diff options
Diffstat (limited to 'Source/Core/GraphAlgorithms.cs')
| -rw-r--r-- | Source/Core/GraphAlgorithms.cs | 244 |
1 files changed, 0 insertions, 244 deletions
diff --git a/Source/Core/GraphAlgorithms.cs b/Source/Core/GraphAlgorithms.cs deleted file mode 100644 index a19cf96c..00000000 --- a/Source/Core/GraphAlgorithms.cs +++ /dev/null @@ -1,244 +0,0 @@ -//-----------------------------------------------------------------------------
-//
-// Copyright (C) Microsoft Corporation. All Rights Reserved.
-//
-//-----------------------------------------------------------------------------
-using System.Collections.Generic;
-using System.Diagnostics.Contracts;
-
-namespace Microsoft.Boogie {
- public delegate System.Collections.IEnumerable/*<Node!>*//*!*/ Adjacency<T>(T/*!*/ node);
-
-
- // An SCC is a set of nodes
- public sealed class SCC<Node> : ICollection<Node> {
- [ContractInvariantMethod]
- void ObjectInvariant() {
- Contract.Invariant(nodesMap != null);
- }
-
- private IDictionary<Node, object>/*!*/ nodesMap = new Dictionary<Node, object>();
- private ICollection<Node>/*!*/ nodes {
- get {
- return cce.NonNull(nodesMap.Keys);
- }
- }
-
- [Pure]
- [GlobalAccess(false)]
- [Escapes(true, false)]
- System.Collections.IEnumerator/*!*/ System.Collections.IEnumerable.GetEnumerator() {
- Contract.Ensures(Contract.Result<System.Collections.IEnumerator>() != null);
-
- return ((System.Collections.IEnumerable)nodes).GetEnumerator();
- }
-
- [Pure]
- [GlobalAccess(false)]
- [Escapes(true, false)]
- IEnumerator<Node>/*!*/ IEnumerable<Node>.GetEnumerator() {
- Contract.Ensures(Contract.Result<IEnumerator<Node>>() != null);
-
- return ((IEnumerable<Node>)nodes).GetEnumerator();
- }
-
- public int Count {
- get {
- return nodes.Count;
- }
- }
- public bool IsReadOnly {
- get {
- return nodesMap.IsReadOnly;
- }
- }
- public void Add(Node item) {
- nodesMap.Add(item, null);
- }
- public void Clear() {
- nodesMap.Clear();
- }
- [Pure]
- public bool Contains(Node item) {
- return nodesMap.ContainsKey(item);
- }
- public void CopyTo(Node[] array, int arrayIndex) {
- //Contract.Requires(array != null);
- nodes.CopyTo(array, arrayIndex);
- }
- public bool Remove(Node item) {
- return nodesMap.Remove(item);
- }
- }
-
- public sealed class StronglyConnectedComponents<Node> : IEnumerable<SCC<Node>/*!*/> where Node : class {
- private readonly IDictionary<Node/*!*/, object>/*!*/ graph;
- [ContractInvariantMethod]
- void graphInvariantMethod() {
- Contract.Invariant(Contract.ForAll(graph, entry => entry.Key != null));
- Contract.Invariant(preds != null);
- Contract.Invariant(succs != null);
- }
- private readonly Adjacency<Node>/*!*/ preds;
- private readonly Adjacency<Node>/*!*/ succs;
-
- private bool computed = false;
- public bool Computed {
- get {
- return computed;
- }
- }
-
- [NotDelayed]
- public StronglyConnectedComponents(System.Collections.IEnumerable/*<Node!>*/ graph, Adjacency<Node> preds, Adjacency<Node> succs)
- : base() {//BASEMOVE DANGER
- Contract.Requires(succs != null);
- Contract.Requires(preds != null);
- Contract.Requires(graph != null);
- Contract.Ensures(!Computed);
- IDictionary<Node/*!*/, object>/*!*/ dict = new Dictionary<Node/*!*/, object>();
- foreach (Node/*!*/ n in graph) {
- Contract.Assert(n != null);
- dict.Add(n, null);
- }
-
- this.graph = dict;
- this.preds = preds;
- this.succs = succs;
- //:base();
- }
-
- [Pure]
- [GlobalAccess(false)]
- [Escapes(true, false)]
- System.Collections.IEnumerator/*!*/ System.Collections.IEnumerable.GetEnumerator() {
- Contract.Ensures(Contract.Result<System.Collections.IEnumerator>() != null);
-
- return ((System.Collections.IEnumerable)sccs).GetEnumerator();
- }
-
- [Pure]
- [GlobalAccess(false)]
- [Escapes(true, false)]
- IEnumerator<SCC<Node>/*!*/>/*!*/ IEnumerable<SCC<Node>/*!*/>.GetEnumerator() {
- Contract.Ensures(Contract.Result<IEnumerator<SCC<Node>>>() != null);
-
- Contract.Assume(Computed);
- Contract.Assert(cce.NonNullElements((IEnumerable<SCC<Node>/*!*/>)sccs));//REVIEW
- return ((IEnumerable<SCC<Node>/*!*/>)sccs).GetEnumerator();
- }
-
- private readonly IList<SCC<Node>/*!*/>/*!*/ sccs = new List<SCC<Node>/*!*/>();
- [ContractInvariantMethod]
- void sccsInvariant() {
- Contract.Invariant(cce.NonNullElements(sccs));
- }
-
-
- public void Compute() {
- Contract.Requires(!Computed);
- Contract.Ensures(Computed);
- // Compute post times on graph with edges reversed
- this.dfsNext = this.preds;
- foreach (Node/*!*/ n in cce.NonNull(graph.Keys)) {
- Contract.Assert(n != null);
- if (!seen.ContainsKey(n)) {
- OrderNodes(n);
- }
- }
-
- // Clear seen
- seen.Clear();
-
- // Compute SCCs
- this.dfsNext = this.succs;
- while (postOrder.Count > 0) {
- Node/*!*/ n = postOrder.Pop();
- Contract.Assert(n != null);
-
- if (!seen.ContainsKey(n)) {
- SCC<Node>/*!*/ curr = new SCC<Node>();
- FindSCCs(n, curr);
- sccs.Add(curr);
- }
- }
-
- // Clear seen
- seen.Clear();
-
- this.computed = true;
- }
-
- private Adjacency<Node>/*?*/ dfsNext = null;
-
- private readonly IDictionary<Node/*!*/, object>/*!*/ seen = new Dictionary<Node/*!*/, object>();
- private readonly Stack<Node/*!*/>/*!*/ postOrder = new Stack<Node/*!*/>();
- [ContractInvariantMethod]
- void ObjectInvariant() {
- Contract.Invariant(seen != null);
- Contract.Invariant(cce.NonNullElements(postOrder));
- }
-
-
- // DFS to order nodes by post times
- private void OrderNodes(Node node) {
- Contract.Requires(node != null);
- seen.Add(node, null);
-
- Contract.Assert(dfsNext != null);
- System.Collections.IEnumerable/*!*/ nexts = dfsNext(node);
- Contract.Assert(nexts != null);
- foreach (Node/*!*/ n in nexts) {
- Contract.Assert(n != null);
- if (graph.ContainsKey(n) && !seen.ContainsKey(n)) {
- OrderNodes(n);
- }
- }
-
- postOrder.Push(node);
- }
-
- // DFS to compute SCCs
- private void FindSCCs(Node node, SCC<Node> currSCC) {
- Contract.Requires(currSCC != null);
- Contract.Requires(node != null);
- //modifies currSCC.*;
- seen.Add(node, null);
- currSCC.Add(node);
-
- Contract.Assert(dfsNext != null);
- System.Collections.IEnumerable/*!*/ nexts = dfsNext(node);
- Contract.Assert(nexts != null);
- foreach (Node/*!*/ n in nexts) {
- Contract.Assert(n != null);
- if (graph.ContainsKey(n) && !seen.ContainsKey(n)) {
- FindSCCs(n, currSCC);
- }
- }
- }
-
- [Pure]
- public override string ToString() {
- Contract.Ensures(Contract.Result<string>() != null);
- string outStr = "";
- int i = 0;
-
- foreach (ICollection<Node> component in this) {
- string/*!*/ tmp = System.String.Format("\nComponent #{0} = ", i++);
- Contract.Assert(tmp != null);
- outStr += tmp;
-
- bool firstInRow = true;
-
- foreach (Node b in component) {
- string/*!*/ tmpComponent = System.String.Format("{0}{1}", firstInRow ? "" : ", ", b);
- Contract.Assert(tmpComponent != null);
- outStr += tmpComponent;
- firstInRow = false;
- }
- }
- return outStr;
- }
-
- }
-}
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