IBSkipSpan (Javadocs [I2P+ 2.13.0+]

java.lang.Object
- net.metanotion.util.skiplist.SkipSpan<K,V>
- - net.metanotion.io.block.index.BSkipSpan<K,V>
  - - net.metanotion.io.block.index.IBSkipSpan<K,V>

Type Parameters:
K - type of keys maintained by this skip span
V - type of values stored in this skip span
All Implemented Interfaces:
Flushable
```
public class IBSkipSpan<K extends Comparable<? super K>,V>
extends BSkipSpan<K,V>
```
Memory-efficient SkipList span implementation (I2P version).
Stores only first key in memory to reduce memory usage. Loads keys and values from disk on-demand during operations.
Comparison with BSkipSpan:
- BSkipSpan stores all keys and values in-memory, backed by file
- IBSkipSpan stores only first key, and no values, in-memory
For get(): performs linear search through span in file and loads only found value (super() does binary search in-memory).
For put() or remove(): loads all keys and values for span from file, makes modification, flushes out keys and values, and nulls out keys and values in-memory.
Recommended span size is 16.

Field Summary
- Fields inherited from class net.metanotion.io.block.index.BSkipSpan
  bf, CONT_HEADER_LEN, HEADER_LEN, isKilled, keySer, MAGIC, nextPage, overflowPage, page, prevPage, spanSize, valSer
- Fields inherited from class net.metanotion.util.skiplist.SkipSpan
  keys, MAX_SIZE, next, nKeys, prev, vals

Constructor Summary
Constructors
Constructor and Description
IBSkipSpan(BlockFile bf, BSkipList<K,V> bsl, int spanPage, Serializer<K> key, Serializer<V> val)
Constructor.

Constructors
Constructor and Description
`IBSkipSpan(BlockFile bf, BSkipList<K,V> bsl, int spanPage, Serializer<K> key, Serializer<V> val)` Constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`K`	`firstKey()` Does not call super, we always store first key here
`void`	`flush()` Flush to disk and null out in-memory keys and values, saving only the first key
`V`	`get(K key)` Linear search if in file, Binary search if in memory
`SkipSpan<K,V>`	`getSpan(K key, int[] search)` Load whole span from file, do the operation, flush out, then null out in-memory data again.
`protected void`	`loadData()` I2P - second half of load() Load the whole span's keys and values into memory
`SkipSpan<K,V>`	`newInstance(SkipList<K,V> sl)` Create a new span instance for a page split.
`SkipSpan<K,V>`	`put(K key, V val, SkipList<K,V> sl)` Load whole span from file, do the operation, flush out, then null out in-memory data again.
`Object[]`	`remove(K key, SkipList<K,V> sl)` Load whole span from file, do the operation, flush out, then null out in-memory data again.
`(package private) void`	`seekAndLoadData()` Seek to the start of the span and load the data Package private so BSkipIterator can call it

Methods inherited from class net.metanotion.io.block.index.BSkipSpan
init, killInstance, loadData, loadInit, lostEntries, toString

Methods inherited from class net.metanotion.util.skiplist.SkipSpan
getEnd, print

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

- Constructor Detail
  - IBSkipSpan
```
public IBSkipSpan(BlockFile bf,
                  BSkipList<K,V> bsl,
                  int spanPage,
                  Serializer<K> key,
                  Serializer<V> val)
           throws IOException
```
    Constructor.
    Parameters:
    bf - the block file
    bsl - the B-skip list
    spanPage - page number of the span
    key - key serializer
    val - value serializer
    Throws:
    IOException - on I/O error
- Method Detail
  - firstKey
```
public K firstKey()
```
    Does not call super, we always store first key here
    Overrides:
    firstKey in class SkipSpan<K extends Comparable<? super K>,V>
    Returns:
    the first key, or null if empty
  - flush
```
public void flush()
```
    Flush to disk and null out in-memory keys and values, saving only the first key
    Specified by:
    flush in interface Flushable
    Overrides:
    flush in class BSkipSpan<K extends Comparable<? super K>,V>
  - get
```
public V get(K key)
```
    Linear search if in file, Binary search if in memory
    Overrides:
    get in class SkipSpan<K extends Comparable<? super K>,V>
    Parameters:
    key - the key
    Returns:
    the value, or null if not found
  - getSpan
```
public SkipSpan<K,V> getSpan(K key,
                             int[] search)
```
    Load whole span from file, do the operation, flush out, then null out in-memory data again. This is called only via SkipList.find()
    Overrides:
    getSpan in class SkipSpan<K extends Comparable<? super K>,V>
    Parameters:
    key - the key
    search - search parameters and results
    Returns:
    the span
  - loadData
```
protected void loadData()
                 throws IOException
```
    I2P - second half of load() Load the whole span's keys and values into memory
    Overrides:
    loadData in class BSkipSpan<K extends Comparable<? super K>,V>
    Throws:
    IOException - if an I/O error occurs
  - newInstance
```
public SkipSpan<K,V> newInstance(SkipList<K,V> sl)
```
    Create a new span instance for a page split.
    Overrides:
    newInstance in class BSkipSpan<K extends Comparable<? super K>,V>
    Parameters:
    sl - the parent skip list
    Returns:
    the new span
  - put
```
public SkipSpan<K,V> put(K key,
                         V val,
                         SkipList<K,V> sl)
```
    Load whole span from file, do the operation, flush out, then null out in-memory data again.
    Overrides:
    put in class SkipSpan<K extends Comparable<? super K>,V>
    Parameters:
    key - the key
    val - the value
    sl - the SkipList
    Returns:
    the new span if it caused a split, else null if it went in this span
  - remove
```
public Object[] remove(K key,
                       SkipList<K,V> sl)
```
    Load whole span from file, do the operation, flush out, then null out in-memory data again.
    Overrides:
    remove in class SkipSpan<K extends Comparable<? super K>,V>
    Parameters:
    key - the key
    sl - the SkipList
    Returns:
    An array of two objects or null. rv[0] is the removed object. rv[1] is the deleted SkipSpan if the removed object was the last in the SkipSpan. rv is null if no object was removed.
  - seekAndLoadData
```
void seekAndLoadData()
              throws IOException
```
    Seek to the start of the span and load the data Package private so BSkipIterator can call it
    Throws:
    IOException

Class IBSkipSpan<K extends Comparable<? super K>,V>

Field Summary

Fields inherited from class net.metanotion.io.block.index.BSkipSpan

Fields inherited from class net.metanotion.util.skiplist.SkipSpan

Constructor Summary

Method Summary

Methods inherited from class net.metanotion.io.block.index.BSkipSpan

Methods inherited from class net.metanotion.util.skiplist.SkipSpan

Methods inherited from class java.lang.Object

Constructor Detail

IBSkipSpan

Method Detail

firstKey

flush

get

getSpan

loadData

newInstance

put

remove

seekAndLoadData