001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.client;
019
020import java.util.Map;
021import org.apache.hadoop.hbase.exceptions.DeserializationException;
022import org.apache.hadoop.hbase.filter.Filter;
023import org.apache.hadoop.hbase.io.TimeRange;
024import org.apache.hadoop.hbase.security.access.AccessControlConstants;
025import org.apache.hadoop.hbase.security.access.AccessControlUtil;
026import org.apache.hadoop.hbase.security.access.Permission;
027import org.apache.hadoop.hbase.security.visibility.Authorizations;
028import org.apache.hadoop.hbase.security.visibility.VisibilityConstants;
029import org.apache.hadoop.hbase.util.Bytes;
030import org.apache.yetus.audience.InterfaceAudience;
031
032import org.apache.hbase.thirdparty.com.google.common.collect.ArrayListMultimap;
033import org.apache.hbase.thirdparty.com.google.common.collect.ListMultimap;
034import org.apache.hbase.thirdparty.com.google.common.collect.Maps;
035
036import org.apache.hadoop.hbase.shaded.protobuf.ProtobufUtil;
037
038/**
039 * Base class for HBase read operations; e.g. Scan and Get.
040 */
041@InterfaceAudience.Public
042public abstract class Query extends OperationWithAttributes {
043  private static final String ISOLATION_LEVEL = "_isolationlevel_";
044  protected Filter filter = null;
045  protected int targetReplicaId = -1;
046  protected Consistency consistency = Consistency.STRONG;
047  protected Map<byte[], TimeRange> colFamTimeRangeMap = Maps.newTreeMap(Bytes.BYTES_COMPARATOR);
048  protected Boolean loadColumnFamiliesOnDemand = null;
049
050  /**
051   * n
052   */
053  public Filter getFilter() {
054    return filter;
055  }
056
057  /**
058   * Apply the specified server-side filter when performing the Query. Only
059   * {@link Filter#filterCell(org.apache.hadoop.hbase.Cell)} is called AFTER all tests for ttl,
060   * column match, deletes and column family's max versions have been run.
061   * @param filter filter to run on the server
062   * @return this for invocation chaining
063   */
064  public Query setFilter(Filter filter) {
065    this.filter = filter;
066    return this;
067  }
068
069  /**
070   * Sets the authorizations to be used by this Query n
071   */
072  public Query setAuthorizations(Authorizations authorizations) {
073    this.setAttribute(VisibilityConstants.VISIBILITY_LABELS_ATTR_KEY,
074      ProtobufUtil.toAuthorizations(authorizations).toByteArray());
075    return this;
076  }
077
078  /** Returns The authorizations this Query is associated with. n */
079  public Authorizations getAuthorizations() throws DeserializationException {
080    byte[] authorizationsBytes = this.getAttribute(VisibilityConstants.VISIBILITY_LABELS_ATTR_KEY);
081    if (authorizationsBytes == null) return null;
082    return ProtobufUtil.toAuthorizations(authorizationsBytes);
083  }
084
085  /** Returns The serialized ACL for this operation, or null if none */
086  public byte[] getACL() {
087    return getAttribute(AccessControlConstants.OP_ATTRIBUTE_ACL);
088  }
089
090  /**
091   * Set the ACL for the operation.
092   * @param user  User short name
093   * @param perms Permissions for the user
094   */
095  public Query setACL(String user, Permission perms) {
096    setAttribute(AccessControlConstants.OP_ATTRIBUTE_ACL,
097      AccessControlUtil.toUsersAndPermissions(user, perms).toByteArray());
098    return this;
099  }
100
101  /**
102   * Set the ACL for the operation.
103   * @param perms A map of permissions for a user or users
104   */
105  public Query setACL(Map<String, Permission> perms) {
106    ListMultimap<String, Permission> permMap = ArrayListMultimap.create();
107    for (Map.Entry<String, Permission> entry : perms.entrySet()) {
108      permMap.put(entry.getKey(), entry.getValue());
109    }
110    setAttribute(AccessControlConstants.OP_ATTRIBUTE_ACL,
111      AccessControlUtil.toUsersAndPermissions(permMap).toByteArray());
112    return this;
113  }
114
115  /**
116   * Returns the consistency level for this operation
117   * @return the consistency level
118   */
119  public Consistency getConsistency() {
120    return consistency;
121  }
122
123  /**
124   * Sets the consistency level for this operation
125   * @param consistency the consistency level
126   */
127  public Query setConsistency(Consistency consistency) {
128    this.consistency = consistency;
129    return this;
130  }
131
132  /**
133   * Specify region replica id where Query will fetch data from. Use this together with
134   * {@link #setConsistency(Consistency)} passing {@link Consistency#TIMELINE} to read data from a
135   * specific replicaId. <br>
136   * <b> Expert: </b>This is an advanced API exposed. Only use it if you know what you are doing n
137   */
138  public Query setReplicaId(int Id) {
139    this.targetReplicaId = Id;
140    return this;
141  }
142
143  /**
144   * Returns region replica id where Query will fetch data from.
145   * @return region replica id or -1 if not set.
146   */
147  public int getReplicaId() {
148    return this.targetReplicaId;
149  }
150
151  /**
152   * Set the isolation level for this query. If the isolation level is set to READ_UNCOMMITTED, then
153   * this query will return data from committed and uncommitted transactions. If the isolation level
154   * is set to READ_COMMITTED, then this query will return data from committed transactions only. If
155   * a isolation level is not explicitly set on a Query, then it is assumed to be READ_COMMITTED.
156   * @param level IsolationLevel for this query
157   */
158  public Query setIsolationLevel(IsolationLevel level) {
159    setAttribute(ISOLATION_LEVEL, level.toBytes());
160    return this;
161  }
162
163  /**
164   * Returns The isolation level of this query. If no isolation level was set for this query object,
165   * then it returns READ_COMMITTED.
166   */
167  public IsolationLevel getIsolationLevel() {
168    byte[] attr = getAttribute(ISOLATION_LEVEL);
169    return attr == null ? IsolationLevel.READ_COMMITTED : IsolationLevel.fromBytes(attr);
170  }
171
172  /**
173   * Set the value indicating whether loading CFs on demand should be allowed (cluster default is
174   * false). On-demand CF loading doesn't load column families until necessary, e.g. if you filter
175   * on one column, the other column family data will be loaded only for the rows that are included
176   * in result, not all rows like in normal case. With column-specific filters, like
177   * SingleColumnValueFilter w/filterIfMissing == true, this can deliver huge perf gains when
178   * there's a cf with lots of data; however, it can also lead to some inconsistent results, as
179   * follows: - if someone does a concurrent update to both column families in question you may get
180   * a row that never existed, e.g. for { rowKey = 5, { cat_videos =&gt; 1 }, { video =&gt; "my cat"
181   * } } someone puts rowKey 5 with { cat_videos =&gt; 0 }, { video =&gt; "my dog" }, concurrent
182   * scan filtering on "cat_videos == 1" can get { rowKey = 5, { cat_videos =&gt; 1 }, { video =&gt;
183   * "my dog" } }. - if there's a concurrent split and you have more than 2 column families, some
184   * rows may be missing some column families.
185   */
186  public Query setLoadColumnFamiliesOnDemand(boolean value) {
187    this.loadColumnFamiliesOnDemand = value;
188    return this;
189  }
190
191  /**
192   * Get the raw loadColumnFamiliesOnDemand setting; if it's not set, can be null.
193   */
194  public Boolean getLoadColumnFamiliesOnDemandValue() {
195    return this.loadColumnFamiliesOnDemand;
196  }
197
198  /**
199   * Get the logical value indicating whether on-demand CF loading should be allowed.
200   */
201  public boolean doLoadColumnFamiliesOnDemand() {
202    return (this.loadColumnFamiliesOnDemand != null) && this.loadColumnFamiliesOnDemand;
203  }
204
205  /**
206   * Get versions of columns only within the specified timestamp range, [minStamp, maxStamp) on a
207   * per CF bases. Note, default maximum versions to return is 1. If your time range spans more than
208   * one version and you want all versions returned, up the number of versions beyond the default.
209   * Column Family time ranges take precedence over the global time range.
210   * @param cf       the column family for which you want to restrict
211   * @param minStamp minimum timestamp value, inclusive
212   * @param maxStamp maximum timestamp value, exclusive n
213   */
214
215  public Query setColumnFamilyTimeRange(byte[] cf, long minStamp, long maxStamp) {
216    colFamTimeRangeMap.put(cf, new TimeRange(minStamp, maxStamp));
217    return this;
218  }
219
220  /** Returns A map of column families to time ranges */
221  public Map<byte[], TimeRange> getColumnFamilyTimeRange() {
222    return this.colFamTimeRangeMap;
223  }
224}