root/branches/Abonament/BazaReklam.Updater/ICSharpCode.SharpZipLib/Zip/ZipNameTransform.cs @ 759

// ZipNameTransform.cs
//
// Copyright 2005 John Reilly
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library.  Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
// 
// As a special exception, the copyright holders of this library give you
// permission to link this library with independent modules to produce an
// executable, regardless of the license terms of these independent
// modules, and to copy and distribute the resulting executable under
// terms of your choice, provided that you also meet, for each linked
// independent module, the terms and conditions of the license of that
// module.  An independent module is a module which is not derived from
// or based on this library.  If you modify this library, you may extend
// this exception to your version of the library, but you are not
// obligated to do so.  If you do not wish to do so, delete this
// exception statement from your version.


using System;
using System.IO;
using System.Text;

using ICSharpCode.SharpZipLib.Core;

namespace ICSharpCode.SharpZipLib.Zip
{
        /// <summary>
        /// ZipNameTransform transforms names as per the Zip file naming convention.
        /// </summary>
        /// <remarks>The use of absolute names is supported although its use is not valid 
        /// according to Zip naming conventions, and should not be used if maximum compatability is desired.</remarks>
        public class ZipNameTransform : INameTransform
        {
                #region Constructors
                /// <summary>
                /// Initialize a new instance of <see cref="ZipNameTransform"></see>
                /// </summary>
                public ZipNameTransform()
                {
                }

                /// <summary>
                /// Initialize a new instance of <see cref="ZipNameTransform"></see>
                /// </summary>
                /// <param name="trimPrefix">The string to trim from the front of paths if found.</param>
                public ZipNameTransform(string trimPrefix)
                {
                        TrimPrefix = trimPrefix;
                }
                #endregion
                
                /// <summary>
                /// Static constructor.
                /// </summary>
                static ZipNameTransform()
                {
                        char[] invalidPathChars;
#if NET_1_0 || NET_1_1 || NETCF_1_0
                        invalidPathChars = Path.InvalidPathChars;
#else
                        invalidPathChars = Path.GetInvalidPathChars();
#endif
                        int howMany = invalidPathChars.Length + 2;

                        InvalidEntryCharsRelaxed = new char[howMany];
                        Array.Copy(invalidPathChars, 0, InvalidEntryCharsRelaxed, 0, invalidPathChars.Length);
                        InvalidEntryCharsRelaxed[howMany - 1] = '*';
                        InvalidEntryCharsRelaxed[howMany - 2] = '?';

                        howMany = invalidPathChars.Length + 4; 
                        InvalidEntryChars = new char[howMany];
                        Array.Copy(invalidPathChars, 0, InvalidEntryChars, 0, invalidPathChars.Length);
                        InvalidEntryChars[howMany - 1] = ':';
                        InvalidEntryChars[howMany - 2] = '\\';
                        InvalidEntryChars[howMany - 3] = '*';
                        InvalidEntryChars[howMany - 4] = '?';
                }

                /// <summary>
                /// Transform a windows directory name according to the Zip file naming conventions.
                /// </summary>
                /// <param name="name">The directory name to transform.</param>
                /// <returns>The transformed name.</returns>
                public string TransformDirectory(string name)
                {
                        name = TransformFile(name);
                        if (name.Length > 0) {
                                if ( !name.EndsWith("/") ) {
                                        name += "/";
                                }
                        }
                        else {
                                throw new ZipException("Cannot have an empty directory name");
                        }
                        return name;
                }
                
                /// <summary>
                /// Transform a windows file name according to the Zip file naming conventions.
                /// </summary>
                /// <param name="name">The file name to transform.</param>
                /// <returns>The transformed name.</returns>
                public string TransformFile(string name)
                {
                        if (name != null) {
                                string lowerName = name.ToLower();
                                if ( (trimPrefix_ != null) && (lowerName.IndexOf(trimPrefix_) == 0) ) {
                                        name = name.Substring(trimPrefix_.Length);
                                }

                                name = name.Replace(@"\", "/");
                                name = WindowsPathUtils.DropPathRoot(name);

                                // Drop any leading slashes.
                                while ((name.Length > 0) && (name[0] == '/'))
                                {
                                        name = name.Remove(0, 1);
                                }

                                // Drop any trailing slashes.
                                while ((name.Length > 0) && (name[name.Length - 1] == '/'))
                                {
                                        name = name.Remove(name.Length - 1, 1);
                                }

                                // Convert consecutive // characters to /
                                int index = name.IndexOf("//");
                                while (index >= 0)
                                {
                                        name = name.Remove(index, 1);
                                        index = name.IndexOf("//");
                                }

                                name = MakeValidName(name, '_');
                        }
                        else {
                                name = string.Empty;
                        }
                        return name;
                }
                
                /// <summary>
                /// Get/set the path prefix to be trimmed from paths if present.
                /// </summary>
                /// <remarks>The prefix is trimmed before any conversion from
                /// a windows path is done.</remarks>
                public string TrimPrefix
                {
                        get { return trimPrefix_; }
                        set {
                                trimPrefix_ = value;
                                if (trimPrefix_ != null) {
                                        trimPrefix_ = trimPrefix_.ToLower();
                                }
                        }
                }

                /// <summary>
                /// Force a name to be valid by replacing invalid characters with a fixed value
                /// </summary>
                /// <param name="name">The name to force valid</param>
                /// <param name="replacement">The replacement character to use.</param>
                /// <returns>Returns a valid name</returns>
                static string MakeValidName(string name, char replacement)
                {
                        int index = name.IndexOfAny(InvalidEntryChars);
                        if (index >= 0) {
                                StringBuilder builder = new StringBuilder(name);

                                while (index >= 0 ) {
                                        builder[index] = replacement;

                                        if (index >= name.Length) {
                                                index = -1;
                                        }
                                        else {
                                                index = name.IndexOfAny(InvalidEntryChars, index + 1);
                                        }
                                }
                                name = builder.ToString();
                        }

                        if (name.Length > 0xffff) {
                                throw new PathTooLongException();
                        }

                        return name;
                }

                /// <summary>
                /// Test a name to see if it is a valid name for a zip entry.
                /// </summary>
                /// <param name="name">The name to test.</param>
                /// <param name="relaxed">If true checking is relaxed about windows file names and absolute paths.</param>
                /// <returns>Returns true if the name is a valid zip name; false otherwise.</returns>
                /// <remarks>Zip path names are actually in Unix format, and should only contain relative paths.
                /// This means that any path stored should not contain a drive or
                /// device letter, or a leading slash.  All slashes should forward slashes '/'.
                /// An empty name is valid for a file where the input comes from standard input.
                /// A null name is not considered valid.
                /// </remarks>
                public static bool IsValidName(string name, bool relaxed)
                {
                        bool result = (name != null);

                        if ( result ) {
                                if ( relaxed ) {
                                        result = name.IndexOfAny(InvalidEntryCharsRelaxed) < 0;
                                }
                                else {
                                        result = 
                                                (name.IndexOfAny(InvalidEntryChars) < 0) &&
                                                (name.IndexOf('/') != 0);
                                }
                        }

                        return result;
                }

                /// <summary>
                /// Test a name to see if it is a valid name for a zip entry.
                /// </summary>
                /// <param name="name">The name to test.</param>
                /// <returns>Returns true if the name is a valid zip name; false otherwise.</returns>
                /// <remarks>Zip path names are actually in unix format,
                /// and should only contain relative paths if a path is present.
                /// This means that the path stored should not contain a drive or
                /// device letter, or a leading slash.  All slashes should forward slashes '/'.
                /// An empty name is valid where the input comes from standard input.
                /// A null name is not considered valid.
                /// </remarks>
                public static bool IsValidName(string name)
                {
                        bool result = 
                                (name != null) &&
                                (name.IndexOfAny(InvalidEntryChars) < 0) &&
                                (name.IndexOf('/') != 0)
                                ;
                        return result;
                }

                #region Instance Fields
                string trimPrefix_;
                #endregion
                
                #region Class Fields
                static readonly char[] InvalidEntryChars;
                static readonly char[] InvalidEntryCharsRelaxed;
                #endregion
        }
}