org.apache.directory.mavibot.btree

Class PersistedBTree<K,V>

java.lang.Object

org.apache.directory.mavibot.btree.AbstractBTree<K,V>

org.apache.directory.mavibot.btree.PersistedBTree<K,V>

Type Parameters:

K - The type for the keys

V - The type for the stored values

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, BTree<K,V>

public class PersistedBTree<K,V>
extends AbstractBTree<K,V>
implements java.io.Closeable

The B+Tree MVCC data structure.

Field Summary

Fields

Modifier and Type	Field and Description
private long	btreeInfoOffset The BtreeInfo offset
protected org.apache.commons.collections.map.LRUMap	cache The cache associated with this B-tree
protected int	cacheSize The cache size, default to 1000 elements
static int	DEFAULT_CACHE_SIZE The default number of pages to keep in memory
private static int	DEFAULT_VALUE_THRESHOLD_LOW The number of stored Values before we switch back to an array
private static int	DEFAULT_VALUE_THRESHOLD_UP The number of stored Values before we switch to a B-tree
protected static org.slf4j.Logger	LOG The LoggerFactory used by this class
protected static org.slf4j.Logger	LOG_PAGES
private RecordManager	recordManager The internal recordManager
(package private) static int	valueThresholdLow
(package private) static int	valueThresholdUp The configuration for the array <-> B-tree switch

Fields inherited from class org.apache.directory.mavibot.btree.AbstractBTree

allowDuplicates, btreeRevisions, btreeType, currentBtreeHeader, currentRevision, keySerializer, keySerializerFQCN, name, pageSize, readTimeOut, readTransactions, readTransactionsThread, transactionManager, transactionStarted, valueSerializer, valueSerializerFQCN, writeBufferSize

Fields inherited from interface org.apache.directory.mavibot.btree.BTree

ALLOW_DUPLICATES, DEFAULT_PAGE_SIZE, DEFAULT_READ_TIMEOUT, DEFAULT_WRITE_BUFFER_SIZE, FORBID_DUPLICATES

Constructor Summary

Constructors

Constructor and Description
PersistedBTree() Creates a new BTree, with no initialization.
PersistedBTree(PersistedBTreeConfiguration<K,V> configuration) Creates a new persisted B-tree using the BTreeConfiguration to initialize the BTree

Method Summary

Modifier and Type	Method and Description
protected ReadTransaction<K,V>	beginReadTransaction() Starts a Read Only transaction.
protected ReadTransaction<K,V>	beginReadTransaction(long revision) Starts a Read Only transaction.
void	close() Close the BTree, cleaning up all the data structure
(package private) Tuple<K,V>	delete(K key, V value, long revision) Deletes the given pair if both key and value match.
private BTreeHeader<K,V>	getBTreeHeader(java.lang.String name)
long	getBtreeInfoOffset()
(package private) long	getBtreeOffset()
(package private) org.apache.commons.collections.map.LRUMap	getCache() Return the cache we use in this BTree
private BTreeHeader<K,V>	getNewBTreeHeader(java.lang.String name)
(package private) java.util.concurrent.ConcurrentLinkedQueue<ReadTransaction<K,V>>	getReadTransactions() Return the cache we use in this BTree
(package private) RecordManager	getRecordManager() Gets the RecordManager for a managed BTree
Page<K,V>	getRootPage() Get the current rootPage
Page<K,V>	getRootPage(long revision) Get the rootPzge associated to a give revision.
(package private) long	getRootPageOffset()
void	init(BTree<K,V> parentBTree) Initialize the BTree.
(package private) InsertResult<K,V>	insert(K key, V value, long revision) Insert an entry in the BTree.
private DeleteResult<K,V>	processDelete(K key, V value, long revision) Insert the tuple into the B-tree rootPage, get back the new rootPage
private InsertResult<K,V>	processInsert(K key, V value, long revision) Insert the tuple into the B-tree rootPage, get back the new rootPage
(package private) void	setBtreeHeaderOffset(long btreeHeaderOffset)
void	setBtreeInfoOffset(long btreeInfoOffset)
(package private) void	setRecordManager(RecordManager recordManager) Inject a RecordManager for a managed BTree
(package private) void	setRootPage(Page<K,V> root)
java.lang.String	toString()
private void	writeBuffer(java.nio.channels.FileChannel channel, java.nio.ByteBuffer bb, byte[] buffer) Write the data in the ByteBuffer, and eventually on disk if needed.
private PageHolder<K,V>	writePage(Page<K,V> modifiedPage, long revision) Write a page either in the pending pages if the transaction is started, or directly on disk.

Methods inherited from class org.apache.directory.mavibot.btree.AbstractBTree

browse, browse, browseFrom, browseFrom, browseKeys, contains, contains, createTransactionManager, delete, delete, delete, flush, get, get, getBtreeHeader, getBtreeHeader, getKeyComparator, getKeySerializer, getKeySerializerFQCN, getName, getNbElems, getPageSize, getReadTimeOut, getRevision, getType, getValueComparator, getValues, getValueSerializer, getValueSerializerFQCN, getWriteBufferSize, hasKey, hasKey, insert, isAllowDuplicates, setAllowDuplicates, setKeySerializer, setName, setNbElems, setPageSize, setReadTimeOut, setRevision, setType, setValueSerializer, setWriteBufferSize, storeRevision, storeRevision

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

LOG

protected static final org.slf4j.Logger LOG

The LoggerFactory used by this class

LOG_PAGES

protected static final org.slf4j.Logger LOG_PAGES

cache

protected org.apache.commons.collections.map.LRUMap cache

The cache associated with this B-tree

DEFAULT_CACHE_SIZE

public static final int DEFAULT_CACHE_SIZE

The default number of pages to keep in memory

See Also:

Constant Field Values

cacheSize

protected int cacheSize

The cache size, default to 1000 elements

DEFAULT_VALUE_THRESHOLD_UP

private static final int DEFAULT_VALUE_THRESHOLD_UP

The number of stored Values before we switch to a B-tree

See Also:

Constant Field Values

DEFAULT_VALUE_THRESHOLD_LOW

private static final int DEFAULT_VALUE_THRESHOLD_LOW

The number of stored Values before we switch back to an array

See Also:

Constant Field Values

valueThresholdUp

static int valueThresholdUp

The configuration for the array <-> B-tree switch

valueThresholdLow

static int valueThresholdLow

btreeInfoOffset

private long btreeInfoOffset

The BtreeInfo offset

recordManager

private RecordManager recordManager

The internal recordManager

Constructor Detail

PersistedBTree

PersistedBTree()

Creates a new BTree, with no initialization.

PersistedBTree

PersistedBTree(PersistedBTreeConfiguration<K,V> configuration)

Creates a new persisted B-tree using the BTreeConfiguration to initialize the BTree

Parameters:

configuration - The configuration to use

Method Detail

init

public void init(BTree<K,V> parentBTree)

Initialize the BTree.

Throws:

java.io.IOException - If we get some exception while initializing the BTree

getCache

org.apache.commons.collections.map.LRUMap getCache()

Return the cache we use in this BTree

getReadTransactions

java.util.concurrent.ConcurrentLinkedQueue<ReadTransaction<K,V>> getReadTransactions()

Return the cache we use in this BTree

close

public void close()
           throws java.io.IOException

Close the BTree, cleaning up all the data structure

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface BTree<K,V>

Throws:

java.io.IOException

getBtreeOffset

long getBtreeOffset()

Returns:

the btreeOffset

setBtreeHeaderOffset

void setBtreeHeaderOffset(long btreeHeaderOffset)

Parameters:

btreeOffset - the B-tree header Offset to set

getRootPageOffset

long getRootPageOffset()

Returns:

the rootPageOffset

getRecordManager

RecordManager getRecordManager()

Gets the RecordManager for a managed BTree

Returns:

The recordManager if the B-tree is managed

setRecordManager

void setRecordManager(RecordManager recordManager)

Inject a RecordManager for a managed BTree

Parameters:

recordManager - The injected RecordManager

delete

Tuple<K,V> delete(K key,
                  V value,
                  long revision)
           throws java.io.IOException

Deletes the given pair if both key and value match. If the given value is null and there is no null value associated with the given key then the entry with the given key will be removed.

Specified by:

delete in class AbstractBTree<K,V>

Parameters:

key - The key to be removed

value - The value to be removed (can be null, and when no null value exists the key will be removed irrespective of the value)

revision - The revision to be associated with this operation

Returns:

Throws:

java.io.IOException

processDelete

private DeleteResult<K,V> processDelete(K key,
                                        V value,
                                        long revision)
                                 throws java.io.IOException

Insert the tuple into the B-tree rootPage, get back the new rootPage

Throws:

java.io.IOException

insert

InsertResult<K,V> insert(K key,
                         V value,
                         long revision)
                  throws java.io.IOException

Insert an entry in the BTree.

We will replace the value if the provided key already exists in the btree.

The revision number is the revision to use to insert the data.

Specified by:

insert in class AbstractBTree<K,V>

Parameters:

key - Inserted key

value - Inserted value

revision - The revision to use

Returns:

an instance of the InsertResult.

Throws:

java.io.IOException

getBTreeHeader

private BTreeHeader<K,V> getBTreeHeader(java.lang.String name)

getNewBTreeHeader

private BTreeHeader<K,V> getNewBTreeHeader(java.lang.String name)

processInsert

private InsertResult<K,V> processInsert(K key,
                                        V value,
                                        long revision)
                                 throws java.io.IOException

Insert the tuple into the B-tree rootPage, get back the new rootPage

Throws:

java.io.IOException

writeBuffer

private void writeBuffer(java.nio.channels.FileChannel channel,
                         java.nio.ByteBuffer bb,
                         byte[] buffer)
                  throws java.io.IOException

Write the data in the ByteBuffer, and eventually on disk if needed.

Parameters:

channel - The channel we want to write to

bb - The ByteBuffer we want to feed

buffer - The data to inject

Throws:

java.io.IOException - If the write failed

writePage

private PageHolder<K,V> writePage(Page<K,V> modifiedPage,
                                  long revision)
                           throws java.io.IOException

Write a page either in the pending pages if the transaction is started, or directly on disk.

Throws:

java.io.IOException

getRootPage

public Page<K,V> getRootPage(long revision)
                      throws java.io.IOException,
                             KeyNotFoundException

Get the rootPzge associated to a give revision.

Specified by:

getRootPage in interface BTree<K,V>

Parameters:

revision - The revision we are looking for

Returns:

The rootPage associated to this revision

Throws:

java.io.IOException - If we had an issue while accessing the underlying file

KeyNotFoundException - If the revision does not exist for this Btree

getRootPage

public Page<K,V> getRootPage()

Get the current rootPage

Specified by:

getRootPage in interface BTree<K,V>

Specified by:

getRootPage in class AbstractBTree<K,V>

Returns:

The rootPage

setRootPage

void setRootPage(Page<K,V> root)

Description copied from class: AbstractBTree

Specified by:

setRootPage in class AbstractBTree<K,V>

getBtreeInfoOffset

public long getBtreeInfoOffset()

Returns:

the btreeInfoOffset

setBtreeInfoOffset

public void setBtreeInfoOffset(long btreeInfoOffset)

Parameters:

btreeInfoOffset - the btreeInfoOffset to set

beginReadTransaction

protected ReadTransaction<K,V> beginReadTransaction()

Starts a Read Only transaction. If the transaction is not closed, it will be automatically closed after the timeout

Specified by:

beginReadTransaction in class AbstractBTree<K,V>

Returns:

The created transaction

beginReadTransaction

protected ReadTransaction<K,V> beginReadTransaction(long revision)

Starts a Read Only transaction. If the transaction is not closed, it will be automatically closed after the timeout

Specified by:

beginReadTransaction in class AbstractBTree<K,V>

Returns:

The created transaction

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

See Also:

Object.toString()