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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
#if DEBUG
using System.Collections.Generic;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.IO;
using System.Net;
namespace System.Text.RegularExpressions.Symbolic
{
internal sealed partial class SymbolicRegexMatcher<TSet>
{
/// <inheritdoc cref="Regex.SaveDGML(TextWriter, int)"/>
[ExcludeFromCodeCoverage(Justification = "Currently only used for testing")]
public override void SaveDGML(TextWriter writer, int maxLabelLength)
{
lock (this)
{
if (maxLabelLength < 0)
maxLabelLength = int.MaxValue;
Dictionary<(int Source, int Target), (TSet Rule, List<int> NfaTargets)> transitions = GatherTransitions(this);
writer.WriteLine("<?xml version=\"1.0\" encoding=\"utf-8\"?>");
writer.WriteLine("<DirectedGraph xmlns=\"http://schemas.microsoft.com/vs/2009/dgml\" ZoomLevel=\"1.5\" GraphDirection=\"TopToBottom\" >");
writer.WriteLine(" <Nodes>");
writer.WriteLine(" <Node Id=\"dfa\" Label=\" \" Group=\"Collapsed\" Category=\"DFA\" DFAInfo=\"{0}\" />", FormatInfo(this, transitions.Count));
writer.WriteLine(" <Node Id=\"dfainfo\" Category=\"DFAInfo\" Label=\"{0}\"/>", FormatInfo(this, transitions.Count));
foreach (MatchingState<TSet> state in _stateCache.Values)
{
string info = CharKind.DescribePrev(state.PrevCharKind);
string deriv = WebUtility.HtmlEncode(state.Node.ToString());
string nodeDgmlView = $"{(string.IsNullOrEmpty(info) ? info : $"Previous: {info} ")}{(string.IsNullOrEmpty(deriv) ? "()" : deriv)}";
writer.WriteLine(" <Node Id=\"{0}\" Label=\"{0}\" Category=\"State\" Group=\"Collapsed\" StateInfo=\"{1}\">", state.Id, nodeDgmlView);
if (_stateFlagsArray[state.Id].IsInitial())
{
writer.WriteLine(" <Category Ref=\"InitialState\" />");
}
if (state.Node.CanBeNullable)
{
writer.WriteLine(" <Category Ref=\"FinalState\" />");
}
writer.WriteLine(" </Node>");
writer.WriteLine(" <Node Id=\"{0}info\" Label=\"{1}\" Category=\"StateInfo\"/>", state.Id, nodeDgmlView);
}
writer.WriteLine(" </Nodes>");
writer.WriteLine(" <Links>");
foreach (MatchingState<TSet> initialState in GetInitialStates(this))
{
writer.WriteLine(" <Link Source=\"dfa\" Target=\"{0}\" Label=\"\" Category=\"StartTransition\" />", initialState.Id);
}
writer.WriteLine(" <Link Source=\"dfa\" Target=\"dfainfo\" Label=\"\" Category=\"Contains\" />");
foreach (KeyValuePair<(int Source, int Target), (TSet Rule, List<int> NfaTargets)> transition in transitions)
{
string label = DescribeLabel(transition.Value.Rule, _builder);
string info = "";
if (label.Length > maxLabelLength)
{
info = $"FullLabel = \"{label}\" ";
label = string.Concat(label.AsSpan(0, maxLabelLength), "..");
}
writer.WriteLine($" <Link Source=\"{transition.Key.Source}\" Target=\"{transition.Key.Target}\" Label=\"{label}\" Category=\"NonEpsilonTransition\" {info}/>");
// Render NFA transitions as labelless "epsilon" transitions (i.e. ones that don't consume a character)
// from the target of the DFA transition.
foreach (int nfaTarget in transition.Value.NfaTargets)
{
writer.WriteLine($" <Link Source=\"{transition.Key.Target}\" Target=\"{nfaTarget}\" Category=\"EpsilonTransition\"/>");
}
}
foreach (MatchingState<TSet> state in _stateCache.Values)
{
writer.WriteLine(" <Link Source=\"{0}\" Target=\"{0}info\" Category=\"Contains\" />", state.Id);
}
writer.WriteLine(" </Links>");
writer.WriteLine(" <Categories>");
writer.WriteLine(" <Category Id=\"DFA\" Label=\"DFA\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"EpsilonTransition\" Label=\"Epsilon transition\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"StartTransition\" Label=\"Initial transition\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"FinalLabel\" Label=\"Final transition\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"FinalState\" Label=\"Final\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"SinkState\" Label=\"Sink state\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"EpsilonState\" Label=\"Epsilon state\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"InitialState\" Label=\"Initial\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"NonEpsilonTransition\" Label=\"Nonepsilon transition\" IsTag=\"True\" />");
writer.WriteLine(" <Category Id=\"State\" Label=\"State\" IsTag=\"True\" />");
writer.WriteLine(" </Categories>");
writer.WriteLine(" <Styles>");
writer.WriteLine(" <Style TargetType=\"Node\" GroupLabel=\"InitialState\" ValueLabel=\"True\">");
writer.WriteLine(" <Condition Expression=\"HasCategory('InitialState')\" />");
writer.WriteLine(" <Setter Property=\"Background\" Value=\"lightblue\" />");
writer.WriteLine(" <Setter Property=\"MinWidth\" Value=\"0\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" <Style TargetType=\"Node\" GroupLabel=\"FinalState\" ValueLabel=\"True\">");
writer.WriteLine(" <Condition Expression=\"HasCategory('FinalState')\" />");
writer.WriteLine(" <Setter Property=\"Background\" Value=\"lightgreen\" />");
writer.WriteLine(" <Setter Property=\"StrokeThickness\" Value=\"4\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" <Style TargetType=\"Node\" GroupLabel=\"State\" ValueLabel=\"True\">");
writer.WriteLine(" <Condition Expression=\"HasCategory('State')\" />");
writer.WriteLine(" <Setter Property=\"Stroke\" Value=\"black\" />");
writer.WriteLine(" <Setter Property=\"Background\" Value=\"white\" />");
writer.WriteLine(" <Setter Property=\"MinWidth\" Value=\"0\" />");
writer.WriteLine(" <Setter Property=\"FontSize\" Value=\"12\" />");
writer.WriteLine(" <Setter Property=\"FontFamily\" Value=\"Arial\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" <Style TargetType=\"Link\" GroupLabel=\"NonEpsilonTransition\" ValueLabel=\"True\">");
writer.WriteLine(" <Condition Expression=\"HasCategory('NonEpsilonTransition')\" />");
writer.WriteLine(" <Setter Property=\"FontSize\" Value=\"18\" />");
writer.WriteLine(" <Setter Property=\"FontFamily\" Value=\"Arial\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" <Style TargetType=\"Link\" GroupLabel=\"StartTransition\" ValueLabel=\"True\">");
writer.WriteLine(" <Condition Expression=\"HasCategory('StartTransition')\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" <Style TargetType=\"Link\" GroupLabel=\"EpsilonTransition\" ValueLabel=\"True\">");
writer.WriteLine(" <Condition Expression=\"HasCategory('EpsilonTransition')\" />");
writer.WriteLine(" <Setter Property=\"StrokeDashArray\" Value=\"8 8\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" <Style TargetType=\"Link\" GroupLabel=\"FinalLabel\" ValueLabel=\"False\">");
writer.WriteLine(" <Condition Expression=\"HasCategory('FinalLabel')\" />");
writer.WriteLine(" <Setter Property=\"StrokeDashArray\" Value=\"8 8\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" <Style TargetType=\"Node\" GroupLabel=\"StateInfo\" ValueLabel=\"True\">");
writer.WriteLine(" <Setter Property=\"Stroke\" Value=\"white\" />");
writer.WriteLine(" <Setter Property=\"FontSize\" Value=\"18\" />");
writer.WriteLine(" <Setter Property=\"FontFamily\" Value=\"Arial\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" <Style TargetType=\"Node\" GroupLabel=\"DFAInfo\" ValueLabel=\"True\">");
writer.WriteLine(" <Setter Property=\"Stroke\" Value=\"white\" />");
writer.WriteLine(" <Setter Property=\"FontSize\" Value=\"18\" />");
writer.WriteLine(" <Setter Property=\"FontFamily\" Value=\"Arial\" />");
writer.WriteLine(" </Style>");
writer.WriteLine(" </Styles>");
writer.WriteLine("</DirectedGraph>");
}
// This function gathers all transitions in the given builder and groups them by (source,destination) state ID
static Dictionary<(int Source, int Target), (TSet Rule, List<int> NfaTargets)> GatherTransitions(SymbolicRegexMatcher<TSet> matcher)
{
Dictionary<(int Source, int Target), (TSet Rule, List<int> NfaTargets)> result = new();
foreach (MatchingState<TSet> source in matcher._stateCache.Values)
{
// Get the span of entries in delta that gives the transitions for the different minterms
Span<int> deltas = matcher.GetDeltasFor(source);
Span<int[]?> nfaDeltas = matcher.GetNfaDeltasFor(source);
Debug.Assert(deltas.Length == matcher._minterms.Length);
for (int i = 0; i < deltas.Length; ++i)
{
// negative entries are transitions not explored yet, so skip them
int targetId = deltas[i];
if (targetId >= 0)
{
// Get or create the data for this (source,destination) state ID pair
(int Source, int Target) key = (source.Id, targetId);
if (!result.TryGetValue(key, out (TSet Rule, List<int> NfaTargets) entry))
{
entry = (matcher.Solver.Empty, new List<int>());
}
// If this state has an NFA transition for the same minterm, then associate
// those with the transition.
if (nfaDeltas.Length > 0 && nfaDeltas[i] is int[] nfaTargets)
{
foreach (int nfaTarget in nfaTargets)
{
entry.NfaTargets.Add(matcher._nfaCoreIdArray[nfaTarget]);
}
}
// Expand the rule for this minterm
result[key] = (matcher.Solver.Or(entry.Rule, matcher._minterms[i]), entry.NfaTargets);
}
}
}
return result;
}
static string FormatInfo(SymbolicRegexMatcher<TSet> matcher, int transitionCount)
{
StringBuilder sb = new();
sb.Append($"States = {matcher._stateCache.Count} ");
sb.Append($"Transitions = {transitionCount} ");
sb.Append($"Min Terms ({matcher.Solver.GetMinterms()!.Length}) = ").AppendJoin(',',
DescribeLabels(matcher.Solver.GetMinterms()!, matcher._builder));
return sb.ToString();
}
static IEnumerable<string> DescribeLabels(IEnumerable<TSet> labels, SymbolicRegexBuilder<TSet> builder)
{
foreach (TSet label in labels)
{
yield return DescribeLabel(label, builder);
}
}
static string DescribeLabel(TSet label, SymbolicRegexBuilder<TSet> builder) =>
WebUtility.HtmlEncode(builder._solver.PrettyPrint(label, builder._charSetSolver));
static IEnumerable<MatchingState<TSet>> GetInitialStates(SymbolicRegexMatcher<TSet> matcher)
{
foreach (MatchingState<TSet> state in matcher._dotstarredInitialStates)
yield return state;
foreach (MatchingState<TSet> state in matcher._initialStates)
yield return state;
foreach (MatchingState<TSet> state in matcher._reverseInitialStates)
yield return state;
}
}
}
}
#endif
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