Class SortedArrayStringMap
- java.lang.Object
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- org.apache.logging.log4j.util.SortedArrayStringMap
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- All Implemented Interfaces:
Serializable
,IndexedReadOnlyStringMap
,IndexedStringMap
,ReadOnlyStringMap
,StringMap
public class SortedArrayStringMap extends Object implements IndexedStringMap
Consider this class private. Array-based implementation of theReadOnlyStringMap
interface. Keys are held in a sorted array.This is not a generic collection, but makes some trade-offs to optimize for the Log4j context data use case:
- Garbage-free iteration over key-value pairs with
BiConsumer
andTriConsumer
. - Fast copy. If the ThreadContextMap is also an instance of
SortedArrayStringMap
, the full thread context data can be transferred with two array copies and two field updates. - Acceptable performance for small data sets. The current implementation stores keys in a sorted array, values
are stored in a separate array at the same index.
Worst-case performance of
get
andcontainsKey
is O(log N), worst-case performance ofput
andremove
is O(N log N). The expectation is that for the small values ofN
(less than 100) that are the vast majority of ThreadContext use cases, the constants dominate performance more than the asymptotic performance of the algorithms used. - Compact representation.
- Since:
- 2.7
- See Also:
- Serialized Form
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Constructor Summary
Constructors Constructor Description SortedArrayStringMap()
SortedArrayStringMap(int initialCapacity)
SortedArrayStringMap(Map<String,?> map)
SortedArrayStringMap(ReadOnlyStringMap other)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description void
clear()
Removes all key-value pairs from this collection.boolean
containsKey(String key)
Returnstrue
if this data structure contains the specified key,false
otherwise.boolean
equals(Object obj)
Indicates whether some other object is "equal to" this one.<V> void
forEach(BiConsumer<String,? super V> action)
Performs the given action for each key-value pair in this data structure until all entries have been processed or the action throws an exception.<V,T>
voidforEach(TriConsumer<String,? super V,T> action, T state)
Performs the given action for each key-value pair in this data structure until all entries have been processed or the action throws an exception.void
freeze()
Makes this collection immutable.String
getKeyAt(int index)
Viewing all key-value pairs as a sequence sorted by key, this method returns the key at the specified index, ornull
if the specified index is less than zero or greater or equal to the size of this collection.<V> V
getValue(String key)
Returns the value for the specified key, ornull
if the specified key does not exist in this collection.<V> V
getValueAt(int index)
Viewing all key-value pairs as a sequence sorted by key, this method returns the value at the specified index, ornull
if the specified index is less than zero or greater or equal to the size of this collection.int
hashCode()
Returns a hash code value for the object.int
indexOfKey(String key)
Viewing all key-value pairs as a sequence sorted by key, this method returns the index of the specified key in that sequence.boolean
isEmpty()
Returnstrue
if this collection is empty (size is zero),false
otherwise.boolean
isFrozen()
void
putAll(ReadOnlyStringMap source)
Copies all key-value pairs from the specifiedReadOnlyStringMap
into thisStringMap
.void
putValue(String key, Object value)
Puts the specified key-value pair into the collection.void
remove(String key)
Removes the key-value pair for the specified key from this data structure.int
size()
Returns the number of key-value pairs in this collection.Map<String,String>
toMap()
Returns a non-null
mutableMap<String, String>
containing a snapshot of this data structure.String
toString()
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Constructor Detail
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SortedArrayStringMap
public SortedArrayStringMap()
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SortedArrayStringMap
public SortedArrayStringMap(int initialCapacity)
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SortedArrayStringMap
public SortedArrayStringMap(ReadOnlyStringMap other)
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Method Detail
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clear
public void clear()
Description copied from interface:StringMap
Removes all key-value pairs from this collection.
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containsKey
public boolean containsKey(String key)
Description copied from interface:ReadOnlyStringMap
Returnstrue
if this data structure contains the specified key,false
otherwise.- Specified by:
containsKey
in interfaceReadOnlyStringMap
- Parameters:
key
- the key whose presence to check. May benull
.- Returns:
true
if this data structure contains the specified key,false
otherwise.
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toMap
public Map<String,String> toMap()
Description copied from interface:ReadOnlyStringMap
Returns a non-null
mutableMap<String, String>
containing a snapshot of this data structure.- Specified by:
toMap
in interfaceReadOnlyStringMap
- Returns:
- a mutable copy of this data structure in
Map<String, String>
form.
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freeze
public void freeze()
Description copied from interface:StringMap
Makes this collection immutable. Attempts to modify the collection after thefreeze()
method was called will result in anUnsupportedOperationException
being thrown.
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isFrozen
public boolean isFrozen()
Description copied from interface:StringMap
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getValue
public <V> V getValue(String key)
Description copied from interface:ReadOnlyStringMap
Returns the value for the specified key, ornull
if the specified key does not exist in this collection.- Specified by:
getValue
in interfaceReadOnlyStringMap
- Parameters:
key
- the key whose value to return.- Returns:
- the value for the specified key or
null
.
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isEmpty
public boolean isEmpty()
Description copied from interface:ReadOnlyStringMap
Returnstrue
if this collection is empty (size is zero),false
otherwise.- Specified by:
isEmpty
in interfaceReadOnlyStringMap
- Returns:
true
if this collection is empty (size is zero).
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indexOfKey
public int indexOfKey(String key)
Description copied from interface:IndexedReadOnlyStringMap
Viewing all key-value pairs as a sequence sorted by key, this method returns the index of the specified key in that sequence. If the specified key is not found, this method returns(-(insertion point) - 1)
.- Specified by:
indexOfKey
in interfaceIndexedReadOnlyStringMap
- Parameters:
key
- the key whose index in the ordered sequence of keys to return- Returns:
- the index of the specified key or
(-(insertion point) - 1)
if the key is not found. The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, orsize()
if all elements are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.
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putValue
public void putValue(String key, Object value)
Description copied from interface:StringMap
Puts the specified key-value pair into the collection.
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putAll
public void putAll(ReadOnlyStringMap source)
Description copied from interface:StringMap
Copies all key-value pairs from the specifiedReadOnlyStringMap
into thisStringMap
.
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remove
public void remove(String key)
Description copied from interface:StringMap
Removes the key-value pair for the specified key from this data structure.
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getKeyAt
public String getKeyAt(int index)
Description copied from interface:IndexedReadOnlyStringMap
Viewing all key-value pairs as a sequence sorted by key, this method returns the key at the specified index, ornull
if the specified index is less than zero or greater or equal to the size of this collection.- Specified by:
getKeyAt
in interfaceIndexedReadOnlyStringMap
- Parameters:
index
- the index of the key to return- Returns:
- the key at the specified index or
null
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getValueAt
public <V> V getValueAt(int index)
Description copied from interface:IndexedReadOnlyStringMap
Viewing all key-value pairs as a sequence sorted by key, this method returns the value at the specified index, ornull
if the specified index is less than zero or greater or equal to the size of this collection.- Specified by:
getValueAt
in interfaceIndexedReadOnlyStringMap
- Parameters:
index
- the index of the value to return- Returns:
- the value at the specified index or
null
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size
public int size()
Description copied from interface:ReadOnlyStringMap
Returns the number of key-value pairs in this collection.- Specified by:
size
in interfaceReadOnlyStringMap
- Returns:
- the number of key-value pairs in this collection.
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forEach
public <V> void forEach(BiConsumer<String,? super V> action)
Description copied from interface:ReadOnlyStringMap
Performs the given action for each key-value pair in this data structure until all entries have been processed or the action throws an exception.Some implementations may not support structural modifications (adding new elements or removing elements) while iterating over the contents. In such implementations, attempts to add or remove elements from the
BiConsumer
'sBiConsumer.accept(Object, Object)
accept} method may cause aConcurrentModificationException
to be thrown.- Specified by:
forEach
in interfaceReadOnlyStringMap
- Type Parameters:
V
- type of the value.- Parameters:
action
- The action to be performed for each key-value pair in this collection.
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forEach
public <V,T> void forEach(TriConsumer<String,? super V,T> action, T state)
Description copied from interface:ReadOnlyStringMap
Performs the given action for each key-value pair in this data structure until all entries have been processed or the action throws an exception.The third parameter lets callers pass in a stateful object to be modified with the key-value pairs, so the TriConsumer implementation itself can be stateless and potentially reusable.
Some implementations may not support structural modifications (adding new elements or removing elements) while iterating over the contents. In such implementations, attempts to add or remove elements from the
TriConsumer
'saccept
method may cause aConcurrentModificationException
to be thrown.- Specified by:
forEach
in interfaceReadOnlyStringMap
- Type Parameters:
V
- type of the value.T
- type of the third parameter.- Parameters:
action
- The action to be performed for each key-value pair in this collection.state
- the object to be passed as the third parameter to each invocation on the specified triconsumer.
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equals
public boolean equals(Object obj)
Description copied from interface:StringMap
Indicates whether some other object is "equal to" this one.- Specified by:
equals
in interfaceStringMap
- Overrides:
equals
in classObject
- Parameters:
obj
- the reference object with which to compare.- Returns:
true
if this object is the same as the obj argument;false
otherwise.- See Also:
StringMap.hashCode()
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hashCode
public int hashCode()
Description copied from interface:StringMap
Returns a hash code value for the object.
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