| 1 | // Copyright (c) .NET Foundation and contributors. All rights reserved. Licensed under the Microsoft Reciprocal License. See LICENSE.TXT file in the project root for full license information. |
| 2 | |
| 3 | using System; |
| 4 | using System.IO; |
| 5 | using System.Diagnostics; |
| 6 | |
| 7 | namespace WixToolset.Dtf.Tools.DDiff |
| 8 | { |
| 9 | public class TextFileDiffEngine : IDiffEngine |
| 10 | { |
| 11 | public TextFileDiffEngine() |
| 12 | { |
| 13 | } |
| 14 | |
| 15 | private bool IsTextFile(string file) |
| 16 | { |
| 17 | // Guess whether this is a text file by reading the first few bytes and checking for non-ascii chars. |
| 18 | |
| 19 | bool isText = true; |
| 20 | FileStream stream = new FileStream(file, FileMode.Open, FileAccess.Read, FileShare.Read); |
| 21 | byte[] buf = new byte[256]; |
| 22 | int count = stream.Read(buf, 0, buf.Length); |
| 23 | for(int i = 0; i < count; i++) |
| 24 | { |
| 25 | if((buf[i] & 0x80) != 0) |
| 26 | { |
| 27 | isText = false; |
| 28 | break; |
| 29 | } |
| 30 | } |
| 31 | stream.Close(); |
| 32 | return isText; |
| 33 | } |
| 34 | |
| 35 | public float GetDiffQuality(string diffInput1, string diffInput2, string[] options, IDiffEngineFactory diffFactory) |
| 36 | { |
| 37 | if(diffInput1 != null && File.Exists(diffInput1) && |
| 38 | diffInput2 != null && File.Exists(diffInput2) && |
| 39 | (IsTextFile(diffInput1) && IsTextFile(diffInput2))) |
| 40 | { |
| 41 | return .70f; |
| 42 | } |
| 43 | else |
| 44 | { |
| 45 | return 0; |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | public bool GetDiff(string diffInput1, string diffInput2, string[] options, TextWriter diffOutput, string linePrefix, IDiffEngineFactory diffFactory) |
| 50 | { |
| 51 | try |
| 52 | { |
| 53 | bool difference = false; |
| 54 | ProcessStartInfo psi = new ProcessStartInfo("diff.exe"); |
| 55 | psi.Arguments = String.Format("\"{0}\" \"{1}\"", diffInput1, diffInput2); |
| 56 | psi.WorkingDirectory = null; |
| 57 | psi.UseShellExecute = false; |
| 58 | psi.WindowStyle = ProcessWindowStyle.Hidden; |
| 59 | psi.RedirectStandardOutput = true; |
| 60 | Process proc = Process.Start(psi); |
| 61 | |
| 62 | string line; |
| 63 | while((line = proc.StandardOutput.ReadLine()) != null) |
| 64 | { |
| 65 | diffOutput.WriteLine("{0}{1}", linePrefix, line); |
| 66 | difference = true; |
| 67 | } |
| 68 | |
| 69 | proc.WaitForExit(); |
| 70 | return difference; |
| 71 | } |
| 72 | catch(System.ComponentModel.Win32Exception) // If diff.exe is not found, just compare the bytes |
| 73 | { |
| 74 | return new FileDiffEngine().GetDiff(diffInput1, diffInput2, options, diffOutput, linePrefix, diffFactory); |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | public IDiffEngine Clone() |
| 79 | { |
| 80 | return new TextFileDiffEngine(); |
| 81 | } |
| 82 | } |
| 83 | } |