Package org.dizitart.no2.mvstore.compat.v1.mvstore

Class MVMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.dizitart.no2.mvstore.compat.v1.mvstore.MVMap<K,V>

Type Parameters:

K - the key class

V - the value class

All Implemented Interfaces:

ConcurrentMap<K,V>, Map<K,V>

public class MVMap<K,V>
extends AbstractMap<K,V>
implements ConcurrentMap<K,V>

A stored map.

All read and write operations can happen concurrently with all other operations, without risk of corruption.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MVMap.BasicBuilder<M extends MVMap<K,V>,K,V>	A builder for this class.
static class	MVMap.Builder<K,V>	A builder for this class.
static class	MVMap.Decision
static class	MVMap.DecisionMaker<V>	Class DecisionMaker provides callback interface (and should become a such in Java 8) for MVMap.operate method.
static interface	MVMap.MapBuilder<M extends MVMap<K,V>,K,V>	A builder for maps.

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

AbstractMap.SimpleEntry<K extends Object,V extends Object>, AbstractMap.SimpleImmutableEntry<K extends Object,V extends Object>

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

Map.Entry<K extends Object,V extends Object>

Field Summary

Fields

Modifier and Type	Field	Description
MVStore	store	The store.

Method Summary

Modifier and Type	Method	Description
void	append(K key, V value)	Appends entry to this map.
K	ceilingKey(K key)	Get the smallest key that is larger or equal to this key.
K	ceilingKey(Page p, K key)	Get the smallest key that is larger or equal to this key, for the given root page.
void	clear()	Remove all entries.
boolean	containsKey(Object key)
Cursor<K,V>	cursor(K from)	Get a cursor to iterate over a number of keys and values.
Set<Map.Entry<K,V>>	entrySet()
boolean	equals(Object o)
K	firstKey()	Get the first key, or null if the map is empty.
K	firstKey(Page p)	Get the first key of this page.
K	floorKey(K key)	Get the largest key that is smaller or equal to this key.
K	floorKey(Page p, K key)	Get the largest key that is smaller or equal to this key, for the given root page.
RootReference	flushAndGetRoot()	Get the root reference, flushing any current append buffer.
V	get(Object key)	Get the value for the given key, or null if not found.
V	get(Page p, Object key)	Get the value for the given key from a snapshot, or null if not found.
long	getCreateVersion()
int	getId()	Get the map id.
K	getKey(long index)	Get the key at the given index.
long	getKeyIndex(K key)	Get the index of the given key in the map.
DataType	getKeyType()	Get the key type.
String	getName()	Get the map name.
RootReference	getRoot()
Page	getRootPage()	The current root page (may not be null).
MVStore	getStore()
String	getType()	Get the map type.
DataType	getValueType()	Get the value type.
long	getVersion()	Get version of the map, which is the version of the store, at the moment when map was modified last time.
int	hashCode()
K	higherKey(K key)	Get the smallest key that is larger than the given key, or null if no such key exists.
K	higherKey(Page p, K key)	Get the smallest key that is larger than the given key, for the given root page, or null if no such key exists.
boolean	isClosed()
boolean	isEmpty()
boolean	isReadOnly()
boolean	isVolatile()	Whether this is volatile map, meaning that changes are not persisted.
Iterator<K>	keyIterator(K from)	Iterate over a number of keys.
List<K>	keyList()	Get the key list.
Set<K>	keySet()
K	lastKey()	Get the last key, or null if the map is empty.
K	lastKey(Page p)	Get the last key of this page.
K	lowerKey(K key)	Get the largest key that is smaller than the given key, or null if no such key exists.
K	lowerKey(Page p, K key)	Get the largest key that is smaller than the given key, for the given root page, or null if no such key exists.
MVMap<K,V>	openVersion(long version)	Open an old version for the given map.
V	operate(K key, V value, MVMap.DecisionMaker<? super V> decisionMaker)	Add, replace or remove a key-value pair.
V	put(K key, V value)	Add or replace a key-value pair.
V	putIfAbsent(K key, V value)	Add a key-value pair if it does not yet exist.
V	remove(Object key)	Remove a key-value pair, if the key exists.
boolean	remove(Object key, Object value)	Remove a key-value pair if the value matches the stored one.
V	replace(K key, V value)	Replace a value for an existing key.
boolean	replace(K key, V oldValue, V newValue)	Replace a value for an existing key, if the value matches.
void	setVolatile(boolean isVolatile)	Set the volatile flag of the map.
int	size()	Get the number of entries, as a integer.
long	sizeAsLong()	Get the number of entries, as a long.
String	toString()
void	trimLast()	Removes last entry from this map.

Methods inherited from class java.util.AbstractMap

containsValue, putAll, values

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.concurrent.ConcurrentMap

compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, replaceAll

Methods inherited from interface java.util.Map

containsValue, putAll, values

Field Detail

store

public final MVStore store

The store.

Method Detail

put

public V put(K key,
             V value)

Add or replace a key-value pair.

Specified by:

put in interface Map<K,V>

Overrides:

put in class 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

firstKey

public final K firstKey()

Get the first key, or null if the map is empty.

Returns:

the first key, or null

firstKey

public final K firstKey(Page p)

Get the first key of this page.

Parameters:

p - the page

Returns:

the key, or null

lastKey

public final K lastKey()

Get the last key, or null if the map is empty.

Returns:

the last key, or null

lastKey

public final K lastKey(Page p)

Get the last key of this page.

Parameters:

p - the page

Returns:

the key, or null

getKey

public final K getKey(long index)

Get the key at the given index.

This is a O(log(size)) operation.

Parameters:

index - the index

Returns:

the key

keyList

public final List<K> keyList()

Get the key list. The list is a read-only representation of all keys.

The get and indexOf methods are O(log(size)) operations. The result of indexOf is cast to an int.

Returns:

the key list

getKeyIndex

public final long getKeyIndex(K key)

Get the index of the given key in the map.

This is a O(log(size)) operation.

If the key was found, the returned value is the index in the key array. If not found, the returned value is negative, where -1 means the provided key is smaller than any keys. See also Arrays.binarySearch.

Parameters:

key - the key

Returns:

the index

higherKey

public final K higherKey(K key)

Get the smallest key that is larger than the given key, or null if no such key exists.

Parameters:

key - the key

Returns:

the result

higherKey

public final K higherKey(Page p,
                         K key)

Get the smallest key that is larger than the given key, for the given root page, or null if no such key exists.

Parameters:

p - the root page

key - the key

Returns:

the result

ceilingKey

public final K ceilingKey(K key)

Get the smallest key that is larger or equal to this key.

Parameters:

key - the key

Returns:

the result

ceilingKey

public final K ceilingKey(Page p,
                          K key)

Get the smallest key that is larger or equal to this key, for the given root page.

Parameters:

p - the root page

key - the key

Returns:

the result

floorKey

public final K floorKey(K key)

Get the largest key that is smaller or equal to this key.

Parameters:

key - the key

Returns:

the result

floorKey

public final K floorKey(Page p,
                        K key)

Get the largest key that is smaller or equal to this key, for the given root page.

Parameters:

p - the root page

key - the key

Returns:

the result

lowerKey

public final K lowerKey(K key)

Get the largest key that is smaller than the given key, or null if no such key exists.

Parameters:

key - the key

Returns:

the result

lowerKey

public final K lowerKey(Page p,
                        K key)

Get the largest key that is smaller than the given key, for the given root page, or null if no such key exists.

Parameters:

p - the root page

key - the key

Returns:

the result

get

public final V get(Object key)

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

Specified by:

get in interface Map<K,V>

Overrides:

get in class AbstractMap<K,V>

Parameters:

key - the key

Returns:

the value, or null if not found

Throws:

ClassCastException - if type of the specified key is not compatible with this map

get

public V get(Page p,
             Object key)

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

Parameters:

p - the root of a snapshot

key - the key

Returns:

the value, or null if not found

Throws:

ClassCastException - if type of the specified key is not compatible with this map

containsKey

public final boolean containsKey(Object key)

Specified by:

containsKey in interface Map<K,V>

Overrides:

containsKey in class AbstractMap<K,V>

clear

public void clear()

Remove all entries.

Specified by:

clear in interface Map<K,V>

Overrides:

clear in class AbstractMap<K,V>

isClosed

public final boolean isClosed()

remove

public V remove(Object key)

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

Specified by:

remove in interface Map<K,V>

Overrides:

remove in class AbstractMap<K,V>

Parameters:

key - the key (may not be null)

Returns:

the old value if the key existed, or null otherwise

Throws:

ClassCastException - if type of the specified key is not compatible with this map

putIfAbsent

public final V putIfAbsent(K key,
                           V value)

Add a key-value pair if it does not yet exist.

Specified by:

putIfAbsent in interface ConcurrentMap<K,V>

Specified by:

putIfAbsent in interface Map<K,V>

Parameters:

key - the key (may not be null)

value - the new value

Returns:

the old value if the key existed, or null otherwise

remove

public boolean remove(Object key,
                      Object value)

Remove a key-value pair if the value matches the stored one.

Specified by:

remove in interface ConcurrentMap<K,V>

Specified by:

remove in interface Map<K,V>

Parameters:

key - the key (may not be null)

value - the expected value

Returns:

true if the item was removed

replace

public final boolean replace(K key,
                             V oldValue,
                             V newValue)

Replace a value for an existing key, if the value matches.

Specified by:

replace in interface ConcurrentMap<K,V>

Specified by:

replace in interface Map<K,V>

Parameters:

key - the key (may not be null)

oldValue - the expected value

newValue - the new value

Returns:

true if the value was replaced

replace

public final V replace(K key,
                       V value)

Replace a value for an existing key.

Specified by:

replace in interface ConcurrentMap<K,V>

Specified by:

replace in interface Map<K,V>

Parameters:

key - the key (may not be null)

value - the new value

Returns:

the old value, if the value was replaced, or null

getKeyType

public final DataType getKeyType()

Get the key type.

Returns:

the key type

getValueType

public final DataType getValueType()

Get the value type.

Returns:

the value type

keyIterator

public final Iterator<K> keyIterator(K from)

Iterate over a number of keys.

Parameters:

from - the first key to return

Returns:

the iterator

cursor

public final Cursor<K,V> cursor(K from)

Get a cursor to iterate over a number of keys and values.

Parameters:

from - the first key to return

Returns:

the cursor

entrySet

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

Specified by:

entrySet in interface Map<K,V>

Specified by:

entrySet in class AbstractMap<K,V>

keySet

public Set<K> keySet()

Specified by:

keySet in interface Map<K,V>

Overrides:

keySet in class AbstractMap<K,V>

getName

public final String getName()

Get the map name.

Returns:

the name

getStore

public final MVStore getStore()

getId

public final int getId()

Get the map id. Please note the map id may be different after compacting a store.

Returns:

the map id

getRootPage

public final Page getRootPage()

The current root page (may not be null).

Returns:

the root page

getRoot

public RootReference getRoot()

flushAndGetRoot

public RootReference flushAndGetRoot()

Get the root reference, flushing any current append buffer.

Returns:

current root reference

isReadOnly

public final boolean isReadOnly()

setVolatile

public final void setVolatile(boolean isVolatile)

Set the volatile flag of the map.

Parameters:

isVolatile - the volatile flag

isVolatile

public final boolean isVolatile()

Whether this is volatile map, meaning that changes are not persisted. By default (even if the store is not persisted), maps are not volatile.

Returns:

whether this map is volatile

hashCode

public final int hashCode()

Specified by:

hashCode in interface Map<K,V>

Overrides:

hashCode in class AbstractMap<K,V>

equals

public final boolean equals(Object o)

Specified by:

equals in interface Map<K,V>

Overrides:

equals in class AbstractMap<K,V>

size

public final int size()

Get the number of entries, as a integer. Integer.MAX_VALUE is returned if there are more than this entries.

Specified by:

size in interface Map<K,V>

Overrides:

size in class AbstractMap<K,V>

Returns:

the number of entries, as an integer

See Also:

sizeAsLong()

sizeAsLong

public final long sizeAsLong()

Get the number of entries, as a long.

Returns:

the number of entries

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<K,V>

Overrides:

isEmpty in class AbstractMap<K,V>

getCreateVersion

public final long getCreateVersion()

openVersion

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

Open an old version for the given map. It will restore map at last known state of the version specified. (at the point right before the commit() call, which advanced map to the next version) Map is opened in read-only mode.

Parameters:

version - the version

Returns:

the map

getVersion

public final long getVersion()

Get version of the map, which is the version of the store, at the moment when map was modified last time.

Returns:

version

getType

public String getType()

Get the map type. When opening an existing map, the map type must match.

Returns:

the map type

append

public void append(K key,
                   V value)

Appends entry to this map. this method is NOT thread safe and can not be used neither concurrently, nor in combination with any method that updates this map. Non-updating method may be used concurrently, but latest appended values are not guaranteed to be visible.

Parameters:

key - should be higher in map's order than any existing key

value - to be appended

trimLast

public void trimLast()

Removes last entry from this map. this method is NOT thread safe and can not be used neither concurrently, nor in combination with any method that updates this map. Non-updating method may be used concurrently, but latest removal may not be visible.

toString

public final String toString()

Overrides:

toString in class AbstractMap<K,V>

operate

public V operate(K key,
                 V value,
                 MVMap.DecisionMaker<? super V> decisionMaker)

Add, replace or remove a key-value pair.

Parameters:

key - the key (may not be null)

value - new value, it may be null when removal is intended

decisionMaker - command object to make choices during transaction.

Returns:

previous value, if mapping for that key existed, or null otherwise