org.eclipse.jgit.util
Class RefMap

java.lang.Object
  java.util.AbstractMap<String,Ref>
      org.eclipse.jgit.util.RefMap

All Implemented Interfaces:

Map<String,Ref>

public class RefMap
extends AbstractMap<String,Ref>

Specialized Map to present a RefDatabase namespace.

Although not declared as a SortedMap, iterators from this map's projections always return references in RefComparator ordering. The map's internal representation is a sorted array of Ref objects, which means lookup and replacement is O(log N), while insertion and removal can be as expensive as O(N + log N) while the list expands or contracts. Since this is not a general map implementation, all entries must be keyed by the reference name.

This class is really intended as a helper for RefDatabase, which needs to perform a merge-join of three sorted RefLists in order to present the unified namespace of the packed-refs file, the loose refs/ directory tree, and the resolved form of any symbolic references.

Nested Class Summary

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

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

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

Map.Entry<K,V>

Constructor Summary

RefMap()
Construct an empty map with a small initial capacity.

RefMap(String prefix, RefList<? extends Ref> packed, RefList<? extends Ref> loose, RefList<? extends Ref> resolved)
Construct a map to merge 3 collections together.

Method Summary

boolean	containsKey(Object name)
Set<Map.Entry<String,Ref>>	entrySet()
Ref	get(Object key)
boolean	isEmpty()
Ref	put(String keyName, Ref value)
Ref	remove(Object key)
String	toString()

Methods inherited from class java.util.AbstractMap

clear, clone, containsValue, equals, hashCode, keySet, putAll, size, values

Methods inherited from class java.lang.Object

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

Constructor Detail

RefMap

public RefMap()

Construct an empty map with a small initial capacity.

RefMap

public RefMap(String prefix,
              RefList<? extends Ref> packed,
              RefList<? extends Ref> loose,
              RefList<? extends Ref> resolved)

Construct a map to merge 3 collections together.

Parameters:

prefix - prefix used to slice the lists down. Only references whose names start with this prefix will appear to reside in the map. Must not be null, use "" (the empty string) to select all list items.

packed - items from the packed reference list, this is the last list searched.

loose - items from the loose reference list, this list overrides packed if a name appears in both.

resolved - resolved symbolic references. This list overrides the prior list loose, if an item appears in both. Items in this list must also appear in loose.

Method Detail

containsKey

public boolean containsKey(Object name)

Specified by:

containsKey in interface Map<String,Ref>

Overrides:

containsKey in class AbstractMap<String,Ref>

get

public Ref get(Object key)

Specified by:

get in interface Map<String,Ref>

Overrides:

get in class AbstractMap<String,Ref>

put

public Ref put(String keyName,
               Ref value)

Specified by:

put in interface Map<String,Ref>

Overrides:

put in class AbstractMap<String,Ref>

remove

public Ref remove(Object key)

Specified by:

remove in interface Map<String,Ref>

Overrides:

remove in class AbstractMap<String,Ref>

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in interface Map<String,Ref>

Overrides:

isEmpty in class AbstractMap<String,Ref>

entrySet

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

Specified by:

entrySet in interface Map<String,Ref>

Specified by:

entrySet in class AbstractMap<String,Ref>

toString

public String toString()

Overrides:

toString in class AbstractMap<String,Ref>