| /* |
| * Copyright 2010 The Apache Software Foundation |
| * |
| * 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 org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hbase.HConstants; |
| import org.apache.hadoop.hbase.KeyValue; |
| import org.apache.hadoop.hbase.filter.Filter; |
| import org.apache.hadoop.hbase.filter.IncompatibleFilterException; |
| import org.apache.hadoop.hbase.io.TimeRange; |
| import org.apache.hadoop.hbase.util.Bytes; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableFactories; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import java.util.Map; |
| import java.util.NavigableSet; |
| import java.util.TreeMap; |
| import java.util.TreeSet; |
| |
| /** |
| * Used to perform Scan operations. |
| * <p> |
| * All operations are identical to {@link Get} with the exception of |
| * instantiation. Rather than specifying a single row, an optional startRow |
| * and stopRow may be defined. If rows are not specified, the Scanner will |
| * iterate over all rows. |
| * <p> |
| * To scan everything for each row, instantiate a Scan object. |
| * <p> |
| * To modify scanner caching for just this scan, use {@link #setCaching(int) setCaching}. |
| * If caching is NOT set, we will use the caching value of the hosting |
| * {@link HTable}. See {@link HTable#setScannerCaching(int)}. |
| * <p> |
| * To further define the scope of what to get when scanning, perform additional |
| * methods as outlined below. |
| * <p> |
| * To get all columns from specific families, execute {@link #addFamily(byte[]) addFamily} |
| * for each family to retrieve. |
| * <p> |
| * To get specific columns, execute {@link #addColumn(byte[], byte[]) addColumn} |
| * for each column to retrieve. |
| * <p> |
| * To only retrieve columns within a specific range of version timestamps, |
| * execute {@link #setTimeRange(long, long) setTimeRange}. |
| * <p> |
| * To only retrieve columns with a specific timestamp, execute |
| * {@link #setTimeStamp(long) setTimestamp}. |
| * <p> |
| * To limit the number of versions of each column to be returned, execute |
| * {@link #setMaxVersions(int) setMaxVersions}. |
| * <p> |
| * To limit the maximum number of values returned for each call to next(), |
| * execute {@link #setBatch(int) setBatch}. |
| * <p> |
| * To add a filter, execute {@link #setFilter(org.apache.hadoop.hbase.filter.Filter) setFilter}. |
| * <p> |
| * Expert: To explicitly disable server-side block caching for this scan, |
| * execute {@link #setCacheBlocks(boolean)}. |
| */ |
| public class Scan implements Writable { |
| private static final byte SCAN_VERSION = (byte)1; |
| private byte [] startRow = HConstants.EMPTY_START_ROW; |
| private byte [] stopRow = HConstants.EMPTY_END_ROW; |
| private int maxVersions = 1; |
| private int batch = -1; |
| /* |
| * -1 means no caching |
| */ |
| private int caching = -1; |
| private boolean cacheBlocks = true; |
| private Filter filter = null; |
| private TimeRange tr = new TimeRange(); |
| private Map<byte [], NavigableSet<byte []>> familyMap = |
| new TreeMap<byte [], NavigableSet<byte []>>(Bytes.BYTES_COMPARATOR); |
| |
| /** |
| * Create a Scan operation across all rows. |
| */ |
| public Scan() {} |
| |
| public Scan(byte [] startRow, Filter filter) { |
| this(startRow); |
| this.filter = filter; |
| } |
| |
| /** |
| * Create a Scan operation starting at the specified row. |
| * <p> |
| * If the specified row does not exist, the Scanner will start from the |
| * next closest row after the specified row. |
| * @param startRow row to start scanner at or after |
| */ |
| public Scan(byte [] startRow) { |
| this.startRow = startRow; |
| } |
| |
| /** |
| * Create a Scan operation for the range of rows specified. |
| * @param startRow row to start scanner at or after (inclusive) |
| * @param stopRow row to stop scanner before (exclusive) |
| */ |
| public Scan(byte [] startRow, byte [] stopRow) { |
| this.startRow = startRow; |
| this.stopRow = stopRow; |
| } |
| |
| /** |
| * Creates a new instance of this class while copying all values. |
| * |
| * @param scan The scan instance to copy from. |
| * @throws IOException When copying the values fails. |
| */ |
| public Scan(Scan scan) throws IOException { |
| startRow = scan.getStartRow(); |
| stopRow = scan.getStopRow(); |
| maxVersions = scan.getMaxVersions(); |
| batch = scan.getBatch(); |
| caching = scan.getCaching(); |
| cacheBlocks = scan.getCacheBlocks(); |
| filter = scan.getFilter(); // clone? |
| TimeRange ctr = scan.getTimeRange(); |
| tr = new TimeRange(ctr.getMin(), ctr.getMax()); |
| Map<byte[], NavigableSet<byte[]>> fams = scan.getFamilyMap(); |
| for (Map.Entry<byte[],NavigableSet<byte[]>> entry : fams.entrySet()) { |
| byte [] fam = entry.getKey(); |
| NavigableSet<byte[]> cols = entry.getValue(); |
| if (cols != null && cols.size() > 0) { |
| for (byte[] col : cols) { |
| addColumn(fam, col); |
| } |
| } else { |
| addFamily(fam); |
| } |
| } |
| } |
| |
| /** |
| * Builds a scan object with the same specs as get. |
| * @param get get to model scan after |
| */ |
| public Scan(Get get) { |
| this.startRow = get.getRow(); |
| this.stopRow = get.getRow(); |
| this.filter = get.getFilter(); |
| this.cacheBlocks = get.getCacheBlocks(); |
| this.maxVersions = get.getMaxVersions(); |
| this.tr = get.getTimeRange(); |
| this.familyMap = get.getFamilyMap(); |
| } |
| |
| public boolean isGetScan() { |
| return this.startRow != null && this.startRow.length > 0 && |
| Bytes.equals(this.startRow, this.stopRow); |
| } |
| |
| /** |
| * Get all columns from the specified family. |
| * <p> |
| * Overrides previous calls to addColumn for this family. |
| * @param family family name |
| * @return this |
| */ |
| public Scan addFamily(byte [] family) { |
| familyMap.remove(family); |
| familyMap.put(family, null); |
| return this; |
| } |
| |
| /** |
| * Get the column from the specified family with the specified qualifier. |
| * <p> |
| * Overrides previous calls to addFamily for this family. |
| * @param family family name |
| * @param qualifier column qualifier |
| * @return this |
| */ |
| public Scan addColumn(byte [] family, byte [] qualifier) { |
| NavigableSet<byte []> set = familyMap.get(family); |
| if(set == null) { |
| set = new TreeSet<byte []>(Bytes.BYTES_COMPARATOR); |
| } |
| set.add(qualifier); |
| familyMap.put(family, set); |
| |
| return this; |
| } |
| |
| /** |
| * Get versions of columns only within the specified timestamp range, |
| * [minStamp, maxStamp). Note, default maximum versions to return is 1. If |
| * your time range spans more than one version and you want all versions |
| * returned, up the number of versions beyond the defaut. |
| * @param minStamp minimum timestamp value, inclusive |
| * @param maxStamp maximum timestamp value, exclusive |
| * @throws IOException if invalid time range |
| * @see #setMaxVersions() |
| * @see #setMaxVersions(int) |
| * @return this |
| */ |
| public Scan setTimeRange(long minStamp, long maxStamp) |
| throws IOException { |
| tr = new TimeRange(minStamp, maxStamp); |
| return this; |
| } |
| |
| /** |
| * Get versions of columns with the specified timestamp. Note, default maximum |
| * versions to return is 1. If your time range spans more than one version |
| * and you want all versions returned, up the number of versions beyond the |
| * defaut. |
| * @param timestamp version timestamp |
| * @see #setMaxVersions() |
| * @see #setMaxVersions(int) |
| * @return this |
| */ |
| public Scan setTimeStamp(long timestamp) { |
| try { |
| tr = new TimeRange(timestamp, timestamp+1); |
| } catch(IOException e) { |
| // Will never happen |
| } |
| return this; |
| } |
| |
| /** |
| * Set the start row of the scan. |
| * @param startRow row to start scan on, inclusive |
| * @return this |
| */ |
| public Scan setStartRow(byte [] startRow) { |
| this.startRow = startRow; |
| return this; |
| } |
| |
| /** |
| * Set the stop row. |
| * @param stopRow row to end at (exclusive) |
| * @return this |
| */ |
| public Scan setStopRow(byte [] stopRow) { |
| this.stopRow = stopRow; |
| return this; |
| } |
| |
| /** |
| * Get all available versions. |
| * @return this |
| */ |
| public Scan setMaxVersions() { |
| this.maxVersions = Integer.MAX_VALUE; |
| return this; |
| } |
| |
| /** |
| * Get up to the specified number of versions of each column. |
| * @param maxVersions maximum versions for each column |
| * @return this |
| */ |
| public Scan setMaxVersions(int maxVersions) { |
| this.maxVersions = maxVersions; |
| return this; |
| } |
| |
| /** |
| * Set the maximum number of values to return for each call to next() |
| * @param batch the maximum number of values |
| */ |
| public void setBatch(int batch) { |
| if(this.hasFilter() && this.filter.hasFilterRow()) { |
| throw new IncompatibleFilterException( |
| "Cannot set batch on a scan using a filter" + |
| " that returns true for filter.hasFilterRow"); |
| } |
| this.batch = batch; |
| } |
| |
| /** |
| * Set the number of rows for caching that will be passed to scanners. |
| * If not set, the default setting from {@link HTable#getScannerCaching()} will apply. |
| * Higher caching values will enable faster scanners but will use more memory. |
| * @param caching the number of rows for caching |
| */ |
| public void setCaching(int caching) { |
| this.caching = caching; |
| } |
| |
| /** |
| * Apply the specified server-side filter when performing the Scan. |
| * @param filter filter to run on the server |
| * @return this |
| */ |
| public Scan setFilter(Filter filter) { |
| this.filter = filter; |
| return this; |
| } |
| |
| /** |
| * Setting the familyMap |
| * @param familyMap map of family to qualifier |
| * @return this |
| */ |
| public Scan setFamilyMap(Map<byte [], NavigableSet<byte []>> familyMap) { |
| this.familyMap = familyMap; |
| return this; |
| } |
| |
| /** |
| * Getting the familyMap |
| * @return familyMap |
| */ |
| public Map<byte [], NavigableSet<byte []>> getFamilyMap() { |
| return this.familyMap; |
| } |
| |
| /** |
| * @return the number of families in familyMap |
| */ |
| public int numFamilies() { |
| if(hasFamilies()) { |
| return this.familyMap.size(); |
| } |
| return 0; |
| } |
| |
| /** |
| * @return true if familyMap is non empty, false otherwise |
| */ |
| public boolean hasFamilies() { |
| return !this.familyMap.isEmpty(); |
| } |
| |
| /** |
| * @return the keys of the familyMap |
| */ |
| public byte[][] getFamilies() { |
| if(hasFamilies()) { |
| return this.familyMap.keySet().toArray(new byte[0][0]); |
| } |
| return null; |
| } |
| |
| /** |
| * @return the startrow |
| */ |
| public byte [] getStartRow() { |
| return this.startRow; |
| } |
| |
| /** |
| * @return the stoprow |
| */ |
| public byte [] getStopRow() { |
| return this.stopRow; |
| } |
| |
| /** |
| * @return the max number of versions to fetch |
| */ |
| public int getMaxVersions() { |
| return this.maxVersions; |
| } |
| |
| /** |
| * @return maximum number of values to return for a single call to next() |
| */ |
| public int getBatch() { |
| return this.batch; |
| } |
| |
| /** |
| * @return caching the number of rows fetched when calling next on a scanner |
| */ |
| public int getCaching() { |
| return this.caching; |
| } |
| |
| /** |
| * @return TimeRange |
| */ |
| public TimeRange getTimeRange() { |
| return this.tr; |
| } |
| |
| /** |
| * @return RowFilter |
| */ |
| public Filter getFilter() { |
| return filter; |
| } |
| |
| /** |
| * @return true is a filter has been specified, false if not |
| */ |
| public boolean hasFilter() { |
| return filter != null; |
| } |
| |
| /** |
| * Set whether blocks should be cached for this Scan. |
| * <p> |
| * 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 void setCacheBlocks(boolean cacheBlocks) { |
| this.cacheBlocks = cacheBlocks; |
| } |
| |
| /** |
| * Get whether blocks should be cached for this Scan. |
| * @return true if default caching should be used, false if blocks should not |
| * be cached |
| */ |
| public boolean getCacheBlocks() { |
| return cacheBlocks; |
| } |
| |
| /** |
| * @return String |
| */ |
| @Override |
| public String toString() { |
| StringBuilder sb = new StringBuilder(); |
| sb.append("startRow="); |
| sb.append(Bytes.toStringBinary(this.startRow)); |
| sb.append(", stopRow="); |
| sb.append(Bytes.toStringBinary(this.stopRow)); |
| sb.append(", maxVersions="); |
| sb.append(this.maxVersions); |
| sb.append(", batch="); |
| sb.append(this.batch); |
| sb.append(", caching="); |
| sb.append(this.caching); |
| sb.append(", cacheBlocks="); |
| sb.append(this.cacheBlocks); |
| sb.append(", timeRange="); |
| sb.append("[").append(this.tr.getMin()).append(","); |
| sb.append(this.tr.getMax()).append(")"); |
| sb.append(", families="); |
| if(this.familyMap.size() == 0) { |
| sb.append("ALL"); |
| return sb.toString(); |
| } |
| boolean moreThanOne = false; |
| for(Map.Entry<byte [], NavigableSet<byte[]>> entry : this.familyMap.entrySet()) { |
| if(moreThanOne) { |
| sb.append("), "); |
| } else { |
| moreThanOne = true; |
| sb.append("{"); |
| } |
| sb.append("(family="); |
| sb.append(Bytes.toStringBinary(entry.getKey())); |
| sb.append(", columns="); |
| if(entry.getValue() == null) { |
| sb.append("ALL"); |
| } else { |
| sb.append("{"); |
| boolean moreThanOneB = false; |
| for(byte [] column : entry.getValue()) { |
| if(moreThanOneB) { |
| sb.append(", "); |
| } else { |
| moreThanOneB = true; |
| } |
| sb.append(Bytes.toStringBinary(column)); |
| } |
| sb.append("}"); |
| } |
| } |
| sb.append("}"); |
| return sb.toString(); |
| } |
| |
| @SuppressWarnings("unchecked") |
| private Writable createForName(String className) { |
| try { |
| Class<? extends Writable> clazz = |
| (Class<? extends Writable>) Class.forName(className); |
| return WritableFactories.newInstance(clazz, new Configuration()); |
| } catch (ClassNotFoundException e) { |
| throw new RuntimeException("Can't find class " + className); |
| } |
| } |
| |
| //Writable |
| public void readFields(final DataInput in) |
| throws IOException { |
| int version = in.readByte(); |
| if (version > (int)SCAN_VERSION) { |
| throw new IOException("version not supported"); |
| } |
| this.startRow = Bytes.readByteArray(in); |
| this.stopRow = Bytes.readByteArray(in); |
| this.maxVersions = in.readInt(); |
| this.batch = in.readInt(); |
| this.caching = in.readInt(); |
| this.cacheBlocks = in.readBoolean(); |
| if(in.readBoolean()) { |
| this.filter = (Filter)createForName(Bytes.toString(Bytes.readByteArray(in))); |
| this.filter.readFields(in); |
| } |
| this.tr = new TimeRange(); |
| tr.readFields(in); |
| int numFamilies = in.readInt(); |
| this.familyMap = |
| new TreeMap<byte [], NavigableSet<byte []>>(Bytes.BYTES_COMPARATOR); |
| for(int i=0; i<numFamilies; i++) { |
| byte [] family = Bytes.readByteArray(in); |
| int numColumns = in.readInt(); |
| TreeSet<byte []> set = new TreeSet<byte []>(Bytes.BYTES_COMPARATOR); |
| for(int j=0; j<numColumns; j++) { |
| byte [] qualifier = Bytes.readByteArray(in); |
| set.add(qualifier); |
| } |
| this.familyMap.put(family, set); |
| } |
| } |
| |
| public void write(final DataOutput out) |
| throws IOException { |
| out.writeByte(SCAN_VERSION); |
| Bytes.writeByteArray(out, this.startRow); |
| Bytes.writeByteArray(out, this.stopRow); |
| out.writeInt(this.maxVersions); |
| out.writeInt(this.batch); |
| out.writeInt(this.caching); |
| out.writeBoolean(this.cacheBlocks); |
| if(this.filter == null) { |
| out.writeBoolean(false); |
| } else { |
| out.writeBoolean(true); |
| Bytes.writeByteArray(out, Bytes.toBytes(filter.getClass().getName())); |
| filter.write(out); |
| } |
| tr.write(out); |
| out.writeInt(familyMap.size()); |
| for(Map.Entry<byte [], NavigableSet<byte []>> entry : familyMap.entrySet()) { |
| Bytes.writeByteArray(out, entry.getKey()); |
| NavigableSet<byte []> columnSet = entry.getValue(); |
| if(columnSet != null){ |
| out.writeInt(columnSet.size()); |
| for(byte [] qualifier : columnSet) { |
| Bytes.writeByteArray(out, qualifier); |
| } |
| } else { |
| out.writeInt(0); |
| } |
| } |
| } |
| |
| /** |
| * Parses a combined family and qualifier and adds either both or just the |
| * family in case there is not qualifier. This assumes the older colon |
| * divided notation, e.g. "data:contents" or "meta:". |
| * <p> |
| * Note: It will through an error when the colon is missing. |
| * |
| * @param familyAndQualifier family and qualifier |
| * @return A reference to this instance. |
| * @throws IllegalArgumentException When the colon is missing. |
| * @deprecated use {@link #addColumn(byte[], byte[])} instead |
| */ |
| public Scan addColumn(byte[] familyAndQualifier) { |
| byte [][] fq = KeyValue.parseColumn(familyAndQualifier); |
| if (fq.length > 1 && fq[1] != null && fq[1].length > 0) { |
| addColumn(fq[0], fq[1]); |
| } else { |
| addFamily(fq[0]); |
| } |
| return this; |
| } |
| |
| /** |
| * Adds an array of columns specified using old format, family:qualifier. |
| * <p> |
| * Overrides previous calls to addFamily for any families in the input. |
| * |
| * @param columns array of columns, formatted as <pre>family:qualifier</pre> |
| * @deprecated issue multiple {@link #addColumn(byte[], byte[])} instead |
| * @return this |
| */ |
| public Scan addColumns(byte [][] columns) { |
| for (byte[] column : columns) { |
| addColumn(column); |
| } |
| return this; |
| } |
| |
| /** |
| * Convenience method to help parse old style (or rather user entry on the |
| * command line) column definitions, e.g. "data:contents mime:". The columns |
| * must be space delimited and always have a colon (":") to denote family |
| * and qualifier. |
| * |
| * @param columns The columns to parse. |
| * @return A reference to this instance. |
| * @deprecated use {@link #addColumn(byte[], byte[])} instead |
| */ |
| public Scan addColumns(String columns) { |
| String[] cols = columns.split(" "); |
| for (String col : cols) { |
| addColumn(Bytes.toBytes(col)); |
| } |
| return this; |
| } |
| |
| /** |
| * Helps to convert the binary column families and qualifiers to a text |
| * representation, e.g. "data:mimetype data:contents meta:". Binary values |
| * are properly encoded using {@link Bytes#toBytesBinary(String)}. |
| * |
| * @return The columns in an old style string format. |
| * @deprecated |
| */ |
| public String getInputColumns() { |
| StringBuilder cols = new StringBuilder(""); |
| for (Map.Entry<byte[], NavigableSet<byte[]>> e : |
| familyMap.entrySet()) { |
| byte[] fam = e.getKey(); |
| if (cols.length() > 0) cols.append(" "); |
| NavigableSet<byte[]> quals = e.getValue(); |
| // check if this family has qualifiers |
| if (quals != null && quals.size() > 0) { |
| StringBuilder cs = new StringBuilder(""); |
| for (byte[] qual : quals) { |
| if (cs.length() > 0) cs.append(" "); |
| // encode values to make parsing easier later |
| cs.append(Bytes.toStringBinary(fam)).append(":").append(Bytes.toStringBinary(qual)); |
| } |
| cols.append(cs); |
| } else { |
| // only add the family but with old style delimiter |
| cols.append(Bytes.toStringBinary(fam)).append(":"); |
| } |
| } |
| return cols.toString(); |
| } |
| } |