    * Overrides previous calls to deleteColumn and deleteColumns for the
183    * specified family.
184    * @param family family name
185    * @param timestamp maximum version timestamp
186    * @return this for invocation chaining
187    */
188   public Delete deleteFamily(byte [] family, long timestamp) {
189     List<KeyValue> list = familyMap.get(family);
190     if(list == null) {
191       list = new ArrayList<KeyValue>();
192     } else if(!list.isEmpty()) {
193       list.clear();
194     }
195     list.add(new KeyValue(row, family, null, timestamp, KeyValue.Type.DeleteFamily));
196     familyMap.put(family, list);
197     return this;
198   }
199 
200   /**
201    * Delete all versions of the specified column.
202    * @param family family name
203    * @param qualifier column qualifier
204    * @return this for invocation chaining
205    */
206   public Delete deleteColumns(byte [] family, byte [] qualifier) {
207     this.deleteColumns(family, qualifier, HConstants.LATEST_TIMESTAMP);
208     return this;
209   }
210 
211   /**
212    * Delete all versions of the specified column with a timestamp less than
213    * or equal to the specified timestamp.
214    * @param family family name
215    * @param qualifier column qualifier
216    * @param timestamp maximum version timestamp
217    * @return this for invocation chaining
218    */
219   public Delete deleteColumns(byte [] family, byte [] qualifier, long timestamp) {
220     List<KeyValue> list = familyMap.get(family);
221     if (list == null) {
222       list = new ArrayList<KeyValue>();
223     }
224     list.add(new KeyValue(this.row, family, qualifier, timestamp,
225       KeyValue.Type.DeleteColumn));
226     familyMap.put(family, list);
227     return this;
228   }
229 
230   /**
231    * Delete the latest version of the specified column.
232    * This is an expensive call in that on the server-side, it first does a
233    * get to find the latest versions timestamp.  Then it adds a delete using
234    * the fetched cells timestamp.
235    * @param family family name
236    * @param qualifier column qualifier
237    * @return this for invocation chaining
238    */
239   public Delete deleteColumn(byte [] family, byte [] qualifier) {
240     this.deleteColumn(family, qualifier, HConstants.LATEST_TIMESTAMP);
241     return this;
242   }
243 
244   /**
245    * Delete the specified version of the specified column.
246    * @param family family name
247    * @param qualifier column qualifier
248    * @param timestamp version timestamp
249    * @return this for invocation chaining
250    */
251   public Delete deleteColumn(byte [] family, byte [] qualifier, long timestamp) {
252     List<KeyValue> list = familyMap.get(family);
253     if(list == null) {
254       list = new ArrayList<KeyValue>();
255     }
256     list.add(new KeyValue(
257         this.row, family, qualifier, timestamp, KeyValue.Type.Delete));
258     familyMap.put(family, list);
259     return this;
260   }
261 
262   /**
263    * Set the timestamp of the delete.
264    * 
265    * @param timestamp
266    */
267   public void setTimestamp(long timestamp) {
268     this.ts = timestamp;
269   }
270 
271   @Override
272   public Map<String, Object> toMap(int maxCols) {
273     // we start with the fingerprint map and build on top of it.
274     Map<String, Object> map = super.toMap(maxCols);
275     // why is put not doing this?
276     map.put("ts", this.ts);
277     return map;
278   }
279 
280   //Writable
281   public void readFields(final DataInput in) throws IOException {
282     int version = in.readByte();
283     if (version > DELETE_VERSION) {
284       throw new IOException("version not supported");
285     }
286     this.row = Bytes.readByteArray(in);
287     this.ts = in.readLong();
288     this.lockId = in.readLong();
289     if (version > 2) {
290       this.writeToWAL = in.readBoolean();
291     }
292     this.familyMap.clear();
293     int numFamilies = in.readInt();
294     for(int i=0;i<numFamilies;i++) {
295       byte [] family = Bytes.readByteArray(in);
296       int numColumns = in.readInt();
297       List<KeyValue> list = new ArrayList<KeyValue>(numColumns);
298       for(int j=0;j<numColumns;j++) {
299        KeyValue kv = new KeyValue();
300        kv.readFields(in);
301        list.add(kv);
302       }
303       this.familyMap.put(family, list);
304     }
305     if (version > 1) {
306       readAttributes(in);
307     }
308   }
309 
310   public void write(final DataOutput out) throws IOException {
311     out.writeByte(DELETE_VERSION);
312     Bytes.writeByteArray(out, this.row);
313     out.writeLong(this.ts);
314     out.writeLong(this.lockId);
315     out.writeBoolean(this.writeToWAL);
316     out.writeInt(familyMap.size());
317     for(Map.Entry<byte [], List<KeyValue>> entry : familyMap.entrySet()) {
318       Bytes.writeByteArray(out, entry.getKey());
319       List<KeyValue> list = entry.getValue();
320       out.writeInt(list.size());
321       for(KeyValue kv : list) {
322         kv.write(out);
323       }
324     }
325     writeAttributes(out);
326   }
327 }