Package org.apache.groovy.json.internal

Class LazyMap

java.lang.Object

java.util.AbstractMap<String,Object>

org.apache.groovy.json.internal.LazyMap

All Implemented Interfaces:

Map<String,Object>

public class LazyMap
extends AbstractMap<String,Object>

This maps only builds once you ask for a key for the first time. It is designed to not incur the overhead of creating a map unless needed.

Nested Class Summary

Nested classes/interfaces inherited from class java.util.AbstractMap

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

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K extends Object,V extends Object>

Constructor Summary

Constructors

Constructor	Description
LazyMap()	Creates a lazy map with the default key and value buffer size.
LazyMap(int initialSize)	Creates a lazy map with a caller-supplied key and value buffer size.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clears the compact buffers or hydrated map, depending on the current state.
LazyMap	clearAndCopy()	Copies the compact entries into a new LazyMap and clears this instance.
protected Object	clone()	Clones the hydrated backing map when one already exists.
boolean	containsKey(Object key)	Hydrates the backing map if needed and tests whether the key is present.
boolean	containsValue(Object value)	Hydrates the backing map if needed and tests whether the value is present.
Set<Map.Entry<String,Object>>	entrySet()	Returns the hydrated entry set, building the backing map if necessary.
boolean	equals(Object o)	Hydrates the backing map if needed and compares it with another object.
Object	get(Object key)	Hydrates the backing map if needed and returns the value for the supplied key.
static <V> V[]	grow(V[] array)	Doubles the capacity of the supplied array while preserving its component type.
int	hashCode()	Hydrates the backing map if needed and returns its hash code.
boolean	isEmpty()	Returns whether the map currently contains any entries.
Set<String>	keySet()	Hydrates the backing map if needed and returns its key set.
Object	put(String key, Object value)	Stores a mapping while keeping the compact array-backed representation until hydration is needed.
void	putAll(Map m)	Hydrates the backing map if needed and copies all supplied entries into it.
Object	remove(Object key)	Hydrates the backing map if needed and removes the supplied key.
int	size()	Returns the current size without hydrating when the compact representation is still active.
String	toString()	Hydrates the backing map if needed and returns its string form.
Collection<Object>	values()	Hydrates the backing map if needed and returns its values collection.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

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

Constructor Details

LazyMap

public LazyMap()

Creates a lazy map with the default key and value buffer size.

LazyMap

public LazyMap(int initialSize)

Creates a lazy map with a caller-supplied key and value buffer size.

Parameters:

initialSize - initial buffer size

Method Details

put

public Object put(String key,
 Object value)

Stores a mapping while keeping the compact array-backed representation until hydration is needed.

Specified by:

put in interface Map<String,Object>

Overrides:

put in class AbstractMap<String,Object>

Parameters:

key - entry key

value - entry value

Returns:

previous value for key, or null

entrySet

public Set<Map.Entry<String,Object>> entrySet()

Returns the hydrated entry set, building the backing map if necessary.

Specified by:

entrySet in interface Map<String,Object>

Specified by:

entrySet in class AbstractMap<String,Object>

Returns:

hydrated entry set

size

public int size()

Returns the current size without hydrating when the compact representation is still active.

Specified by:

size in interface Map<String,Object>

Overrides:

size in class AbstractMap<String,Object>

Returns:

map size

isEmpty

public boolean isEmpty()

Returns whether the map currently contains any entries.

Specified by:

isEmpty in interface Map<String,Object>

Overrides:

isEmpty in class AbstractMap<String,Object>

Returns:

true when no entries are stored

containsValue

public boolean containsValue(Object value)

Hydrates the backing map if needed and tests whether the value is present.

Specified by:

containsValue in interface Map<String,Object>

Overrides:

containsValue in class AbstractMap<String,Object>

Parameters:

value - value to test

Returns:

true when the value is present

containsKey

public boolean containsKey(Object key)

Hydrates the backing map if needed and tests whether the key is present.

Specified by:

containsKey in interface Map<String,Object>

Overrides:

containsKey in class AbstractMap<String,Object>

Parameters:

key - key to test

Returns:

true when the key is present

get

public Object get(Object key)

Hydrates the backing map if needed and returns the value for the supplied key.

Specified by:

get in interface Map<String,Object>

Overrides:

get in class AbstractMap<String,Object>

Parameters:

key - key to look up

Returns:

mapped value, or null

remove

public Object remove(Object key)

Hydrates the backing map if needed and removes the supplied key.

Specified by:

remove in interface Map<String,Object>

Overrides:

remove in class AbstractMap<String,Object>

Parameters:

key - key to remove

Returns:

removed value, or null

putAll

public void putAll(Map m)

Hydrates the backing map if needed and copies all supplied entries into it.

Specified by:

putAll in interface Map<String,Object>

Overrides:

putAll in class AbstractMap<String,Object>

Parameters:

m - entries to copy

clear

public void clear()

Clears the compact buffers or hydrated map, depending on the current state.

Specified by:

clear in interface Map<String,Object>

Overrides:

clear in class AbstractMap<String,Object>

keySet

public Set<String> keySet()

Hydrates the backing map if needed and returns its key set.

Specified by:

keySet in interface Map<String,Object>

Overrides:

keySet in class AbstractMap<String,Object>

Returns:

hydrated key set

values

public Collection<Object> values()

Hydrates the backing map if needed and returns its values collection.

Specified by:

values in interface Map<String,Object>

Overrides:

values in class AbstractMap<String,Object>

Returns:

hydrated values collection

equals

public boolean equals(Object o)

Hydrates the backing map if needed and compares it with another object.

Specified by:

equals in interface Map<String,Object>

Overrides:

equals in class AbstractMap<String,Object>

Parameters:

o - other object

Returns:

true when equal

hashCode

public int hashCode()

Hydrates the backing map if needed and returns its hash code.

Specified by:

hashCode in interface Map<String,Object>

Overrides:

hashCode in class AbstractMap<String,Object>

Returns:

hydrated hash code

toString

public String toString()

Hydrates the backing map if needed and returns its string form.

Overrides:

toString in class AbstractMap<String,Object>

Returns:

hydrated map text

clone

protected Object clone()
                throws CloneNotSupportedException

Clones the hydrated backing map when one already exists.

Overrides:

clone in class AbstractMap<String,Object>

Returns:

a clone of the hydrated backing map, or null when still compact

Throws:

CloneNotSupportedException - never thrown by the current implementation

clearAndCopy

public LazyMap clearAndCopy()

Copies the compact entries into a new LazyMap and clears this instance.

Returns:

a copy containing the current compact entries

grow

public static <V> V[] grow(V[] array)

Doubles the capacity of the supplied array while preserving its component type.

Type Parameters:

V - component type

Parameters:

array - array to grow

Returns:

the expanded array