TransactionStore.TransactionMap

java.lang.Object
- org.h2.mvstore.db.TransactionStore.TransactionMap<K,V>

Type Parameters:

K - the key type

V - the value type

Enclosing class:

TransactionStore
```
public static class TransactionStore.TransactionMap<K,V>
extends java.lang.Object
```
A map that supports transactions.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`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(K key)` Whether the map contains the key.
`java.util.Iterator<java.util.Map.Entry<K,V>>`	`entryIterator(K from, K to)` Iterate over entries.
`K`	`firstKey()` Get the first key.
`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(K key)` Get the value for the given key at the time when this map was opened.
`V`	`get(K key, long maxLogId)` Get the value for the given key.
`TransactionStore.TransactionMap<K,V>`	`getInstance(TransactionStore.Transaction transaction, long savepoint)` Get a clone of this map for the given transaction.
`DataType`	`getKeyType()`
`V`	`getLatest(K key)` Get the most recent value for the given key.
`TransactionStore.Transaction`	`getTransaction()`
`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`	`isSameTransaction(K key)` Whether the entry for this key was added or removed from this session.
`java.util.Iterator<K>`	`keyIterator(K from)` Iterate over keys.
`java.util.Iterator<K>`	`keyIterator(K from, boolean includeUncommitted)` Iterate over keys.
`K`	`lastKey()` Get the last key.
`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.
`K`	`relativeKey(K key, long offset)` Get one of the previous or next keys.
`V`	`remove(K key)` Remove an entry.
`void`	`setSavepoint(long savepoint)` Set the savepoint.
`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, boolean onlyIfUnchanged)` Try to set or remove the value.
`java.util.Iterator<K>`	`wrapIterator(java.util.Iterator<K> iterator, boolean includeUncommitted)` Iterate over keys.

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

- Method Detail
  - setSavepoint
```
public void setSavepoint(long savepoint)
```
    Set the savepoint. Afterwards, reads are based on the specified savepoint.
    
    Parameters:
    
    savepoint - the savepoint
  - getInstance
```
public TransactionStore.TransactionMap<K,V> getInstance(TransactionStore.Transaction transaction,
                                                        long savepoint)
```
    Get a clone of this map for the given transaction.
    
    Parameters:
    
    transaction - the transaction
    
    savepoint - the savepoint
    
    Returns:
    
    the map
  - 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.
    
    Returns:
    
    the maximum size
  - sizeAsLong
```
public long sizeAsLong()
```
    Get the size of the map as seen by this transaction.
    
    Returns:
    
    the size
  - remove
```
public V remove(K key)
```
    Remove an entry.
    If the row is locked, this method will retry until the row could be updated or until a lock timeout.
    
    Parameters:
    
    key - the key
    
    Throws:
    
    java.lang.IllegalStateException - if a lock timeout occurs
  - 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.
    
    Parameters:
    
    key - the key
    
    value - the new value (not null)
    
    Returns:
    
    the old value
    
    Throws:
    
    java.lang.IllegalStateException - 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.
    
    Parameters:
    
    key - the key
    
    value - the value
    
    Returns:
    
    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).
    
    Parameters:
    
    key - the key
    
    Returns:
    
    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).
    
    Parameters:
    
    key - the key
    
    value - the new value
    
    Returns:
    
    whether the entry could be updated
  - trySet
```
public boolean trySet(K key,
                      V value,
                      boolean onlyIfUnchanged)
```
    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.
    
    Parameters:
    
    key - the key
    
    value - the new value (null to remove the value)
    
    onlyIfUnchanged - only set the value if it was not changed (by this or another transaction) since the map was opened
    
    Returns:
    
    true if the value was set, false if there was a concurrent update
  - get
```
public V get(K key)
```
    Get the value for the given key at the time when this map was opened.
    
    Parameters:
    
    key - the key
    
    Returns:
    
    the value or null
  - getLatest
```
public V getLatest(K key)
```
    Get the most recent value for the given key.
    
    Parameters:
    
    key - the key
    
    Returns:
    
    the value or null
  - containsKey
```
public boolean containsKey(K key)
```
    Whether the map contains the key.
    
    Parameters:
    
    key - the key
    
    Returns:
    
    true if the map contains an entry for this key
  - get
```
public V get(K key,
             long maxLogId)
```
    Get the value for the given key.
    
    Parameters:
    
    key - the key
    
    maxLogId - the maximum log id
    
    Returns:
    
    the value or null
  - isSameTransaction
```
public boolean isSameTransaction(K key)
```
    Whether the entry for this key was added or removed from this session.
    
    Parameters:
    
    key - the key
    
    Returns:
    
    true if yes
  - isClosed
```
public boolean isClosed()
```
    Check whether this map is closed.
    
    Returns:
    
    true if closed
  - clear
```
public void clear()
```
    Clear the map.
  - firstKey
```
public K firstKey()
```
    Get the first key.
    
    Returns:
    
    the first key, or null if empty
  - lastKey
```
public K lastKey()
```
    Get the last key.
    
    Returns:
    
    the last key, or null if empty
  - higherKey
```
public 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 (may not be null)
    
    Returns:
    
    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.
    
    Parameters:
    
    key - the key (may not be null)
    
    Returns:
    
    the result
  - relativeKey
```
public K relativeKey(K key,
                     long offset)
```
    Get one of the previous or next keys. There might be no value available for the returned key.
    
    Parameters:
    
    key - the key (may not be null)
    
    offset - how many keys to skip (-1 for previous, 1 for next)
    
    Returns:
    
    the key
  - 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.
    
    Parameters:
    
    key - the key (may not be null)
    
    Returns:
    
    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.
    
    Parameters:
    
    key - the key (may not be null)
    
    Returns:
    
    the result
  - keyIterator
```
public java.util.Iterator<K> keyIterator(K from)
```
    Iterate over keys.
    
    Parameters:
    
    from - the first key to return
    
    Returns:
    
    the iterator
  - keyIterator
```
public java.util.Iterator<K> keyIterator(K from,
                                         boolean includeUncommitted)
```
    Iterate over keys.
    
    Parameters:
    
    from - the first key to return
    
    includeUncommitted - whether uncommitted entries should be included
    
    Returns:
    
    the iterator
  - entryIterator
```
public java.util.Iterator<java.util.Map.Entry<K,V>> entryIterator(K from,
                                                                  K to)
```
    Iterate over entries.
    
    Parameters:
    
    from - the first key to return
    
    to - the last key to return
    
    Returns:
    
    the iterator
  - wrapIterator
```
public java.util.Iterator<K> wrapIterator(java.util.Iterator<K> iterator,
                                          boolean includeUncommitted)
```
    Iterate over keys.
    
    Parameters:
    
    iterator - the iterator to wrap
    
    includeUncommitted - whether uncommitted entries should be included
    
    Returns:
    
    the iterator
  - getTransaction
```
public TransactionStore.Transaction getTransaction()
```
  - getKeyType
```
public DataType getKeyType()
```

Class TransactionStore.TransactionMap<K,V>

Method Summary

Methods inherited from class java.lang.Object

Method Detail

setSavepoint

getInstance

sizeAsLongMax

sizeAsLong

remove

put

putCommitted

tryRemove

tryPut

trySet

get

getLatest

containsKey

get

isSameTransaction

isClosed

clear

firstKey

lastKey

higherKey

ceilingKey

relativeKey

floorKey

lowerKey

keyIterator

keyIterator

entryIterator

wrapIterator

getTransaction

getKeyType