MVMap (H2 Database Engine wt-1.0.1 API)

java.lang.Object
- java.util.AbstractMap<K,V>
- - org.h2.mvstore.MVMap<K,V>

类型参数:

K - the key class

V - the value class

所有已实现的接口:

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

直接已知子类:

MVMapConcurrent, MVRTreeMap
```
public class MVMap<K,V>
extends AbstractMap<K,V>
implements ConcurrentMap<K,V>
```
A stored map.
Read operations can happen concurrently with all other operations, without risk of corruption.
Write operations first read the relevant area from disk to memory concurrently, and only then modify the data. The in-memory part of write operations is synchronized. For scalable concurrent in-memory write operations, the map should be split into multiple smaller sub-maps that are then synchronized independently.

嵌套类概要

嵌套类
限定符和类型类和说明

static class MVMap.Builder<K,V>
A builder for this class.

static interface MVMap.MapBuilder<M extends MVMap<K,V>,K,V>
A builder for maps.
- 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>

嵌套类
限定符和类型	类和说明
`static class`	`MVMap.Builder<K,V>` A builder for this class.
`static interface`	`MVMap.MapBuilder<M extends MVMap<K,V>,K,V>` A builder for maps.

字段概要

字段
限定符和类型	字段和说明
`protected Page`	`root` The current root page (may not be null).
`protected MVStore`	`store` The store.
`protected long`	`writeVersion` The version used for writing.

构造器概要

构造器
限定符构造器和说明

protected MVMap(DataType keyType, DataType valueType)

构造器
限定符	构造器和说明
`protected`	`MVMap(DataType keyType, DataType valueType)`

方法概要

所有方法实例方法具体方法
限定符和类型	方法和说明
`boolean`	`areValuesEqual(Object a, Object b)` Check whether the two values are equal.
`protected void`	`beforeWrite()` This method is called before writing to the map.
`protected Object`	`binarySearch(Page p, Object key)` Get the value for the given key, or null if not found.
`protected Page`	`binarySearchPage(Page p, Object key)` Get the value for the given key, or null if not found.
`K`	`ceilingKey(K key)` Get the smallest key that is larger or equal to this key.
`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`	`floorKey(K key)` Get the largest key that is smaller or equal to this key.
`V`	`get(Object key)` Get a value.
`protected int`	`getChildPageCount(Page p)` Get the child page count for this page.
`long`	`getCreateVersion()`
`protected K`	`getFirstLast(boolean first)` Get the first (lowest) or last (largest) key.
`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.
`protected K`	`getMinMax(K key, boolean min, boolean excluding)` Get the smallest or largest key using the given bounds.
`String`	`getName()` Get the map name.
`Page`	`getRoot()` Get the root page.
`MVStore`	`getStore()`
`String`	`getType()` Get the map type.
`DataType`	`getValueType()` Get the value type.
`long`	`getVersion()`
`int`	`hashCode()`
`K`	`higherKey(K key)` Get the smallest key that is larger than the given key, or null if no such key exists.
`protected void`	`init(MVStore store, HashMap<String,Object> config)` Open this map with the given store and configuration.
`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`	`lowerKey(K key)` Get the largest key that is smaller than the given key, or null if no such key exists.
`protected void`	`newRoot(Page newRoot)` Use the new root page from now on.
`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 Object`	`put(Page p, long writeVersion, Object key, Object value)` Add or update 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.
`protected Object`	`remove(Page p, long writeVersion, Object key)` Remove a key-value pair.
`protected void`	`removePage(long pos, int memory)` Remove the given page (make the space available).
`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.
`protected Page`	`splitRootIfNeeded(Page p, long writeVersion)` Split the root page if necessary.
`String`	`toString()`

从类继承的方法 java.util.AbstractMap
clone, containsValue, putAll, 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.concurrent.ConcurrentMap
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, replaceAll

从接口继承的方法 java.util.Map
containsValue, putAll, values

- 字段详细资料
  - store
```
protected MVStore store
```
    The store.
  - root
```
protected volatile Page root
```
    The current root page (may not be null).
  - writeVersion
```
protected volatile long writeVersion
```
    The version used for writing.
- 构造器详细资料
  - MVMap
```
protected MVMap(DataType keyType,
                DataType valueType)
```
- 方法详细资料
  - init
```
protected void init(MVStore store,
                    HashMap<String,Object> config)
```
    Open this map with the given store and configuration.
    
    参数:
    
    store - the store
    
    config - the configuration
  - put
```
public V put(K key,
             V value)
```
    Add or replace a key-value pair.
    
    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 (may not be null)
    
    value - the value (may not be null)
    
    返回:
    
    the old value if the key existed, or null otherwise
  - splitRootIfNeeded
```
protected Page splitRootIfNeeded(Page p,
                                 long writeVersion)
```
    Split the root page if necessary.
    
    参数:
    
    p - the page
    
    writeVersion - the write version
    
    返回:
    
    the new sibling
  - put
```
protected Object put(Page p,
                     long writeVersion,
                     Object key,
                     Object value)
```
    Add or update a key-value pair.
    
    参数:
    
    p - the page
    
    writeVersion - the write version
    
    key - the key (may not be null)
    
    value - the value (may not be null)
    
    返回:
    
    the old value, or null
  - firstKey
```
public K firstKey()
```
    Get the first key, or null if the map is empty.
    
    返回:
    
    the first key, or null
  - lastKey
```
public K lastKey()
```
    Get the last key, or null if the map is empty.
    
    返回:
    
    the last key, or null
  - getKey
```
public K getKey(long index)
```
    Get the key at the given index.
    This is a O(log(size)) operation.
    
    参数:
    
    index - the index
    
    返回:
    
    the key
  - keyList
```
public 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.
    
    返回:
    
    the key list
  - getKeyIndex
```
public 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.
    
    参数:
    
    key - the key
    
    返回:
    
    the index
  - getFirstLast
```
protected K getFirstLast(boolean first)
```
    Get the first (lowest) or last (largest) key.
    
    参数:
    
    first - whether to retrieve the first key
    
    返回:
    
    the key, or null if the map is 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.
    
    参数:
    
    key - the key
    
    返回:
    
    the result
  - ceilingKey
```
public K ceilingKey(K key)
```
    Get the smallest key that is larger or equal to this key.
    
    参数:
    
    key - the key
    
    返回:
    
    the result
  - floorKey
```
public K floorKey(K key)
```
    Get the largest key that is smaller or equal to this key.
    
    参数:
    
    key - the key
    
    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
    
    返回:
    
    the result
  - getMinMax
```
protected K getMinMax(K key,
                      boolean min,
                      boolean excluding)
```
    Get the smallest or largest key using the given bounds.
    
    参数:
    
    key - the key
    
    min - whether to retrieve the smallest key
    
    excluding - if the given upper/lower bound is exclusive
    
    返回:
    
    the key, or null if no such key exists
  - get
```
public V get(Object key)
```
    Get a value.
    
    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 if not found
  - binarySearch
```
protected Object binarySearch(Page p,
                              Object key)
```
    Get the value for the given key, or null if not found.
    
    参数:
    
    p - the page
    
    key - the key
    
    返回:
    
    the value or null
  - containsKey
```
public boolean containsKey(Object key)
```
    指定者:
    
    containsKey 在接口中 Map<K,V>
    
    覆盖:
    
    containsKey 在类中 AbstractMap<K,V>
  - binarySearchPage
```
protected Page binarySearchPage(Page p,
                                Object key)
```
    Get the value for the given key, or null if not found.
    
    参数:
    
    p - the parent page
    
    key - the key
    
    返回:
    
    the page or null
  - clear
```
public void clear()
```
    Remove all entries.
    
    指定者:
    
    clear 在接口中 Map<K,V>
    
    覆盖:
    
    clear 在类中 AbstractMap<K,V>
  - isClosed
```
public boolean isClosed()
```
  - remove
```
public V remove(Object key)
```
    Remove a key-value pair, if the key exists.
    
    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 (may not be null)
    
    返回:
    
    the old value if the key existed, or null otherwise
  - putIfAbsent
```
public V putIfAbsent(K key,
                     V value)
```
    Add a key-value pair if it does not yet exist.
    
    指定者:
    
    putIfAbsent 在接口中 ConcurrentMap<K,V>
    
    指定者:
    
    putIfAbsent 在接口中 Map<K,V>
    
    参数:
    
    key - the key (may not be null)
    
    value - the new value
    
    返回:
    
    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.
    
    指定者:
    
    remove 在接口中 ConcurrentMap<K,V>
    
    指定者:
    
    remove 在接口中 Map<K,V>
    
    参数:
    
    key - the key (may not be null)
    
    value - the expected value
    
    返回:
    
    true if the item was removed
  - areValuesEqual
```
public boolean areValuesEqual(Object a,
                              Object b)
```
    Check whether the two values are equal.
    
    参数:
    
    a - the first value
    
    b - the second value
    
    返回:
    
    true if they are equal
  - replace
```
public boolean replace(K key,
                       V oldValue,
                       V newValue)
```
    Replace a value for an existing key, if the value matches.
    
    指定者:
    
    replace 在接口中 ConcurrentMap<K,V>
    
    指定者:
    
    replace 在接口中 Map<K,V>
    
    参数:
    
    key - the key (may not be null)
    
    oldValue - the expected value
    
    newValue - the new value
    
    返回:
    
    true if the value was replaced
  - replace
```
public V replace(K key,
                 V value)
```
    Replace a value for an existing key.
    
    指定者:
    
    replace 在接口中 ConcurrentMap<K,V>
    
    指定者:
    
    replace 在接口中 Map<K,V>
    
    参数:
    
    key - the key (may not be null)
    
    value - the new value
    
    返回:
    
    the old value, if the value was replaced, or null
  - remove
```
protected Object remove(Page p,
                        long writeVersion,
                        Object key)
```
    Remove a key-value pair.
    
    参数:
    
    p - the page (may not be null)
    
    writeVersion - the write version
    
    key - the key
    
    返回:
    
    the old value, or null if the key did not exist
  - newRoot
```
protected void newRoot(Page newRoot)
```
    Use the new root page from now on.
    
    参数:
    
    newRoot - the new root page
  - getKeyType
```
public DataType getKeyType()
```
    Get the key type.
    
    返回:
    
    the key type
  - getValueType
```
public DataType getValueType()
```
    Get the value type.
    
    返回:
    
    the value type
  - keyIterator
```
public Iterator<K> keyIterator(K from)
```
    Iterate over a number of keys.
    
    参数:
    
    from - the first key to return
    
    返回:
    
    the iterator
  - cursor
```
public Cursor<K,V> cursor(K from)
```
    Get a cursor to iterate over a number of keys and values.
    
    参数:
    
    from - the first key to return
    
    返回:
    
    the cursor
  - 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>
  - keySet
```
public Set<K> keySet()
```
    指定者:
    
    keySet 在接口中 Map<K,V>
    
    覆盖:
    
    keySet 在类中 AbstractMap<K,V>
  - getRoot
```
public Page getRoot()
```
    Get the root page.
    
    返回:
    
    the root page
  - getName
```
public String getName()
```
    Get the map name.
    
    返回:
    
    the name
  - getStore
```
public MVStore getStore()
```
  - getId
```
public int getId()
```
    Get the map id. Please note the map id may be different after compacting a store.
    
    返回:
    
    the map id
  - isReadOnly
```
public boolean isReadOnly()
```
  - setVolatile
```
public void setVolatile(boolean isVolatile)
```
    Set the volatile flag of the map.
    
    参数:
    
    isVolatile - the volatile flag
  - isVolatile
```
public 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.
    
    返回:
    
    whether this map is volatile
  - beforeWrite
```
protected void beforeWrite()
```
    This method is called before writing to the map. The default implementation checks whether writing is allowed, and tries to detect concurrent modification.
    
    抛出:
    
    UnsupportedOperationException - if the map is read-only, or if another thread is concurrently writing
  - hashCode
```
public int hashCode()
```
    指定者:
    
    hashCode 在接口中 Map<K,V>
    
    覆盖:
    
    hashCode 在类中 AbstractMap<K,V>
  - equals
```
public boolean equals(Object o)
```
    指定者:
    
    equals 在接口中 Map<K,V>
    
    覆盖:
    
    equals 在类中 AbstractMap<K,V>
  - 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
  - sizeAsLong
```
public long sizeAsLong()
```
    Get the number of entries, as a long.
    
    返回:
    
    the number of entries
  - isEmpty
```
public boolean isEmpty()
```
    指定者:
    
    isEmpty 在接口中 Map<K,V>
    
    覆盖:
    
    isEmpty 在类中 AbstractMap<K,V>
  - getCreateVersion
```
public long getCreateVersion()
```
  - removePage
```
protected void removePage(long pos,
                          int memory)
```
    Remove the given page (make the space available).
    
    参数:
    
    pos - the position of the page to remove
    
    memory - the number of bytes used for this page
  - openVersion
```
public MVMap<K,V> openVersion(long version)
```
    Open an old version for the given map.
    
    参数:
    
    version - the version
    
    返回:
    
    the map
  - getVersion
```
public long getVersion()
```
  - getChildPageCount
```
protected int getChildPageCount(Page p)
```
    Get the child page count for this page. This is to allow another map implementation to override the default, in case the last child is not to be used.
    
    参数:
    
    p - the page
    
    返回:
    
    the number of direct children
  - getType
```
public String getType()
```
    Get the map type. When opening an existing map, the map type must match.
    
    返回:
    
    the map type
  - toString
```
public String toString()
```
    覆盖:
    
    toString 在类中 AbstractMap<K,V>

类 MVMap<K,V>

嵌套类概要

从类继承的嵌套类/接口 java.util.AbstractMap

从接口继承的嵌套类/接口 java.util.Map

字段概要

构造器概要

方法概要

从类继承的方法 java.util.AbstractMap

从类继承的方法 java.lang.Object

从接口继承的方法 java.util.concurrent.ConcurrentMap

从接口继承的方法 java.util.Map

字段详细资料

store

root

writeVersion

构造器详细资料

MVMap

方法详细资料

init

put

splitRootIfNeeded

put

firstKey

lastKey

getKey

keyList

getKeyIndex

getFirstLast

higherKey

ceilingKey

floorKey

lowerKey

getMinMax

get

binarySearch

containsKey

binarySearchPage

clear

isClosed

remove

putIfAbsent

remove

areValuesEqual

replace

replace

remove

newRoot

getKeyType

getValueType

keyIterator

cursor

entrySet

keySet

getRoot

getName

getStore

getId

isReadOnly

setVolatile

isVolatile

beforeWrite

hashCode

equals

size

sizeAsLong

isEmpty

getCreateVersion

removePage

openVersion

getVersion

getChildPageCount

getType

toString