SortedArrayStringMap

java.lang.Object
- org.apache.logging.log4j.util.SortedArrayStringMap

All Implemented Interfaces:

java.io.Serializable, IndexedReadOnlyStringMap, IndexedStringMap, ReadOnlyStringMap, StringMap
```
public class SortedArrayStringMap
extends java.lang.Object
implements IndexedStringMap
```
Consider this class private. Array-based implementation of the ReadOnlyStringMap 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 and TriConsumer.
- 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 and containsKey is O(log N), worst-case performance of put and remove is O(N log N). The expectation is that for the small values of N (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

Field Summary

Fields
Modifier and Type	Field and Description
`private static int`	`DEFAULT_INITIAL_CAPACITY` The default initial capacity.
`private static java.lang.String[]`	`EMPTY` An empty array instance to share when the table is not inflated.
`private static java.lang.String`	`FROZEN`
`private static int`	`HASHVAL`
`private boolean`	`immutable`
`private boolean`	`iterating`
`private java.lang.String[]`	`keys`
`private static TriConsumer<java.lang.String,java.lang.Object,StringMap>`	`PUT_ALL`
`private static long`	`serialVersionUID`
`private int`	`size` The number of key-value mappings contained in this map.
`private int`	`threshold` The next size value at which to resize (capacity * load factor).
`private java.lang.Object[]`	`values`

Constructor Summary

Constructors
Constructor and Description
`SortedArrayStringMap()`
`SortedArrayStringMap(int initialCapacity)`
`SortedArrayStringMap(java.util.Map<java.lang.String,?> map)`
`SortedArrayStringMap(ReadOnlyStringMap other)`

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`private void`	`assertNoConcurrentModification()`
`private void`	`assertNotFrozen()`
`private static int`	`ceilingNextPowerOfTwo(int x)` Calculate the next power of 2, greater than or equal to x.
`void`	`clear()` Removes all key-value pairs from this collection.
`boolean`	`containsKey(java.lang.String key)` Returns `true` if this data structure contains the specified key, `false` otherwise.
`private void`	`ensureCapacity()`
`boolean`	`equals(java.lang.Object obj)` Indicates whether some other object is "equal to" this one.
`<V> void`	`forEach(BiConsumer<java.lang.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> void`	`forEach(TriConsumer<java.lang.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.
`java.lang.String`	`getKeyAt(int index)` Viewing all key-value pairs as a sequence sorted by key, this method returns the key at the specified index, or `null` if the specified index is less than zero or greater or equal to the size of this collection.
`<V> V`	`getValue(java.lang.String key)` Returns the value for the specified key, or `null` 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, or `null` if the specified index is less than zero or greater or equal to the size of this collection.
`private void`	`handleSerializationException(java.lang.Throwable t, int i, java.lang.String key)`
`int`	`hashCode()` Returns a hash code value for the object.
`private static int`	`hashCode(java.lang.Object[] values, int length)`
`int`	`indexOfKey(java.lang.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.
`private void`	`inflateTable(int toSize)` Inflates the table.
`private void`	`initFrom0(SortedArrayStringMap other)`
`private void`	`insertAt(int index, java.lang.String key, java.lang.Object value)`
`boolean`	`isEmpty()` Returns `true` if this collection is empty (size is zero), `false` otherwise.
`boolean`	`isFrozen()` Returns `true` if this object has been frozen, `false` otherwise.
`private void`	`merge(SortedArrayStringMap other)`
`private int`	`nullKeyIndex()`
`void`	`putAll(ReadOnlyStringMap source)` Copy all key-value pairs from the specified `ReadOnlyStringMap` into this `StringMap`.
`void`	`putValue(java.lang.String key, java.lang.Object value)` Puts the specified key-value pair into the collection.
`private void`	`readObject(java.io.ObjectInputStream s)` Reconstitute the `SortedArrayStringMap` instance from a stream (i.e., deserialize it).
`void`	`remove(java.lang.String key)` Removes the key-value pair for the specified key from this data structure.
`private void`	`resize(int newCapacity)`
`int`	`size()` Returns the number of key-value pairs in this collection.
`java.util.Map<java.lang.String,java.lang.String>`	`toMap()` Returns a non-`null` mutable `Map<String, String>` containing a snapshot of this data structure.
`java.lang.String`	`toString()`
`private void`	`writeObject(java.io.ObjectOutputStream s)` Save the state of the `SortedArrayStringMap` instance to a stream (i.e., serialize it).

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

- Field Detail
  - DEFAULT_INITIAL_CAPACITY
```
private static final int DEFAULT_INITIAL_CAPACITY
```
    The default initial capacity.
    
    See Also:
    
    Constant Field Values
  - serialVersionUID
```
private static final long serialVersionUID
```
    See Also:
    
    Constant Field Values
  - HASHVAL
```
private static final int HASHVAL
```
    See Also:
    
    Constant Field Values
  - PUT_ALL
```
private static final TriConsumer<java.lang.String,java.lang.Object,StringMap> PUT_ALL
```
  - EMPTY
```
private static final java.lang.String[] EMPTY
```
    An empty array instance to share when the table is not inflated.
  - FROZEN
```
private static final java.lang.String FROZEN
```
    See Also:
    
    Constant Field Values
  - keys
```
private transient java.lang.String[] keys
```
  - values
```
private transient java.lang.Object[] values
```
  - size
```
private transient int size
```
    The number of key-value mappings contained in this map.
  - threshold
```
private int threshold
```
    The next size value at which to resize (capacity * load factor).
  - immutable
```
private boolean immutable
```
  - iterating
```
private transient boolean iterating
```
- Constructor Detail
  - SortedArrayStringMap
```
public SortedArrayStringMap()
```
  - SortedArrayStringMap
```
public SortedArrayStringMap(int initialCapacity)
```
  - SortedArrayStringMap
```
public SortedArrayStringMap(ReadOnlyStringMap other)
```
  - SortedArrayStringMap
```
public SortedArrayStringMap(java.util.Map<java.lang.String,?> map)
```
- Method Detail
  - assertNotFrozen
```
private void assertNotFrozen()
```
  - assertNoConcurrentModification
```
private void assertNoConcurrentModification()
```
  - clear
```
public void clear()
```
    Description copied from interface: StringMap
    
    Removes all key-value pairs from this collection.
    
    Specified by:
    
    clear in interface StringMap
  - containsKey
```
public boolean containsKey(java.lang.String key)
```
    Description copied from interface: ReadOnlyStringMap
    
    Returns true if this data structure contains the specified key, false otherwise.
    
    Specified by:
    
    containsKey in interface ReadOnlyStringMap
    
    Parameters:
    
    key - the key whose presence to check. May be null.
    
    Returns:
    
    true if this data structure contains the specified key, false otherwise
  - toMap
```
public java.util.Map<java.lang.String,java.lang.String> toMap()
```
    Description copied from interface: ReadOnlyStringMap
    
    Returns a non-null mutable Map<String, String> containing a snapshot of this data structure.
    
    Specified by:
    
    toMap in interface ReadOnlyStringMap
    
    Returns:
    
    a mutable copy of this data structure in Map<String, String> form
  - freeze
```
public void freeze()
```
    Description copied from interface: StringMap
    
    Makes this collection immutable. Attempts to modify the collection after the freeze() method was called will result in an UnsupportedOperationException being thrown.
    
    Specified by:
    
    freeze in interface StringMap
  - isFrozen
```
public boolean isFrozen()
```
    Description copied from interface: StringMap
    
    Returns true if this object has been frozen, false otherwise.
    
    Specified by:
    
    isFrozen in interface StringMap
    
    Returns:
    
    true if this object has been frozen, false otherwise
  - getValue
```
public <V> V getValue(java.lang.String key)
```
    Description copied from interface: ReadOnlyStringMap
    
    Returns the value for the specified key, or null if the specified key does not exist in this collection.
    
    Specified by:
    
    getValue in interface ReadOnlyStringMap
    
    Parameters:
    
    key - the key whose value to return
    
    Returns:
    
    the value for the specified key or null
  - isEmpty
```
public boolean isEmpty()
```
    Description copied from interface: ReadOnlyStringMap
    
    Returns true if this collection is empty (size is zero), false otherwise.
    
    Specified by:
    
    isEmpty in interface ReadOnlyStringMap
    
    Returns:
    
    true if this collection is empty (size is zero)
  - indexOfKey
```
public int indexOfKey(java.lang.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 interface IndexedReadOnlyStringMap
    
    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, or size() 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.
  - nullKeyIndex
```
private int nullKeyIndex()
```
  - putValue
```
public void putValue(java.lang.String key,
                     java.lang.Object value)
```
    Description copied from interface: StringMap
    
    Puts the specified key-value pair into the collection.
    
    Specified by:
    
    putValue in interface StringMap
    
    Parameters:
    
    key - the key to add or remove. Keys may be null.
    
    value - the value to add. Values may be null.
  - insertAt
```
private void insertAt(int index,
                      java.lang.String key,
                      java.lang.Object value)
```
  - putAll
```
public void putAll(ReadOnlyStringMap source)
```
    Description copied from interface: StringMap
    
    Copy all key-value pairs from the specified ReadOnlyStringMap into this StringMap.
    
    Specified by:
    
    putAll in interface StringMap
    
    Parameters:
    
    source - the ReadOnlyStringMap to copy key-value pairs from
  - initFrom0
```
private void initFrom0(SortedArrayStringMap other)
```
  - merge
```
private void merge(SortedArrayStringMap other)
```
  - ensureCapacity
```
private void ensureCapacity()
```
  - resize
```
private void resize(int newCapacity)
```
  - inflateTable
```
private void inflateTable(int toSize)
```
    Inflates the table.
  - remove
```
public void remove(java.lang.String key)
```
    Description copied from interface: StringMap
    
    Removes the key-value pair for the specified key from this data structure.
    
    Specified by:
    
    remove in interface StringMap
    
    Parameters:
    
    key - the key to remove. May be null.
  - getKeyAt
```
public java.lang.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, or null if the specified index is less than zero or greater or equal to the size of this collection.
    
    Specified by:
    
    getKeyAt in interface IndexedReadOnlyStringMap
    
    Parameters:
    
    index - the index of the key to return
    
    Returns:
    
    the key at the specified index or null
  - 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, or null if the specified index is less than zero or greater or equal to the size of this collection.
    
    Specified by:
    
    getValueAt in interface IndexedReadOnlyStringMap
    
    Parameters:
    
    index - the index of the value to return
    
    Returns:
    
    the value at the specified index or null
  - size
```
public int size()
```
    Description copied from interface: ReadOnlyStringMap
    
    Returns the number of key-value pairs in this collection.
    
    Specified by:
    
    size in interface ReadOnlyStringMap
    
    Returns:
    
    the number of key-value pairs in this collection
  - forEach
```
public <V> void forEach(BiConsumer<java.lang.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's BiConsumer.accept(Object, Object) accept} method may cause a ConcurrentModificationException to be thrown.
    
    Specified by:
    
    forEach in interface ReadOnlyStringMap
    
    Type Parameters:
    
    V - type of the value
    
    Parameters:
    
    action - The action to be performed for each key-value pair in this collection
  - forEach
```
public <V,T> void forEach(TriConsumer<java.lang.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's accept method may cause a ConcurrentModificationException to be thrown.
    
    Specified by:
    
    forEach in interface ReadOnlyStringMap
    
    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
  - equals
```
public boolean equals(java.lang.Object obj)
```
    Description copied from interface: StringMap
    
    Indicates whether some other object is "equal to" this one.
    
    Specified by:
    
    equals in interface StringMap
    
    Overrides:
    
    equals in class java.lang.Object
    
    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()
  - hashCode
```
public int hashCode()
```
    Description copied from interface: StringMap
    
    Returns a hash code value for the object.
    
    Specified by:
    
    hashCode in interface StringMap
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    a hash code value for this object.
  - hashCode
```
private static int hashCode(java.lang.Object[] values,
                            int length)
```
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - writeObject
```
private void writeObject(java.io.ObjectOutputStream s)
                  throws java.io.IOException
```
    Save the state of the SortedArrayStringMap instance to a stream (i.e., serialize it).
    
    Throws:
    
    java.io.IOException
  - ceilingNextPowerOfTwo
```
private static int ceilingNextPowerOfTwo(int x)
```
    Calculate the next power of 2, greater than or equal to x.
    From Hacker's Delight, Chapter 3, Harry S. Warren Jr.
    
    Parameters:
    
    x - Value to round up
    
    Returns:
    
    The next power of 2 from x inclusive
  - readObject
```
private void readObject(java.io.ObjectInputStream s)
                 throws java.io.IOException,
                        java.lang.ClassNotFoundException
```
    Reconstitute the SortedArrayStringMap instance from a stream (i.e., deserialize it).
    
    Throws:
    
    java.io.IOException
    
    java.lang.ClassNotFoundException
  - handleSerializationException
```
private void handleSerializationException(java.lang.Throwable t,
                                          int i,
                                          java.lang.String key)
```

Class SortedArrayStringMap

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_INITIAL_CAPACITY

serialVersionUID

HASHVAL

PUT_ALL

EMPTY

FROZEN

keys

values

size

threshold

immutable

iterating

Constructor Detail

SortedArrayStringMap

SortedArrayStringMap

SortedArrayStringMap

SortedArrayStringMap

Method Detail

assertNotFrozen

assertNoConcurrentModification

clear

containsKey

toMap

freeze

isFrozen

getValue

isEmpty

indexOfKey

nullKeyIndex

putValue

insertAt

putAll

initFrom0

merge

ensureCapacity

resize

inflateTable

remove

getKeyAt

getValueAt

size

forEach

forEach

equals

hashCode

hashCode

toString

writeObject

ceilingNextPowerOfTwo

readObject

handleSerializationException