org.h2.mvstore.tx

类 TransactionMap<K,V>

java.lang.Object

java.util.AbstractMap<K,V>

org.h2.mvstore.tx.TransactionMap<K,V>

类型参数:

K - the key type

V - the value type

所有已实现的接口:

Map<K,V>

public final class TransactionMap<K,V>
extends AbstractMap<K,V>

A map that supports transactions.

Methods of this class may be changed at any time without notice. If you use this class directly make sure that your application or library requires exactly the same version of MVStore or H2 jar as the version that you use during its development and build.

嵌套类概要

嵌套类

限定符和类型	类和说明
static class	TransactionMap.TMIterator<K,V,X>

从类继承的嵌套类/接口 java.util.AbstractMap

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

从接口继承的嵌套类/接口 java.util.Map

Map.Entry<K,V>

字段概要

字段

限定符和类型	字段和说明
MVMap<K,VersionedValue<V>>	map The map used for writing (the latest version).

方法概要

限定符和类型	方法和说明
void	append(K key, V value) Appends entry to underlying map.
Map.Entry<K,V>	ceilingEntry(K key) Get the entry with smallest key that is larger than or equal to this key, or null if no such key exists.
K	ceilingKey(K key) Get the smallest key that is larger than or equal to this key, or null if no such key exists.
void	clear() Clear the map.
boolean	containsKey(Object key) Whether the map contains the key.
TransactionMap.TMIterator<K,V,Map.Entry<K,V>>	entryIterator(K from, K to) Iterate over entries.
Set<Map.Entry<K,V>>	entrySet()
Map.Entry<K,V>	firstEntry() Get the first entry.
K	firstKey() Get the first key.
Map.Entry<K,V>	floorEntry(K key) Get the entry with largest key that is smaller than or equal to this key, or null if no such key exists.
K	floorKey(K key) Get the largest key that is smaller than or equal to this key, or null if no such key exists.
V	get(Object key) Get the effective value for the given key.
V	getFromSnapshot(K key) Get the value for the given key, or null if value does not exist in accordance with transactional rules.
V	getImmediate(K key) Get the value for the given key, or null if not found.
TransactionMap<K,V>	getInstance(Transaction transaction) Get a clone of this map for the given transaction.
DataType<K>	getKeyType()
Transaction	getTransaction()
Map.Entry<K,V>	higherEntry(K key) Get the entry with smallest key that is larger than the given key, or null if no such key exists.
K	higherKey(K key) Get the smallest key that is larger than the given key, or null if no such key exists.
boolean	isClosed() Check whether this map is closed.
boolean	isDeletedByCurrentTransaction(K key) Check if the row was deleted by this transaction.
boolean	isSameTransaction(K key) Whether the entry for this key was added or removed from this session.
Iterator<K>	keyIterator(K from) Iterate over keys.
TransactionMap.TMIterator<K,V,K>	keyIterator(K from, boolean reverse) Iterate over keys in the specified order.
TransactionMap.TMIterator<K,V,K>	keyIterator(K from, K to) Iterate over keys.
TransactionMap.TMIterator<K,V,K>	keyIteratorUncommitted(K from, K to) Iterate over keys, including keys from uncommitted entries.
Map.Entry<K,V>	lastEntry() Get the last entry.
K	lastKey() Get the last key.
V	lock(K key) Lock row for the given key.
Map.Entry<K,V>	lowerEntry(K key) Get the entry with largest key that is smaller than the given key, or null if no such key exists.
K	lowerKey(K key) Get the largest key that is smaller than the given key, or null if no such key exists.
V	put(K key, V value) Update the value for the given key.
V	putCommitted(K key, V value) Update the value for the given key, without adding an undo log entry.
V	putIfAbsent(K key, V value) Put the value for the given key if entry for this key does not exist.
V	remove(Object key) Remove an entry.
int	size() Get the number of entries, as a integer.
long	sizeAsLong() Get the size of the map as seen by this transaction.
long	sizeAsLongMax() Get the size of the raw map.
boolean	tryPut(K key, V value) Try to update the value for the given key.
boolean	tryRemove(K key) Try to remove the value for the given key.
boolean	trySet(K key, V value) Try to set or remove the value.

从类继承的方法 java.util.AbstractMap

clone, containsValue, equals, hashCode, isEmpty, keySet, putAll, toString, values

从类继承的方法 java.lang.Object

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

从接口继承的方法 java.util.Map

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

字段详细资料

map

public final MVMap<K,VersionedValue<V>> map

The map used for writing (the latest version).

Key: key the key of the data. Value: { transactionId, oldVersion, value }

方法详细资料

getInstance

public TransactionMap<K,V> getInstance(Transaction transaction)

Get a clone of this map for the given transaction.

参数:

transaction - the transaction

返回:

the map

size

public int size()

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

指定者:

size 在接口中 Map<K,V>

覆盖:

size 在类中 AbstractMap<K,V>

返回:

the number of entries, as an integer

另请参阅:

sizeAsLong()

sizeAsLongMax

public long sizeAsLongMax()

Get the size of the raw map. This includes uncommitted entries, and transiently removed entries, so it is the maximum number of entries.

返回:

the maximum size

sizeAsLong

public long sizeAsLong()

Get the size of the map as seen by this transaction.

返回:

the size

remove

public V remove(Object key)

Remove an entry.

If the row is locked, this method will retry until the row could be updated or until a lock timeout.

指定者:

remove 在接口中 Map<K,V>

覆盖:

remove 在类中 AbstractMap<K,V>

参数:

key - the key

抛出:

MVStoreException - if a lock timeout occurs

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

put

public V put(K key,
             V value)

Update the value for the given key.

If the row is locked, this method will retry until the row could be updated or until a lock timeout.

指定者:

put 在接口中 Map<K,V>

覆盖:

put 在类中 AbstractMap<K,V>

参数:

key - the key

value - the new value (not null)

返回:

the old value

抛出:

MVStoreException - if a lock timeout occurs

putIfAbsent

public V putIfAbsent(K key,
                     V value)

Put the value for the given key if entry for this key does not exist. It is atomic equivalent of the following expression: contains(key) ? get(k) : put(key, value);

参数:

key - the key

value - the new value (not null)

返回:

the old value

append

public void append(K key,
                   V value)

Appends entry to underlying map. This method may be used concurrently, but latest appended values are not guaranteed to be visible.

参数:

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

value - to be appended

lock

public V lock(K key)

Lock row for the given key.

If the row is locked, this method will retry until the row could be updated or until a lock timeout.

参数:

key - the key

返回:

the locked value

抛出:

MVStoreException - if a lock timeout occurs

putCommitted

public V putCommitted(K key,
                      V value)

Update the value for the given key, without adding an undo log entry.

参数:

key - the key

value - the value

返回:

the old value

tryRemove

public boolean tryRemove(K key)

Try to remove the value for the given key.

This will fail if the row is locked by another transaction (that means, if another open transaction changed the row).

参数:

key - the key

返回:

whether the entry could be removed

tryPut

public boolean tryPut(K key,
                      V value)

Try to update the value for the given key.

This will fail if the row is locked by another transaction (that means, if another open transaction changed the row).

参数:

key - the key

value - the new value

返回:

whether the entry could be updated

trySet

public boolean trySet(K key,
                      V value)

Try to set or remove the value. When updating only unchanged entries, then the value is only changed if it was not changed after opening the map.

参数:

key - the key

value - the new value (null to remove the value)

返回:

true if the value was set, false if there was a concurrent update

get

public V get(Object key)

Get the effective value for the given key.

指定者:

get 在接口中 Map<K,V>

覆盖:

get 在类中 AbstractMap<K,V>

参数:

key - the key

返回:

the value or null

抛出:

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

getFromSnapshot

public V getFromSnapshot(K key)

Get the value for the given key, or null if value does not exist in accordance with transactional rules. Value is taken from a snapshot, appropriate for an isolation level of the related transaction

参数:

key - the key

返回:

the value, or null if not found

getImmediate

public V getImmediate(K key)

Get the value for the given key, or null if not found. Operation is performed on a snapshot of the map taken during this call.

参数:

key - the key

返回:

the value, or null if not found

containsKey

public boolean containsKey(Object key)

Whether the map contains the key.

指定者:

containsKey 在接口中 Map<K,V>

覆盖:

containsKey 在类中 AbstractMap<K,V>

参数:

key - the key

返回:

true if the map contains an entry for this key

抛出:

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

isDeletedByCurrentTransaction

public boolean isDeletedByCurrentTransaction(K key)

Check if the row was deleted by this transaction.

参数:

key - the key

返回:

true if it was

isSameTransaction

public boolean isSameTransaction(K key)

Whether the entry for this key was added or removed from this session.

参数:

key - the key

返回:

true if yes

isClosed

public boolean isClosed()

Check whether this map is closed.

返回:

true if closed

clear

public void clear()

Clear the map.

指定者:

clear 在接口中 Map<K,V>

覆盖:

clear 在类中 AbstractMap<K,V>

entrySet

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

指定者:

entrySet 在接口中 Map<K,V>

指定者:

entrySet 在类中 AbstractMap<K,V>

firstEntry

public Map.Entry<K,V> firstEntry()

Get the first entry.

返回:

the first entry, or null if empty

firstKey

public K firstKey()

Get the first key.

返回:

the first key, or null if empty

lastEntry

public Map.Entry<K,V> lastEntry()

Get the last entry.

返回:

the last entry, or null if empty

lastKey

public K lastKey()

Get the last key.

返回:

the last key, or null if empty

higherEntry

public Map.Entry<K,V> higherEntry(K key)

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

参数:

key - the key (may not be null)

返回:

the result

higherKey

public K higherKey(K key)

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

参数:

key - the key (may not be null)

返回:

the result

ceilingEntry

public Map.Entry<K,V> ceilingEntry(K key)

Get the entry with smallest key that is larger than or equal to this key, or null if no such key exists.

参数:

key - the key (may not be null)

返回:

the result

ceilingKey

public K ceilingKey(K key)

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

参数:

key - the key (may not be null)

返回:

the result

floorEntry

public Map.Entry<K,V> floorEntry(K key)

Get the entry with largest key that is smaller than or equal to this key, or null if no such key exists.

参数:

key - the key (may not be null)

返回:

the result

floorKey

public K floorKey(K key)

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

参数:

key - the key (may not be null)

返回:

the result

lowerEntry

public Map.Entry<K,V> lowerEntry(K key)

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

参数:

key - the key (may not be null)

返回:

the result

lowerKey

public K lowerKey(K key)

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

参数:

key - the key (may not be null)

返回:

the result

keyIterator

public Iterator<K> keyIterator(K from)

Iterate over keys.

参数:

from - the first key to return

返回:

the iterator

keyIterator

public TransactionMap.TMIterator<K,V,K> keyIterator(K from,
                                                    boolean reverse)

Iterate over keys in the specified order.

参数:

from - the first key to return

reverse - if true, iterate in reverse (descending) order

返回:

the iterator

keyIterator

public TransactionMap.TMIterator<K,V,K> keyIterator(K from,
                                                    K to)

Iterate over keys.

参数:

from - the first key to return

to - the last key to return or null if there is no limit

返回:

the iterator

keyIteratorUncommitted

public TransactionMap.TMIterator<K,V,K> keyIteratorUncommitted(K from,
                                                               K to)

Iterate over keys, including keys from uncommitted entries.

参数:

from - the first key to return

to - the last key to return or null if there is no limit

返回:

the iterator

entryIterator

public TransactionMap.TMIterator<K,V,Map.Entry<K,V>> entryIterator(K from,
                                                                   K to)

Iterate over entries.

参数:

from - the first key to return

to - the last key to return

返回:

the iterator

getTransaction

public Transaction getTransaction()

getKeyType

public DataType<K> getKeyType()