diff options
Diffstat (limited to 'src/library/scala/collection/immutable/HashMap.scala')
| -rw-r--r-- | src/library/scala/collection/immutable/HashMap.scala | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/src/library/scala/collection/immutable/HashMap.scala b/src/library/scala/collection/immutable/HashMap.scala index 9cde20f1df..6b11371bec 100644 --- a/src/library/scala/collection/immutable/HashMap.scala +++ b/src/library/scala/collection/immutable/HashMap.scala @@ -138,8 +138,10 @@ object HashMap extends ImmutableMapFactory[HashMap] with BitOperations.Int { override def updated0[B1 >: B](key: A, hash: Int, level: Int, value: B1, kv: (A, B1), merger: Merger[B1]): HashMap[A, B1] = if (hash == this.hash && key == this.key ) { - if (merger eq null) new HashMap1(key, hash, value, kv) - else new HashMap1(key, hash, value, merger(this.kv, kv)) + if (merger eq null) { + if(this.value.asInstanceOf[AnyRef] eq value.asInstanceOf[AnyRef]) this + else new HashMap1(key, hash, value, kv) + } else new HashMap1(key, hash, value, merger(this.kv, kv)) } else { var thatindex = (hash >>> level) & 0x1f var thisindex = (this.hash >>> level) & 0x1f @@ -271,13 +273,15 @@ object HashMap extends ImmutableMapFactory[HashMap] with BitOperations.Int { val mask = (1 << index) val offset = Integer.bitCount(bitmap & (mask-1)) if ((bitmap & mask) != 0) { - val elemsNew = new Array[HashMap[A,B1]](elems.length) - Array.copy(elems, 0, elemsNew, 0, elems.length) val sub = elems(offset) // TODO: might be worth checking if sub is HashTrieMap (-> monomorphic call site) val subNew = sub.updated0(key, hash, level + 5, value, kv, merger) - elemsNew(offset) = subNew - new HashTrieMap(bitmap, elemsNew, size + (subNew.size - sub.size)) + if(subNew eq sub) this else { + val elemsNew = new Array[HashMap[A,B1]](elems.length) + Array.copy(elems, 0, elemsNew, 0, elems.length) + elemsNew(offset) = subNew + new HashTrieMap(bitmap, elemsNew, size + (subNew.size - sub.size)) + } } else { val elemsNew = new Array[HashMap[A,B1]](elems.length + 1) Array.copy(elems, 0, elemsNew, 0, offset) @@ -295,7 +299,8 @@ object HashMap extends ImmutableMapFactory[HashMap] with BitOperations.Int { val sub = elems(offset) // TODO: might be worth checking if sub is HashTrieMap (-> monomorphic call site) val subNew = sub.removed0(key, hash, level + 5) - if (subNew.isEmpty) { + if (subNew eq sub) this + else if (subNew.isEmpty) { val bitmapNew = bitmap ^ mask if (bitmapNew != 0) { val elemsNew = new Array[HashMap[A,B]](elems.length - 1) |