Package org.apache.jena.dboe.trans.bplustree

Class BPlusTree

  • All Implemented Interfaces:
    java.lang.Iterable<org.apache.jena.dboe.base.record.Record>, org.apache.jena.atlas.lib.Closeable, org.apache.jena.atlas.lib.Sync, Index, RangeIndex, TransactionalComponent
    public class BPlusTree
extends TransactionalComponentLifecycle<org.apache.jena.dboe.trans.bplustree.BptTxnState>
implements RangeIndex
    B-Tree taken from: 
     Introduction to Algorithms, Second Edition
 Chapter 18: B-Trees
 by Thomas H. Cormen, Charles E. Leiserson,
    Ronald L. Rivest and Clifford Stein
    Includes implementation of removal then the B-Tree code converted to a B+Tree, then made MVCC/transactional.

    Notes:

    • Stores "records", which are a key and value (the value may be absent).
    • In this B+Tree implementation, the (key,value) pairs are held in RecordBuffer, which wraps a ByteBuffer that only has records in it. BPTreeRecords provides the B+Tree view of a RecordBuffer. All records are in RecordBuffer - the "tree" part is an index for finding the right page. The tree only holds keys, copies from the (key, value) pairs in the RecordBuffers.
    • The version above splits nodes on the way down when full, not when needed where a split can bubble up from below. It means it only ever walks down the tree on insert. Similarly, the delete code ensures a node is suitable before descending.

    • Method Detail

      • newRoot

        public void newRoot​(BPTreeNode newRoot)

      • getRootId

        public int getRootId()

      • getParams

        public BPlusTreeParams getParams()
        Get the parameters describing this B+Tree

      • getStateManager

        public BPTStateMgr getStateManager()
        Only use for careful manipulation of structures

      • getNodeManager

        public BPTreeNodeMgr getNodeManager()
        Only use for careful manipulation of structures

      • getRecordsMgr

        public BPTreeRecordsMgr getRecordsMgr()
        Only use for careful manipulation of structures

      • getRecordFactory

        public org.apache.jena.dboe.base.record.RecordFactory getRecordFactory()
        Specified by:
        getRecordFactory in interface Index

      • find

        public org.apache.jena.dboe.base.record.Record find​(org.apache.jena.dboe.base.record.Record record)
        Specified by:
        find in interface Index

      • contains

        public boolean contains​(org.apache.jena.dboe.base.record.Record record)
        Specified by:
        contains in interface Index

      • minKey

        public org.apache.jena.dboe.base.record.Record minKey()
        Specified by:
        minKey in interface RangeIndex

      • maxKey

        public org.apache.jena.dboe.base.record.Record maxKey()
        Specified by:
        maxKey in interface RangeIndex

      • insert

        public boolean insert​(org.apache.jena.dboe.base.record.Record record)
        Specified by:
        insert in interface Index

      • insertAndReturnOld

        public org.apache.jena.dboe.base.record.Record insertAndReturnOld​(org.apache.jena.dboe.base.record.Record record)
        Add a record into the B+Tree

      • delete

        public boolean delete​(org.apache.jena.dboe.base.record.Record record)
        Specified by:
        delete in interface Index

      • deleteAndReturnOld

        public org.apache.jena.dboe.base.record.Record deleteAndReturnOld​(org.apache.jena.dboe.base.record.Record record)

      • iterator

        public java.util.Iterator<org.apache.jena.dboe.base.record.Record> iterator()
        Specified by:
        iterator in interface Index
        Specified by:
        iterator in interface java.lang.Iterable<org.apache.jena.dboe.base.record.Record>

      • iterator

        public java.util.Iterator<org.apache.jena.dboe.base.record.Record> iterator​(org.apache.jena.dboe.base.record.Record fromRec,
                                                                            org.apache.jena.dboe.base.record.Record toRec)
        Specified by:
        iterator in interface RangeIndex

      • iterator

        public <X> java.util.Iterator<X> iterator​(org.apache.jena.dboe.base.record.Record minRec,
                                          org.apache.jena.dboe.base.record.Record maxRec,
                                          org.apache.jena.dboe.base.record.RecordMapper<X> mapper)
        Specified by:
        iterator in interface RangeIndex

      • isEmpty

        public boolean isEmpty()
        Specified by:
        isEmpty in interface Index

      • clear

        public void clear()
        Specified by:
        clear in interface Index

      • sync

        public void sync()
        Specified by:
        sync in interface org.apache.jena.atlas.lib.Sync

      • close

        public void close()
        Specified by:
        close in interface org.apache.jena.atlas.lib.Closeable
        Specified by:
        close in interface Index

      • size

        public long size()
        Specified by:
        size in interface Index

      • check

        public void check()
        Specified by:
        check in interface Index

      • dump

        public void dump()

      • dump

        public void dump​(org.apache.jena.atlas.io.IndentedWriter out)

      • nonTransactional

        public void nonTransactional()