mcs/class/System/System.Collections.Generic/SortedSet.cs

   1 //
   2 // SortedSet.cs
   3 //
   4 // Authors:
   5 //  Jb Evain  <jbevain@novell.com>
   6 //
   7 // Copyright (C) 2010 Novell, Inc (http://www.novell.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System;
  30 using System.Collections;
  31 using System.Collections.Generic;
  32 using System.Linq;
  33 using System.Runtime.Serialization;
  34 using System.Runtime.InteropServices;
  35 using System.Security;
  36 using System.Security.Permissions;
  37 using System.Diagnostics;
  38
  39 // SortedSet is basically implemented as a reduction of SortedDictionary<K, V>
  40
  41 #if NET_4_0
  42
  43 namespace System.Collections.Generic {
  44
  45         [Serializable]
  46         [DebuggerDisplay ("Count={Count}")]
  47         [DebuggerTypeProxy (typeof (CollectionDebuggerView))]
  48         public class SortedSet<T> : ISet<T>, ICollection, ISerializable, IDeserializationCallback
  49         {
  50                 class Node : RBTree.Node {
  51
  52                         public T item;
  53
  54                         public Node (T item)
  55                         {
  56                                 this.item = item;
  57                         }
  58
  59                         public override void SwapValue (RBTree.Node other)
  60                         {
  61                                 var o = (Node) other;
  62                                 var i = this.item;
  63                                 this.item = o.item;
  64                                 o.item = i;
  65                         }
  66                 }
  67
  68                 class NodeHelper : RBTree.INodeHelper<T> {
  69
  70                         static NodeHelper Default = new NodeHelper (Comparer<T>.Default);
  71
  72                         public IComparer<T> comparer;
  73
  74                         public int Compare (T item, RBTree.Node node)
  75                         {
  76                                 return comparer.Compare (item, ((Node) node).item);
  77                         }
  78
  79                         public RBTree.Node CreateNode (T item)
  80                         {
  81                                 return new Node (item);
  82                         }
  83
  84                         NodeHelper (IComparer<T> comparer)
  85                         {
  86                                 this.comparer = comparer;
  87                         }
  88
  89                         public static NodeHelper GetHelper (IComparer<T> comparer)
  90                         {
  91                                 if (comparer == null || comparer == Comparer<T>.Default)
  92                                         return Default;
  93
  94                                 return new NodeHelper (comparer);
  95                         }
  96                 }
  97
  98                 RBTree tree;
  99                 NodeHelper helper;
 100                 SerializationInfo si;
 101
 102                 public SortedSet ()
 103                         : this (Comparer<T>.Default)
 104                 {
 105                 }
 106
 107                 public SortedSet (IEnumerable<T> collection)
 108                         : this (collection, Comparer<T>.Default)
 109                 {
 110                 }
 111
 112                 public SortedSet (IEnumerable<T> collection, IComparer<T> comparer)
 113                         : this (comparer)
 114                 {
 115                         if (collection == null)
 116                                 throw new ArgumentNullException ("collection");
 117
 118                         foreach (var item in collection)
 119                                 Add (item);
 120                 }
 121
 122                 public SortedSet (IComparer<T> comparer)
 123                 {
 124                         this.helper = NodeHelper.GetHelper (comparer);
 125                         this.tree = new RBTree (this.helper);
 126                 }
 127
 128                 protected SortedSet (SerializationInfo info, StreamingContext context)
 129                 {
 130                         this.si = info;
 131                 }
 132
 133                 public IComparer<T> Comparer {
 134                         get { return helper.comparer; }
 135                 }
 136
 137                 public int Count {
 138                         get { return GetCount (); }
 139                 }
 140
 141                 public T Max {
 142                         get { return GetMax (); }
 143                 }
 144
 145                 public T Min {
 146                         get {  return GetMin (); }
 147                 }
 148
 149                 internal virtual T GetMax ()
 150                 {
 151                         if (tree.Count == 0)
 152                                 return default (T);
 153
 154                         return GetItem (tree.Count - 1);
 155                 }
 156
 157                 internal virtual T GetMin ()
 158                 {
 159                         if (tree.Count == 0)
 160                                 return default (T);
 161
 162                         return GetItem (0);
 163                 }
 164
 165                 internal virtual int GetCount ()
 166                 {
 167                         return tree.Count;
 168                 }
 169
 170                 T GetItem (int index)
 171                 {
 172                         return ((Node) tree [index]).item;
 173                 }
 174
 175                 public bool Add (T item)
 176                 {
 177                         return TryAdd (item);
 178                 }
 179
 180                 internal virtual bool TryAdd (T item)
 181                 {
 182                         var node = new Node (item);
 183                         return tree.Intern (item, node) == node;
 184                 }
 185
 186                 public virtual void Clear ()
 187                 {
 188                         tree.Clear ();
 189                 }
 190
 191                 public virtual bool Contains (T item)
 192                 {
 193                         return tree.Lookup (item) != null;
 194                 }
 195
 196                 public void CopyTo (T [] array)
 197                 {
 198                         CopyTo (array, 0, Count);
 199                 }
 200
 201                 public void CopyTo (T [] array, int index)
 202                 {
 203                         CopyTo (array, index, Count);
 204                 }
 205
 206                 public void CopyTo (T [] array, int index, int count)
 207                 {
 208                         if (array == null)
 209                                 throw new ArgumentNullException ("array");
 210                         if (index < 0)
 211                                 throw new ArgumentOutOfRangeException ("index");
 212                         if (index > array.Length)
 213                                 throw new ArgumentException ("index larger than largest valid index of array");
 214                         if (array.Length - index < count)
 215                                 throw new ArgumentException ("destination array cannot hold the requested elements");
 216
 217                         foreach (Node node in tree) {
 218                                 if (count-- == 0)
 219                                         break;
 220
 221                                 array [index++] = node.item;
 222                         }
 223                 }
 224
 225                 public bool Remove (T item)
 226                 {
 227                         return TryRemove (item);
 228                 }
 229
 230                 internal virtual bool TryRemove (T item)
 231                 {
 232                         return tree.Remove (item) != null;
 233                 }
 234
 235                 public int RemoveWhere (Predicate<T> match)
 236                 {
 237                         var array = ToArray ();
 238
 239                         int count = 0;
 240                         foreach (var item in array) {
 241                                 if (!match (item))
 242                                         continue;
 243
 244                                 Remove (item);
 245                                 count++;
 246                         }
 247
 248                         return count;
 249                 }
 250
 251                 public IEnumerable<T> Reverse ()
 252                 {
 253                         for (int i = tree.Count - 1; i >= 0; i--)
 254                                 yield return GetItem (i);
 255                 }
 256
 257                 T [] ToArray ()
 258                 {
 259                         var array = new T [this.Count];
 260                         CopyTo (array);
 261                         return array;
 262                 }
 263
 264                 public Enumerator GetEnumerator ()
 265                 {
 266                         return TryGetEnumerator ();
 267                 }
 268
 269                 internal virtual Enumerator TryGetEnumerator ()
 270                 {
 271                         return new Enumerator (this);
 272                 }
 273
 274                 IEnumerator<T> IEnumerable<T>.GetEnumerator ()
 275                 {
 276                         return GetEnumerator ();
 277                 }
 278
 279                 IEnumerator IEnumerable.GetEnumerator ()
 280                 {
 281                         return GetEnumerator ();
 282                 }
 283
 284                 public static IEqualityComparer<SortedSet<T>> CreateSetComparer ()
 285                 {
 286                         return CreateSetComparer (EqualityComparer<T>.Default);
 287                 }
 288
 289                 [MonoTODO]
 290                 public static IEqualityComparer<SortedSet<T>> CreateSetComparer (IEqualityComparer<T> memberEqualityComparer)
 291                 {
 292                         throw new NotImplementedException ();
 293                 }
 294
 295                 [MonoTODO]
 296                 protected virtual void GetObjectData (SerializationInfo info, StreamingContext context)
 297                 {
 298                         throw new NotImplementedException ();
 299                 }
 300
 301                 void ISerializable.GetObjectData (SerializationInfo info, StreamingContext context)
 302                 {
 303                         GetObjectData (info, context);
 304                 }
 305
 306                 [MonoTODO]
 307                 protected virtual void OnDeserialization (object sender)
 308                 {
 309                         if (si == null)
 310                                 return;
 311
 312                         throw new NotImplementedException ();
 313                 }
 314
 315                 void IDeserializationCallback.OnDeserialization (object sender)
 316                 {
 317                         OnDeserialization (sender);
 318                 }
 319
 320                 [MonoLimitation ("Isn't O(n) when other is SortedSet<T>")]
 321                 public void ExceptWith (IEnumerable<T> other)
 322                 {
 323                         CheckArgumentNotNull (other, "other");
 324                         foreach (T item in other)
 325                                 Remove (item);
 326                 }
 327
 328                 public virtual SortedSet<T> GetViewBetween (T lowerValue, T upperValue)
 329                 {
 330                         if (Comparer.Compare (lowerValue, upperValue) > 0)
 331                                 throw new ArgumentException ("The lowerValue is bigger than upperValue");
 332
 333                         return new SortedSubSet (this, lowerValue, upperValue);
 334                 }
 335
 336                 [MonoLimitation ("Isn't O(n) when other is SortedSet<T>")]
 337                 public virtual void IntersectWith (IEnumerable<T> other)
 338                 {
 339                         CheckArgumentNotNull (other, "other");
 340
 341                         RBTree newtree = new RBTree (helper);
 342                         foreach (T item in other) {
 343                                 var node = tree.Remove (item);
 344                                 if (node != null)
 345                                         newtree.Intern (item, node);
 346                         }
 347                         tree = newtree;
 348                 }
 349
 350                 public bool IsProperSubsetOf (IEnumerable<T> other)
 351                 {
 352                         CheckArgumentNotNull (other, "other");
 353
 354                         if (Count == 0) {
 355                                 foreach (T item in other)
 356                                         return true; // this idiom means: if 'other' is non-empty, return true
 357                                 return false;
 358                         }
 359
 360                         return is_subset_of (other, true);
 361                 }
 362
 363                 public bool IsProperSupersetOf (IEnumerable<T> other)
 364                 {
 365                         CheckArgumentNotNull (other, "other");
 366
 367                         if (Count == 0)
 368                                 return false;
 369
 370                         return is_superset_of (other, true);
 371                 }
 372
 373                 public bool IsSubsetOf (IEnumerable<T> other)
 374                 {
 375                         CheckArgumentNotNull (other, "other");
 376
 377                         if (Count == 0)
 378                                 return true;
 379
 380                         return is_subset_of (other, false);
 381                 }
 382
 383                 public bool IsSupersetOf (IEnumerable<T> other)
 384                 {
 385                         CheckArgumentNotNull (other, "other");
 386
 387                         if (Count == 0) {
 388                                 foreach (T item in other)
 389                                         return false; // this idiom means: if 'other' is non-empty, return false
 390                                 return true;
 391                         }
 392
 393                         return is_superset_of (other, false);
 394                 }
 395
 396                 // Precondition: Count != 0, other != null
 397                 bool is_subset_of (IEnumerable<T> other, bool proper)
 398                 {
 399                         SortedSet<T> that = nodups (other);
 400
 401                         if (Count > that.Count)
 402                                 return false;
 403                         // Count != 0 && Count <= that.Count => that.Count != 0
 404                         if (proper && Count == that.Count)
 405                                 return false;
 406                         return that.covers (this);
 407                 }
 408
 409                 // Precondition: Count != 0, other != null
 410                 bool is_superset_of (IEnumerable<T> other, bool proper)
 411                 {
 412                         SortedSet<T> that = nodups (other);
 413
 414                         if (that.Count == 0)
 415                                 return true;
 416                         if (Count < that.Count)
 417                                 return false;
 418                         if (proper && Count == that.Count)
 419                                 return false;
 420                         return this.covers (that);
 421                 }
 422
 423                 public bool Overlaps (IEnumerable<T> other)
 424                 {
 425                         CheckArgumentNotNull (other, "other");
 426
 427                         if (Count == 0)
 428                                 return false;
 429
 430                         // Don't use 'nodups' here.  Only optimize the SortedSet<T> case
 431                         SortedSet<T> that = other as SortedSet<T>;
 432                         if (that != null && that.Comparer != Comparer)
 433                                 that = null;
 434
 435                         if (that != null)
 436                                 return that.Count != 0 && overlaps (that);
 437
 438                         foreach (T item in other)
 439                                 if (Contains (item))
 440                                         return true;
 441                         return false;
 442                 }
 443
 444                 public bool SetEquals (IEnumerable<T> other)
 445                 {
 446                         CheckArgumentNotNull (other, "other");
 447
 448                         if (Count == 0) {
 449                                 foreach (T item in other)
 450                                         return false;
 451                                 return true;
 452                         }
 453
 454                         SortedSet<T> that = nodups (other);
 455
 456                         if (Count != that.Count)
 457                                 return false;
 458
 459                         using (var t = that.GetEnumerator ()) {
 460                                 foreach (T item in this) {
 461                                         if (!t.MoveNext ())
 462                                                 throw new SystemException ("count wrong somewhere: this longer than that");
 463                                         if (Comparer.Compare (item, t.Current) != 0)
 464                                                 return false;
 465                                 }
 466                                 if (t.MoveNext ())
 467                                         throw new SystemException ("count wrong somewhere: this shorter than that");
 468                                 return true;
 469                         }
 470                 }
 471
 472                 SortedSet<T> nodups (IEnumerable<T> other)
 473                 {
 474                         SortedSet<T> that = other as SortedSet<T>;
 475                         if (that != null && that.Comparer == Comparer)
 476                                 return that;
 477                         return new SortedSet<T> (other, Comparer);
 478                 }
 479
 480                 bool covers (SortedSet<T> that)
 481                 {
 482                         using (var t = that.GetEnumerator ()) {
 483                                 if (!t.MoveNext ())
 484                                         return true;
 485                                 foreach (T item in this) {
 486                                         int cmp = Comparer.Compare (item, t.Current);
 487                                         if (cmp > 0)
 488                                                 return false;
 489                                         if (cmp == 0 && !t.MoveNext ())
 490                                                 return true;
 491                                 }
 492                                 return false;
 493                         }
 494                 }
 495
 496                 bool overlaps (SortedSet<T> that)
 497                 {
 498                         using (var t = that.GetEnumerator ()) {
 499                                 if (!t.MoveNext ())
 500                                         return false;
 501                                 foreach (T item in this) {
 502                                         int cmp;
 503                                         while ((cmp = Comparer.Compare (item, t.Current)) > 0) {
 504                                                 if (!t.MoveNext ())
 505                                                         return false;
 506                                         }
 507                                         if (cmp == 0)
 508                                                 return true;
 509                                 }
 510                                 return false;
 511                         }
 512                 }
 513
 514                 [MonoLimitation ("Isn't O(n) when other is SortedSet<T>")]
 515                 public void SymmetricExceptWith (IEnumerable<T> other)
 516                 {
 517                         SortedSet<T> that_minus_this = new SortedSet<T> (Comparer);
 518
 519                         // compute this - that and that - this in parallel
 520                         foreach (T item in nodups (other))
 521                                 if (!Remove (item))
 522                                         that_minus_this.Add (item);
 523
 524                         UnionWith (that_minus_this);
 525                 }
 526
 527                 [MonoLimitation ("Isn't O(n) when other is SortedSet<T>")]
 528                 public void UnionWith (IEnumerable<T> other)
 529                 {
 530                         CheckArgumentNotNull (other, "other");
 531
 532                         foreach (T item in other)
 533                                 Add (item);
 534                 }
 535
 536                 static void CheckArgumentNotNull (object arg, string name)
 537                 {
 538                         if (arg == null)
 539                                 throw new ArgumentNullException (name);
 540                 }
 541
 542                 void ICollection<T>.Add (T item)
 543                 {
 544                         Add (item);
 545                 }
 546
 547                 void ICollection<T>.CopyTo (T [] array, int index)
 548                 {
 549                         CopyTo (array, index, Count);
 550                 }
 551
 552                 bool ICollection<T>.IsReadOnly {
 553                         get { return false; }
 554                 }
 555
 556                 void ICollection.CopyTo (Array array, int index)
 557                 {
 558                         if (Count == 0)
 559                                 return;
 560                         if (array == null)
 561                                 throw new ArgumentNullException ("array");
 562                         if (index < 0 || array.Length <= index)
 563                                 throw new ArgumentOutOfRangeException ("index");
 564                         if (array.Length - index < Count)
 565                                 throw new ArgumentException ();
 566
 567                         foreach (Node node in tree)
 568                                 array.SetValue (node.item, index++);
 569                 }
 570
 571                 bool ICollection.IsSynchronized {
 572                         get { return false; }
 573                 }
 574
 575                 // TODO:Is this correct? If this is wrong,please fix.
 576                 object ICollection.SyncRoot {
 577                         get { return this; }
 578                 }
 579
 580                 [Serializable]
 581                 public struct Enumerator : IEnumerator<T>, IDisposable {
 582
 583                         RBTree.NodeEnumerator host;
 584
 585                         IComparer<T> comparer;
 586
 587                         T current;
 588                         T upper;
 589
 590                         internal Enumerator (SortedSet<T> set)
 591                                 : this ()
 592                         {
 593                                 host = set.tree.GetEnumerator ();
 594                         }
 595
 596                         internal Enumerator (SortedSet<T> set, T lower, T upper)
 597                                 : this ()
 598                         {
 599                                 host = set.tree.GetSuffixEnumerator (lower);
 600                                 comparer = set.Comparer;
 601                                 this.upper = upper;
 602                         }
 603
 604                         public T Current {
 605                                 get { return current; }
 606                         }
 607
 608                         object IEnumerator.Current {
 609                                 get {
 610                                         host.check_current ();
 611                                         return ((Node) host.Current).item;
 612                                 }
 613                         }
 614
 615                         public bool MoveNext ()
 616                         {
 617                                 if (!host.MoveNext ())
 618                                         return false;
 619
 620                                 current = ((Node) host.Current).item;
 621                                 return comparer == null || comparer.Compare (upper, current) >= 0;
 622                         }
 623
 624                         public void Dispose ()
 625                         {
 626                                 host.Dispose ();
 627                         }
 628
 629                         void IEnumerator.Reset ()
 630                         {
 631                                 host.Reset ();
 632                         }
 633                 }
 634
 635                 [Serializable]
 636                 sealed class SortedSubSet : SortedSet<T>, IEnumerable<T>, IEnumerable {
 637
 638                         SortedSet<T> set;
 639                         T lower;
 640                         T upper;
 641
 642                         public SortedSubSet (SortedSet<T> set, T lower, T upper)
 643                                 : base (set.Comparer)
 644                         {
 645                                 this.set = set;
 646                                 this.lower = lower;
 647                                 this.upper = upper;
 648
 649                         }
 650
 651                         internal override T GetMin ()
 652                         {
 653                                 RBTree.Node lb = null, ub = null;
 654                                 set.tree.Bound (lower, ref lb, ref ub);
 655
 656                                 if (ub == null || set.helper.Compare (upper, ub) < 0)
 657                                         return default (T);
 658
 659                                 return ((Node) ub).item;
 660                         }
 661
 662                         internal override T GetMax ()
 663                         {
 664                                 RBTree.Node lb = null, ub = null;
 665                                 set.tree.Bound (upper, ref lb, ref ub);
 666
 667                                 if (lb == null || set.helper.Compare (lower, lb) > 0)
 668                                         return default (T);
 669
 670                                 return ((Node) lb).item;
 671                         }
 672
 673                         internal override int GetCount ()
 674                         {
 675                                 int count = 0;
 676                                 using (var e = set.tree.GetSuffixEnumerator (lower)) {
 677                                         while (e.MoveNext () && set.helper.Compare (upper, e.Current) >= 0)
 678                                                 ++count;
 679                                 }
 680                                 return count;
 681                         }
 682
 683                         internal override bool TryAdd (T item)
 684                         {
 685                                 if (!InRange (item))
 686                                         throw new ArgumentOutOfRangeException ("item");
 687
 688                                 return set.TryAdd (item);
 689                         }
 690
 691                         internal override bool TryRemove (T item)
 692                         {
 693                                 if (!InRange (item))
 694                                         return false;
 695
 696                                 return set.TryRemove (item);
 697                         }
 698
 699                         public override bool Contains (T item)
 700                         {
 701                                 if (!InRange (item))
 702                                         return false;
 703
 704                                 return set.Contains (item);
 705                         }
 706
 707                         public override void Clear ()
 708                         {
 709                                 set.RemoveWhere (InRange);
 710                         }
 711
 712                         bool InRange (T item)
 713                         {
 714                                 return Comparer.Compare (item, lower) >= 0
 715                                         && Comparer.Compare (item, upper) <= 0;
 716                         }
 717
 718                         public override SortedSet<T> GetViewBetween (T lowerValue, T upperValue)
 719                         {
 720                                 if (Comparer.Compare (lowerValue, upperValue) > 0)
 721                                         throw new ArgumentException ("The lowerValue is bigger than upperValue");
 722                                 if (!InRange (lowerValue))
 723                                         throw new ArgumentOutOfRangeException ("lowerValue");
 724                                 if (!InRange (upperValue))
 725                                         throw new ArgumentOutOfRangeException ("upperValue");
 726
 727                                 return new SortedSubSet (set, lowerValue, upperValue);
 728                         }
 729
 730                         internal override Enumerator TryGetEnumerator ()
 731                         {
 732                                 return new Enumerator (set, lower, upper);
 733                         }
 734
 735                         public override void IntersectWith (IEnumerable<T> other)
 736                         {
 737                                 CheckArgumentNotNull (other, "other");
 738
 739                                 var slice = new SortedSet<T> (this);
 740                                 slice.IntersectWith (other);
 741
 742                                 Clear ();
 743                                 set.UnionWith (slice);
 744                         }
 745                 }
 746         }
 747 }
 748
 749 #endif