StateMachineHistory.cs source code in C# .NET

                        Code:
                         / WCF / WCF / 3.5.30729.1 / untmp / Orcas / SP / ndp / cdf / src / WCF / TransactionBridge / Microsoft / Transactions / Bridge / StateMachineHistory.cs / 1 / StateMachineHistory.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// Copyright (c) Microsoft Corporation.  All rights reserved.
//-----------------------------------------------------------------------------
using System;
using System.Collections.Generic; 
using System.Text;
using System.Xml; 
using System.Xml.Schema; 
using System.Xml.Serialization;
 

namespace Microsoft.Transactions.Bridge
{
    struct StringCount 
    {
        public StringCount (string name) 
        { 
            this.Name = name;
            this.Count = 1; 
        }

        public string Name;
        public int Count; 

        static StringCount nullCount = new StringCount (null); 
        public static StringCount Null 
        {
            get { return nullCount; } 
        }
    }

    // 
    // This class is implicitly single-threaded
    // 
    class StateMachineHistory : IXmlSerializable 
    {
        // The list contains a sequence of strings 
        // States are preceded by a null string, events follow a state
        List history = new List (30);

        string ReadState (ref int cursor) 
        {
            int entries = this.history.Count; 
            if (cursor >= entries) 
                return null;
 
            // If this slot has a name, it's not a state
            if (this.history[cursor].Name != null)
                return null;
 
            // We saw a null, so there must be a state name too
            cursor ++; 
            if (cursor >= entries) 
            {
                // The cursor should never advance pass the end of the list. 
                DiagnosticUtility.DebugAssert("The state machine history store is corrupt.");
            }

            return this.history[cursor ++].Name; 
        }
 
        StringCount ReadEvent (ref int cursor) 
        {
            if (cursor >= this.history.Count) 
                return StringCount.Null;

            // If this slot doesn't have a name, it's not an event
            if (this.history[cursor].Name == null) 
                return StringCount.Null;
 
            return this.history[cursor ++]; 
        }
 
        //
        // Public interface
        //
 
        public void AddState (string newState)
        { 
            this.history.Add (new StringCount (null)); 
            this.history.Add (new StringCount (newState));
        } 

        // An event should always arrive in the context of a state
        // It is an error to call the first AddEvent without having called AddStateChange
        public void AddEvent (string newEvent) 
        {
            int count = this.history.Count; 
            if (count > 0) 
            {
                StringCount lastEvent = this.history[count - 1]; 
                if (lastEvent.Name == newEvent)
                {
                    lastEvent.Count ++;
                    this.history[count - 1] = lastEvent; 
                    return;
                } 
            } 

            this.history.Add (new StringCount (newEvent)); 
        }

        /*
        Example: 
        [State1]
            {Event1} 
            {Event2} 
        [State2]
            {Event3} 
        [State3]
        */
        public override string ToString()
        { 
            int entries = this.history.Count;
            if (entries == 0) 
            { 
                return string.Empty;
            } 

            StringBuilder builder = new StringBuilder();

            int cursor = 0; 
            while (cursor < entries)
            { 
                // Read a state 
                string state = ReadState (ref cursor);
                if (state == null) 
                {
                    // The state should never be null.
                    DiagnosticUtility.DebugAssert("The state machine history store is corrupt.");
                } 

                builder.Append ("["); 
                builder.Append (state); 
                builder.AppendLine ("]");
 
                // Read the events that occurred on the state
                while (true)
                {
                    StringCount newEvent = ReadEvent (ref cursor); 
                    if (newEvent.Name == null)
                        break; 
 
                    for (int i = 0; i < newEvent.Count; i ++)
                    { 
                        builder.Append ("\t{");
                        builder.Append (newEvent.Name);
                        builder.AppendLine ("}");
                    } 
                }
            } 
 
            // We should have consumed all the entries
            if (cursor != entries) 
            {
                DiagnosticUtility.DebugAssert("The state machine history store is corrupt.");
            }
 
            return builder.ToString();
        } 
 
        //
        // IXmlSerializable 
        //

        XmlSchema IXmlSerializable.GetSchema()
        { 
            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new NotSupportedException());
        } 
 
        void IXmlSerializable.ReadXml (XmlReader reader)
        { 
            throw Microsoft.Transactions.Bridge.DiagnosticUtility.ExceptionUtility.ThrowHelperError(new NotSupportedException());
        }

        /* 
        Example:
             
                 
                
             
            
                
            
        */ 
        void IXmlSerializable.WriteXml (XmlWriter writer)
        { 
            // Open the envelope 
            writer.WriteStartElement ("StateMachineHistory");
 
            int cursor = 0, entries = this.history.Count;
            while (cursor < entries)
            {
                // Read a state 
                string state = ReadState (ref cursor);
                if (state == null) 
                { 
                    // The state should never be null.
                    DiagnosticUtility.DebugAssert("The state machine history store is corrupt."); 
                }

                writer.WriteStartElement ("state");
                writer.WriteAttributeString ("name", state); 

                // Read the events that occurred on the state 
                while (true) 
                {
                    StringCount newEvent = ReadEvent (ref cursor); 
                    if (newEvent.Name == null)
                        break;

                    for (int i = 0; i < newEvent.Count; i ++) 
                    {
                        writer.WriteStartElement ("event"); 
                        writer.WriteAttributeString ("name", newEvent.Name); 
                        writer.WriteEndElement();
                    } 
                }

                // Close the state element
                writer.WriteEndElement(); 
            }
 
            // Close the envelope 
            writer.WriteEndElement();
        } 
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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StateMachineHistory.cs source code in C# .NET

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