org.h2.dev.store.btree
Class MVMap<K,V>

java.lang.Object
  java.util.AbstractMap<K,V>
      org.h2.dev.store.btree.MVMap<K,V>

Type Parameters:

K - the key class

V - the value class

All Implemented Interfaces:

java.util.Map<K,V>

Direct Known Subclasses:

MVRTreeMap, SequenceMap

public class MVMap<K,V>
extends java.util.AbstractMap<K,V>

A stored map.

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

java.util.AbstractMap.SimpleEntry<K,V>, java.util.AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface java.util.Map

java.util.Map.Entry<K,V>

Field Summary

protected Page	root The root page (may not be null).
protected MVStore	store The store.

Constructor Summary

protected

MVMap(MVStore store, int id, java.lang.String name, DataType keyType, DataType valueType, long createVersion)

Method Summary

protected java.lang.Object	binarySearch(Page p, java.lang.Object key) Get the value for the given key, or null if not found.
protected Page	binarySearchPage(Page p, java.lang.Object key) Get the value for the given key, or null if not found.
java.util.Iterator<K>	changeIterator(long minVersion) Iterate over all keys in changed pages.
protected void	checkOpen() Check whether the map is open.
protected void	checkWrite() Check whether writing is allowed.
void	clear() Remove all entries.
void	close() Close the map, making it read only and release the memory.
boolean	containsKey(java.lang.Object key)
java.util.Set<java.util.Map.Entry<K,V>>	entrySet()
boolean	equals(java.lang.Object o)
V	get(java.lang.Object key) Get a value.
protected Page	getPage(K key) Get the page for the given value.
Page	getRoot() Get the root page.
long	getSize()
int	hashCode()
boolean	hasUnsavedChanges() Check whether this map has any unsaved changes.
boolean	isClosed()
boolean	isReadOnly()
java.util.Iterator<K>	keyIterator(K from) Iterate over all keys.
java.util.Set<K>	keySet()
protected CursorPos	min(Page p, Cursor<K,V> cursor, java.lang.Object key) Go to the first element for the given key.
protected java.lang.Object	nextKey(CursorPos p, Cursor<K,V> cursor) Get the next key.
MVMap<K,V>	openVersion(long version) Open an old version for the given map.
V	put(K key, V value) Add or replace a key-value pair.
protected java.lang.Object	put(Page p, long writeVersion, java.lang.Object key, java.lang.Object value) Add or update a key-value pair.
V	remove(java.lang.Object key) Remove a key-value pair, if the key exists.
protected java.lang.Object	remove(Page p, long writeVersion, java.lang.Object key) Remove a key-value pair.
void	removeMap() Remove all entries, and close the map.
protected void	removePage(Page p) Remove the given page (make the space available).
void	setReadOnly(boolean readOnly)
protected void	setRoot(Page newRoot)
int	size()
java.lang.String	toString()

Methods inherited from class java.util.AbstractMap

clone, containsValue, isEmpty, putAll, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

store

protected final MVStore store

The store.

root

protected Page root

The root page (may not be null).

Constructor Detail

MVMap

protected MVMap(MVStore store,
                int id,
                java.lang.String name,
                DataType keyType,
                DataType valueType,
                long createVersion)

Method Detail

put

public V put(K key,
             V value)

Add or replace a key-value pair.

Specified by:

put in interface java.util.Map<K,V>

Overrides:

put in class java.util.AbstractMap<K,V>

Parameters:

key - the key (may not be null)

value - the value (may not be null)

Returns:

the old value if the key existed, or null otherwise

put

protected java.lang.Object put(Page p,
                               long writeVersion,
                               java.lang.Object key,
                               java.lang.Object value)

Add or update a key-value pair.

Parameters:

p - the page

writeVersion - the write version

key - the key (may not be null)

value - the value (may not be null)

Returns:

the old value, or null

get

public V get(java.lang.Object key)

Get a value.

Specified by:

get in interface java.util.Map<K,V>

Overrides:

get in class java.util.AbstractMap<K,V>

Parameters:

key - the key

Returns:

the value, or null if not found

min

protected CursorPos min(Page p,
                        Cursor<K,V> cursor,
                        java.lang.Object key)

Go to the first element for the given key.

Parameters:

p - the current page

cursor - the cursor

key - the key

Returns:

the cursor position

nextKey

protected java.lang.Object nextKey(CursorPos p,
                                   Cursor<K,V> cursor)

Get the next key.

Parameters:

p - the cursor position

cursor - the cursor

Returns:

the next key

binarySearch

protected java.lang.Object binarySearch(Page p,
                                        java.lang.Object key)

Get the value for the given key, or null if not found.

Parameters:

p - the page

key - the key

Returns:

the value or null

containsKey

public boolean containsKey(java.lang.Object key)

Specified by:

containsKey in interface java.util.Map<K,V>

Overrides:

containsKey in class java.util.AbstractMap<K,V>

getPage

protected Page getPage(K key)

Get the page for the given value.

Parameters:

key - the key

Returns:

the value, or null if not found

binarySearchPage

protected Page binarySearchPage(Page p,
                                java.lang.Object key)

Get the value for the given key, or null if not found.

Parameters:

p - the parent page

key - the key

Returns:

the page or null

clear

public void clear()

Remove all entries.

Specified by:

clear in interface java.util.Map<K,V>

Overrides:

clear in class java.util.AbstractMap<K,V>

removeMap

public void removeMap()

Remove all entries, and close the map.

close

public void close()

Close the map, making it read only and release the memory.

isClosed

public boolean isClosed()

remove

public V remove(java.lang.Object key)

Remove a key-value pair, if the key exists.

Specified by:

remove in interface java.util.Map<K,V>

Overrides:

remove in class java.util.AbstractMap<K,V>

Parameters:

key - the key (may not be null)

Returns:

the old value if the key existed, or null otherwise

remove

protected java.lang.Object remove(Page p,
                                  long writeVersion,
                                  java.lang.Object key)

Remove a key-value pair.

Parameters:

p - the page (may not be null)

writeVersion - the write version

key - the key

Returns:

the old value, or null if the key did not exist

setRoot

protected void setRoot(Page newRoot)

hasUnsavedChanges

public boolean hasUnsavedChanges()

Check whether this map has any unsaved changes.

Returns:

true if there are unsaved changes.

keyIterator

public java.util.Iterator<K> keyIterator(K from)

Iterate over all keys.

Parameters:

from - the first key to return

Returns:

the iterator

changeIterator

public java.util.Iterator<K> changeIterator(long minVersion)

Iterate over all keys in changed pages. This does not include deleted deleted pages.

Parameters:

minVersion - the minimum version

Returns:

the iterator

entrySet

public java.util.Set<java.util.Map.Entry<K,V>> entrySet()

Specified by:

entrySet in interface java.util.Map<K,V>

Specified by:

entrySet in class java.util.AbstractMap<K,V>

keySet

public java.util.Set<K> keySet()

Specified by:

keySet in interface java.util.Map<K,V>

Overrides:

keySet in class java.util.AbstractMap<K,V>

getRoot

public Page getRoot()

Get the root page.

Returns:

the root page

setReadOnly

public void setReadOnly(boolean readOnly)

isReadOnly

public boolean isReadOnly()

checkOpen

protected void checkOpen()

Check whether the map is open.

Throws:

java.lang.IllegalStateException - if the map is closed

checkWrite

protected void checkWrite()

Check whether writing is allowed.

Throws:

java.lang.IllegalStateException - if the map is read-only

toString

public java.lang.String toString()

Overrides:

toString in class java.util.AbstractMap<K,V>

hashCode

public int hashCode()

Specified by:

hashCode in interface java.util.Map<K,V>

Overrides:

hashCode in class java.util.AbstractMap<K,V>

equals

public boolean equals(java.lang.Object o)

Specified by:

equals in interface java.util.Map<K,V>

Overrides:

equals in class java.util.AbstractMap<K,V>

size

public int size()

Specified by:

size in interface java.util.Map<K,V>

Overrides:

size in class java.util.AbstractMap<K,V>

getSize

public long getSize()

removePage

protected void removePage(Page p)

Remove the given page (make the space available).

Parameters:

p - the page

openVersion

public MVMap<K,V> openVersion(long version)

Open an old version for the given map.

Parameters:

version - the version

Returns:

the map