HBASE-13510 - Purge ByteBloomFilter (Ram)

This commit is contained in:
ramkrishna 2015-05-19 10:22:56 +05:30
parent 901714d75d
commit 5e7e626ef5
14 changed files with 760 additions and 790 deletions

View File

@ -59,8 +59,8 @@ import org.apache.hadoop.hbase.io.FSDataInputStreamWrapper;
import org.apache.hadoop.hbase.io.hfile.HFile.FileInfo;
import org.apache.hadoop.hbase.regionserver.TimeRangeTracker;
import org.apache.hadoop.hbase.util.BloomFilter;
import org.apache.hadoop.hbase.util.BloomFilterUtil;
import org.apache.hadoop.hbase.util.BloomFilterFactory;
import org.apache.hadoop.hbase.util.ByteBloomFilter;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.FSUtils;
import org.apache.hadoop.hbase.util.Writables;
@ -424,7 +424,7 @@ public class HFilePrettyPrinter extends Configured implements Tool {
System.out.println("Bloom filter:");
if (bloomFilter != null) {
System.out.println(FOUR_SPACES + bloomFilter.toString().replaceAll(
ByteBloomFilter.STATS_RECORD_SEP, "\n" + FOUR_SPACES));
BloomFilterUtil.STATS_RECORD_SEP, "\n" + FOUR_SPACES));
} else {
System.out.println(FOUR_SPACES + "Not present");
}
@ -438,7 +438,7 @@ public class HFilePrettyPrinter extends Configured implements Tool {
System.out.println("Delete Family Bloom filter:");
if (bloomFilter != null) {
System.out.println(FOUR_SPACES
+ bloomFilter.toString().replaceAll(ByteBloomFilter.STATS_RECORD_SEP,
+ bloomFilter.toString().replaceAll(BloomFilterUtil.STATS_RECORD_SEP,
"\n" + FOUR_SPACES));
} else {
System.out.println(FOUR_SPACES + "Not present");

View File

@ -707,7 +707,6 @@ public class StoreFile {
private final BloomType bloomType;
private byte[] lastBloomKey;
private int lastBloomKeyOffset, lastBloomKeyLen;
private CellComparator kvComparator;
private Cell lastCell = null;
private long earliestPutTs = HConstants.LATEST_TIMESTAMP;
private Cell lastDeleteFamilyCell = null;
@ -754,8 +753,6 @@ public class StoreFile {
.withFileContext(fileContext)
.create();
this.kvComparator = comparator;
generalBloomFilterWriter = BloomFilterFactory.createGeneralBloomAtWrite(
conf, cacheConf, bloomType,
(int) Math.min(maxKeys, Integer.MAX_VALUE), writer);
@ -864,7 +861,9 @@ public class StoreFile {
* 1. Row = Row
* 2. RowCol = Row + Qualifier
*/
byte[] bloomKey;
byte[] bloomKey = null;
// Used with ROW_COL bloom
KeyValue bloomKeyKV = null;
int bloomKeyOffset, bloomKeyLen;
switch (bloomType) {
@ -877,11 +876,14 @@ public class StoreFile {
// merge(row, qualifier)
// TODO: could save one buffer copy in case of compound Bloom
// filters when this involves creating a KeyValue
bloomKey = generalBloomFilterWriter.createBloomKey(cell.getRowArray(),
cell.getRowOffset(), cell.getRowLength(), cell.getQualifierArray(),
cell.getQualifierOffset(), cell.getQualifierLength());
bloomKeyOffset = 0;
bloomKeyLen = bloomKey.length;
bloomKeyKV = KeyValueUtil.createFirstOnRow(cell.getRowArray(), cell.getRowOffset(),
cell.getRowLength(),
HConstants.EMPTY_BYTE_ARRAY, 0, 0, cell.getQualifierArray(),
cell.getQualifierOffset(),
cell.getQualifierLength());
bloomKey = bloomKeyKV.getBuffer();
bloomKeyOffset = bloomKeyKV.getKeyOffset();
bloomKeyLen = bloomKeyKV.getKeyLength();
break;
default:
throw new IOException("Invalid Bloom filter type: " + bloomType +
@ -889,17 +891,17 @@ public class StoreFile {
}
generalBloomFilterWriter.add(bloomKey, bloomKeyOffset, bloomKeyLen);
if (lastBloomKey != null) {
boolean res = false;
int res = 0;
// hbase:meta does not have blooms. So we need not have special interpretation
// of the hbase:meta cells. We can safely use Bytes.BYTES_RAWCOMPARATOR for ROW Bloom
if (bloomType == BloomType.ROW) {
res = Bytes.BYTES_RAWCOMPARATOR.compare(bloomKey, bloomKeyOffset, bloomKeyLen,
lastBloomKey, lastBloomKeyOffset, lastBloomKeyLen) <= 0;
lastBloomKey, lastBloomKeyOffset, lastBloomKeyLen);
} else {
res = (CellComparator.COMPARATOR.compare(lastBloomKeyOnlyKV, bloomKey,
bloomKeyOffset, bloomKeyLen) >= 0);
// TODO : Caching of kv components becomes important in these cases
res = CellComparator.COMPARATOR.compare(bloomKeyKV, lastBloomKeyOnlyKV);
}
if (res) {
if (res <= 0) {
throw new IOException("Non-increasing Bloom keys: "
+ Bytes.toStringBinary(bloomKey, bloomKeyOffset, bloomKeyLen) + " after "
+ Bytes.toStringBinary(lastBloomKey, lastBloomKeyOffset, lastBloomKeyLen));
@ -1252,7 +1254,10 @@ public class StoreFile {
return true;
}
byte[] key;
// Used in ROW bloom
byte[] key = null;
// Used in ROW_COL bloom
KeyValue kvKey = null;
switch (bloomFilterType) {
case ROW:
if (col != null) {
@ -1267,8 +1272,9 @@ public class StoreFile {
break;
case ROWCOL:
key = bloomFilter.createBloomKey(row, rowOffset, rowLen, col,
colOffset, colLen);
kvKey = KeyValueUtil.createFirstOnRow(row, rowOffset, rowLen,
HConstants.EMPTY_BYTE_ARRAY, 0, 0, col, colOffset,
colLen);
break;
default:
@ -1304,9 +1310,7 @@ public class StoreFile {
if (bloomFilterType == BloomType.ROW) {
keyIsAfterLast = (Bytes.BYTES_RAWCOMPARATOR.compare(key, lastBloomKey) > 0);
} else {
// TODO : Convert key to Cell so that we could use compare(Cell, Cell)
keyIsAfterLast = (CellComparator.COMPARATOR.compare(lastBloomKeyOnlyKV, key, 0,
key.length)) < 0;
keyIsAfterLast = (CellComparator.COMPARATOR.compare(kvKey, lastBloomKeyOnlyKV)) > 0;
}
}
@ -1315,19 +1319,17 @@ public class StoreFile {
// columns, a file might be skipped if using row+col Bloom filter.
// In order to ensure this file is included an additional check is
// required looking only for a row bloom.
byte[] rowBloomKey = bloomFilter.createBloomKey(row, rowOffset, rowLen,
null, 0, 0);
KeyValue rowBloomKey = KeyValueUtil.createFirstOnRow(row, rowOffset, rowLen,
HConstants.EMPTY_BYTE_ARRAY, 0, 0, HConstants.EMPTY_BYTE_ARRAY, 0, 0);
// hbase:meta does not have blooms. So we need not have special interpretation
// of the hbase:meta cells. We can safely use Bytes.BYTES_RAWCOMPARATOR for ROW Bloom
if (keyIsAfterLast
&& (CellComparator.COMPARATOR.compare(lastBloomKeyOnlyKV, rowBloomKey, 0,
rowBloomKey.length)) < 0) {
&& (CellComparator.COMPARATOR.compare(rowBloomKey, lastBloomKeyOnlyKV)) > 0) {
exists = false;
} else {
exists =
bloomFilter.contains(key, 0, key.length, bloom) ||
bloomFilter.contains(rowBloomKey, 0, rowBloomKey.length,
bloom);
bloomFilter.contains(kvKey, bloom) ||
bloomFilter.contains(rowBloomKey, bloom);
}
} else {
exists = !keyIsAfterLast

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@ -20,24 +20,57 @@ package org.apache.hadoop.hbase.util;
import java.nio.ByteBuffer;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
/**
* Defines the general behavior of a bloom filter.
*
* Implements a <i>Bloom filter</i>, as defined by Bloom in 1970.
* <p>
* The Bloom filter is a data structure that was introduced in 1970 and that
* has been adopted by the networking research community in the past decade
* thanks to the bandwidth efficiencies that it offers for the transmission of
* set membership information between networked hosts. A sender encodes the
* The Bloom filter is a data structure that was introduced in 1970 and that has
* been adopted by the networking research community in the past decade thanks
* to the bandwidth efficiencies that it offers for the transmission of set
* membership information between networked hosts. A sender encodes the
* information into a bit vector, the Bloom filter, that is more compact than a
* conventional representation. Computation and space costs for construction
* are linear in the number of elements. The receiver uses the filter to test
* conventional representation. Computation and space costs for construction are
* linear in the number of elements. The receiver uses the filter to test
* whether various elements are members of the set. Though the filter will
* occasionally return a false positive, it will never return a false negative.
* When creating the filter, the sender can choose its desired point in a
* trade-off between the false positive rate and the size.
*
* <p>
* Originally inspired by <a href="http://www.one-lab.org">European Commission
* One-Lab Project 034819</a>.
*
* Bloom filters are very sensitive to the number of elements inserted into
* them. For HBase, the number of entries depends on the size of the data stored
* in the column. Currently the default region size is 256MB, so entry count ~=
* 256MB / (average value size for column). Despite this rule of thumb, there is
* no efficient way to calculate the entry count after compactions. Therefore,
* it is often easier to use a dynamic bloom filter that will add extra space
* instead of allowing the error rate to grow.
*
* ( http://www.eecs.harvard.edu/~michaelm/NEWWORK/postscripts/BloomFilterSurvey
* .pdf )
*
* m denotes the number of bits in the Bloom filter (bitSize) n denotes the
* number of elements inserted into the Bloom filter (maxKeys) k represents the
* number of hash functions used (nbHash) e represents the desired false
* positive rate for the bloom (err)
*
* If we fix the error rate (e) and know the number of entries, then the optimal
* bloom size m = -(n * ln(err) / (ln(2)^2) ~= n * ln(err) / ln(0.6185)
*
* The probability of false positives is minimized when k = m/n ln(2).
*
* @see BloomFilter The general behavior of a filter
*
* @see <a
* href="http://portal.acm.org/citation.cfm?id=362692&dl=ACM&coll=portal">
* Space/Time Trade-Offs in Hash Coding with Allowable Errors</a>
*
* @see BloomFilterWriter for the ability to add elements to a Bloom filter
*/
@InterfaceAudience.Private
@ -45,7 +78,17 @@ public interface BloomFilter extends BloomFilterBase {
/**
* Check if the specified key is contained in the bloom filter.
*
* Used in ROW_COL blooms where the blooms are serialized as KeyValues
* @param keyCell the key to check for the existence of
* @param bloom bloom filter data to search. This can be null if auto-loading
* is supported.
* @return true if matched by bloom, false if not
*/
boolean contains(Cell keyCell, ByteBuffer bloom);
/**
* Check if the specified key is contained in the bloom filter.
* Used in ROW bloom where the blooms are just plain byte[]
* @param buf data to check for existence of
* @param offset offset into the data
* @param length length of the data

View File

@ -41,11 +41,4 @@ public interface BloomFilterBase {
* @return Size of the bloom, in bytes
*/
long getByteSize();
/**
* Create a key for a row-column Bloom filter.
*/
byte[] createBloomKey(byte[] rowBuf, int rowOffset, int rowLen,
byte[] qualBuf, int qualOffset, int qualLen);
}

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@ -0,0 +1,322 @@
/*
*
* 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.util;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.nio.ByteBuffer;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import com.google.common.annotations.VisibleForTesting;
/**
* The basic building block for the {@link CompoundBloomFilter}
*/
@InterfaceAudience.Private
public class BloomFilterChunk implements BloomFilterBase {
/** Bytes (B) in the array. This actually has to fit into an int. */
protected long byteSize;
/** Number of hash functions */
protected int hashCount;
/** Hash type */
protected final int hashType;
/** Hash Function */
protected final Hash hash;
/** Keys currently in the bloom */
protected int keyCount;
/** Max Keys expected for the bloom */
protected int maxKeys;
/** Bloom bits */
protected ByteBuffer bloom;
/**
* Loads bloom filter meta data from file input.
* @param meta stored bloom meta data
* @throws IllegalArgumentException meta data is invalid
*/
public BloomFilterChunk(DataInput meta)
throws IOException, IllegalArgumentException {
this.byteSize = meta.readInt();
this.hashCount = meta.readInt();
this.hashType = meta.readInt();
this.keyCount = meta.readInt();
this.maxKeys = this.keyCount;
this.hash = Hash.getInstance(this.hashType);
if (hash == null) {
throw new IllegalArgumentException("Invalid hash type: " + hashType);
}
sanityCheck();
}
/**
* Computes the error rate for this Bloom filter, taking into account the
* actual number of hash functions and keys inserted. The return value of
* this function changes as a Bloom filter is being populated. Used for
* reporting the actual error rate of compound Bloom filters when writing
* them out.
*
* @return error rate for this particular Bloom filter
*/
public double actualErrorRate() {
return BloomFilterUtil.actualErrorRate(keyCount, byteSize * 8, hashCount);
}
public BloomFilterChunk(int hashType) {
this.hashType = hashType;
this.hash = Hash.getInstance(hashType);
}
/**
* Determines & initializes bloom filter meta data from user config. Call
* {@link #allocBloom()} to allocate bloom filter data.
*
* @param maxKeys Maximum expected number of keys that will be stored in this
* bloom
* @param errorRate Desired false positive error rate. Lower rate = more
* storage required
* @param hashType Type of hash function to use
* @param foldFactor When finished adding entries, you may be able to 'fold'
* this bloom to save space. Tradeoff potentially excess bytes in
* bloom for ability to fold if keyCount is exponentially greater
* than maxKeys.
* @throws IllegalArgumentException
*/
public BloomFilterChunk(int maxKeys, double errorRate, int hashType,
int foldFactor) throws IllegalArgumentException {
this(hashType);
long bitSize = BloomFilterUtil.computeBitSize(maxKeys, errorRate);
hashCount = BloomFilterUtil.optimalFunctionCount(maxKeys, bitSize);
this.maxKeys = maxKeys;
// increase byteSize so folding is possible
byteSize = BloomFilterUtil.computeFoldableByteSize(bitSize, foldFactor);
sanityCheck();
}
/**
* Creates another similar Bloom filter. Does not copy the actual bits, and
* sets the new filter's key count to zero.
*
* @return a Bloom filter with the same configuration as this
*/
public BloomFilterChunk createAnother() {
BloomFilterChunk bbf = new BloomFilterChunk(hashType);
bbf.byteSize = byteSize;
bbf.hashCount = hashCount;
bbf.maxKeys = maxKeys;
return bbf;
}
public void allocBloom() {
if (this.bloom != null) {
throw new IllegalArgumentException("can only create bloom once.");
}
this.bloom = ByteBuffer.allocate((int)this.byteSize);
assert this.bloom.hasArray();
}
void sanityCheck() throws IllegalArgumentException {
if(0 >= this.byteSize || this.byteSize > Integer.MAX_VALUE) {
throw new IllegalArgumentException("Invalid byteSize: " + this.byteSize);
}
if(this.hashCount <= 0) {
throw new IllegalArgumentException("Hash function count must be > 0");
}
if (this.hash == null) {
throw new IllegalArgumentException("hashType must be known");
}
if (this.keyCount < 0) {
throw new IllegalArgumentException("must have positive keyCount");
}
}
void bloomCheck(ByteBuffer bloom) throws IllegalArgumentException {
if (this.byteSize != bloom.limit()) {
throw new IllegalArgumentException(
"Configured bloom length should match actual length");
}
}
public void add(byte [] buf) {
add(buf, 0, buf.length);
}
public void add(byte [] buf, int offset, int len) {
/*
* For faster hashing, use combinatorial generation
* http://www.eecs.harvard.edu/~kirsch/pubs/bbbf/esa06.pdf
*/
int hash1 = this.hash.hash(buf, offset, len, 0);
int hash2 = this.hash.hash(buf, offset, len, hash1);
for (int i = 0; i < this.hashCount; i++) {
long hashLoc = Math.abs((hash1 + i * hash2) % (this.byteSize * 8));
set(hashLoc);
}
++this.keyCount;
}
@VisibleForTesting
boolean contains(byte [] buf) {
return contains(buf, 0, buf.length, this.bloom);
}
@VisibleForTesting
boolean contains(byte [] buf, int offset, int length) {
return contains(buf, offset, length, bloom);
}
@VisibleForTesting
boolean contains(byte[] buf, ByteBuffer bloom) {
return contains(buf, 0, buf.length, bloom);
}
public boolean contains(byte[] buf, int offset, int length, ByteBuffer theBloom) {
if (theBloom == null) {
theBloom = bloom;
}
if (theBloom.limit() != byteSize) {
throw new IllegalArgumentException("Bloom does not match expected size:"
+ " theBloom.limit()=" + theBloom.limit() + ", byteSize=" + byteSize);
}
return BloomFilterUtil.contains(buf, offset, length, theBloom, 0, (int) byteSize, hash,
hashCount);
}
//---------------------------------------------------------------------------
/** Private helpers */
/**
* Set the bit at the specified index to 1.
*
* @param pos index of bit
*/
void set(long pos) {
int bytePos = (int)(pos / 8);
int bitPos = (int)(pos % 8);
byte curByte = bloom.get(bytePos);
curByte |= BloomFilterUtil.bitvals[bitPos];
bloom.put(bytePos, curByte);
}
/**
* Check if bit at specified index is 1.
*
* @param pos index of bit
* @return true if bit at specified index is 1, false if 0.
*/
static boolean get(int pos, ByteBuffer bloomBuf, int bloomOffset) {
int bytePos = pos >> 3; //pos / 8
int bitPos = pos & 0x7; //pos % 8
// TODO access this via Util API which can do Unsafe access if possible(?)
byte curByte = bloomBuf.get(bloomOffset + bytePos);
curByte &= BloomFilterUtil.bitvals[bitPos];
return (curByte != 0);
}
@Override
public long getKeyCount() {
return keyCount;
}
@Override
public long getMaxKeys() {
return maxKeys;
}
@Override
public long getByteSize() {
return byteSize;
}
public int getHashType() {
return hashType;
}
public void compactBloom() {
// see if the actual size is exponentially smaller than expected.
if (this.keyCount > 0 && this.bloom.hasArray()) {
int pieces = 1;
int newByteSize = (int)this.byteSize;
int newMaxKeys = this.maxKeys;
// while exponentially smaller & folding is lossless
while ((newByteSize & 1) == 0 && newMaxKeys > (this.keyCount<<1)) {
pieces <<= 1;
newByteSize >>= 1;
newMaxKeys >>= 1;
}
// if we should fold these into pieces
if (pieces > 1) {
byte[] array = this.bloom.array();
int start = this.bloom.arrayOffset();
int end = start + newByteSize;
int off = end;
for(int p = 1; p < pieces; ++p) {
for(int pos = start; pos < end; ++pos) {
array[pos] |= array[off++];
}
}
// folding done, only use a subset of this array
this.bloom.rewind();
this.bloom.limit(newByteSize);
this.bloom = this.bloom.slice();
this.byteSize = newByteSize;
this.maxKeys = newMaxKeys;
}
}
}
/**
* Writes just the bloom filter to the output array
* @param out OutputStream to place bloom
* @throws IOException Error writing bloom array
*/
public void writeBloom(final DataOutput out)
throws IOException {
if (!this.bloom.hasArray()) {
throw new IOException("Only writes ByteBuffer with underlying array.");
}
out.write(this.bloom.array(), this.bloom.arrayOffset(), this.bloom.limit());
}
public int getHashCount() {
return hashCount;
}
@Override
public String toString() {
return BloomFilterUtil.toString(this);
}
}

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@ -99,13 +99,6 @@ public final class BloomFilterFactory {
throws IllegalArgumentException, IOException {
int version = meta.readInt();
switch (version) {
case ByteBloomFilter.VERSION:
// This is only possible in a version 1 HFile. We are ignoring the
// passed comparator because raw byte comparators are always used
// in version 1 Bloom filters.
// TODO:Remove this code - use only CompoundBloomFilter
return new ByteBloomFilter(meta);
case CompoundBloomFilterBase.VERSION:
return new CompoundBloomFilter(meta, reader);

View File

@ -0,0 +1,269 @@
/*
* 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.util;
import java.nio.ByteBuffer;
import java.text.NumberFormat;
import java.util.Random;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
/**
* Utility methods related to BloomFilters
*/
@InterfaceAudience.Private
public class BloomFilterUtil {
/** Record separator for the Bloom filter statistics human-readable string */
public static final String STATS_RECORD_SEP = "; ";
/**
* Used in computing the optimal Bloom filter size. This approximately equals
* 0.480453.
*/
public static final double LOG2_SQUARED = Math.log(2) * Math.log(2);
/**
* A random number generator to use for "fake lookups" when testing to
* estimate the ideal false positive rate.
*/
private static Random randomGeneratorForTest;
/** Bit-value lookup array to prevent doing the same work over and over */
public static final byte [] bitvals = {
(byte) 0x01,
(byte) 0x02,
(byte) 0x04,
(byte) 0x08,
(byte) 0x10,
(byte) 0x20,
(byte) 0x40,
(byte) 0x80
};
/**
* @param maxKeys
* @param errorRate
* @return the number of bits for a Bloom filter than can hold the given
* number of keys and provide the given error rate, assuming that the
* optimal number of hash functions is used and it does not have to
* be an integer.
*/
public static long computeBitSize(long maxKeys, double errorRate) {
return (long) Math.ceil(maxKeys * (-Math.log(errorRate) / LOG2_SQUARED));
}
public static void setFakeLookupMode(boolean enabled) {
if (enabled) {
randomGeneratorForTest = new Random(283742987L);
} else {
randomGeneratorForTest = null;
}
}
/**
* The maximum number of keys we can put into a Bloom filter of a certain
* size to maintain the given error rate, assuming the number of hash
* functions is chosen optimally and does not even have to be an integer
* (hence the "ideal" in the function name).
*
* @param bitSize
* @param errorRate
* @return maximum number of keys that can be inserted into the Bloom filter
* @see #computeMaxKeys(long, double, int) for a more precise estimate
*/
public static long idealMaxKeys(long bitSize, double errorRate) {
// The reason we need to use floor here is that otherwise we might put
// more keys in a Bloom filter than is allowed by the target error rate.
return (long) (bitSize * (LOG2_SQUARED / -Math.log(errorRate)));
}
/**
* The maximum number of keys we can put into a Bloom filter of a certain
* size to get the given error rate, with the given number of hash functions.
*
* @param bitSize
* @param errorRate
* @param hashCount
* @return the maximum number of keys that can be inserted in a Bloom filter
* to maintain the target error rate, if the number of hash functions
* is provided.
*/
public static long computeMaxKeys(long bitSize, double errorRate,
int hashCount) {
return (long) (-bitSize * 1.0 / hashCount *
Math.log(1 - Math.exp(Math.log(errorRate) / hashCount)));
}
/**
* Computes the actual error rate for the given number of elements, number
* of bits, and number of hash functions. Taken directly from the
* <a href=
* "http://en.wikipedia.org/wiki/Bloom_filter#Probability_of_false_positives"
* > Wikipedia Bloom filter article</a>.
*
* @param maxKeys
* @param bitSize
* @param functionCount
* @return the actual error rate
*/
public static double actualErrorRate(long maxKeys, long bitSize,
int functionCount) {
return Math.exp(Math.log(1 - Math.exp(-functionCount * maxKeys * 1.0
/ bitSize)) * functionCount);
}
/**
* Increases the given byte size of a Bloom filter until it can be folded by
* the given factor.
*
* @param bitSize
* @param foldFactor
* @return Foldable byte size
*/
public static int computeFoldableByteSize(long bitSize, int foldFactor) {
long byteSizeLong = (bitSize + 7) / 8;
int mask = (1 << foldFactor) - 1;
if ((mask & byteSizeLong) != 0) {
byteSizeLong >>= foldFactor;
++byteSizeLong;
byteSizeLong <<= foldFactor;
}
if (byteSizeLong > Integer.MAX_VALUE) {
throw new IllegalArgumentException("byteSize=" + byteSizeLong + " too "
+ "large for bitSize=" + bitSize + ", foldFactor=" + foldFactor);
}
return (int) byteSizeLong;
}
public static int optimalFunctionCount(int maxKeys, long bitSize) {
long i = bitSize / maxKeys;
double result = Math.ceil(Math.log(2) * i);
if (result > Integer.MAX_VALUE){
throw new IllegalArgumentException("result too large for integer value.");
}
return (int)result;
}
/**
* Creates a Bloom filter chunk of the given size.
*
* @param byteSizeHint the desired number of bytes for the Bloom filter bit
* array. Will be increased so that folding is possible.
* @param errorRate target false positive rate of the Bloom filter
* @param hashType Bloom filter hash function type
* @param foldFactor
* @return the new Bloom filter of the desired size
*/
public static BloomFilterChunk createBySize(int byteSizeHint,
double errorRate, int hashType, int foldFactor) {
BloomFilterChunk bbf = new BloomFilterChunk(hashType);
bbf.byteSize = computeFoldableByteSize(byteSizeHint * 8L, foldFactor);
long bitSize = bbf.byteSize * 8;
bbf.maxKeys = (int) idealMaxKeys(bitSize, errorRate);
bbf.hashCount = optimalFunctionCount(bbf.maxKeys, bitSize);
// Adjust max keys to bring error rate closer to what was requested,
// because byteSize was adjusted to allow for folding, and hashCount was
// rounded.
bbf.maxKeys = (int) computeMaxKeys(bitSize, errorRate, bbf.hashCount);
return bbf;
}
/** Should only be used in tests */
public static boolean contains(byte[] buf, int offset, int length, ByteBuffer bloom) {
return contains(buf, offset, length, bloom);
}
/** Should only be used in tests */
boolean contains(byte[] buf, ByteBuffer bloom) {
return contains(buf, 0, buf.length, bloom);
}
public static boolean contains(byte[] buf, int offset, int length,
ByteBuffer bloomBuf, int bloomOffset, int bloomSize, Hash hash,
int hashCount) {
int hash1 = hash.hash(buf, offset, length, 0);
int hash2 = hash.hash(buf, offset, length, hash1);
int bloomBitSize = bloomSize << 3;
if (randomGeneratorForTest == null) {
// Production mode.
int compositeHash = hash1;
for (int i = 0; i < hashCount; i++) {
int hashLoc = Math.abs(compositeHash % bloomBitSize);
compositeHash += hash2;
if (!get(hashLoc, bloomBuf, bloomOffset)) {
return false;
}
}
} else {
// Test mode with "fake lookups" to estimate "ideal false positive rate".
for (int i = 0; i < hashCount; i++) {
int hashLoc = randomGeneratorForTest.nextInt(bloomBitSize);
if (!get(hashLoc, bloomBuf, bloomOffset)){
return false;
}
}
}
return true;
}
/**
* Check if bit at specified index is 1.
*
* @param pos index of bit
* @return true if bit at specified index is 1, false if 0.
*/
public static boolean get(int pos, ByteBuffer bloomBuf, int bloomOffset) {
int bytePos = pos >> 3; //pos / 8
int bitPos = pos & 0x7; //pos % 8
// TODO access this via Util API which can do Unsafe access if possible(?)
byte curByte = bloomBuf.get(bloomOffset + bytePos);
curByte &= bitvals[bitPos];
return (curByte != 0);
}
/**
* A human-readable string with statistics for the given Bloom filter.
*
* @param bloomFilter the Bloom filter to output statistics for;
* @return a string consisting of "&lt;key&gt;: &lt;value&gt;" parts
* separated by {@link #STATS_RECORD_SEP}.
*/
public static String formatStats(BloomFilterBase bloomFilter) {
StringBuilder sb = new StringBuilder();
long k = bloomFilter.getKeyCount();
long m = bloomFilter.getMaxKeys();
sb.append("BloomSize: " + bloomFilter.getByteSize() + STATS_RECORD_SEP);
sb.append("No of Keys in bloom: " + k + STATS_RECORD_SEP);
sb.append("Max Keys for bloom: " + m);
if (m > 0) {
sb.append(STATS_RECORD_SEP + "Percentage filled: "
+ NumberFormat.getPercentInstance().format(k * 1.0 / m));
}
return sb.toString();
}
public static String toString(BloomFilterChunk bloomFilter) {
return formatStats(bloomFilter) + STATS_RECORD_SEP + "Actual error rate: "
+ String.format("%.8f", bloomFilter.actualErrorRate());
}
}

View File

@ -29,12 +29,8 @@ import org.apache.hadoop.io.Writable;
@InterfaceAudience.Private
public interface BloomFilterWriter extends BloomFilterBase {
/** Allocate memory for the bloom filter data. */
void allocBloom();
/** Compact the Bloom filter before writing metadata & data to disk. */
void compactBloom();
/**
* Get a writable interface into bloom filter meta data.
*

View File

@ -1,654 +0,0 @@
/*
*
* 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.util;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.text.NumberFormat;
import java.util.Random;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.io.Writable;
/**
* Implements a <i>Bloom filter</i>, as defined by Bloom in 1970.
* <p>
* The Bloom filter is a data structure that was introduced in 1970 and that has
* been adopted by the networking research community in the past decade thanks
* to the bandwidth efficiencies that it offers for the transmission of set
* membership information between networked hosts. A sender encodes the
* information into a bit vector, the Bloom filter, that is more compact than a
* conventional representation. Computation and space costs for construction are
* linear in the number of elements. The receiver uses the filter to test
* whether various elements are members of the set. Though the filter will
* occasionally return a false positive, it will never return a false negative.
* When creating the filter, the sender can choose its desired point in a
* trade-off between the false positive rate and the size.
*
* <p>
* Originally inspired by <a href="http://www.one-lab.org">European Commission
* One-Lab Project 034819</a>.
*
* Bloom filters are very sensitive to the number of elements inserted into
* them. For HBase, the number of entries depends on the size of the data stored
* in the column. Currently the default region size is 256MB, so entry count ~=
* 256MB / (average value size for column). Despite this rule of thumb, there is
* no efficient way to calculate the entry count after compactions. Therefore,
* it is often easier to use a dynamic bloom filter that will add extra space
* instead of allowing the error rate to grow.
*
* ( http://www.eecs.harvard.edu/~michaelm/NEWWORK/postscripts/BloomFilterSurvey
* .pdf )
*
* m denotes the number of bits in the Bloom filter (bitSize) n denotes the
* number of elements inserted into the Bloom filter (maxKeys) k represents the
* number of hash functions used (nbHash) e represents the desired false
* positive rate for the bloom (err)
*
* If we fix the error rate (e) and know the number of entries, then the optimal
* bloom size m = -(n * ln(err) / (ln(2)^2) ~= n * ln(err) / ln(0.6185)
*
* The probability of false positives is minimized when k = m/n ln(2).
*
* @see BloomFilter The general behavior of a filter
*
* @see <a
* href="http://portal.acm.org/citation.cfm?id=362692&dl=ACM&coll=portal">
* Space/Time Trade-Offs in Hash Coding with Allowable Errors</a>
*/
@InterfaceAudience.Private
// TODO : Remove this ByteBloomFilter as an instance of BloomFilter
public class ByteBloomFilter implements BloomFilter, BloomFilterWriter {
/** Current file format version */
public static final int VERSION = 1;
/** Bytes (B) in the array. This actually has to fit into an int. */
protected long byteSize;
/** Number of hash functions */
protected int hashCount;
/** Hash type */
protected final int hashType;
/** Hash Function */
protected final Hash hash;
/** Keys currently in the bloom */
protected int keyCount;
/** Max Keys expected for the bloom */
protected int maxKeys;
/** Bloom bits */
protected ByteBuffer bloom;
/** Record separator for the Bloom filter statistics human-readable string */
public static final String STATS_RECORD_SEP = "; ";
/**
* Used in computing the optimal Bloom filter size. This approximately equals
* 0.480453.
*/
public static final double LOG2_SQUARED = Math.log(2) * Math.log(2);
/**
* A random number generator to use for "fake lookups" when testing to
* estimate the ideal false positive rate.
*/
private static Random randomGeneratorForTest;
/** Bit-value lookup array to prevent doing the same work over and over */
private static final byte [] bitvals = {
(byte) 0x01,
(byte) 0x02,
(byte) 0x04,
(byte) 0x08,
(byte) 0x10,
(byte) 0x20,
(byte) 0x40,
(byte) 0x80
};
/**
* Loads bloom filter meta data from file input.
* @param meta stored bloom meta data
* @throws IllegalArgumentException meta data is invalid
*/
public ByteBloomFilter(DataInput meta)
throws IOException, IllegalArgumentException {
this.byteSize = meta.readInt();
this.hashCount = meta.readInt();
this.hashType = meta.readInt();
this.keyCount = meta.readInt();
this.maxKeys = this.keyCount;
this.hash = Hash.getInstance(this.hashType);
if (hash == null) {
throw new IllegalArgumentException("Invalid hash type: " + hashType);
}
sanityCheck();
}
/**
* @param maxKeys
* @param errorRate
* @return the number of bits for a Bloom filter than can hold the given
* number of keys and provide the given error rate, assuming that the
* optimal number of hash functions is used and it does not have to
* be an integer.
*/
public static long computeBitSize(long maxKeys, double errorRate) {
return (long) Math.ceil(maxKeys * (-Math.log(errorRate) / LOG2_SQUARED));
}
/**
* The maximum number of keys we can put into a Bloom filter of a certain
* size to maintain the given error rate, assuming the number of hash
* functions is chosen optimally and does not even have to be an integer
* (hence the "ideal" in the function name).
*
* @param bitSize
* @param errorRate
* @return maximum number of keys that can be inserted into the Bloom filter
* @see #computeMaxKeys(long, double, int) for a more precise estimate
*/
public static long idealMaxKeys(long bitSize, double errorRate) {
// The reason we need to use floor here is that otherwise we might put
// more keys in a Bloom filter than is allowed by the target error rate.
return (long) (bitSize * (LOG2_SQUARED / -Math.log(errorRate)));
}
/**
* The maximum number of keys we can put into a Bloom filter of a certain
* size to get the given error rate, with the given number of hash functions.
*
* @param bitSize
* @param errorRate
* @param hashCount
* @return the maximum number of keys that can be inserted in a Bloom filter
* to maintain the target error rate, if the number of hash functions
* is provided.
*/
public static long computeMaxKeys(long bitSize, double errorRate,
int hashCount) {
return (long) (-bitSize * 1.0 / hashCount *
Math.log(1 - Math.exp(Math.log(errorRate) / hashCount)));
}
/**
* Computes the error rate for this Bloom filter, taking into account the
* actual number of hash functions and keys inserted. The return value of
* this function changes as a Bloom filter is being populated. Used for
* reporting the actual error rate of compound Bloom filters when writing
* them out.
*
* @return error rate for this particular Bloom filter
*/
public double actualErrorRate() {
return actualErrorRate(keyCount, byteSize * 8, hashCount);
}
/**
* Computes the actual error rate for the given number of elements, number
* of bits, and number of hash functions. Taken directly from the
* <a href=
* "http://en.wikipedia.org/wiki/Bloom_filter#Probability_of_false_positives"
* > Wikipedia Bloom filter article</a>.
*
* @param maxKeys
* @param bitSize
* @param functionCount
* @return the actual error rate
*/
public static double actualErrorRate(long maxKeys, long bitSize,
int functionCount) {
return Math.exp(Math.log(1 - Math.exp(-functionCount * maxKeys * 1.0
/ bitSize)) * functionCount);
}
/**
* Increases the given byte size of a Bloom filter until it can be folded by
* the given factor.
*
* @param bitSize
* @param foldFactor
* @return Foldable byte size
*/
public static int computeFoldableByteSize(long bitSize, int foldFactor) {
long byteSizeLong = (bitSize + 7) / 8;
int mask = (1 << foldFactor) - 1;
if ((mask & byteSizeLong) != 0) {
byteSizeLong >>= foldFactor;
++byteSizeLong;
byteSizeLong <<= foldFactor;
}
if (byteSizeLong > Integer.MAX_VALUE) {
throw new IllegalArgumentException("byteSize=" + byteSizeLong + " too "
+ "large for bitSize=" + bitSize + ", foldFactor=" + foldFactor);
}
return (int) byteSizeLong;
}
private static int optimalFunctionCount(int maxKeys, long bitSize) {
long i = bitSize / maxKeys;
double result = Math.ceil(Math.log(2) * i);
if (result > Integer.MAX_VALUE){
throw new IllegalArgumentException("result too large for integer value.");
}
return (int)result;
}
/** Private constructor used by other constructors. */
private ByteBloomFilter(int hashType) {
this.hashType = hashType;
this.hash = Hash.getInstance(hashType);
}
/**
* Determines & initializes bloom filter meta data from user config. Call
* {@link #allocBloom()} to allocate bloom filter data.
*
* @param maxKeys Maximum expected number of keys that will be stored in this
* bloom
* @param errorRate Desired false positive error rate. Lower rate = more
* storage required
* @param hashType Type of hash function to use
* @param foldFactor When finished adding entries, you may be able to 'fold'
* this bloom to save space. Tradeoff potentially excess bytes in
* bloom for ability to fold if keyCount is exponentially greater
* than maxKeys.
* @throws IllegalArgumentException
*/
public ByteBloomFilter(int maxKeys, double errorRate, int hashType,
int foldFactor) throws IllegalArgumentException {
this(hashType);
long bitSize = computeBitSize(maxKeys, errorRate);
hashCount = optimalFunctionCount(maxKeys, bitSize);
this.maxKeys = maxKeys;
// increase byteSize so folding is possible
byteSize = computeFoldableByteSize(bitSize, foldFactor);
sanityCheck();
}
/**
* Creates a Bloom filter of the given size.
*
* @param byteSizeHint the desired number of bytes for the Bloom filter bit
* array. Will be increased so that folding is possible.
* @param errorRate target false positive rate of the Bloom filter
* @param hashType Bloom filter hash function type
* @param foldFactor
* @return the new Bloom filter of the desired size
*/
public static ByteBloomFilter createBySize(int byteSizeHint,
double errorRate, int hashType, int foldFactor) {
ByteBloomFilter bbf = new ByteBloomFilter(hashType);
bbf.byteSize = computeFoldableByteSize(byteSizeHint * 8L, foldFactor);
long bitSize = bbf.byteSize * 8;
bbf.maxKeys = (int) idealMaxKeys(bitSize, errorRate);
bbf.hashCount = optimalFunctionCount(bbf.maxKeys, bitSize);
// Adjust max keys to bring error rate closer to what was requested,
// because byteSize was adjusted to allow for folding, and hashCount was
// rounded.
bbf.maxKeys = (int) computeMaxKeys(bitSize, errorRate, bbf.hashCount);
return bbf;
}
/**
* Creates another similar Bloom filter. Does not copy the actual bits, and
* sets the new filter's key count to zero.
*
* @return a Bloom filter with the same configuration as this
*/
public ByteBloomFilter createAnother() {
ByteBloomFilter bbf = new ByteBloomFilter(hashType);
bbf.byteSize = byteSize;
bbf.hashCount = hashCount;
bbf.maxKeys = maxKeys;
return bbf;
}
@Override
public void allocBloom() {
if (this.bloom != null) {
throw new IllegalArgumentException("can only create bloom once.");
}
this.bloom = ByteBuffer.allocate((int)this.byteSize);
assert this.bloom.hasArray();
}
void sanityCheck() throws IllegalArgumentException {
if(0 >= this.byteSize || this.byteSize > Integer.MAX_VALUE) {
throw new IllegalArgumentException("Invalid byteSize: " + this.byteSize);
}
if(this.hashCount <= 0) {
throw new IllegalArgumentException("Hash function count must be > 0");
}
if (this.hash == null) {
throw new IllegalArgumentException("hashType must be known");
}
if (this.keyCount < 0) {
throw new IllegalArgumentException("must have positive keyCount");
}
}
void bloomCheck(ByteBuffer bloom) throws IllegalArgumentException {
if (this.byteSize != bloom.limit()) {
throw new IllegalArgumentException(
"Configured bloom length should match actual length");
}
}
public void add(byte [] buf) {
add(buf, 0, buf.length);
}
@Override
public void add(byte [] buf, int offset, int len) {
/*
* For faster hashing, use combinatorial generation
* http://www.eecs.harvard.edu/~kirsch/pubs/bbbf/esa06.pdf
*/
int hash1 = this.hash.hash(buf, offset, len, 0);
int hash2 = this.hash.hash(buf, offset, len, hash1);
for (int i = 0; i < this.hashCount; i++) {
long hashLoc = Math.abs((hash1 + i * hash2) % (this.byteSize * 8));
set(hashLoc);
}
++this.keyCount;
}
/** Should only be used in tests */
boolean contains(byte [] buf) {
return contains(buf, 0, buf.length, this.bloom);
}
/** Should only be used in tests */
boolean contains(byte [] buf, int offset, int length) {
return contains(buf, offset, length, bloom);
}
/** Should only be used in tests */
boolean contains(byte[] buf, ByteBuffer bloom) {
return contains(buf, 0, buf.length, bloom);
}
@Override
public boolean contains(byte[] buf, int offset, int length, ByteBuffer theBloom) {
if (theBloom == null) {
// In a version 1 HFile Bloom filter data is stored in a separate meta
// block which is loaded on demand, but in version 2 it is pre-loaded.
// We want to use the same API in both cases.
theBloom = bloom;
}
if (theBloom.limit() != byteSize) {
throw new IllegalArgumentException("Bloom does not match expected size:"
+ " theBloom.limit()=" + theBloom.limit() + ", byteSize=" + byteSize);
}
return contains(buf, offset, length, theBloom, 0, (int) byteSize, hash, hashCount);
}
public static boolean contains(byte[] buf, int offset, int length,
ByteBuffer bloomBuf, int bloomOffset, int bloomSize, Hash hash,
int hashCount) {
int hash1 = hash.hash(buf, offset, length, 0);
int hash2 = hash.hash(buf, offset, length, hash1);
int bloomBitSize = bloomSize << 3;
if (randomGeneratorForTest == null) {
// Production mode.
int compositeHash = hash1;
for (int i = 0; i < hashCount; i++) {
int hashLoc = Math.abs(compositeHash % bloomBitSize);
compositeHash += hash2;
if (!get(hashLoc, bloomBuf, bloomOffset)) {
return false;
}
}
} else {
// Test mode with "fake lookups" to estimate "ideal false positive rate".
for (int i = 0; i < hashCount; i++) {
int hashLoc = randomGeneratorForTest.nextInt(bloomBitSize);
if (!get(hashLoc, bloomBuf, bloomOffset)){
return false;
}
}
}
return true;
}
//---------------------------------------------------------------------------
/** Private helpers */
/**
* Set the bit at the specified index to 1.
*
* @param pos index of bit
*/
void set(long pos) {
int bytePos = (int)(pos / 8);
int bitPos = (int)(pos % 8);
byte curByte = bloom.get(bytePos);
curByte |= bitvals[bitPos];
bloom.put(bytePos, curByte);
}
/**
* Check if bit at specified index is 1.
*
* @param pos index of bit
* @return true if bit at specified index is 1, false if 0.
*/
static boolean get(int pos, ByteBuffer bloomBuf, int bloomOffset) {
int bytePos = pos >> 3; //pos / 8
int bitPos = pos & 0x7; //pos % 8
// TODO access this via Util API which can do Unsafe access if possible(?)
byte curByte = bloomBuf.get(bloomOffset + bytePos);
curByte &= bitvals[bitPos];
return (curByte != 0);
}
@Override
public long getKeyCount() {
return keyCount;
}
@Override
public long getMaxKeys() {
return maxKeys;
}
@Override
public long getByteSize() {
return byteSize;
}
public int getHashType() {
return hashType;
}
@Override
public void compactBloom() {
// see if the actual size is exponentially smaller than expected.
if (this.keyCount > 0 && this.bloom.hasArray()) {
int pieces = 1;
int newByteSize = (int)this.byteSize;
int newMaxKeys = this.maxKeys;
// while exponentially smaller & folding is lossless
while ((newByteSize & 1) == 0 && newMaxKeys > (this.keyCount<<1) ) {
pieces <<= 1;
newByteSize >>= 1;
newMaxKeys >>= 1;
}
// if we should fold these into pieces
if (pieces > 1) {
byte[] array = this.bloom.array();
int start = this.bloom.arrayOffset();
int end = start + newByteSize;
int off = end;
for(int p = 1; p < pieces; ++p) {
for(int pos = start; pos < end; ++pos) {
array[pos] |= array[off++];
}
}
// folding done, only use a subset of this array
this.bloom.rewind();
this.bloom.limit(newByteSize);
this.bloom = this.bloom.slice();
this.byteSize = newByteSize;
this.maxKeys = newMaxKeys;
}
}
}
//---------------------------------------------------------------------------
/**
* Writes just the bloom filter to the output array
* @param out OutputStream to place bloom
* @throws IOException Error writing bloom array
*/
public void writeBloom(final DataOutput out) throws IOException {
if (!this.bloom.hasArray()) {
throw new IOException("Only writes ByteBuffer with underlying array.");
}
out.write(bloom.array(), bloom.arrayOffset(), bloom.limit());
}
@Override
public Writable getMetaWriter() {
return new MetaWriter();
}
@Override
public Writable getDataWriter() {
return new DataWriter();
}
private class MetaWriter implements Writable {
protected MetaWriter() {}
@Override
public void readFields(DataInput arg0) throws IOException {
throw new IOException("Cant read with this class.");
}
@Override
public void write(DataOutput out) throws IOException {
out.writeInt(VERSION);
out.writeInt((int) byteSize);
out.writeInt(hashCount);
out.writeInt(hashType);
out.writeInt(keyCount);
}
}
private class DataWriter implements Writable {
protected DataWriter() {}
@Override
public void readFields(DataInput arg0) throws IOException {
throw new IOException("Cant read with this class.");
}
@Override
public void write(DataOutput out) throws IOException {
writeBloom(out);
}
}
public int getHashCount() {
return hashCount;
}
@Override
public boolean supportsAutoLoading() {
return bloom != null;
}
public static void setFakeLookupMode(boolean enabled) {
if (enabled) {
randomGeneratorForTest = new Random(283742987L);
} else {
randomGeneratorForTest = null;
}
}
/**
* {@inheritDoc}
* Just concatenate row and column by default. May return the original row
* buffer if the column qualifier is empty.
*/
@Override
public byte[] createBloomKey(byte[] rowBuf, int rowOffset, int rowLen,
byte[] qualBuf, int qualOffset, int qualLen) {
// Optimize the frequent case when only the row is provided.
if (qualLen <= 0 && rowOffset == 0 && rowLen == rowBuf.length)
return rowBuf;
byte [] result = new byte[rowLen + qualLen];
System.arraycopy(rowBuf, rowOffset, result, 0, rowLen);
if (qualLen > 0)
System.arraycopy(qualBuf, qualOffset, result, rowLen, qualLen);
return result;
}
/**
* A human-readable string with statistics for the given Bloom filter.
*
* @param bloomFilter the Bloom filter to output statistics for;
* @return a string consisting of "&lt;key&gt;: &lt;value&gt;" parts
* separated by {@link #STATS_RECORD_SEP}.
*/
public static String formatStats(BloomFilterBase bloomFilter) {
StringBuilder sb = new StringBuilder();
long k = bloomFilter.getKeyCount();
long m = bloomFilter.getMaxKeys();
sb.append("BloomSize: " + bloomFilter.getByteSize() + STATS_RECORD_SEP);
sb.append("No of Keys in bloom: " + k + STATS_RECORD_SEP);
sb.append("Max Keys for bloom: " + m);
if (m > 0) {
sb.append(STATS_RECORD_SEP + "Percentage filled: "
+ NumberFormat.getPercentInstance().format(k * 1.0 / m));
}
return sb.toString();
}
@Override
public String toString() {
return formatStats(this) + STATS_RECORD_SEP + "Actual error rate: "
+ String.format("%.8f", actualErrorRate());
}
}

View File

@ -23,6 +23,8 @@ import java.io.DataInput;
import java.io.IOException;
import java.nio.ByteBuffer;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.io.hfile.BlockType;
import org.apache.hadoop.hbase.io.hfile.FixedFileTrailer;
@ -31,7 +33,7 @@ import org.apache.hadoop.hbase.io.hfile.HFileBlock;
import org.apache.hadoop.hbase.io.hfile.HFileBlockIndex;
/**
* A Bloom filter implementation built on top of {@link ByteBloomFilter},
* A Bloom filter implementation built on top of {@link BloomFilterChunk},
* encapsulating a set of fixed-size Bloom filters written out at the time of
* {@link org.apache.hadoop.hbase.io.hfile.HFile} generation into the data
* block stream, and loaded on demand at query time. This class only provides
@ -90,10 +92,14 @@ public class CompoundBloomFilter extends CompoundBloomFilterBase
public boolean contains(byte[] key, int keyOffset, int keyLength, ByteBuffer bloom) {
// We try to store the result in this variable so we can update stats for
// testing, but when an error happens, we log a message and return.
boolean result;
int block = index.rootBlockContainingKey(key, keyOffset,
keyLength, comparator);
keyLength);
return checkContains(key, keyOffset, keyLength, block);
}
private boolean checkContains(byte[] key, int keyOffset, int keyLength, int block) {
boolean result;
if (block < 0) {
result = false; // This key is not in the file.
} else {
@ -111,7 +117,7 @@ public class CompoundBloomFilter extends CompoundBloomFilterBase
}
ByteBuffer bloomBuf = bloomBlock.getBufferReadOnly();
result = ByteBloomFilter.contains(key, keyOffset, keyLength,
result = BloomFilterUtil.contains(key, keyOffset, keyLength,
bloomBuf, bloomBlock.headerSize(),
bloomBlock.getUncompressedSizeWithoutHeader(), hash, hashCount);
}
@ -126,6 +132,18 @@ public class CompoundBloomFilter extends CompoundBloomFilterBase
return result;
}
@Override
public boolean contains(Cell keyCell, ByteBuffer bloom) {
// We try to store the result in this variable so we can update stats for
// testing, but when an error happens, we log a message and return.
int block = index.rootBlockContainingKey(keyCell);
// TODO : Will be true KeyValue for now.
// When Offheap comes in we can add an else condition to work
// on the bytes in offheap
KeyValue kvKey = (KeyValue) keyCell;
return checkContains(kvKey.getBuffer(), kvKey.getKeyOffset(), kvKey.getKeyLength(), block);
}
public boolean supportsAutoLoading() {
return true;
}
@ -166,10 +184,10 @@ public class CompoundBloomFilter extends CompoundBloomFilterBase
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append(ByteBloomFilter.formatStats(this));
sb.append(ByteBloomFilter.STATS_RECORD_SEP +
sb.append(BloomFilterUtil.formatStats(this));
sb.append(BloomFilterUtil.STATS_RECORD_SEP +
"Number of chunks: " + numChunks);
sb.append(ByteBloomFilter.STATS_RECORD_SEP +
sb.append(BloomFilterUtil.STATS_RECORD_SEP +
((comparator != null) ? "Comparator: "
+ comparator.getClass().getSimpleName() : "Comparator: "
+ Bytes.BYTES_RAWCOMPARATOR.getClass().getSimpleName()));

View File

@ -22,8 +22,6 @@ package org.apache.hadoop.hbase.util;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.CellComparator;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.KeyValueUtil;
@InterfaceAudience.Private
public class CompoundBloomFilterBase implements BloomFilterBase {
@ -69,24 +67,4 @@ public class CompoundBloomFilterBase implements BloomFilterBase {
return totalByteSize;
}
private static final byte[] DUMMY = new byte[0];
/**
* Prepare an ordered pair of row and qualifier to be compared using
* KeyValue.KeyComparator. This is only used for row-column Bloom
* filters.
*/
@Override
public byte[] createBloomKey(byte[] row, int roffset, int rlength,
byte[] qualifier, int qoffset, int qlength) {
if (qualifier == null)
qualifier = DUMMY;
// Make sure this does not specify a timestamp so that the default maximum
// (most recent) timestamp is used.
KeyValue kv = KeyValueUtil.createFirstOnRow(row, roffset, rlength, DUMMY, 0, 0,
qualifier, qoffset, qlength);
return kv.getKey();
}
}

View File

@ -47,10 +47,10 @@ public class CompoundBloomFilterWriter extends CompoundBloomFilterBase
LogFactory.getLog(CompoundBloomFilterWriter.class);
/** The current chunk being written to */
private ByteBloomFilter chunk;
private BloomFilterChunk chunk;
/** Previous chunk, so that we can create another similar chunk */
private ByteBloomFilter prevChunk;
private BloomFilterChunk prevChunk;
/** Maximum fold factor */
private int maxFold;
@ -62,7 +62,7 @@ public class CompoundBloomFilterWriter extends CompoundBloomFilterBase
private static class ReadyChunk {
int chunkId;
byte[] firstKey;
ByteBloomFilter chunk;
BloomFilterChunk chunk;
}
private Queue<ReadyChunk> readyChunks = new LinkedList<ReadyChunk>();
@ -90,7 +90,7 @@ public class CompoundBloomFilterWriter extends CompoundBloomFilterBase
public CompoundBloomFilterWriter(int chunkByteSizeHint, float errorRate,
int hashType, int maxFold, boolean cacheOnWrite,
CellComparator comparator) {
chunkByteSize = ByteBloomFilter.computeFoldableByteSize(
chunkByteSize = BloomFilterUtil.computeFoldableByteSize(
chunkByteSizeHint * 8L, maxFold);
this.errorRate = errorRate;
@ -174,7 +174,7 @@ public class CompoundBloomFilterWriter extends CompoundBloomFilterBase
if (prevChunk == null) {
// First chunk
chunk = ByteBloomFilter.createBySize(chunkByteSize, errorRate,
chunk = BloomFilterUtil.createBySize(chunkByteSize, errorRate,
hashType, maxFold);
} else {
// Use the same parameters as the last chunk, but a new array and
@ -201,8 +201,8 @@ public class CompoundBloomFilterWriter extends CompoundBloomFilterBase
// again for cache-on-write.
ReadyChunk readyChunk = readyChunks.peek();
ByteBloomFilter readyChunkBloom = readyChunk.chunk;
readyChunkBloom.getDataWriter().write(out);
BloomFilterChunk readyChunkBloom = readyChunk.chunk;
readyChunkBloom.writeBloom(out);
}
@Override
@ -225,7 +225,7 @@ public class CompoundBloomFilterWriter extends CompoundBloomFilterBase
}
/**
* This is modeled after {@link ByteBloomFilter.MetaWriter} for simplicity,
* This is modeled after {@link BloomFilterChunk.MetaWriter} for simplicity,
* although the two metadata formats do not have to be consistent. This
* does have to be consistent with how {@link
* CompoundBloomFilter#CompoundBloomFilter(DataInput,
@ -255,18 +255,13 @@ public class CompoundBloomFilterWriter extends CompoundBloomFilterBase
}
}
@Override
public Writable getMetaWriter() {
return new MetaWriter();
}
@Override
public void compactBloom() {
}
@Override
public void allocBloom() {
// Nothing happens here. All allocation happens on demand.
public Writable getMetaWriter() {
return new MetaWriter();
}
@Override

View File

@ -51,11 +51,11 @@ import org.apache.hadoop.hbase.io.hfile.HFileContext;
import org.apache.hadoop.hbase.io.hfile.HFileContextBuilder;
import org.apache.hadoop.hbase.io.hfile.TestHFileWriterV2;
import org.apache.hadoop.hbase.util.BloomFilterFactory;
import org.apache.hadoop.hbase.util.ByteBloomFilter;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.CompoundBloomFilter;
import org.apache.hadoop.hbase.util.CompoundBloomFilterBase;
import org.apache.hadoop.hbase.util.CompoundBloomFilterWriter;
import org.apache.hadoop.hbase.util.BloomFilterUtil;
import org.junit.Before;
import org.junit.Test;
import org.junit.experimental.categories.Category;
@ -220,7 +220,7 @@ public class TestCompoundBloomFilter {
// Test for false positives (some percentage allowed). We test in two modes:
// "fake lookup" which ignores the key distribution, and production mode.
for (boolean fakeLookupEnabled : new boolean[] { true, false }) {
ByteBloomFilter.setFakeLookupMode(fakeLookupEnabled);
BloomFilterUtil.setFakeLookupMode(fakeLookupEnabled);
try {
String fakeLookupModeStr = ", fake lookup is " + (fakeLookupEnabled ?
"enabled" : "disabled");
@ -270,7 +270,7 @@ public class TestCompoundBloomFilter {
validateFalsePosRate(falsePosRate, nTrials, -2.58, cbf,
fakeLookupModeStr);
} finally {
ByteBloomFilter.setFakeLookupMode(false);
BloomFilterUtil.setFakeLookupMode(false);
}
}
@ -337,11 +337,11 @@ public class TestCompoundBloomFilter {
int bloomBlockByteSize = 4096;
int bloomBlockBitSize = bloomBlockByteSize * 8;
double targetErrorRate = 0.01;
long maxKeysPerChunk = ByteBloomFilter.idealMaxKeys(bloomBlockBitSize,
long maxKeysPerChunk = BloomFilterUtil.idealMaxKeys(bloomBlockBitSize,
targetErrorRate);
long bloomSize1 = bloomBlockByteSize * 8;
long bloomSize2 = ByteBloomFilter.computeBitSize(maxKeysPerChunk,
long bloomSize2 = BloomFilterUtil.computeBitSize(maxKeysPerChunk,
targetErrorRate);
double bloomSizeRatio = (bloomSize2 * 1.0 / bloomSize1);
@ -350,13 +350,12 @@ public class TestCompoundBloomFilter {
@Test
public void testCreateKey() {
CompoundBloomFilterBase cbfb = new CompoundBloomFilterBase();
byte[] row = "myRow".getBytes();
byte[] qualifier = "myQualifier".getBytes();
byte[] rowKey = cbfb.createBloomKey(row, 0, row.length,
row, 0, 0);
byte[] rowColKey = cbfb.createBloomKey(row, 0, row.length,
qualifier, 0, qualifier.length);
// Mimic what Storefile.createBloomKeyValue() does
byte[] rowKey = KeyValueUtil.createFirstOnRow(row, 0, row.length, new byte[0], 0, 0, row, 0, 0).getKey();
byte[] rowColKey = KeyValueUtil.createFirstOnRow(row, 0, row.length,
new byte[0], 0, 0, qualifier, 0, qualifier.length).getKey();
KeyValue rowKV = KeyValueUtil.createKeyValueFromKey(rowKey);
KeyValue rowColKV = KeyValueUtil.createKeyValueFromKey(rowColKey);
assertEquals(rowKV.getTimestamp(), rowColKV.getTimestamp());

View File

@ -29,11 +29,11 @@ import org.apache.hadoop.hbase.testclassification.SmallTests;
import org.junit.experimental.categories.Category;
@Category({MiscTests.class, SmallTests.class})
public class TestByteBloomFilter extends TestCase {
public class TestBloomFilterChunk extends TestCase {
public void testBasicBloom() throws Exception {
ByteBloomFilter bf1 = new ByteBloomFilter(1000, (float)0.01, Hash.MURMUR_HASH, 0);
ByteBloomFilter bf2 = new ByteBloomFilter(1000, (float)0.01, Hash.MURMUR_HASH, 0);
BloomFilterChunk bf1 = new BloomFilterChunk(1000, (float)0.01, Hash.MURMUR_HASH, 0);
BloomFilterChunk bf2 = new BloomFilterChunk(1000, (float)0.01, Hash.MURMUR_HASH, 0);
bf1.allocBloom();
bf2.allocBloom();
@ -44,10 +44,14 @@ public class TestByteBloomFilter extends TestCase {
bf1.add(key1);
bf2.add(key2);
assertTrue(bf1.contains(key1));
assertFalse(bf1.contains(key2));
assertFalse(bf2.contains(key1));
assertTrue(bf2.contains(key2));
assertTrue(BloomFilterUtil.contains(key1, 0, key1.length, bf1.bloom, 0, (int) bf1.byteSize,
bf1.hash, bf1.hashCount));
assertFalse(BloomFilterUtil.contains(key2, 0, key2.length, bf1.bloom, 0, (int) bf1.byteSize,
bf1.hash, bf1.hashCount));
assertFalse(BloomFilterUtil.contains(key1, 0, key1.length, bf2.bloom, 0, (int) bf2.byteSize,
bf2.hash, bf2.hashCount));
assertTrue(BloomFilterUtil.contains(key2, 0, key2.length, bf2.bloom, 0, (int) bf2.byteSize,
bf2.hash, bf2.hashCount));
byte [] bkey = {1,2,3,4};
byte [] bval = "this is a much larger byte array".getBytes();
@ -55,24 +59,32 @@ public class TestByteBloomFilter extends TestCase {
bf1.add(bkey);
bf1.add(bval, 1, bval.length-1);
assertTrue( bf1.contains(bkey) );
assertTrue( bf1.contains(bval, 1, bval.length-1) );
assertFalse( bf1.contains(bval) );
assertFalse( bf1.contains(bval) );
assertTrue(BloomFilterUtil.contains(bkey, 0, bkey.length, bf1.bloom, 0, (int) bf1.byteSize,
bf1.hash, bf1.hashCount));
assertTrue(BloomFilterUtil.contains(bval, 1, bval.length - 1, bf1.bloom, 0, (int) bf1.byteSize,
bf1.hash, bf1.hashCount));
assertFalse(BloomFilterUtil.contains(bval, 0, bval.length, bf1.bloom, 0, (int) bf1.byteSize,
bf1.hash, bf1.hashCount));
// test 2: serialization & deserialization.
// (convert bloom to byte array & read byte array back in as input)
ByteArrayOutputStream bOut = new ByteArrayOutputStream();
bf1.writeBloom(new DataOutputStream(bOut));
ByteBuffer bb = ByteBuffer.wrap(bOut.toByteArray());
ByteBloomFilter newBf1 = new ByteBloomFilter(1000, (float)0.01,
BloomFilterChunk newBf1 = new BloomFilterChunk(1000, (float)0.01,
Hash.MURMUR_HASH, 0);
assertTrue(newBf1.contains(key1, bb));
assertFalse(newBf1.contains(key2, bb));
assertTrue( newBf1.contains(bkey, bb) );
assertTrue( newBf1.contains(bval, 1, bval.length-1, bb) );
assertFalse( newBf1.contains(bval, bb) );
assertFalse( newBf1.contains(bval, bb) );
assertTrue(BloomFilterUtil.contains(key1, 0, key1.length, bb, 0, (int) newBf1.byteSize,
newBf1.hash, newBf1.hashCount));
assertFalse(BloomFilterUtil.contains(key2, 0, key2.length, bb, 0, (int) newBf1.byteSize,
newBf1.hash, newBf1.hashCount));
assertTrue(BloomFilterUtil.contains(bkey, 0, bkey.length, bb, 0, (int) newBf1.byteSize,
newBf1.hash, newBf1.hashCount));
assertTrue(BloomFilterUtil.contains(bval, 1, bval.length - 1, bb, 0, (int) newBf1.byteSize,
newBf1.hash, newBf1.hashCount));
assertFalse(BloomFilterUtil.contains(bval, 0, bval.length, bb, 0, (int) newBf1.byteSize,
newBf1.hash, newBf1.hashCount));
assertFalse(BloomFilterUtil.contains(bval, 0, bval.length, bb, 0, (int) newBf1.byteSize,
newBf1.hash, newBf1.hashCount));
System.out.println("Serialized as " + bOut.size() + " bytes");
assertTrue(bOut.size() - bf1.byteSize < 10); //... allow small padding
@ -80,7 +92,7 @@ public class TestByteBloomFilter extends TestCase {
public void testBloomFold() throws Exception {
// test: foldFactor < log(max/actual)
ByteBloomFilter b = new ByteBloomFilter(1003, (float) 0.01,
BloomFilterChunk b = new BloomFilterChunk(1003, (float) 0.01,
Hash.MURMUR_HASH, 2);
b.allocBloom();
long origSize = b.getByteSize();
@ -92,7 +104,9 @@ public class TestByteBloomFilter extends TestCase {
assertEquals(origSize>>2, b.getByteSize());
int falsePositives = 0;
for (int i = 0; i < 25; ++i) {
if (b.contains(Bytes.toBytes(i))) {
byte[] bytes = Bytes.toBytes(i);
if (BloomFilterUtil.contains(bytes, 0, bytes.length, b.bloom, 0, (int) b.byteSize, b.hash,
b.hashCount)) {
if(i >= 12) falsePositives++;
} else {
assertFalse(i < 12);
@ -106,7 +120,7 @@ public class TestByteBloomFilter extends TestCase {
public void testBloomPerf() throws Exception {
// add
float err = (float)0.01;
ByteBloomFilter b = new ByteBloomFilter(10*1000*1000, (float)err, Hash.MURMUR_HASH, 3);
BloomFilterChunk b = new BloomFilterChunk(10*1000*1000, (float)err, Hash.MURMUR_HASH, 3);
b.allocBloom();
long startTime = System.currentTimeMillis();
long origSize = b.getByteSize();
@ -128,7 +142,9 @@ public class TestByteBloomFilter extends TestCase {
int falsePositives = 0;
for (int i = 0; i < 2*1000*1000; ++i) {
if (b.contains(Bytes.toBytes(i))) {
byte[] bytes = Bytes.toBytes(i);
if (BloomFilterUtil.contains(bytes, 0, bytes.length, b.bloom, 0, (int) b.byteSize, b.hash,
b.hashCount)) {
if(i >= 1*1000*1000) falsePositives++;
} else {
assertFalse(i < 1*1000*1000);
@ -148,20 +164,20 @@ public class TestByteBloomFilter extends TestCase {
// How many keys can we store in a Bloom filter of this size maintaining
// the given false positive rate, not taking into account that the n
long maxKeys = ByteBloomFilter.idealMaxKeys(bitSize, errorRate);
long maxKeys = BloomFilterUtil.idealMaxKeys(bitSize, errorRate);
assertEquals(136570, maxKeys);
// A reverse operation: how many bits would we need to store this many keys
// and keep the same low false positive rate?
long bitSize2 = ByteBloomFilter.computeBitSize(maxKeys, errorRate);
long bitSize2 = BloomFilterUtil.computeBitSize(maxKeys, errorRate);
// The bit size comes out a little different due to rounding.
assertTrue(Math.abs(bitSize2 - bitSize) * 1.0 / bitSize < 1e-5);
}
public void testFoldableByteSize() {
assertEquals(128, ByteBloomFilter.computeFoldableByteSize(1000, 5));
assertEquals(640, ByteBloomFilter.computeFoldableByteSize(5001, 4));
assertEquals(128, BloomFilterUtil.computeFoldableByteSize(1000, 5));
assertEquals(640, BloomFilterUtil.computeFoldableByteSize(5001, 4));
}