root / trunk / Pithos.Core / Agents / FileInfoExtensions.cs @ ab2f6f79
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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.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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namespace Pithos.Core.Agents |
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{ |
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static class FileInfoExtensions |
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{ |
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public static int Read(this FileInfo fileInfo,byte[] buffer,int offset,int count) |
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{ |
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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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public static Task<int> ReadAsync(this FileInfo fileInfo, byte[] buffer, int offset, int count) |
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{ |
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//The using statement is not used because we will work asyncronously |
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var stream = FileAsync.OpenRead(fileInfo.FullName); |
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try |
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{ |
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stream.Seek(offset, SeekOrigin.Begin); |
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var read = stream.ReadAsync(buffer, offset, count); |
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return read.ContinueWith(t => |
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{ |
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//Make sure the stream closes |
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stream.Close(); |
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stream = null; |
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t.PropagateExceptions(); |
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return t.Result; |
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}); |
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} |
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catch (Exception) |
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{ |
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//In case of error make sure we close the stream |
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//The stream may have been |
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if (stream!=null) |
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stream.Close(); |
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throw; |
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} |
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} |
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public static string CalculateHash(this FileInfo 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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if (info.Length <= blockSize) |
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return Signature.CalculateMD5(info.FullName); |
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else |
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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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} |