code.grnet.gr Git - pithos-ms-client/blob - trunk/Pithos.Core/Agents/BlockExtensions.cs

   1 #region
   2 /* -----------------------------------------------------------------------
   3  * <copyright file="BlockExtensions.cs" company="GRNet">
   4  *
   5  * Copyright 2011-2012 GRNET S.A. All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or
   8  * without modification, are permitted provided that the following
   9  * conditions are met:
  10  *
  11  *   1. Redistributions of source code must retain the above
  12  *      copyright notice, this list of conditions and the following
  13  *      disclaimer.
  14  *
  15  *   2. Redistributions in binary form must reproduce the above
  16  *      copyright notice, this list of conditions and the following
  17  *      disclaimer in the documentation and/or other materials
  18  *      provided with the distribution.
  19  *
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
  22  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  23  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  24  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
  25  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  28  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  31  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  *
  34  * The views and conclusions contained in the software and
  35  * documentation are those of the authors and should not be
  36  * interpreted as representing official policies, either expressed
  37  * or implied, of GRNET S.A.
  38  * </copyright>
  39  * -----------------------------------------------------------------------
  40  */
  41 #endregion
  42 using System;
  43 using System.Collections.Generic;
  44 using System.Diagnostics;
  45 using System.Diagnostics.Contracts;
  46 using System.Linq;
  47 using System.Reflection;
  48 using System.Security.Cryptography;
  49 using System.Text;
  50 using System.IO;
  51 using System.Text.RegularExpressions;
  52 using System.Threading.Tasks;
  53 using Pithos.Network;
  54 using log4net;
  55
  56 namespace Pithos.Core.Agents
  57 {
  58     static class BlockExtensions
  59     {
  60
  61         private static readonly ILog Log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
  62
  63         public static int Read(this FileInfo fileInfo,byte[] buffer,long offset,int count)
  64         {
  65             if (offset < 0)
  66                 throw new ArgumentOutOfRangeException("offset", offset, "The file offset can't be negative");
  67             Contract.EndContractBlock();
  68             //Open the stream only long enough to read a block
  69             using (var stream = fileInfo.OpenRead())
  70             {
  71                 stream.Seek(offset, SeekOrigin.Begin);
  72                 return  stream.Read(buffer, 0, count);
  73             }
  74         }
  75
  76        public static string CalculateHash(this FileSystemInfo info,int blockSize,string algorithm)
  77         {
  78             if (info==null)
  79                 throw new ArgumentNullException("info");
  80             if (String.IsNullOrWhiteSpace(info.FullName))
  81                 throw new ArgumentException("info");
  82             if (blockSize<=0)
  83                 throw new ArgumentOutOfRangeException("blockSize",blockSize,"blockSize must be greater than 0");
  84             if (String.IsNullOrWhiteSpace(algorithm))
  85                 throw new ArgumentNullException("algorithm");
  86             Contract.EndContractBlock();
  87            info.Refresh();
  88            //The hash for directories is an empty string
  89            if (info is DirectoryInfo)
  90                 return String.Empty;
  91            //The hash for non-existent files is an empty string
  92            if (!info.Exists)
  93                return String.Empty;
  94
  95            return Signature.CalculateTreeHash(info.FullName, blockSize, algorithm).TopHash.ToHashString();
  96
  97         }
  98
  99        /// <summary>
 100        ///Calculates a simple hash for an entire file
 101        /// </summary>
 102        /// <param name="info">The file to hash</param>
 103        /// <param name="hasher">The hash algorithm to use</param>
 104        /// <returns>A hash value for the entire file. An empty string if the file does not exist.</returns>
 105        public static string ComputeShortHash(this FileInfo info, HashAlgorithm hasher,IStatusNotification notification)
 106        {
 107            if(info == null)
 108                throw new ArgumentNullException("info");
 109            if(hasher== null)
 110                throw new ArgumentNullException("hasher");
 111            Contract.EndContractBlock();
 112            info.Refresh();
 113            if (!info.Exists)
 114                return String.Empty;
 115
 116            if (Log.IsDebugEnabled)
 117                 Log.DebugFormat("Short Hashing [{0}] ",info.FullName);
 118
 119            var progress = new StatusNotification("");
 120
 121            using (var stream = new FileStream(info.FullName,FileMode.Open, FileAccess.Read, FileShare.Read,65536))
 122            {
 123                var buffer = new byte[65536];
 124                int counter=0;
 125                int bytesRead;
 126                do
 127                {
 128                    bytesRead = stream.Read(buffer, 0, 32768);
 129                    if (bytesRead > 0)
 130                    {
 131                        hasher.TransformBlock(buffer, 0, bytesRead, null, 0);
 132                    }
 133                    counter++;
 134                    if (counter % 100 == 0)
 135                    {
 136                        progress.Title = String.Format("Hashing {0:p} of {1}", stream.Position*1.0/stream.Length,
 137                                                       info.Name);
 138                        notification.Notify(progress);
 139                    }
 140                } while (bytesRead > 0);
 141                hasher.TransformFinalBlock(buffer, 0, 0);
 142                var hash = hasher.Hash;
 143
 144                progress.Title = String.Format("Hashed {0} ", info.Name);
 145                notification.Notify(progress);
 146
 147                var hashString = hash.ToHashString();
 148
 149                return hashString;
 150            }
 151        }
 152
 153         public static string ComputeShortHash(this FileInfo info,IStatusNotification notification)
 154        {
 155            if(info == null)
 156                throw new ArgumentNullException("info");
 157             Contract.EndContractBlock();
 158
 159            using (var hasher=HashAlgorithm.Create("md5"))
 160            {
 161                return ComputeShortHash(info,hasher,notification);
 162            }
 163        }
 164
 165     }
 166 }