org.apache.hadoop.hbase.client.Get Maven / Gradle / Ivy
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* 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.hadoop.hbase.client;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.NavigableSet;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.filter.Filter;
import org.apache.hadoop.hbase.io.TimeRange;
import org.apache.hadoop.hbase.security.access.Permission;
import org.apache.hadoop.hbase.security.visibility.Authorizations;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.yetus.audience.InterfaceAudience;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Used to perform Get operations on a single row.
*
* To get everything for a row, instantiate a Get object with the row to get. To further narrow the
* scope of what to Get, use the methods below.
*
* To get all columns from specific families, execute {@link #addFamily(byte[]) addFamily} for each
* family to retrieve.
*
* To get specific columns, execute {@link #addColumn(byte[], byte[]) addColumn} for each column to
* retrieve.
*
* To only retrieve columns within a specific range of version timestamps, execute
* {@link #setTimeRange(long, long) setTimeRange}.
*
* To only retrieve columns with a specific timestamp, execute {@link #setTimestamp(long)
* setTimestamp}.
*
* To limit the number of versions of each column to be returned, execute
* {@link #setMaxVersions(int) setMaxVersions}.
*
* To add a filter, call {@link #setFilter(Filter) setFilter}.
*/
@InterfaceAudience.Public
public class Get extends Query implements Row {
private static final Logger LOG = LoggerFactory.getLogger(Get.class);
private byte[] row = null;
private int maxVersions = 1;
private boolean cacheBlocks = true;
private int storeLimit = -1;
private int storeOffset = 0;
private TimeRange tr = TimeRange.allTime();
private boolean checkExistenceOnly = false;
private boolean closestRowBefore = false;
private Map> familyMap = new TreeMap<>(Bytes.BYTES_COMPARATOR);
/**
* Create a Get operation for the specified row.
*
* If no further operations are done, this will get the latest version of all columns in all
* families of the specified row.
* @param row row key
*/
public Get(byte[] row) {
Mutation.checkRow(row);
this.row = row;
}
/**
* Copy-constructor
*/
public Get(Get get) {
this(get.getRow());
// from Query
this.setFilter(get.getFilter());
this.setReplicaId(get.getReplicaId());
this.setConsistency(get.getConsistency());
// from Get
this.cacheBlocks = get.getCacheBlocks();
this.maxVersions = get.getMaxVersions();
this.storeLimit = get.getMaxResultsPerColumnFamily();
this.storeOffset = get.getRowOffsetPerColumnFamily();
this.tr = get.getTimeRange();
this.checkExistenceOnly = get.isCheckExistenceOnly();
this.loadColumnFamiliesOnDemand = get.getLoadColumnFamiliesOnDemandValue();
Map> fams = get.getFamilyMap();
for (Map.Entry> entry : fams.entrySet()) {
byte[] fam = entry.getKey();
NavigableSet cols = entry.getValue();
if (cols != null && cols.size() > 0) {
for (byte[] col : cols) {
addColumn(fam, col);
}
} else {
addFamily(fam);
}
}
for (Map.Entry attr : get.getAttributesMap().entrySet()) {
setAttribute(attr.getKey(), attr.getValue());
}
for (Map.Entry entry : get.getColumnFamilyTimeRange().entrySet()) {
TimeRange tr = entry.getValue();
setColumnFamilyTimeRange(entry.getKey(), tr.getMin(), tr.getMax());
}
super.setPriority(get.getPriority());
}
/**
* Create a Get operation for the specified row.
*/
public Get(byte[] row, int rowOffset, int rowLength) {
Mutation.checkRow(row, rowOffset, rowLength);
this.row = Bytes.copy(row, rowOffset, rowLength);
}
/**
* Create a Get operation for the specified row.
*/
public Get(ByteBuffer row) {
Mutation.checkRow(row);
this.row = new byte[row.remaining()];
row.get(this.row);
}
public boolean isCheckExistenceOnly() {
return checkExistenceOnly;
}
public Get setCheckExistenceOnly(boolean checkExistenceOnly) {
this.checkExistenceOnly = checkExistenceOnly;
return this;
}
/**
* This will always return the default value which is false as client cannot set the value to this
* property any more.
* @deprecated since 2.0.0 and will be removed in 3.0.0
*/
@Deprecated
public boolean isClosestRowBefore() {
return closestRowBefore;
}
/**
* This is not used any more and does nothing. Use reverse scan instead.
* @deprecated since 2.0.0 and will be removed in 3.0.0
*/
@Deprecated
public Get setClosestRowBefore(boolean closestRowBefore) {
// do Nothing
return this;
}
/**
* Get all columns from the specified family.
*
* Overrides previous calls to addColumn for this family.
* @param family family name
* @return the Get object
*/
public Get addFamily(byte[] family) {
familyMap.remove(family);
familyMap.put(family, null);
return this;
}
/**
* Get the column from the specific family with the specified qualifier.
*
* Overrides previous calls to addFamily for this family.
* @param family family name
* @param qualifier column qualifier
* @return the Get objec
*/
public Get addColumn(byte[] family, byte[] qualifier) {
NavigableSet set = familyMap.get(family);
if (set == null) {
set = new TreeSet<>(Bytes.BYTES_COMPARATOR);
familyMap.put(family, set);
}
if (qualifier == null) {
qualifier = HConstants.EMPTY_BYTE_ARRAY;
}
set.add(qualifier);
return this;
}
/**
* Get versions of columns only within the specified timestamp range, [minStamp, maxStamp).
* @param minStamp minimum timestamp value, inclusive
* @param maxStamp maximum timestamp value, exclusive
* @return this for invocation chaining
*/
public Get setTimeRange(long minStamp, long maxStamp) throws IOException {
tr = new TimeRange(minStamp, maxStamp);
return this;
}
/**
* Get versions of columns with the specified timestamp.
* @param timestamp version timestamp
* @return this for invocation chaining
* @deprecated As of release 2.0.0, this will be removed in HBase 3.0.0. Use
* {@link #setTimestamp(long)} instead
*/
@Deprecated
public Get setTimeStamp(long timestamp) throws IOException {
return this.setTimestamp(timestamp);
}
/**
* Get versions of columns with the specified timestamp.
* @param timestamp version timestamp
* @return this for invocation chaining
*/
public Get setTimestamp(long timestamp) {
try {
tr = new TimeRange(timestamp, timestamp + 1);
} catch (Exception e) {
// This should never happen, unless integer overflow or something extremely wrong...
LOG.error("TimeRange failed, likely caused by integer overflow. ", e);
throw e;
}
return this;
}
@Override
public Get setColumnFamilyTimeRange(byte[] cf, long minStamp, long maxStamp) {
return (Get) super.setColumnFamilyTimeRange(cf, minStamp, maxStamp);
}
/**
* Get all available versions.
* @return this for invocation chaining
* @deprecated It is easy to misunderstand with column family's max versions, so use
* {@link #readAllVersions()} instead.
*/
@Deprecated
public Get setMaxVersions() {
return readAllVersions();
}
/**
* Get up to the specified number of versions of each column.
* @param maxVersions maximum versions for each column
* @throws IOException if invalid number of versions
* @return this for invocation chaining
* @deprecated It is easy to misunderstand with column family's max versions, so use
* {@link #readVersions(int)} instead.
*/
@Deprecated
public Get setMaxVersions(int maxVersions) throws IOException {
return readVersions(maxVersions);
}
/**
* Get all available versions.
* @return this for invocation chaining
*/
public Get readAllVersions() {
this.maxVersions = Integer.MAX_VALUE;
return this;
}
/**
* Get up to the specified number of versions of each column.
* @param versions specified number of versions for each column
* @throws IOException if invalid number of versions
* @return this for invocation chaining
*/
public Get readVersions(int versions) throws IOException {
if (versions <= 0) {
throw new IOException("versions must be positive");
}
this.maxVersions = versions;
return this;
}
@Override
public Get setLoadColumnFamiliesOnDemand(boolean value) {
return (Get) super.setLoadColumnFamiliesOnDemand(value);
}
/**
* Set the maximum number of values to return per row per Column Family
* @param limit the maximum number of values returned / row / CF
* @return this for invocation chaining
*/
public Get setMaxResultsPerColumnFamily(int limit) {
this.storeLimit = limit;
return this;
}
/**
* Set offset for the row per Column Family. This offset is only within a particular row/CF
* combination. It gets reset back to zero when we move to the next row or CF.
* @param offset is the number of kvs that will be skipped.
* @return this for invocation chaining
*/
public Get setRowOffsetPerColumnFamily(int offset) {
this.storeOffset = offset;
return this;
}
@Override
public Get setFilter(Filter filter) {
super.setFilter(filter);
return this;
}
/* Accessors */
/**
* Set whether blocks should be cached for this Get.
*
* This is true by default. When true, default settings of the table and family are used (this
* will never override caching blocks if the block cache is disabled for that family or entirely).
* @param cacheBlocks if false, default settings are overridden and blocks will not be cached
*/
public Get setCacheBlocks(boolean cacheBlocks) {
this.cacheBlocks = cacheBlocks;
return this;
}
/**
* Get whether blocks should be cached for this Get.
* @return true if default caching should be used, false if blocks should not be cached
*/
public boolean getCacheBlocks() {
return cacheBlocks;
}
/**
* Method for retrieving the get's row
*/
@Override
public byte[] getRow() {
return this.row;
}
/**
* Method for retrieving the get's maximum number of version
* @return the maximum number of version to fetch for this get
*/
public int getMaxVersions() {
return this.maxVersions;
}
/**
* Method for retrieving the get's maximum number of values to return per Column Family
* @return the maximum number of values to fetch per CF
*/
public int getMaxResultsPerColumnFamily() {
return this.storeLimit;
}
/**
* Method for retrieving the get's offset per row per column family (#kvs to be skipped)
* @return the row offset
*/
public int getRowOffsetPerColumnFamily() {
return this.storeOffset;
}
/**
* Method for retrieving the get's TimeRange
*/
public TimeRange getTimeRange() {
return this.tr;
}
/**
* Method for retrieving the keys in the familyMap
* @return keys in the current familyMap
*/
public Set familySet() {
return this.familyMap.keySet();
}
/**
* Method for retrieving the number of families to get from
* @return number of families
*/
public int numFamilies() {
return this.familyMap.size();
}
/**
* Method for checking if any families have been inserted into this Get
* @return true if familyMap is non empty false otherwise
*/
public boolean hasFamilies() {
return !this.familyMap.isEmpty();
}
/**
* Method for retrieving the get's familyMap
*/
public Map> getFamilyMap() {
return this.familyMap;
}
/**
* Compile the table and column family (i.e. schema) information into a String. Useful for parsing
* and aggregation by debugging, logging, and administration tools.
*/
@Override
public Map getFingerprint() {
Map map = new HashMap<>();
List families = new ArrayList<>(this.familyMap.entrySet().size());
map.put("families", families);
for (Map.Entry> entry : this.familyMap.entrySet()) {
families.add(Bytes.toStringBinary(entry.getKey()));
}
return map;
}
/**
* Compile the details beyond the scope of getFingerprint (row, columns, timestamps, etc.) into a
* Map along with the fingerprinted information. Useful for debugging, logging, and administration
* tools.
* @param maxCols a limit on the number of columns output prior to truncation
*/
@Override
public Map toMap(int maxCols) {
// we start with the fingerprint map and build on top of it.
Map map = getFingerprint();
// replace the fingerprint's simple list of families with a
// map from column families to lists of qualifiers and kv details
Map> columns = new HashMap<>();
map.put("families", columns);
// add scalar information first
map.put("row", Bytes.toStringBinary(this.row));
map.put("maxVersions", this.maxVersions);
map.put("cacheBlocks", this.cacheBlocks);
List timeRange = new ArrayList<>(2);
timeRange.add(this.tr.getMin());
timeRange.add(this.tr.getMax());
map.put("timeRange", timeRange);
int colCount = 0;
// iterate through affected families and add details
for (Map.Entry> entry : this.familyMap.entrySet()) {
List familyList = new ArrayList<>();
columns.put(Bytes.toStringBinary(entry.getKey()), familyList);
if (entry.getValue() == null) {
colCount++;
--maxCols;
familyList.add("ALL");
} else {
colCount += entry.getValue().size();
if (maxCols <= 0) {
continue;
}
for (byte[] column : entry.getValue()) {
if (--maxCols <= 0) {
continue;
}
familyList.add(Bytes.toStringBinary(column));
}
}
}
map.put("totalColumns", colCount);
if (this.filter != null) {
map.put("filter", this.filter.toString());
}
// add the id if set
if (getId() != null) {
map.put("id", getId());
}
return map;
}
// Row
@Override
public int compareTo(Row other) {
// TODO: This is wrong. Can't have two gets the same just because on same row.
return Bytes.compareTo(this.getRow(), other.getRow());
}
@Override
public int hashCode() {
// TODO: This is wrong. Can't have two gets the same just because on same row. But it
// matches how equals works currently and gets rid of the findbugs warning.
return Bytes.hashCode(this.getRow());
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof Row)) {
return false;
}
Row other = (Row) obj;
// TODO: This is wrong. Can't have two gets the same just because on same row.
return compareTo(other) == 0;
}
@Override
public Get setAttribute(String name, byte[] value) {
return (Get) super.setAttribute(name, value);
}
@Override
public Get setId(String id) {
return (Get) super.setId(id);
}
@Override
public Get setAuthorizations(Authorizations authorizations) {
return (Get) super.setAuthorizations(authorizations);
}
@Override
public Get setACL(Map perms) {
return (Get) super.setACL(perms);
}
@Override
public Get setACL(String user, Permission perms) {
return (Get) super.setACL(user, perms);
}
@Override
public Get setConsistency(Consistency consistency) {
return (Get) super.setConsistency(consistency);
}
@Override
public Get setReplicaId(int Id) {
return (Get) super.setReplicaId(Id);
}
@Override
public Get setIsolationLevel(IsolationLevel level) {
return (Get) super.setIsolationLevel(level);
}
@Override
public Get setPriority(int priority) {
return (Get) super.setPriority(priority);
}
}