/*
* 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.cassandra.utils;
import java.io.DataInput;
import java.io.IOException;
import java.io.Serializable;
import java.util.*;
import com.google.common.base.Preconditions;
import com.google.common.collect.PeekingIterator;
import org.apache.cassandra.db.TypeSizes;
import org.apache.cassandra.dht.IPartitioner;
import org.apache.cassandra.dht.IPartitionerDependentSerializer;
import org.apache.cassandra.dht.Range;
import org.apache.cassandra.dht.Token;
import org.apache.cassandra.exceptions.ConfigurationException;
import org.apache.cassandra.io.IVersionedSerializer;
import org.apache.cassandra.io.util.DataInputPlus;
import org.apache.cassandra.io.util.DataOutputPlus;
/**
* A MerkleTree implemented as a binary tree.
*
* A MerkleTree is a full binary tree that represents a perfect binary tree of
* depth 'hashdepth'. In a perfect binary tree, each leaf contains a
* sequentially hashed range, and each inner node contains the binary hash of
* its two children. In the MerkleTree, many ranges will not be split to the
* full depth of the perfect binary tree: the leaves of this tree are Leaf objects,
* which contain the computed values of the nodes that would be below them if
* the tree were perfect.
*
* The hash values of the inner nodes of the MerkleTree are calculated lazily based
* on their children when the hash of a range is requested with hash(range).
*
* Inputs passed to TreeRange.validate should be calculated using a very secure hash,
* because all hashing internal to the tree is accomplished using XOR.
*
* If two MerkleTrees have the same hashdepth, they represent a perfect tree
* of the same depth, and can always be compared, regardless of size or splits.
*/
public class MerkleTree implements Serializable
{
public static final MerkleTreeSerializer serializer = new MerkleTreeSerializer();
private static final long serialVersionUID = 2L;
public static final byte RECOMMENDED_DEPTH = Byte.MAX_VALUE - 1;
public static final int CONSISTENT = 0;
public static final int FULLY_INCONSISTENT = 1;
public static final int PARTIALLY_INCONSISTENT = 2;
private static final byte[] EMPTY_HASH = new byte[0];
public final byte hashdepth;
/** The top level range that this MerkleTree covers. */
public final Range<Token> fullRange;
private final IPartitioner partitioner;
private long maxsize;
private long size;
private Hashable root;
public static class MerkleTreeSerializer implements IVersionedSerializer<MerkleTree>
{
public void serialize(MerkleTree mt, DataOutputPlus out, int version) throws IOException
{
out.writeByte(mt.hashdepth);
out.writeLong(mt.maxsize);
out.writeLong(mt.size);
out.writeUTF(mt.partitioner.getClass().getCanonicalName());
// full range
Token.serializer.serialize(mt.fullRange.left, out, version);
Token.serializer.serialize(mt.fullRange.right, out, version);
Hashable.serializer.serialize(mt.root, out, version);
}
public MerkleTree deserialize(DataInputPlus in, int version) throws IOException
{
byte hashdepth = in.readByte();
long maxsize = in.readLong();
long size = in.readLong();
IPartitioner partitioner;
try
{
partitioner = FBUtilities.newPartitioner(in.readUTF());
}
catch (ConfigurationException e)
{
throw new IOException(e);
}
// full range
Token left = Token.serializer.deserialize(in, partitioner, version);
Token right = Token.serializer.deserialize(in, partitioner, version);
Range<Token> fullRange = new Range<>(left, right);
MerkleTree mt = new MerkleTree(partitioner, fullRange, hashdepth, maxsize);
mt.size = size;
mt.root = Hashable.serializer.deserialize(in, partitioner, version);
return mt;
}
public long serializedSize(MerkleTree mt, int version)
{
long size = 1 // mt.hashdepth
+ TypeSizes.sizeof(mt.maxsize)
+ TypeSizes.sizeof(mt.size)
+ TypeSizes.sizeof(mt.partitioner.getClass().getCanonicalName());
// full range
size += Token.serializer.serializedSize(mt.fullRange.left, version);
size += Token.serializer.serializedSize(mt.fullRange.right, version);
size += Hashable.serializer.serializedSize(mt.root, version);
return size;
}
}
/**
* @param partitioner The partitioner in use.
* @param range the range this tree covers
* @param hashdepth The maximum depth of the tree. 100/(2^depth) is the %
* of the key space covered by each subrange of a fully populated tree.
* @param maxsize The maximum number of subranges in the tree.
*/
public MerkleTree(IPartitioner partitioner, Range<Token> range, byte hashdepth, long maxsize)
{
assert hashdepth < Byte.MAX_VALUE;
this.fullRange = Preconditions.checkNotNull(range);
this.partitioner = Preconditions.checkNotNull(partitioner);
this.hashdepth = hashdepth;
this.maxsize = maxsize;
size = 1;
root = new Leaf(null);
}
static byte inc(byte in)
{
assert in < Byte.MAX_VALUE;
return (byte)(in + 1);
}
/**
* Initializes this tree by splitting it until hashdepth is reached,
* or until an additional level of splits would violate maxsize.
*
* NB: Replaces all nodes in the tree.
*/
public void init()
{
// determine the depth to which we can safely split the tree
byte sizedepth = (byte)(Math.log10(maxsize) / Math.log10(2));
byte depth = (byte)Math.min(sizedepth, hashdepth);
root = initHelper(fullRange.left, fullRange.right, (byte)0, depth);
size = (long)Math.pow(2, depth);
}
private Hashable initHelper(Token left, Token right, byte depth, byte max)
{
if (depth == max)
// we've reached the leaves
return new Leaf();
Token midpoint = partitioner.midpoint(left, right);
if (midpoint.equals(left) || midpoint.equals(right))
return new Leaf();
Hashable lchild = initHelper(left, midpoint, inc(depth), max);
Hashable rchild = initHelper(midpoint, right, inc(depth), max);
return new Inner(midpoint, lchild, rchild);
}
Hashable root()
{
return root;
}
public IPartitioner partitioner()
{
return partitioner;
}
/**
* The number of distinct ranges contained in this tree. This is a reasonable
* measure of the memory usage of the tree (assuming 'this.order' is significant).
*/
public long size()
{
return size;
}
public long maxsize()
{
return maxsize;
}
public void maxsize(long maxsize)
{
this.maxsize = maxsize;
}
/**
* @param ltree First tree.
* @param rtree Second tree.
* @return A list of the largest contiguous ranges where the given trees disagree.
*/
public static List<TreeRange> difference(MerkleTree ltree, MerkleTree rtree)
{
if (!ltree.fullRange.equals(rtree.fullRange))
throw new IllegalArgumentException("Difference only make sense on tree covering the same range (but " + ltree.fullRange + " != " + rtree.fullRange + ")");
List<TreeRange> diff = new ArrayList<>();
TreeDifference active = new TreeDifference(ltree.fullRange.left, ltree.fullRange.right, (byte)0);
Hashable lnode = ltree.find(active);
Hashable rnode = rtree.find(active);
byte[] lhash = lnode.hash();
byte[] rhash = rnode.hash();
active.setSize(lnode.sizeOfRange(), rnode.sizeOfRange());
if (lhash != null && rhash != null && !Arrays.equals(lhash, rhash))
{
if (FULLY_INCONSISTENT == differenceHelper(ltree, rtree, diff, active))
diff.add(active);
}
else if (lhash == null || rhash == null)
diff.add(active);
return diff;
}
/**
* TODO: This function could be optimized into a depth first traversal of
* the two trees in parallel.
*
* Takes two trees and a range for which they have hashes, but are inconsistent.
* @return FULLY_INCONSISTENT if active is inconsistent, PARTIALLY_INCONSISTENT if only a subrange is inconsistent.
*/
static int differenceHelper(MerkleTree ltree, MerkleTree rtree, List<TreeRange> diff, TreeRange active)
{
if (active.depth == Byte.MAX_VALUE)
return CONSISTENT;
Token midpoint = ltree.partitioner().midpoint(active.left, active.right);
TreeDifference left = new TreeDifference(active.left, midpoint, inc(active.depth));
TreeDifference right = new TreeDifference(midpoint, active.right, inc(active.depth));
byte[] lhash, rhash;
Hashable lnode, rnode;
// see if we should recurse left
lnode = ltree.find(left);
rnode = rtree.find(left);
lhash = lnode.hash();
rhash = rnode.hash();
left.setSize(lnode.sizeOfRange(), rnode.sizeOfRange());
left.setRows(lnode.rowsInRange(), rnode.rowsInRange());
int ldiff = CONSISTENT;
boolean lreso = lhash != null && rhash != null;
if (lreso && !Arrays.equals(lhash, rhash))
ldiff = differenceHelper(ltree, rtree, diff, left);
else if (!lreso)
ldiff = FULLY_INCONSISTENT;
// see if we should recurse right
lnode = ltree.find(right);
rnode = rtree.find(right);
lhash = lnode.hash();
rhash = rnode.hash();
right.setSize(lnode.sizeOfRange(), rnode.sizeOfRange());
right.setRows(lnode.rowsInRange(), rnode.rowsInRange());
int rdiff = CONSISTENT;
boolean rreso = lhash != null && rhash != null;
if (rreso && !Arrays.equals(lhash, rhash))
rdiff = differenceHelper(ltree, rtree, diff, right);
else if (!rreso)
rdiff = FULLY_INCONSISTENT;
if (ldiff == FULLY_INCONSISTENT && rdiff == FULLY_INCONSISTENT)
{
// both children are fully inconsistent
return FULLY_INCONSISTENT;
}
else if (ldiff == FULLY_INCONSISTENT)
{
diff.add(left);
return PARTIALLY_INCONSISTENT;
}
else if (rdiff == FULLY_INCONSISTENT)
{
diff.add(right);
return PARTIALLY_INCONSISTENT;
}
return PARTIALLY_INCONSISTENT;
}
/**
* For testing purposes.
* Gets the smallest range containing the token.
*/
public TreeRange get(Token t)
{
return getHelper(root, fullRange.left, fullRange.right, (byte)0, t);
}
TreeRange getHelper(Hashable hashable, Token pleft, Token pright, byte depth, Token t)
{
while (true)
{
if (hashable instanceof Leaf)
{
// we've reached a hash: wrap it up and deliver it
return new TreeRange(this, pleft, pright, depth, hashable);
}
// else: node.
Inner node = (Inner) hashable;
depth = inc(depth);
if (Range.contains(pleft, node.token, t))
{ // left child contains token
hashable = node.lchild;
pright = node.token;
}
else
{ // else: right child contains token
hashable = node.rchild;
pleft = node.token;
}
}
}
/**
* Invalidates the ranges containing the given token.
* Useful for testing.
*/
public void invalidate(Token t)
{
invalidateHelper(root, fullRange.left, t);
}
private void invalidateHelper(Hashable hashable, Token pleft, Token t)
{
hashable.hash(null);
if (hashable instanceof Leaf)
return;
// else: node.
Inner node = (Inner)hashable;
if (Range.contains(pleft, node.token, t))
// left child contains token
invalidateHelper(node.lchild, pleft, t);
else
// right child contains token
invalidateHelper(node.rchild, node.token, t);
}
/**
* Hash the given range in the tree. The range must have been generated
* with recursive applications of partitioner.midpoint().
*
* NB: Currently does not support wrapping ranges that do not end with
* partitioner.getMinimumToken().
*
* @return Null if any subrange of the range is invalid, or if the exact
* range cannot be calculated using this tree.
*/
public byte[] hash(Range<Token> range)
{
return find(range).hash();
}
/**
* Find the {@link Hashable} node that matches the given {@code range}.
*
* @param range Range to find
* @return {@link Hashable} found. If nothing found, return {@link Leaf} with null hash.
*/
private Hashable find(Range<Token> range)
{
try
{
return findHelper(root, new Range<Token>(fullRange.left, fullRange.right), range);
}
catch (StopRecursion e)
{
return new Leaf();
}
}
/**
* @throws StopRecursion If no match could be found for the range.
*/
private Hashable findHelper(Hashable current, Range<Token> activeRange, Range<Token> find) throws StopRecursion
{
while (true)
{
if (current instanceof Leaf)
{
if (!find.contains(activeRange))
// we are not fully contained in this range!
throw new StopRecursion.BadRange();
return current;
}
// else: node.
Inner node = (Inner) current;
Range<Token> leftRange = new Range<>(activeRange.left, node.token);
Range<Token> rightRange = new Range<>(node.token, activeRange.right);
if (find.contains(activeRange))
// this node is fully contained in the range
return node.calc();
// else: one of our children contains the range
if (leftRange.contains(find))
{ // left child contains/matches the range
current = node.lchild;
activeRange = leftRange;
}
else if (rightRange.contains(find))
{ // right child contains/matches the range
current = node.rchild;
activeRange = rightRange;
}
else
{
throw new StopRecursion.BadRange();
}
}
}
/**
* Splits the range containing the given token, if no tree limits would be
* violated. If the range would be split to a depth below hashdepth, or if
* the tree already contains maxsize subranges, this operation will fail.
*
* @return True if the range was successfully split.
*/
public boolean split(Token t)
{
if (!(size < maxsize))
return false;
try
{
root = splitHelper(root, fullRange.left, fullRange.right, (byte)0, t);
}
catch (StopRecursion.TooDeep e)
{
return false;
}
return true;
}
private Hashable splitHelper(Hashable hashable, Token pleft, Token pright, byte depth, Token t) throws StopRecursion.TooDeep
{
if (depth >= hashdepth)
throw new StopRecursion.TooDeep();
if (hashable instanceof Leaf)
{
Token midpoint = partitioner.midpoint(pleft, pright);
// We should not create a non-sensical range where start and end are the same token (this is non-sensical because range are
// start exclusive). Note that we shouldn't hit that unless the full range is very small or we are fairly deep
if (midpoint.equals(pleft) || midpoint.equals(pright))
throw new StopRecursion.TooDeep();
// split
size++;
return new Inner(midpoint, new Leaf(), new Leaf());
}
// else: node.
// recurse on the matching child
Inner node = (Inner)hashable;
if (Range.contains(pleft, node.token, t))
// left child contains token
node.lchild(splitHelper(node.lchild, pleft, node.token, inc(depth), t));
else
// else: right child contains token
node.rchild(splitHelper(node.rchild, node.token, pright, inc(depth), t));
return node;
}
/**
* Returns a lazy iterator of invalid TreeRanges that need to be filled
* in order to make the given Range valid.
*/
public TreeRangeIterator invalids()
{
return new TreeRangeIterator(this);
}
public EstimatedHistogram histogramOfRowSizePerLeaf()
{
HistogramBuilder histbuild = new HistogramBuilder();
for (TreeRange range : new TreeRangeIterator(this))
{
histbuild.add(range.hashable.sizeOfRange);
}
return histbuild.buildWithStdevRangesAroundMean();
}
public EstimatedHistogram histogramOfRowCountPerLeaf()
{
HistogramBuilder histbuild = new HistogramBuilder();
for (TreeRange range : new TreeRangeIterator(this))
{
histbuild.add(range.hashable.rowsInRange);
}
return histbuild.buildWithStdevRangesAroundMean();
}
public long rowCount()
{
long count = 0;
for (TreeRange range : new TreeRangeIterator(this))
{
count += range.hashable.rowsInRange;
}
return count;
}
@Override
public String toString()
{
StringBuilder buff = new StringBuilder();
buff.append("#<MerkleTree root=");
root.toString(buff, 8);
buff.append(">");
return buff.toString();
}
public static class TreeDifference extends TreeRange
{
private static final long serialVersionUID = 6363654174549968183L;
private long sizeOnLeft;
private long sizeOnRight;
private long rowsOnLeft;
private long rowsOnRight;
void setSize(long sizeOnLeft, long sizeOnRight)
{
this.sizeOnLeft = sizeOnLeft;
this.sizeOnRight = sizeOnRight;
}
void setRows(long rowsOnLeft, long rowsOnRight)
{
this.rowsOnLeft = rowsOnLeft;
this.rowsOnRight = rowsOnRight;
}
public long sizeOnLeft()
{
return sizeOnLeft;
}
public long sizeOnRight()
{
return sizeOnRight;
}
public long rowsOnLeft()
{
return rowsOnLeft;
}
public long rowsOnRight()
{
return rowsOnRight;
}
public TreeDifference(Token left, Token right, byte depth)
{
super(null, left, right, depth, null);
}
public long totalRows()
{
return rowsOnLeft + rowsOnRight;
}
}
/**
* The public interface to a range in the tree.
*
* NB: A TreeRange should not be returned by a public method unless the
* parents of the range it represents are already invalidated, since it
* will allow someone to modify the hash. Alternatively, a TreeRange
* may be created with a null tree, indicating that it is read only.
*/
public static class TreeRange extends Range<Token>
{
public static final long serialVersionUID = 1L;
private final MerkleTree tree;
public final byte depth;
private final Hashable hashable;
TreeRange(MerkleTree tree, Token left, Token right, byte depth, Hashable hashable)
{
super(left, right);
this.tree = tree;
this.depth = depth;
this.hashable = hashable;
}
public void hash(byte[] hash)
{
assert tree != null : "Not intended for modification!";
hashable.hash(hash);
}
public byte[] hash()
{
return hashable.hash();
}
/**
* @param entry Row to mix into the hash for this range.
*/
public void addHash(RowHash entry)
{
assert tree != null : "Not intended for modification!";
assert hashable instanceof Leaf;
hashable.addHash(entry.hash, entry.size);
}
public void ensureHashInitialised()
{
assert tree != null : "Not intended for modification!";
assert hashable instanceof Leaf;
if (hashable.hash == null)
hashable.hash = EMPTY_HASH;
}
public void addAll(Iterator<RowHash> entries)
{
while (entries.hasNext())
addHash(entries.next());
}
@Override
public String toString()
{
StringBuilder buff = new StringBuilder("#<TreeRange ");
buff.append(super.toString()).append(" depth=").append(depth);
return buff.append(">").toString();
}
}
/**
* Returns the leaf (range) of a given tree in increasing order.
* If the full range covered by the tree don't wrap, then it will return the
* ranges in increasing order.
* If the full range wrap, the first *and* last range returned by the
* iterator will be the wrapping range. It is the only case where the same
* leaf will be returned twice.
*/
public static class TreeRangeIterator extends AbstractIterator<TreeRange> implements Iterable<TreeRange>, PeekingIterator<TreeRange>
{
// stack of ranges to visit
private final ArrayDeque<TreeRange> tovisit;
// interesting range
private final MerkleTree tree;
TreeRangeIterator(MerkleTree tree)
{
tovisit = new ArrayDeque<TreeRange>();
tovisit.add(new TreeRange(tree, tree.fullRange.left, tree.fullRange.right, (byte)0, tree.root));
this.tree = tree;
}
/**
* Find the next TreeRange.
*
* @return The next TreeRange.
*/
public TreeRange computeNext()
{
while (!tovisit.isEmpty())
{
TreeRange active = tovisit.pop();
if (active.hashable instanceof Leaf)
{
// found a leaf invalid range
if (active.isWrapAround() && !tovisit.isEmpty())
// put to be taken again last
tovisit.addLast(active);
return active;
}
Inner node = (Inner)active.hashable;
TreeRange left = new TreeRange(tree, active.left, node.token, inc(active.depth), node.lchild);
TreeRange right = new TreeRange(tree, node.token, active.right, inc(active.depth), node.rchild);
if (right.isWrapAround())
{
// whatever is on the left is 'after' everything we have seen so far (it has greater tokens)
tovisit.addLast(left);
tovisit.addFirst(right);
}
else
{
// do left first then right
tovisit.addFirst(right);
tovisit.addFirst(left);
}
}
return endOfData();
}
public Iterator<TreeRange> iterator()
{
return this;
}
}
/**
* An inner node in the MerkleTree. Inners can contain cached hash values, which
* are the binary hash of their two children.
*/
static class Inner extends Hashable
{
public static final long serialVersionUID = 1L;
static final byte IDENT = 2;
public final Token token;
private Hashable lchild;
private Hashable rchild;
private static final InnerSerializer serializer = new InnerSerializer();
/**
* Constructs an Inner with the given token and children, and a null hash.
*/
public Inner(Token token, Hashable lchild, Hashable rchild)
{
super(null);
this.token = token;
this.lchild = lchild;
this.rchild = rchild;
}
public Hashable lchild()
{
return lchild;
}
public Hashable rchild()
{
return rchild;
}
public void lchild(Hashable child)
{
lchild = child;
}
public void rchild(Hashable child)
{
rchild = child;
}
Hashable calc()
{
if (hash == null)
{
// hash and size haven't been calculated; calc children then compute
Hashable lnode = lchild.calc();
Hashable rnode = rchild.calc();
// cache the computed value
hash(lnode.hash, rnode.hash);
sizeOfRange = lnode.sizeOfRange + rnode.sizeOfRange;
rowsInRange = lnode.rowsInRange + rnode.rowsInRange;
}
return this;
}
/**
* Recursive toString.
*/
public void toString(StringBuilder buff, int maxdepth)
{
buff.append("#<").append(getClass().getSimpleName());
buff.append(" ").append(token);
buff.append(" hash=").append(Hashable.toString(hash()));
buff.append(" children=[");
if (maxdepth < 1)
{
buff.append("#");
}
else
{
if (lchild == null)
buff.append("null");
else
lchild.toString(buff, maxdepth-1);
buff.append(" ");
if (rchild == null)
buff.append("null");
else
rchild.toString(buff, maxdepth-1);
}
buff.append("]>");
}
@Override
public String toString()
{
StringBuilder buff = new StringBuilder();
toString(buff, 1);
return buff.toString();
}
private static class InnerSerializer implements IPartitionerDependentSerializer<Inner>
{
public void serialize(Inner inner, DataOutputPlus out, int version) throws IOException
{
Token.serializer.serialize(inner.token, out, version);
Hashable.serializer.serialize(inner.lchild, out, version);
Hashable.serializer.serialize(inner.rchild, out, version);
}
public Inner deserialize(DataInput in, IPartitioner p, int version) throws IOException
{
Token token = Token.serializer.deserialize(in, p, version);
Hashable lchild = Hashable.serializer.deserialize(in, p, version);
Hashable rchild = Hashable.serializer.deserialize(in, p, version);
return new Inner(token, lchild, rchild);
}
public long serializedSize(Inner inner, int version)
{
return Token.serializer.serializedSize(inner.token, version)
+ Hashable.serializer.serializedSize(inner.lchild, version)
+ Hashable.serializer.serializedSize(inner.rchild, version);
}
}
}
/**
* A leaf node in the MerkleTree. Because the MerkleTree represents a much
* larger perfect binary tree of depth hashdepth, a Leaf object contains
* the value that would be contained in the perfect tree at its position.
*
* When rows are added to the MerkleTree using TreeRange.validate(), the
* tree extending below the Leaf is generated in memory, but only the root
* is stored in the Leaf.
*/
static class Leaf extends Hashable
{
public static final long serialVersionUID = 1L;
static final byte IDENT = 1;
private static final LeafSerializer serializer = new LeafSerializer();
/**
* Constructs a null hash.
*/
public Leaf()
{
super(null);
}
public Leaf(byte[] hash)
{
super(hash);
}
public void toString(StringBuilder buff, int maxdepth)
{
buff.append(toString());
}
@Override
public String toString()
{
return "#<Leaf " + Hashable.toString(hash()) + ">";
}
private static class LeafSerializer implements IPartitionerDependentSerializer<Leaf>
{
public void serialize(Leaf leaf, DataOutputPlus out, int version) throws IOException
{
if (leaf.hash == null)
{
out.writeByte(-1);
}
else
{
out.writeByte(leaf.hash.length);
out.write(leaf.hash);
}
}
public Leaf deserialize(DataInput in, IPartitioner p, int version) throws IOException
{
int hashLen = in.readByte();
byte[] hash = hashLen < 0 ? null : new byte[hashLen];
if (hash != null)
in.readFully(hash);
return new Leaf(hash);
}
public long serializedSize(Leaf leaf, int version)
{
long size = 1;
if (leaf.hash != null)
size += leaf.hash().length;
return size;
}
}
}
/**
* Hash value representing a row, to be used to pass hashes to the MerkleTree.
* The byte[] hash value should contain a digest of the key and value of the row
* created using a very strong hash function.
*/
public static class RowHash
{
public final Token token;
public final byte[] hash;
public final long size;
public RowHash(Token token, byte[] hash, long size)
{
this.token = token;
this.hash = hash;
this.size = size;
}
@Override
public String toString()
{
return "#<RowHash " + token + " " + Hashable.toString(hash) + " @ " + size + " bytes>";
}
}
/**
* Abstract class containing hashing logic, and containing a single hash field.
*/
static abstract class Hashable implements Serializable
{
private static final long serialVersionUID = 1L;
private static final IPartitionerDependentSerializer<Hashable> serializer = new HashableSerializer();
protected byte[] hash;
protected long sizeOfRange;
protected long rowsInRange;
protected Hashable(byte[] hash)
{
this.hash = hash;
}
public byte[] hash()
{
return hash;
}
public long sizeOfRange()
{
return sizeOfRange;
}
public long rowsInRange()
{
return rowsInRange;
}
void hash(byte[] hash)
{
this.hash = hash;
}
Hashable calc()
{
return this;
}
/**
* Sets the value of this hash to binaryHash of its children.
* @param lefthash Hash of left child.
* @param righthash Hash of right child.
*/
void hash(byte[] lefthash, byte[] righthash)
{
hash = binaryHash(lefthash, righthash);
}
/**
* Mixes the given value into our hash. If our hash is null,
* our hash will become the given value.
*/
void addHash(byte[] righthash, long sizeOfRow)
{
if (hash == null)
hash = righthash;
else
hash = binaryHash(hash, righthash);
this.sizeOfRange += sizeOfRow;
this.rowsInRange += 1;
}
/**
* The primitive with which all hashing should be accomplished: hashes
* a left and right value together.
*/
static byte[] binaryHash(final byte[] left, final byte[] right)
{
return FBUtilities.xor(left, right);
}
public abstract void toString(StringBuilder buff, int maxdepth);
public static String toString(byte[] hash)
{
if (hash == null)
return "null";
return "[" + Hex.bytesToHex(hash) + "]";
}
private static class HashableSerializer implements IPartitionerDependentSerializer<Hashable>
{
public void serialize(Hashable h, DataOutputPlus out, int version) throws IOException
{
if (h instanceof Inner)
{
out.writeByte(Inner.IDENT);
Inner.serializer.serialize((Inner)h, out, version);
}
else if (h instanceof Leaf)
{
out.writeByte(Leaf.IDENT);
Leaf.serializer.serialize((Leaf) h, out, version);
}
else
throw new IOException("Unexpected Hashable: " + h.getClass().getCanonicalName());
}
public Hashable deserialize(DataInput in, IPartitioner p, int version) throws IOException
{
byte ident = in.readByte();
if (Inner.IDENT == ident)
return Inner.serializer.deserialize(in, p, version);
else if (Leaf.IDENT == ident)
return Leaf.serializer.deserialize(in, p, version);
else
throw new IOException("Unexpected Hashable: " + ident);
}
public long serializedSize(Hashable h, int version)
{
if (h instanceof Inner)
return 1 + Inner.serializer.serializedSize((Inner) h, version);
else if (h instanceof Leaf)
return 1 + Leaf.serializer.serializedSize((Leaf) h, version);
throw new AssertionError(h.getClass());
}
}
}
/**
* Exceptions that stop recursion early when we are sure that no answer
* can be found.
*/
static abstract class StopRecursion extends Exception
{
static class BadRange extends StopRecursion
{
public BadRange(){ super(); }
}
static class InvalidHash extends StopRecursion
{
public InvalidHash(){ super(); }
}
static class TooDeep extends StopRecursion
{
public TooDeep(){ super(); }
}
}
}