java.lang.Object | |||
↳ | java.util.AbstractMap<K, V> | ||
↳ | java.util.TreeMap<K, V> | ||
↳ | org.apache.commons.collections.FastTreeMap |
A customized implementation of java.util.TreeMap
designed
to operate in a multithreaded environment where the large majority of
method calls are read-only, instead of structural changes. When operating
in "fast" mode, read calls are non-synchronized and write calls perform the
following steps:
When first created, objects of this class default to "slow" mode, where
all accesses of any type are synchronized but no cloning takes place. This
is appropriate for initially populating the collection, followed by a switch
to "fast" mode (by calling setFast(true)
) after initialization
is complete.
NOTE: If you are creating and accessing a
TreeMap
only within a single thread, you should use
java.util.TreeMap
directly (with no synchronization), for
maximum performance.
NOTE: This class is not cross-platform. Using it may cause unexpected failures on some architectures. It suffers from the same problems as the double-checked locking idiom. In particular, the instruction that clones the internal collection and the instruction that sets the internal reference to the clone can be executed or perceived out-of-order. This means that any read operation might fail unexpectedly, as it may be reading the state of the internal collection before the internal collection is fully formed. For more information on the double-checked locking idiom, see the Double-Checked Locking Idiom Is Broken Declaration.
Fields | |||||||||||
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fast | Are we operating in "fast" mode? | ||||||||||
map | The underlying map we are managing. |
Public Constructors | |||||||||||
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Construct a an empty map.
| |||||||||||
Construct an empty map with the specified comparator.
| |||||||||||
Construct a new map with the same mappings as the specified map,
sorted according to the keys's natural order
| |||||||||||
Construct a new map with the same mappings as the specified map,
sorted according to the same ordering
|
Public Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Remove all mappings from this map.
| |||||||||||
Return a shallow copy of this
FastTreeMap instance. | |||||||||||
Return the comparator used to order this map, or
null
if this map uses its keys' natural order. | |||||||||||
Return
true if this map contains a mapping for the
specified key. | |||||||||||
Return
true if this map contains one or more keys mapping
to the specified value. | |||||||||||
Return a collection view of the mappings contained in this map.
| |||||||||||
Compare the specified object with this list for equality.
| |||||||||||
Return the first (lowest) key currently in this sorted map.
| |||||||||||
Return the value to which this map maps the specified key.
| |||||||||||
Returns true if this map is operating in fast mode.
| |||||||||||
Return the hash code value for this map.
| |||||||||||
Return a view of the portion of this map whose keys are strictly
less than the specified key.
| |||||||||||
Return
true if this map contains no mappings. | |||||||||||
Return a set view of the keys contained in this map.
| |||||||||||
Return the last (highest) key currently in this sorted map.
| |||||||||||
Associate the specified value with the specified key in this map.
| |||||||||||
Copy all of the mappings from the specified map to this one, replacing
any mappings with the same keys.
| |||||||||||
Remove any mapping for this key, and return any previously
mapped value.
| |||||||||||
Sets whether this map is operating in fast mode.
| |||||||||||
Return the number of key-value mappings in this map.
| |||||||||||
Return a view of the portion of this map whose keys are in the
range fromKey (inclusive) to toKey (exclusive).
| |||||||||||
Return a view of the portion of this map whose keys are greater than
or equal to the specified key.
| |||||||||||
Return a collection view of the values contained in this map.
|
[Expand]
Inherited Methods | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
From class
java.util.TreeMap
| |||||||||||
From class
java.util.AbstractMap
| |||||||||||
From class
java.lang.Object
| |||||||||||
From interface
java.util.Map
| |||||||||||
From interface java.util.NavigableMap | |||||||||||
From interface
java.util.SortedMap
|
Are we operating in "fast" mode?
Construct a an empty map.
Construct an empty map with the specified comparator.
comparator | the comparator to use for ordering tree elements |
---|
Construct a new map with the same mappings as the specified map, sorted according to the keys's natural order
map | the map whose mappings are to be copied |
---|
Construct a new map with the same mappings as the specified map, sorted according to the same ordering
map | the map whose mappings are to be copied |
---|
Remove all mappings from this map.
Return a shallow copy of this FastTreeMap
instance.
The keys and values themselves are not copied.
Return the comparator used to order this map, or null
if this map uses its keys' natural order.
Return true
if this map contains a mapping for the
specified key.
key | the key to be searched for |
---|
Return true
if this map contains one or more keys mapping
to the specified value.
value | the value to be searched for |
---|
Return a collection view of the mappings contained in this map. Each
element in the returned collection is a Map.Entry
.
Compare the specified object with this list for equality. This
implementation uses exactly the code that is used to define the
list equals function in the documentation for the
Map.equals
method.
o | the object to be compared to this list |
---|
Return the first (lowest) key currently in this sorted map.
Return the value to which this map maps the specified key. Returns
null
if the map contains no mapping for this key, or if
there is a mapping with a value of null
. Use the
containsKey()
method to disambiguate these cases.
key | the key whose value is to be returned |
---|
Returns true if this map is operating in fast mode.
Return the hash code value for this map. This implementation uses
exactly the code that is used to define the list hash function in the
documentation for the Map.hashCode
method.
Return a view of the portion of this map whose keys are strictly less than the specified key.
key | Key higher than any in the returned map |
---|
Return true
if this map contains no mappings.
Return the last (highest) key currently in this sorted map.
Associate the specified value with the specified key in this map. If the map previously contained a mapping for this key, the old value is replaced and returned.
key | the key with which the value is to be associated |
---|---|
value | the value to be associated with this key |
Copy all of the mappings from the specified map to this one, replacing any mappings with the same keys.
in | the map whose mappings are to be copied |
---|
Remove any mapping for this key, and return any previously mapped value.
key | the key whose mapping is to be removed |
---|
Sets whether this map is operating in fast mode.
fast | true if this map should operate in fast mode |
---|
Return the number of key-value mappings in this map.
Return a view of the portion of this map whose keys are in the range fromKey (inclusive) to toKey (exclusive).
fromKey | Lower limit of keys for the returned map |
---|---|
toKey | Upper limit of keys for the returned map |
Return a view of the portion of this map whose keys are greater than or equal to the specified key.
key | Key less than or equal to any in the returned map |
---|