diff options
Diffstat (limited to 'src/library/scala/collection/mutable/LongMap.scala')
-rw-r--r-- | src/library/scala/collection/mutable/LongMap.scala | 122 |
1 files changed, 61 insertions, 61 deletions
diff --git a/src/library/scala/collection/mutable/LongMap.scala b/src/library/scala/collection/mutable/LongMap.scala index c124f35cd7..198e34bd29 100644 --- a/src/library/scala/collection/mutable/LongMap.scala +++ b/src/library/scala/collection/mutable/LongMap.scala @@ -5,20 +5,20 @@ package mutable import generic.CanBuildFrom /** This class implements mutable maps with `Long` keys based on a hash table with open addressing. - * - * Basic map operations on single entries, including `contains` and `get`, + * + * Basic map operations on single entries, including `contains` and `get`, * are typically substantially faster with `LongMap` than [[HashMap]]. Methods * that act on the whole map, including `foreach` and `map` are not in * general expected to be faster than with a generic map, save for those * that take particular advantage of the internal structure of the map: * `foreachKey`, `foreachValue`, `mapValuesNow`, and `transformValues`. - * + * * Maps with open addressing may become less efficient at lookup after * repeated addition/removal of elements. Although `LongMap` makes a * decent attempt to remain efficient regardless, calling `repack` * on a map that will no longer have elements removed but will be * used heavily may save both time and storage space. - * + * * This map is not intended to contain more than 2^29 entries (approximately * 500 million). The maximum capacity is 2^30, but performance will degrade * rapidly as 2^30 is approached. @@ -33,20 +33,20 @@ extends AbstractMap[Long, V] import LongMap._ def this() = this(LongMap.exceptionDefault, 16, true) - + /** Creates a new `LongMap` that returns default values according to a supplied key-value mapping. */ def this(defaultEntry: Long => V) = this(defaultEntry, 16, true) - + /** Creates a new `LongMap` with an initial buffer of specified size. - * + * * A LongMap can typically contain half as many elements as its buffer size * before it requires resizing. */ def this(initialBufferSize: Int) = this(LongMap.exceptionDefault, initialBufferSize, true) - + /** Creates a new `LongMap` with specified default values and initial buffer size. */ def this(defaultEntry: Long => V, initialBufferSize: Int) = this(defaultEntry, initialBufferSize, true) - + private[this] var mask = 0 private[this] var extraKeys: Int = 0 private[this] var zeroValue: AnyRef = null @@ -55,43 +55,43 @@ extends AbstractMap[Long, V] private[this] var _vacant = 0 private[this] var _keys: Array[Long] = null private[this] var _values: Array[AnyRef] = null - + if (initBlank) defaultInitialize(initialBufferSize) - + private[this] def defaultInitialize(n: Int) = { - mask = + mask = if (n<0) 0x7 else (((1 << (32 - java.lang.Integer.numberOfLeadingZeros(n-1))) - 1) & 0x3FFFFFFF) | 0x7 _keys = new Array[Long](mask+1) _values = new Array[AnyRef](mask+1) } - + private[collection] def initializeTo( m: Int, ek: Int, zv: AnyRef, mv: AnyRef, sz: Int, vc: Int, kz: Array[Long], vz: Array[AnyRef] ) { mask = m; extraKeys = ek; zeroValue = zv; minValue = mv; _size = sz; _vacant = vc; _keys = kz; _values = vz } - + override def size: Int = _size + (extraKeys+1)/2 override def empty: LongMap[V] = new LongMap() - - private def imbalanced: Boolean = + + private def imbalanced: Boolean = (_size + _vacant) > 0.5*mask || _vacant > _size - + private def toIndex(k: Long): Int = { // Part of the MurmurHash3 32 bit finalizer val h = ((k ^ (k >>> 32)) & 0xFFFFFFFFL).toInt val x = (h ^ (h >>> 16)) * 0x85EBCA6B (x ^ (x >>> 13)) & mask } - + private def seekEmpty(k: Long): Int = { var e = toIndex(k) var x = 0 while (_keys(e) != 0) { x += 1; e = (e + 2*(x+1)*x - 3) & mask } e } - + private def seekEntry(k: Long): Int = { var e = toIndex(k) var x = 0 @@ -99,7 +99,7 @@ extends AbstractMap[Long, V] while ({ q = _keys(e); if (q==k) return e; q != 0}) { x += 1; e = (e + 2*(x+1)*x - 3) & mask } e | MissingBit } - + private def seekEntryOrOpen(k: Long): Int = { var e = toIndex(k) var x = 0 @@ -116,12 +116,12 @@ extends AbstractMap[Long, V] } o } - + override def contains(key: Long): Boolean = { if (key == -key) (((key>>>63).toInt+1) & extraKeys) != 0 else seekEntry(key) >= 0 } - + override def get(key: Long): Option[V] = { if (key == -key) { if ((((key>>>63).toInt+1) & extraKeys) == 0) None @@ -133,7 +133,7 @@ extends AbstractMap[Long, V] if (i < 0) None else Some(_values(i).asInstanceOf[V]) } } - + override def getOrElse[V1 >: V](key: Long, default: => V1): V1 = { if (key == -key) { if ((((key>>>63).toInt+1) & extraKeys) == 0) default @@ -145,7 +145,7 @@ extends AbstractMap[Long, V] if (i < 0) default else _values(i).asInstanceOf[V1] } } - + override def getOrElseUpdate(key: Long, defaultValue: => V): V = { if (key == -key) { val kbits = (key>>>63).toInt + 1 @@ -185,10 +185,10 @@ extends AbstractMap[Long, V] else _values(i).asInstanceOf[V] } } - + /** Retrieves the value associated with a key, or the default for that type if none exists * (null for AnyRef, 0 for floats and integers). - * + * * Note: this is the fastest way to retrieve a value that may or * may not exist, if the default null/zero is acceptable. For key/value * pairs that do exist, `apply` (i.e. `map(key)`) is equally fast. @@ -204,8 +204,8 @@ extends AbstractMap[Long, V] if (i < 0) null.asInstanceOf[V] else _values(i).asInstanceOf[V] } } - - /** Retrieves the value associated with a key. + + /** Retrieves the value associated with a key. * If the key does not exist in the map, the `defaultEntry` for that key * will be returned instead. */ @@ -220,12 +220,12 @@ extends AbstractMap[Long, V] if (i < 0) defaultEntry(key) else _values(i).asInstanceOf[V] } } - + /** The user-supplied default value for the key. Throws an exception * if no other default behavior was specified. */ override def default(key: Long) = defaultEntry(key) - + private def repack(newMask: Int) { val ok = _keys val ov = _values @@ -244,9 +244,9 @@ extends AbstractMap[Long, V] i += 1 } } - + /** Repacks the contents of this `LongMap` for maximum efficiency of lookup. - * + * * For maps that undergo a complex creation process with both addition and * removal of keys, and then are used heavily with no further removal of * elements, calling `repack` after the end of the creation can result in @@ -259,7 +259,7 @@ extends AbstractMap[Long, V] while (m > 8 && 8*_size < m) m = m >>> 1 repack(m) } - + override def put(key: Long, value: V): Option[V] = { if (key == -key) { if (key == 0) { @@ -294,9 +294,9 @@ extends AbstractMap[Long, V] } } } - + /** Updates the map to include a new key-value pair. - * + * * This is the fastest way to add an entry to a `LongMap`. */ override def update(key: Long, value: V): Unit = { @@ -326,12 +326,12 @@ extends AbstractMap[Long, V] } } } - + /** Adds a new key/value pair to this map and returns the map. */ def +=(key: Long, value: V): this.type = { update(key, value); this } - + def +=(kv: (Long, V)): this.type = { update(kv._1, kv._2); this } - + def -=(key: Long): this.type = { if (key == -key) { if (key == 0L) { @@ -354,22 +354,22 @@ extends AbstractMap[Long, V] } this } - + def iterator: Iterator[(Long, V)] = new Iterator[(Long, V)] { private[this] val kz = _keys private[this] val vz = _values - - private[this] var nextPair: (Long, V) = + + private[this] var nextPair: (Long, V) = if (extraKeys==0) null else if ((extraKeys&1)==1) (0L, zeroValue.asInstanceOf[V]) else (Long.MinValue, minValue.asInstanceOf[V]) - private[this] var anotherPair: (Long, V) = + private[this] var anotherPair: (Long, V) = if (extraKeys==3) (Long.MinValue, minValue.asInstanceOf[V]) else null - + private[this] var index = 0 - + def hasNext: Boolean = nextPair != null || (index < kz.length && { var q = kz(index) while (q == -q) { @@ -392,8 +392,8 @@ extends AbstractMap[Long, V] ans } } - - override def foreach[A](f: ((Long,V)) => A) { + + override def foreach[U](f: ((Long,V)) => U) { if ((extraKeys & 1) == 1) f((0L, zeroValue.asInstanceOf[V])) if ((extraKeys & 2) == 2) f((Long.MinValue, minValue.asInstanceOf[V])) var i,j = 0 @@ -406,7 +406,7 @@ extends AbstractMap[Long, V] i += 1 } } - + override def clone(): LongMap[V] = { val kz = java.util.Arrays.copyOf(_keys, _keys.length) val vz = java.util.Arrays.copyOf(_values, _values.length) @@ -414,7 +414,7 @@ extends AbstractMap[Long, V] lm.initializeTo(mask, extraKeys, zeroValue, minValue, _size, _vacant, kz, vz) lm } - + /** Applies a function to all keys of this map. */ def foreachKey[A](f: Long => A) { if ((extraKeys & 1) == 1) f(0L) @@ -444,7 +444,7 @@ extends AbstractMap[Long, V] i += 1 } } - + /** Creates a new `LongMap` with different values. * Unlike `mapValues`, this method generates a new * collection immediately. @@ -467,8 +467,8 @@ extends AbstractMap[Long, V] lm.initializeTo(mask, extraKeys, zv, mv, _size, _vacant, kz, vz) lm } - - /** Applies a transformation function to all values stored in this map. + + /** Applies a transformation function to all values stored in this map. * Note: the default, if any, is not transformed. */ def transformValues(f: V => V): this.type = { @@ -492,15 +492,15 @@ object LongMap { private final val MissingBit = 0x80000000 private final val VacantBit = 0x40000000 private final val MissVacant = 0xC0000000 - + private val exceptionDefault: Long => Nothing = (k: Long) => throw new NoSuchElementException(k.toString) - - implicit def canBuildFrom[V, U]: CanBuildFrom[LongMap[V], (Long, U), LongMap[U]] = + + implicit def canBuildFrom[V, U]: CanBuildFrom[LongMap[V], (Long, U), LongMap[U]] = new CanBuildFrom[LongMap[V], (Long, U), LongMap[U]] { def apply(from: LongMap[V]): LongMapBuilder[U] = apply() def apply(): LongMapBuilder[U] = new LongMapBuilder[U] } - + final class LongMapBuilder[V] extends Builder[(Long, V), LongMap[V]] { private[collection] var elems: LongMap[V] = new LongMap[V] def +=(entry: (Long, V)): this.type = { @@ -519,14 +519,14 @@ object LongMap { if (lm.size < (sz>>3)) lm.repack() lm } - + /** Creates a new empty `LongMap`. */ def empty[V]: LongMap[V] = new LongMap[V] - + /** Creates a new empty `LongMap` with the supplied default */ def withDefault[V](default: Long => V): LongMap[V] = new LongMap[V](default) - - /** Creates a new `LongMap` from arrays of keys and values. + + /** Creates a new `LongMap` from arrays of keys and values. * Equivalent to but more efficient than `LongMap((keys zip values): _*)`. */ def fromZip[V](keys: Array[Long], values: Array[V]): LongMap[V] = { @@ -537,8 +537,8 @@ object LongMap { if (lm.size < (sz>>3)) lm.repack() lm } - - /** Creates a new `LongMap` from keys and values. + + /** Creates a new `LongMap` from keys and values. * Equivalent to but more efficient than `LongMap((keys zip values): _*)`. */ def fromZip[V](keys: Iterable[Long], values: Iterable[V]): LongMap[V] = { |