7da6eb2dd83b34a5400e24bcda9d1894f7874213
1 # This file is part of NIT ( http://www.nitlanguage.org ).
3 # Copyright 2004-2009 Jean Privat <jean@pryen.org>
5 # This file is free software, which comes along with NIT. This software is
6 # distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
7 # without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
8 # PARTICULAR PURPOSE. You can modify it is you want, provided this header
9 # is kept unaltered, and a notification of the changes is added.
10 # You are allowed to redistribute it and sell it, alone or is a part of
13 # Introduce Hashmap and Hashset.
14 module hash_collection
18 # A HashCollection is an array of HashNode[K] indexed by the K hash value
19 private abstract class HashCollection[K
: Object, N
: HashNode[Object]]
20 super ArrayCapable[nullable N
]
22 var _array
: nullable NativeArray[nullable N
] = null # Used to store items
23 var _capacity
: Int = 0 # Size of _array
24 var _length
: Int = 0 # Number of items in the map
26 readable var _first_item
: nullable N
= null # First added item (used to visit items in nice order)
27 var _last_item
: nullable N
= null # Last added item (same)
29 # The last key accessed (used for cache)
30 var _last_accessed_key
: nullable K
= null
32 # The last node accessed (used for cache)
33 var _last_accessed_node
: nullable N
= null
35 # Return the index of the key k
36 fun index_at
(k
: K
): Int
38 var i
= k
.hash
% _capacity
43 # Return the node assosiated with the key
44 fun node_at
(k
: K
): nullable N
46 # cache: `is` is used instead of `==` because it is a faster filter (even if not exact)
47 if k
is _last_accessed_key
then return _last_accessed_node
49 var res
= node_at_idx
(index_at
(k
), k
)
50 _last_accessed_key
= k
51 _last_accessed_node
= res
55 # Return the node assosiated with the key (but with the index already known)
56 fun node_at_idx
(i
: Int, k
: K
): nullable N
61 if ck
is k
or ck
== k
then # prefilter with `is` because the compiler is not smart enought yet
64 c
= c
._next_in_bucklet
69 # Add a new node at a given index
70 fun store
(index
: Int, node
: N
)
72 # Store the item in the list
73 if _first_item
== null then
76 _last_item
._next_item
= node
78 node
._prev_item
= _last_item
79 node
._next_item
= null
82 # Then store it in the array
83 var next
= _array
[index
]
85 node
._next_in_bucklet
= next
86 if next
!= null then next
._prev_in_bucklet
= node
88 _last_accessed_key
= node
._key
89 _last_accessed_node
= node
95 if l
>= _capacity
then
100 # Remove the node assosiated with the key
101 fun remove_node
(k
: K
)
104 var node
= node_at_idx
(i
, k
)
105 if node
== null then return
107 # Remove the item in the list
108 var prev
= node
._prev_item
109 var next
= node
._next_item
111 prev
._next_item
= next
116 next
._prev_item
= prev
121 # Remove the item in the array
123 prev
= node
._prev_in_bucklet
124 next
= node
._next_in_bucklet
126 prev
._next_in_bucklet
= next
131 next
._prev_in_bucklet
= prev
134 _last_accessed_key
= null
137 # Clear the whole structure
140 var i
= _capacity
- 1
148 _last_accessed_key
= null
152 fun enlarge
(cap
: Int)
154 var old_cap
= _capacity
156 if cap
< _length
+ 1 then cap
= _length
+ 1
157 if cap
<= _capacity
then return
159 _last_accessed_key
= null
162 var new_array
= calloc_array
(cap
)
165 # clean the new array
172 if _capacity
<= old_cap
then return
174 # Reput items in the array
175 var node
= _first_item
176 while node
!= null do
177 var index
= index_at
(node
._key
)
178 # Then store it in the array
179 var next
= new_array
[index
]
180 new_array
[index
] = node
181 node
._next_in_bucklet
= next
182 if next
!= null then next
._prev_in_bucklet
= node
183 node
= node
._next_item
188 private abstract class HashNode[K
: Object]
191 readable writable var _next_item
: nullable N
= null
192 readable writable var _prev_item
: nullable N
= null
193 var _prev_in_bucklet
: nullable N
= null
194 var _next_in_bucklet
: nullable N
= null
201 # A map implemented with a hash table.
202 # Keys of such a map cannot be null and require a working `hash` method
203 class HashMap[K
: Object, V
]
205 super HashCollection[K
, HashMapNode[K
, V
]]
217 redef fun iterator
: HashMapIterator[K
, V
] do return new HashMapIterator[K
,V
](self)
224 each
(c
._key
, c
._value
)
229 redef fun length
do return _length
231 redef fun is_empty
do return _length
== 0
233 redef fun []=(key
, v
)
235 var i
= index_at
(key
)
236 var c
= node_at_idx
(i
, key
)
241 store
(i
, new HashMapNode[K
, V
](key
, v
))
245 redef fun clear
do raz
254 redef var keys
: HashMapKeys[K
, V
] = new HashMapKeys[K
, V
](self)
255 redef var values
: HashMapValues[K
, V
] = new HashMapValues[K
, V
](self)
258 # View of the keys of a HashMap
259 class HashMapKeys[K
: Object, V
]
260 super RemovableCollection[K
]
262 var map
: HashMap[K
, V
]
264 redef fun count
(k
) do if self.has
(k
) then return 1 else return 0
265 redef fun first
do return self.map
._first_item
._key
266 redef fun has
(k
) do return self.map
.node_at
(k
) != null
267 redef fun has_only
(k
) do return (self.has
(k
) and self.length
== 1) or self.is_empty
268 redef fun is_empty
do return self.map
.is_empty
269 redef fun length
do return self.map
.length
271 redef fun iterator
do return new MapKeysIterator[K
, V
](self.map
.iterator
)
273 redef fun clear
do self.map
.clear
275 redef fun remove
(key
) do self.map
.remove_node
(key
)
276 redef fun remove_all
(key
) do self.map
.remove_node
(key
)
279 # View of the values of a Map
280 class HashMapValues[K
: Object, V
]
281 super RemovableCollection[V
]
283 var map
: HashMap[K
, V
]
285 redef fun count
(item
)
288 var c
= self.map
._first_item
290 if c
._value
== item
then nb
+= 1
295 redef fun first
do return self.map
._first_item
._value
299 var c
= self.map
._first_item
301 if c
._value
== item
then return true
307 redef fun has_only
(item
)
309 var c
= self.map
._first_item
311 if c
._value
!= item
then return false
317 redef fun is_empty
do return self.map
.is_empty
318 redef fun length
do return self.map
.length
320 redef fun iterator
do return new MapValuesIterator[K
, V
](self.map
.iterator
)
322 redef fun clear
do self.map
.clear
324 redef fun remove
(item
)
327 var c
= map
._first_item
329 if c
._value
== item
then
330 map
.remove_node
(c
._key
)
337 redef fun remove_all
(item
)
340 var c
= map
._first_item
342 if c
._value
== item
then
343 map
.remove_node
(c
._key
)
350 private class HashMapNode[K
: Object, V
]
352 redef type N
: HashMapNode[K
, V
]
362 class HashMapIterator[K
: Object, V
]
363 super MapIterator[K
, V
]
364 redef fun is_ok
do return _node
!= null
372 #redef fun item=(value)
375 # _node.second = value
387 _node
= _node
._next_item
390 # The map to iterate on
391 var _map
: HashMap[K
, V
]
394 var _node
: nullable HashMapNode[K
, V
]
396 init(map
: HashMap[K
, V
])
399 _node
= map
.first_item
403 # A `Set` implemented with a hash table.
404 # Keys of such a map cannot be null and require a working `hash` method
405 class HashSet[E
: Object]
407 super HashCollection[E
, HashSetNode[E
]]
409 redef fun length
do return _length
411 redef fun is_empty
do return _length
== 0
416 return _first_item
._key
421 return node_at
(item
) != null
426 var i
= index_at
(item
)
427 var c
= node_at_idx
(i
, item
)
431 store
(i
,new HashSetNode[E
](item
))
435 redef fun remove
(item
) do remove_node
(item
)
437 redef fun clear
do raz
439 redef fun iterator
do return new HashSetIterator[E
](self)
448 # Build a list filled with the items of `coll`.
449 init from
(coll
: Collection[E
]) do
455 private class HashSetNode[E
: Object]
457 redef type N
: HashSetNode[E
]
465 class HashSetIterator[E
: Object]
467 redef fun is_ok
do return _node
!= null
478 _node
= _node
._next_item
481 # The set to iterate on
484 # The position in the internal map storage
485 var _node
: nullable HashSetNode[E
]
487 init(set
: HashSet[E
])
490 _node
= set
._first_item