AbstractReadOnlyNodeData (Blazegraph Database Platform 2.1.5 API)

java.lang.Object
- com.bigdata.btree.data.AbstractReadOnlyNodeData<U>

```
public abstract class AbstractReadOnlyNodeData<U extends IAbstractNodeData>
extends Object
```
Abstract base class for a read-only view of the data for B+Tree node or leaf. The data are stored in a ByteBuffer. Access to the keys, values and other metadata are via operations on that ByteBuffer.

Version:

$Id$

Author:

Bryan Thompson

Field Summary

Fields
Modifier and Type	Field and Description
`static short`	`currentVersion` The current version.
`static short`	`FLAG_DELETE_MARKERS` Bit flag for a leaf carrying delete markers for each tuple.
`static short`	`FLAG_OVERFLOW_DIRECTORY` Marks a directory page as an overflow directory page (HTree).
`static short`	`FLAG_RAW_RECORDS` Bit flag for a leaf carrying raw record bit flags.
`static short`	`FLAG_RWSTORE_ADDRS` Bit flag for a node or leaf on the RWStore using native int32 addresses for persistence.
`static short`	`FLAG_VERSION_TIMESTAMPS` Bit flag for a leaf carrying version timestamps for each tuple.
`static byte`	`LEAF` A B+Tree leaf data record.
`static byte`	`LINKED_LEAF` A B+Tree leaf data record with with priorAddr and nextAddr fields.
`static byte`	`NODE` A B+Tree node data record.
`static int`	`O_NEXT` The offset of the long field which codes the address of the next leaf.
`static int`	`O_PRIOR` The offset of the long field which codes the address of the previous leaf.
`static int`	`O_TYPE` The offset of the byte field which codes the type of the node or leaf.
`static int`	`SIZEOF_ADDR` The size of a field in the data record which encodes the address of a child node or leaf.
`static int`	`SIZEOF_FLAGS` The size of the field in the data record which encodes bit flags for the node or leaf.
`static int`	`SIZEOF_KEYS_SIZE` The size of the field in the data record which encodes the #of bytes in the coded keys (or the coded values).
`static int`	`SIZEOF_NKEYS` The size of the field in the data record which encodes the #of keys in the node or leaf.
`static int`	`SIZEOF_TIMESTAMP` The size of a field in the data record which encodes the revision timestamp of a tuple in a leaf.
`static int`	`SIZEOF_TYPE` The size of the field in the data record which encodes whether the data record represents a B+Tree `NODE`, a `LEAF`, or a `LINKED_LEAF`.
`static int`	`SIZEOF_VERSION` The size of the field in the data record which encodes the serialization version of the data record.
`static short`	`VERSION0` The initial version.
`static short`	`VERSION1` This version introduces: spannedTupleCount Both the #of children spanned by the node (`nentries`) and the #of children spanned by each child of the node ( `childEntryCount`) are int64 integers in this version.

Constructor Summary

Constructors
Modifier Constructor and Description

protected AbstractReadOnlyNodeData()
Core ctor.

Constructors
Modifier	Constructor and Description
`protected`	`AbstractReadOnlyNodeData()` Core ctor.

Method Summary

Methods
Modifier and Type	Method and Description
`static boolean`	`isLeaf(byte b)` Return `true` iff the byte indicates an `ILeafData` record.
`static boolean`	`isNode(byte b)` Return `true` iff the byte indicates an `INodeData` record.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - NODE
```
public static final byte NODE
```
    A B+Tree node data record.
    
    See Also:
    Constant Field Values
  - LEAF
```
public static final byte LEAF
```
    A B+Tree leaf data record.
    
    See Also:
    Constant Field Values
  - LINKED_LEAF
```
public static final byte LINKED_LEAF
```
    A B+Tree leaf data record with with priorAddr and nextAddr fields. This is used for the leaves in an IndexSegment.
    
    See Also:
    Constant Field Values
  - VERSION0
```
public static final short VERSION0
```
    The initial version.
    
    See Also:
    Constant Field Values
  - VERSION1
```
public static final transient short VERSION1
```
    This version introduces:
    
    spannedTupleCount
    
    Both the #of children spanned by the node (nentries) and the #of children spanned by each child of the node ( childEntryCount) are int64 integers in this version. The manner in which those integers are coded within the record has also changed.
    
    See Also:
    Constant Field Values
  - currentVersion
```
public static final transient short currentVersion
```
    The current version.
    
    See Also:
    Constant Field Values
  - FLAG_DELETE_MARKERS
```
public static final short FLAG_DELETE_MARKERS
```
    Bit flag for a leaf carrying delete markers for each tuple.
    
    See Also:
    Constant Field Values
  - FLAG_VERSION_TIMESTAMPS
```
public static final short FLAG_VERSION_TIMESTAMPS
```
    Bit flag for a leaf carrying version timestamps for each tuple.
    
    See Also:
    Constant Field Values
  - FLAG_RWSTORE_ADDRS
```
public static final short FLAG_RWSTORE_ADDRS
```
    Bit flag for a node or leaf on the RWStore using native int32 addresses for persistence. FIXME Integrate this! Also, make sure that we test with this mode of data storage in the coder test suite.
    
    See Also:
    Constant Field Values
  - FLAG_OVERFLOW_DIRECTORY
```
public static final short FLAG_OVERFLOW_DIRECTORY
```
    Marks a directory page as an overflow directory page (HTree).
    
    See Also:
    Constant Field Values
  - FLAG_RAW_RECORDS
```
public static final short FLAG_RAW_RECORDS
```
    Bit flag for a leaf carrying raw record bit flags.
    
    See Also:
    Constant Field Values
  - SIZEOF_TYPE
```
public static final int SIZEOF_TYPE
```
    The size of the field in the data record which encodes whether the data record represents a B+Tree NODE, a LEAF, or a LINKED_LEAF.
    
    See Also:
    Constant Field Values
  - SIZEOF_VERSION
```
public static final int SIZEOF_VERSION
```
    The size of the field in the data record which encodes the serialization version of the data record. The offset of this field depends on whether the record is a node or leaf versus a linked leaf. For a linked leaf, the version information starts after the prior/next addr fields. Otherwise it starts immediately after the type field.
    
    See Also:
    Constant Field Values
  - SIZEOF_FLAGS
```
public static final int SIZEOF_FLAGS
```
    The size of the field in the data record which encodes bit flags for the node or leaf.
    
    See Also:
    Constant Field Values
  - SIZEOF_NKEYS
```
public static final int SIZEOF_NKEYS
```
    The size of the field in the data record which encodes the #of keys in the node or leaf. The #of children in a node is always nkeys+1.
    
    See Also:
    Constant Field Values
  - SIZEOF_KEYS_SIZE
```
public static final int SIZEOF_KEYS_SIZE
```
    The size of the field in the data record which encodes the #of bytes in the coded keys (or the coded values). This is an int32 because it is possible that an int16 would limit the size of records for RMI.
    
    See Also:
    Constant Field Values
  - SIZEOF_ADDR
```
public static final int SIZEOF_ADDR
```
    The size of a field in the data record which encodes the address of a child node or leaf. TODO Handle int32 addresses natively with FLAG_RWSTORE_ADDRS
    
    See Also:
    Constant Field Values
  - SIZEOF_TIMESTAMP
```
public static final int SIZEOF_TIMESTAMP
```
    The size of a field in the data record which encodes the revision timestamp of a tuple in a leaf.
    
    See Also:
    Constant Field Values
  - O_TYPE
```
public static final int O_TYPE
```
    The offset of the byte field which codes the type of the node or leaf.
    
    See Also:
    Constant Field Values
  - O_PRIOR
```
public static final int O_PRIOR
```
    The offset of the long field which codes the address of the previous leaf. This field IS NOT present unless the record type is LINKED_LEAF.
    
    See Also:
    Constant Field Values
  - O_NEXT
```
public static final int O_NEXT
```
    The offset of the long field which codes the address of the next leaf. This field IS NOT present unless the record type is LINKED_LEAF.
    
    See Also:
    Constant Field Values
- Constructor Detail
  - AbstractReadOnlyNodeData
```
protected AbstractReadOnlyNodeData()
```
    Core ctor. There are two basic use cases. One when you already have the ByteBuffer with the encoded node or leaf data and one when you have a mutable Node or Leaf and you want to persist it. In the latter case, the derived class allocates a ByteBuffer and encodes the data onto that buffer.
- Method Detail
  - isNode
```
public static boolean isNode(byte b)
```
    Return true iff the byte indicates an INodeData record.
    
    Parameters:
    b - The byte value.
    
    Returns:
  - isLeaf
```
public static boolean isLeaf(byte b)
```
    Return true iff the byte indicates an ILeafData record. Note that this will return true for both LEAF and LINKED_LEAF.
    
    Parameters:
    b - The byte value.
    
    Returns:

Class AbstractReadOnlyNodeData<U extends IAbstractNodeData>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

NODE

LEAF

LINKED_LEAF

VERSION0

VERSION1

currentVersion

FLAG_DELETE_MARKERS

FLAG_VERSION_TIMESTAMPS

FLAG_RWSTORE_ADDRS

FLAG_OVERFLOW_DIRECTORY

FLAG_RAW_RECORDS

SIZEOF_TYPE

SIZEOF_VERSION

SIZEOF_FLAGS

SIZEOF_NKEYS

SIZEOF_KEYS_SIZE

SIZEOF_ADDR

SIZEOF_TIMESTAMP

O_TYPE

O_PRIOR

O_NEXT

Constructor Detail

AbstractReadOnlyNodeData

Method Detail

isNode

isLeaf