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Created November 11, 2011 16:13
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A quick hack notes.ini file watcher (with diff) running in a console app
using System;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.IO;
using System.Threading;
namespace my.utils
{
using System;
using System.Collections;
using System.Text;
using System.Text.RegularExpressions;
/// <summary>
/// This Class implements the Difference Algorithm published in
/// "An O(ND) Difference Algorithm and its Variations" by Eugene Myers
/// Algorithmica Vol. 1 No. 2, 1986, p 251.
///
/// There are many C, Java, Lisp implementations public available but they all seem to come
/// from the same source (diffutils) that is under the (unfree) GNU public License
/// and cannot be reused as a sourcecode for a commercial application.
/// There are very old C implementations that use other (worse) algorithms.
/// Microsoft also published sourcecode of a diff-tool (windiff) that uses some tree data.
/// Also, a direct transfer from a C source to C# is not easy because there is a lot of pointer
/// arithmetic in the typical C solutions and i need a managed solution.
/// These are the reasons why I implemented the original published algorithm from the scratch and
/// make it avaliable without the GNU license limitations.
/// I do not need a high performance diff tool because it is used only sometimes.
/// I will do some performace tweaking when needed.
///
/// The algorithm itself is comparing 2 arrays of numbers so when comparing 2 text documents
/// each line is converted into a (hash) number. See DiffText().
///
/// Some chages to the original algorithm:
/// The original algorithm was described using a recursive approach and comparing zero indexed arrays.
/// Extracting sub-arrays and rejoining them is very performance and memory intensive so the same
/// (readonly) data arrays are passed arround together with their lower and upper bounds.
/// This circumstance makes the LCS and SMS functions more complicate.
/// I added some code to the LCS function to get a fast response on sub-arrays that are identical,
/// completely deleted or inserted.
///
/// The result from a comparisation is stored in 2 arrays that flag for modified (deleted or inserted)
/// lines in the 2 data arrays. These bits are then analysed to produce a array of Item objects.
///
/// Further possible optimizations:
/// (first rule: don't do it; second: don't do it yet)
/// The arrays DataA and DataB are passed as parameters, but are never changed after the creation
/// so they can be members of the class to avoid the paramter overhead.
/// In SMS is a lot of boundary arithmetic in the for-D and for-k loops that can be done by increment
/// and decrement of local variables.
/// The DownVector and UpVector arrays are alywas created and destroyed each time the SMS gets called.
/// It is possible to reuse tehm when transfering them to members of the class.
/// See TODO: hints.
///
/// diff.cs: A port of the algorythm to C#
/// Copyright (c) by Matthias Hertel, http://www.mathertel.de
/// This work is licensed under a BSD style license. See http://www.mathertel.de/License.aspx
///
/// Changes:
/// 2002.09.20 There was a "hang" in some situations.
/// Now I undestand a little bit more of the SMS algorithm.
/// There have been overlapping boxes; that where analyzed partial differently.
/// One return-point is enough.
/// A assertion was added in CreateDiffs when in debug-mode, that counts the number of equal (no modified) lines in both arrays.
/// They must be identical.
///
/// 2003.02.07 Out of bounds error in the Up/Down vector arrays in some situations.
/// The two vetors are now accessed using different offsets that are adjusted using the start k-Line.
/// A test case is added.
///
/// 2006.03.05 Some documentation and a direct Diff entry point.
///
/// 2006.03.08 Refactored the API to static methods on the Diff class to make usage simpler.
/// 2006.03.10 using the standard Debug class for self-test now.
/// compile with: csc /target:exe /out:diffTest.exe /d:DEBUG /d:TRACE /d:SELFTEST Diff.cs
/// 2007.01.06 license agreement changed to a BSD style license.
/// 2007.06.03 added the Optimize method.
/// 2007.09.23 UpVector and DownVector optimization by Jan Stoklasa ().
/// 2008.05.31 Adjusted the testing code that failed because of the Optimize method (not a bug in the diff algorithm).
/// 2008.10.08 Fixing a test case and adding a new test case.
/// </summary>
public class Diff
{
/// <summary>details of one difference.</summary>
public struct Item
{
/// <summary>Start Line number in Data A.</summary>
public int StartA;
/// <summary>Start Line number in Data B.</summary>
public int StartB;
/// <summary>Number of changes in Data A.</summary>
public int deletedA;
/// <summary>Number of changes in Data B.</summary>
public int insertedB;
} // Item
/// <summary>
/// Shortest Middle Snake Return Data
/// </summary>
private struct SMSRD
{
internal int x, y;
// internal int u, v; // 2002.09.20: no need for 2 points
}
#region self-Test
#if (SELFTEST)
/// <summary>
/// start a self- / box-test for some diff cases and report to the debug output.
/// </summary>
/// <param name="args">not used</param>
/// <returns>always 0</returns>
public static int Main(string[] args) {
StringBuilder ret = new StringBuilder();
string a, b;
System.Diagnostics.ConsoleTraceListener ctl = new System.Diagnostics.ConsoleTraceListener(false);
System.Diagnostics.Debug.Listeners.Add(ctl);
System.Console.WriteLine("Diff Self Test...");
// test all changes
a = "a,b,c,d,e,f,g,h,i,j,k,l".Replace(',', '\n');
b = "0,1,2,3,4,5,6,7,8,9".Replace(',', '\n');
System.Diagnostics.Debug.Assert(TestHelper(Diff.DiffText(a, b, false, false, false))
== "12.10.0.0*",
"all-changes test failed.");
System.Diagnostics.Debug.WriteLine("all-changes test passed.");
// test all same
a = "a,b,c,d,e,f,g,h,i,j,k,l".Replace(',', '\n');
b = a;
System.Diagnostics.Debug.Assert(TestHelper(Diff.DiffText(a, b, false, false, false))
== "",
"all-same test failed.");
System.Diagnostics.Debug.WriteLine("all-same test passed.");
// test snake
a = "a,b,c,d,e,f".Replace(',', '\n');
b = "b,c,d,e,f,x".Replace(',', '\n');
System.Diagnostics.Debug.Assert(TestHelper(Diff.DiffText(a, b, false, false, false))
== "1.0.0.0*0.1.6.5*",
"snake test failed.");
System.Diagnostics.Debug.WriteLine("snake test passed.");
// 2002.09.20 - repro
a = "c1,a,c2,b,c,d,e,g,h,i,j,c3,k,l".Replace(',', '\n');
b = "C1,a,C2,b,c,d,e,I1,e,g,h,i,j,C3,k,I2,l".Replace(',', '\n');
System.Diagnostics.Debug.Assert(TestHelper(Diff.DiffText(a, b, false, false, false))
== "1.1.0.0*1.1.2.2*0.2.7.7*1.1.11.13*0.1.13.15*",
"repro20020920 test failed.");
System.Diagnostics.Debug.WriteLine("repro20020920 test passed.");
// 2003.02.07 - repro
a = "F".Replace(',', '\n');
b = "0,F,1,2,3,4,5,6,7".Replace(',', '\n');
System.Diagnostics.Debug.Assert(TestHelper(Diff.DiffText(a, b, false, false, false))
== "0.1.0.0*0.7.1.2*",
"repro20030207 test failed.");
System.Diagnostics.Debug.WriteLine("repro20030207 test passed.");
// Muegel - repro
a = "HELLO\nWORLD";
b = "\n\nhello\n\n\n\nworld\n";
System.Diagnostics.Debug.Assert(TestHelper(Diff.DiffText(a, b, false, false, false))
== "2.8.0.0*",
"repro20030409 test failed.");
System.Diagnostics.Debug.WriteLine("repro20030409 test passed.");
// test some differences
a = "a,b,-,c,d,e,f,f".Replace(',', '\n');
b = "a,b,x,c,e,f".Replace(',', '\n');
System.Diagnostics.Debug.Assert(TestHelper(Diff.DiffText(a, b, false, false, false))
== "1.1.2.2*1.0.4.4*1.0.7.6*",
"some-changes test failed.");
System.Diagnostics.Debug.WriteLine("some-changes test passed.");
// test one change within long chain of repeats
a = "a,a,a,a,a,a,a,a,a,a".Replace(',', '\n');
b = "a,a,a,a,-,a,a,a,a,a".Replace(',', '\n');
System.Diagnostics.Debug.Assert(TestHelper(Diff.DiffText(a, b, false, false, false))
== "0.1.4.4*1.0.9.10*",
"long chain of repeats test failed.");
System.Diagnostics.Debug.WriteLine("End.");
System.Diagnostics.Debug.Flush();
return (0);
}
public static string TestHelper(Item []f) {
StringBuilder ret = new StringBuilder();
for (int n = 0; n < f.Length; n++) {
ret.Append(f[n].deletedA.ToString() + "." + f[n].insertedB.ToString() + "." + f[n].StartA.ToString() + "." + f[n].StartB.ToString() + "*");
}
// Debug.Write(5, "TestHelper", ret.ToString());
return (ret.ToString());
}
#endif
#endregion
/// <summary>
/// Find the difference in 2 texts, comparing by textlines.
/// </summary>
/// <param name="TextA">A-version of the text (usualy the old one)</param>
/// <param name="TextB">B-version of the text (usualy the new one)</param>
/// <returns>Returns a array of Items that describe the differences.</returns>
public Item[] DiffText(string TextA, string TextB) {
return (DiffText(TextA, TextB, false, false, false));
} // DiffText
/// <summary>
/// Find the difference in 2 text documents, comparing by textlines.
/// The algorithm itself is comparing 2 arrays of numbers so when comparing 2 text documents
/// each line is converted into a (hash) number. This hash-value is computed by storing all
/// textlines into a common hashtable so i can find dublicates in there, and generating a
/// new number each time a new textline is inserted.
/// </summary>
/// <param name="TextA">A-version of the text (usualy the old one)</param>
/// <param name="TextB">B-version of the text (usualy the new one)</param>
/// <param name="trimSpace">When set to true, all leading and trailing whitespace characters are stripped out before the comparation is done.</param>
/// <param name="ignoreSpace">When set to true, all whitespace characters are converted to a single space character before the comparation is done.</param>
/// <param name="ignoreCase">When set to true, all characters are converted to their lowercase equivivalence before the comparation is done.</param>
/// <returns>Returns a array of Items that describe the differences.</returns>
public static Item[] DiffText(string TextA, string TextB, bool trimSpace, bool ignoreSpace, bool ignoreCase) {
// prepare the input-text and convert to comparable numbers.
Hashtable h = new Hashtable(TextA.Length + TextB.Length);
// The A-Version of the data (original data) to be compared.
DiffData DataA = new DiffData(DiffCodes(TextA, h, trimSpace, ignoreSpace, ignoreCase));
// The B-Version of the data (modified data) to be compared.
DiffData DataB = new DiffData(DiffCodes(TextB, h, trimSpace, ignoreSpace, ignoreCase));
h = null; // free up hashtable memory (maybe)
int MAX = DataA.Length + DataB.Length + 1;
/// vector for the (0,0) to (x,y) search
int[] DownVector = new int[2 * MAX + 2];
/// vector for the (u,v) to (N,M) search
int[] UpVector = new int[2 * MAX + 2];
LCS(DataA, 0, DataA.Length, DataB, 0, DataB.Length, DownVector, UpVector);
Optimize(DataA);
Optimize(DataB);
return CreateDiffs(DataA, DataB);
} // DiffText
/// <summary>
/// If a sequence of modified lines starts with a line that contains the same content
/// as the line that appends the changes, the difference sequence is modified so that the
/// appended line and not the starting line is marked as modified.
/// This leads to more readable diff sequences when comparing text files.
/// </summary>
/// <param name="Data">A Diff data buffer containing the identified changes.</param>
private static void Optimize(DiffData Data) {
int StartPos, EndPos;
StartPos = 0;
while (StartPos < Data.Length) {
while ((StartPos < Data.Length) && (Data.modified[StartPos] == false))
StartPos++;
EndPos = StartPos;
while ((EndPos < Data.Length) && (Data.modified[EndPos] == true))
EndPos++;
if ((EndPos < Data.Length) && (Data.data[StartPos] == Data.data[EndPos])) {
Data.modified[StartPos] = false;
Data.modified[EndPos] = true;
} else {
StartPos = EndPos;
} // if
} // while
} // Optimize
/// <summary>
/// Find the difference in 2 arrays of integers.
/// </summary>
/// <param name="ArrayA">A-version of the numbers (usualy the old one)</param>
/// <param name="ArrayB">B-version of the numbers (usualy the new one)</param>
/// <returns>Returns a array of Items that describe the differences.</returns>
public static Item[] DiffInt(int[] ArrayA, int[] ArrayB) {
// The A-Version of the data (original data) to be compared.
DiffData DataA = new DiffData(ArrayA);
// The B-Version of the data (modified data) to be compared.
DiffData DataB = new DiffData(ArrayB);
int MAX = DataA.Length + DataB.Length + 1;
/// vector for the (0,0) to (x,y) search
int[] DownVector = new int[2 * MAX + 2];
/// vector for the (u,v) to (N,M) search
int[] UpVector = new int[2 * MAX + 2];
LCS(DataA, 0, DataA.Length, DataB, 0, DataB.Length, DownVector, UpVector);
return CreateDiffs(DataA, DataB);
} // Diff
/// <summary>
/// This function converts all textlines of the text into unique numbers for every unique textline
/// so further work can work only with simple numbers.
/// </summary>
/// <param name="aText">the input text</param>
/// <param name="h">This extern initialized hashtable is used for storing all ever used textlines.</param>
/// <param name="trimSpace">ignore leading and trailing space characters</param>
/// <returns>a array of integers.</returns>
private static int[] DiffCodes(string aText, Hashtable h, bool trimSpace, bool ignoreSpace, bool ignoreCase) {
// get all codes of the text
string[] Lines;
int[] Codes;
int lastUsedCode = h.Count;
object aCode;
string s;
// strip off all cr, only use lf as textline separator.
aText = aText.Replace("\r", "");
Lines = aText.Split('\n');
Codes = new int[Lines.Length];
for (int i = 0; i < Lines.Length; ++i) {
s = Lines[i];
if (trimSpace)
s = s.Trim();
if (ignoreSpace) {
s = Regex.Replace(s, "\\s+", " "); // TODO: optimization: faster blank removal.
}
if (ignoreCase)
s = s.ToLower();
aCode = h[s];
if (aCode == null) {
lastUsedCode++;
h[s] = lastUsedCode;
Codes[i] = lastUsedCode;
} else {
Codes[i] = (int)aCode;
} // if
} // for
return (Codes);
} // DiffCodes
/// <summary>
/// This is the algorithm to find the Shortest Middle Snake (SMS).
/// </summary>
/// <param name="DataA">sequence A</param>
/// <param name="LowerA">lower bound of the actual range in DataA</param>
/// <param name="UpperA">upper bound of the actual range in DataA (exclusive)</param>
/// <param name="DataB">sequence B</param>
/// <param name="LowerB">lower bound of the actual range in DataB</param>
/// <param name="UpperB">upper bound of the actual range in DataB (exclusive)</param>
/// <param name="DownVector">a vector for the (0,0) to (x,y) search. Passed as a parameter for speed reasons.</param>
/// <param name="UpVector">a vector for the (u,v) to (N,M) search. Passed as a parameter for speed reasons.</param>
/// <returns>a MiddleSnakeData record containing x,y and u,v</returns>
private static SMSRD SMS(DiffData DataA, int LowerA, int UpperA, DiffData DataB, int LowerB, int UpperB,
int[] DownVector, int[] UpVector) {
SMSRD ret;
int MAX = DataA.Length + DataB.Length + 1;
int DownK = LowerA - LowerB; // the k-line to start the forward search
int UpK = UpperA - UpperB; // the k-line to start the reverse search
int Delta = (UpperA - LowerA) - (UpperB - LowerB);
bool oddDelta = (Delta & 1) != 0;
// The vectors in the publication accepts negative indexes. the vectors implemented here are 0-based
// and are access using a specific offset: UpOffset UpVector and DownOffset for DownVektor
int DownOffset = MAX - DownK;
int UpOffset = MAX - UpK;
int MaxD = ((UpperA - LowerA + UpperB - LowerB) / 2) + 1;
// Debug.Write(2, "SMS", String.Format("Search the box: A[{0}-{1}] to B[{2}-{3}]", LowerA, UpperA, LowerB, UpperB));
// init vectors
DownVector[DownOffset + DownK + 1] = LowerA;
UpVector[UpOffset + UpK - 1] = UpperA;
for (int D = 0; D <= MaxD; D++) {
// Extend the forward path.
for (int k = DownK - D; k <= DownK + D; k += 2) {
// Debug.Write(0, "SMS", "extend forward path " + k.ToString());
// find the only or better starting point
int x, y;
if (k == DownK - D) {
x = DownVector[DownOffset + k + 1]; // down
} else {
x = DownVector[DownOffset + k - 1] + 1; // a step to the right
if ((k < DownK + D) && (DownVector[DownOffset + k + 1] >= x))
x = DownVector[DownOffset + k + 1]; // down
}
y = x - k;
// find the end of the furthest reaching forward D-path in diagonal k.
while ((x < UpperA) && (y < UpperB) && (DataA.data[x] == DataB.data[y])) {
x++; y++;
}
DownVector[DownOffset + k] = x;
// overlap ?
if (oddDelta && (UpK - D < k) && (k < UpK + D)) {
if (UpVector[UpOffset + k] <= DownVector[DownOffset + k]) {
ret.x = DownVector[DownOffset + k];
ret.y = DownVector[DownOffset + k] - k;
// ret.u = UpVector[UpOffset + k]; // 2002.09.20: no need for 2 points
// ret.v = UpVector[UpOffset + k] - k;
return (ret);
} // if
} // if
} // for k
// Extend the reverse path.
for (int k = UpK - D; k <= UpK + D; k += 2) {
// Debug.Write(0, "SMS", "extend reverse path " + k.ToString());
// find the only or better starting point
int x, y;
if (k == UpK + D) {
x = UpVector[UpOffset + k - 1]; // up
} else {
x = UpVector[UpOffset + k + 1] - 1; // left
if ((k > UpK - D) && (UpVector[UpOffset + k - 1] < x))
x = UpVector[UpOffset + k - 1]; // up
} // if
y = x - k;
while ((x > LowerA) && (y > LowerB) && (DataA.data[x - 1] == DataB.data[y - 1])) {
x--; y--; // diagonal
}
UpVector[UpOffset + k] = x;
// overlap ?
if (!oddDelta && (DownK - D <= k) && (k <= DownK + D)) {
if (UpVector[UpOffset + k] <= DownVector[DownOffset + k]) {
ret.x = DownVector[DownOffset + k];
ret.y = DownVector[DownOffset + k] - k;
// ret.u = UpVector[UpOffset + k]; // 2002.09.20: no need for 2 points
// ret.v = UpVector[UpOffset + k] - k;
return (ret);
} // if
} // if
} // for k
} // for D
throw new ApplicationException("the algorithm should never come here.");
} // SMS
/// <summary>
/// This is the divide-and-conquer implementation of the longes common-subsequence (LCS)
/// algorithm.
/// The published algorithm passes recursively parts of the A and B sequences.
/// To avoid copying these arrays the lower and upper bounds are passed while the sequences stay constant.
/// </summary>
/// <param name="DataA">sequence A</param>
/// <param name="LowerA">lower bound of the actual range in DataA</param>
/// <param name="UpperA">upper bound of the actual range in DataA (exclusive)</param>
/// <param name="DataB">sequence B</param>
/// <param name="LowerB">lower bound of the actual range in DataB</param>
/// <param name="UpperB">upper bound of the actual range in DataB (exclusive)</param>
/// <param name="DownVector">a vector for the (0,0) to (x,y) search. Passed as a parameter for speed reasons.</param>
/// <param name="UpVector">a vector for the (u,v) to (N,M) search. Passed as a parameter for speed reasons.</param>
private static void LCS(DiffData DataA, int LowerA, int UpperA, DiffData DataB, int LowerB, int UpperB, int[] DownVector, int[] UpVector) {
// Debug.Write(2, "LCS", String.Format("Analyse the box: A[{0}-{1}] to B[{2}-{3}]", LowerA, UpperA, LowerB, UpperB));
// Fast walkthrough equal lines at the start
while (LowerA < UpperA && LowerB < UpperB && DataA.data[LowerA] == DataB.data[LowerB]) {
LowerA++; LowerB++;
}
// Fast walkthrough equal lines at the end
while (LowerA < UpperA && LowerB < UpperB && DataA.data[UpperA - 1] == DataB.data[UpperB - 1]) {
--UpperA; --UpperB;
}
if (LowerA == UpperA) {
// mark as inserted lines.
while (LowerB < UpperB)
DataB.modified[LowerB++] = true;
} else if (LowerB == UpperB) {
// mark as deleted lines.
while (LowerA < UpperA)
DataA.modified[LowerA++] = true;
} else {
// Find the middle snakea and length of an optimal path for A and B
SMSRD smsrd = SMS(DataA, LowerA, UpperA, DataB, LowerB, UpperB, DownVector, UpVector);
// Debug.Write(2, "MiddleSnakeData", String.Format("{0},{1}", smsrd.x, smsrd.y));
// The path is from LowerX to (x,y) and (x,y) to UpperX
LCS(DataA, LowerA, smsrd.x, DataB, LowerB, smsrd.y, DownVector, UpVector);
LCS(DataA, smsrd.x, UpperA, DataB, smsrd.y, UpperB, DownVector, UpVector); // 2002.09.20: no need for 2 points
}
} // LCS()
/// <summary>Scan the tables of which lines are inserted and deleted,
/// producing an edit script in forward order.
/// </summary>
/// dynamic array
private static Item[] CreateDiffs(DiffData DataA, DiffData DataB) {
ArrayList a = new ArrayList();
Item aItem;
Item[] result;
int StartA, StartB;
int LineA, LineB;
LineA = 0;
LineB = 0;
while (LineA < DataA.Length || LineB < DataB.Length) {
if ((LineA < DataA.Length) && (!DataA.modified[LineA])
&& (LineB < DataB.Length) && (!DataB.modified[LineB])) {
// equal lines
LineA++;
LineB++;
} else {
// maybe deleted and/or inserted lines
StartA = LineA;
StartB = LineB;
while (LineA < DataA.Length && (LineB >= DataB.Length || DataA.modified[LineA]))
// while (LineA < DataA.Length && DataA.modified[LineA])
LineA++;
while (LineB < DataB.Length && (LineA >= DataA.Length || DataB.modified[LineB]))
// while (LineB < DataB.Length && DataB.modified[LineB])
LineB++;
if ((StartA < LineA) || (StartB < LineB)) {
// store a new difference-item
aItem = new Item();
aItem.StartA = StartA;
aItem.StartB = StartB;
aItem.deletedA = LineA - StartA;
aItem.insertedB = LineB - StartB;
a.Add(aItem);
} // if
} // if
} // while
result = new Item[a.Count];
a.CopyTo(result);
return (result);
}
} // class Diff
/// <summary>Data on one input file being compared.
/// </summary>
internal class DiffData
{
/// <summary>Number of elements (lines).</summary>
internal int Length;
/// <summary>Buffer of numbers that will be compared.</summary>
internal int[] data;
/// <summary>
/// Array of booleans that flag for modified data.
/// This is the result of the diff.
/// This means deletedA in the first Data or inserted in the second Data.
/// </summary>
internal bool[] modified;
/// <summary>
/// Initialize the Diff-Data buffer.
/// </summary>
/// <param name="data">reference to the buffer</param>
internal DiffData(int[] initData) {
data = initData;
Length = initData.Length;
modified = new bool[Length + 2];
} // DiffData
} // class DiffData
} // namespace
/// <summary>
/// Flags that define appearance and behaviour of a standard message box displayed by a call to the MessageBox function.
/// </summary>
[Flags]
public enum MessageBoxOptions : uint
{
Ok = 0x000000,
OkCancel = 0x000001,
AbortRetryIgnore = 0x000002,
YesNoCancel = 0x000003,
YesNo = 0x000004,
RetryCancel = 0x000005,
CancelTryContinue = 0x000006,
IconHand = 0x000010,
IconQuestion = 0x000020,
IconExclamation = 0x000030,
IconAsterisk = 0x000040,
UserIcon = 0x000080,
IconWarning = IconExclamation,
IconError = IconHand,
IconInformation = IconAsterisk,
IconStop = IconHand,
DefButton1 = 0x000000,
DefButton2 = 0x000100,
DefButton3 = 0x000200,
DefButton4 = 0x000300,
ApplicationModal = 0x000000,
SystemModal = 0x001000,
TaskModal = 0x002000,
Help = 0x004000, //Help Button
NoFocus = 0x008000,
SetForeground = 0x010000,
DefaultDesktopOnly = 0x020000,
Topmost = 0x040000,
Right = 0x080000,
RTLReading = 0x100000,
}
class NotesWatcher
{
[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern uint MessageBox(IntPtr hWnd, String text, String caption, MessageBoxOptions options);
private static string _before;
private static Object _lockObj = new Object();
static void Main()
{
_before = File.ReadAllText(@"C:\Lotus\Notes\notes.ini");
var monitor = new FileSystemWatcher(@"C:\Lotus\Notes\", "notes.ini");
monitor.Changed += WaitForChanged;
monitor.NotifyFilter = NotifyFilters.LastWrite;
monitor.EnableRaisingEvents = true;
while(true)
{
Thread.Sleep(60000);
}
}
static void WaitForChanged(object source, FileSystemEventArgs e)
{
lock(_lockObj)
{
try
{
string after = File.ReadAllText(@"C:\Lotus\Notes\notes.ini");
my.utils.Diff.Item[] diffs = my.utils.Diff.DiffText(_before, after, false, false, false);
var builder = new StringBuilder();
foreach(my.utils.Diff.Item diff in diffs)
{
builder.AppendLine("@@ -" + diff.StartA + "," + diff.deletedA + " +" + diff.StartB + "," + diff.insertedB + " @@");
builder.AppendLine(string.Join("\n", _before.Split('\n').Skip(diff.StartA).Take(diff.deletedA).Select(s => "-" + s).ToArray()).Trim('\n'));
builder.AppendLine(string.Join("\n", after.Split('\n').Skip(diff.StartB).Take(diff.insertedB).Select(s => "+" + s).ToArray()).Trim('\n'));
}
if(builder.Length > 0)
{
MessageBox(IntPtr.Zero, "notes.ini has changed\n\nDiff:\n" + builder.ToString(), "NotesWatcher", MessageBoxOptions.Topmost | MessageBoxOptions.SetForeground | MessageBoxOptions.SystemModal | MessageBoxOptions.IconExclamation);
}
_before = after;
} catch(IOException ex)
{
Console.WriteLine(ex.ToString());
}
}
}
}
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