root / trunk / Pithos.Core / Agents / BlockExtensions.cs @ 0771dfd7
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#region |
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/* ----------------------------------------------------------------------- |
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* <copyright file="BlockExtensions.cs" company="GRNet"> |
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* |
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* Copyright 2011-2012 GRNET S.A. All rights reserved. |
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* |
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* Redistribution and use in source and binary forms, with or |
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* without modification, are permitted provided that the following |
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* conditions are met: |
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* |
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* 1. Redistributions of source code must retain the above |
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* copyright notice, this list of conditions and the following |
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* disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above |
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* copyright notice, this list of conditions and the following |
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* disclaimer in the documentation and/or other materials |
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* provided with the distribution. |
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* |
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* |
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* THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS |
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR |
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF |
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* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED |
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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* POSSIBILITY OF SUCH DAMAGE. |
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* |
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* The views and conclusions contained in the software and |
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* documentation are those of the authors and should not be |
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* interpreted as representing official policies, either expressed |
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* or implied, of GRNET S.A. |
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* </copyright> |
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* ----------------------------------------------------------------------- |
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*/ |
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#endregion |
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using System; |
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using System.Collections.Generic; |
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using System.Diagnostics.Contracts; |
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using System.Linq; |
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using System.Security.Cryptography; |
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using System.Text; |
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using System.IO; |
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using System.Text.RegularExpressions; |
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using System.Threading.Tasks; |
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using Pithos.Network; |
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|
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namespace Pithos.Core.Agents |
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{ |
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static class BlockExtensions |
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{ |
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|
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|
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public static int Read(this FileInfo fileInfo,byte[] buffer,long offset,int count) |
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{ |
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if (offset < 0) |
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throw new ArgumentOutOfRangeException("offset", offset, "The file offset can't be negative"); |
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Contract.EndContractBlock(); |
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//Open the stream only long enough to read a block |
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using (var stream = fileInfo.OpenRead()) |
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{ |
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stream.Seek(offset, SeekOrigin.Begin); |
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return stream.Read(buffer, 0, count); |
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} |
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} |
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|
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public static string CalculateHash(this FileSystemInfo info,int blockSize,string algorithm) |
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{ |
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if (info==null) |
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throw new ArgumentNullException("info"); |
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if (String.IsNullOrWhiteSpace(info.FullName)) |
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throw new ArgumentException("info"); |
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if (blockSize<=0) |
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throw new ArgumentOutOfRangeException("blockSize",blockSize,"blockSize must be greater than 0"); |
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if (String.IsNullOrWhiteSpace(algorithm)) |
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throw new ArgumentNullException("algorithm"); |
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Contract.EndContractBlock(); |
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|
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//The hash for directories is an empty string |
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if (info is DirectoryInfo) |
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return String.Empty; |
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//The hash for non-existent files is an empty string |
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if (!info.Exists) |
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return String.Empty; |
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|
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return Signature.CalculateTreeHash(info.FullName, blockSize, algorithm).TopHash.ToHashString(); |
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|
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} |
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|
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/// <summary> |
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///Calculates a simple hash for an entire file |
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/// </summary> |
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/// <param name="info">The file to hash</param> |
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/// <param name="hasher">The hash algorithm to use</param> |
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/// <returns>A hash value for the entire file. An empty string if the file does not exist.</returns> |
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public static string ComputeShortHash(this FileInfo info, HashAlgorithm hasher) |
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{ |
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Contract.Requires(info != null); |
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Contract.Requires(hasher!= null); |
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|
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if (!info.Exists) |
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return String.Empty; |
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|
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using (var stream = info.Open(FileMode.Open, FileAccess.Read, FileShare.Read)) |
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{ |
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var hash = hasher.ComputeHash(stream); |
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var hashString = hash.ToHashString(); |
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return hashString; |
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} |
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} |
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|
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public static string ComputeShortHash(this FileInfo info) |
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{ |
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Contract.Requires(info != null); |
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|
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using (var hasher=HashAlgorithm.Create("sha1")) |
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{ |
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return ComputeShortHash(info,hasher); |
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} |
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} |
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|
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} |
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} |