How to decompress a Fody.Costura packed assembly - c#

A friend of mine gave me the challenge to decompress an assembly that was packed with Fody.Costura. The assembly has a dll dependency that was embedded as a resource. I tried to extract this .zip resource with dotPeek and decompress it with this code here
public static void Decompress(string path)
{
using (var stream = File.OpenRead(path))
using (var compressStream = new DeflateStream(stream, CompressionMode.Decompress))
{
compressStream.Seek(0, SeekOrigin.Begin);
var fs = File.Create(path + ".decompressed");
compressStream.CopyTo(fs);
fs.Close();
}
}
This works when it comes to extracting the .zip but the result is quite unuseful
Is there a suitable solution to decompress this packed dll?

This is my simple C# Console App code (Framework 4), which I`m using simply by "drag and drop" (Costura Compressed) files over compiled (ConsoleApp1) executable.
using System;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text.RegularExpressions;
namespace ConsoleApp1
{
class Program
{
static void CopyTo(Stream source, Stream destination) {
int count;
var array = new byte[81920];
while ((count = source.Read(array, 0, array.Length)) != 0) {
destination.Write(array, 0, count);
}
}
static Stream LoadStream(string fullname) {
FileStream stream = default(FileStream);
if (fullname.EndsWith(".zip")) {
using (stream = new FileStream(fullname, FileMode.Open)) {
using (var compressStream = new DeflateStream(stream, CompressionMode.Decompress)) {
var memStream = new MemoryStream();
CopyTo(compressStream, memStream);
memStream.Position = 0;
return memStream;
}
}
}
return stream;
}
static void Main(string[] args) {
Stream stream; Stream file;
string RefilePath = #"^.+[^\\]+\\"; string fullname; string newFile;
for (int i = 0; i < args.Count(); i++) {
fullname = args[i];
newFile = Regex.Replace(fullname, "\\.zip$", string.Empty);
Console.Write("{0} -> {1}\r\n",
Regex.Replace(fullname, RefilePath, string.Empty),
Regex.Replace(newFile, RefilePath, string.Empty));
try
{
stream = LoadStream(fullname);
using (file = File.Create(newFile)) {
CopyTo(stream, file);
}
}
catch (Exception ex) {
Console.Write("{0}", ex.ToString());
}
}
}
}
}
Based On Cameron MacFarland Answer

The code that Costura uses to decompress those resources is here.
https://github.com/Fody/Costura/blob/master/src/Costura.Template/Common.cs
static void CopyTo(Stream source, Stream destination)
{
var array = new byte[81920];
int count;
while ((count = source.Read(array, 0, array.Length)) != 0)
{
destination.Write(array, 0, count);
}
}
static Stream LoadStream(string fullname)
{
var executingAssembly = Assembly.GetExecutingAssembly();
if (fullname.EndsWith(".zip"))
{
using (var stream = executingAssembly.GetManifestResourceStream(fullname))
using (var compressStream = new DeflateStream(stream, CompressionMode.Decompress))
{
var memStream = new MemoryStream();
CopyTo(compressStream, memStream);
memStream.Position = 0;
return memStream;
}
}
return executingAssembly.GetManifestResourceStream(fullname);
}

To decompress those resources there is this project to.

Related

Create zip as byte[] in memory without saving to disk? [duplicate]

I'm trying to create a ZIP archive with a simple demo text file using a MemoryStream as follows:
using (var memoryStream = new MemoryStream())
using (var archive = new ZipArchive(memoryStream , ZipArchiveMode.Create))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
using (var fileStream = new FileStream(#"C:\Temp\test.zip", FileMode.Create))
{
stream.CopyTo(fileStream);
}
}
If I run this code, the archive file itself is created but foo.txt isn't.
However, if I replace the MemoryStream directly with the file stream, the archive is created correctly:
using (var fileStream = new FileStream(#"C:\Temp\test.zip", FileMode.Create))
using (var archive = new ZipArchive(fileStream, FileMode.Create))
{
// ...
}
Is it possible to use a MemoryStream to create the ZIP archive without the FileStream?
Thanks to ZipArchive creates invalid ZIP file, I got:
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
}
using (var fileStream = new FileStream(#"C:\Temp\test.zip", FileMode.Create))
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
That indicated we need to call Dispose on ZipArchive before we can use it, which as Amir suggests is likely because it writes final bytes like checksum to the archive that makes it complete. But in order not close the stream so we can re-use it after you need to pass true as the third parameter to ZipArchive.
Just another version of zipping without writing any file.
string fileName = "export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".xlsx";
byte[] fileBytes = here is your file in bytes
byte[] compressedBytes;
string fileNameZip = "Export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".zip";
using (var outStream = new MemoryStream())
{
using (var archive = new ZipArchive(outStream, ZipArchiveMode.Create, true))
{
var fileInArchive = archive.CreateEntry(fileName, CompressionLevel.Optimal);
using (var entryStream = fileInArchive.Open())
using (var fileToCompressStream = new MemoryStream(fileBytes))
{
fileToCompressStream.CopyTo(entryStream);
}
}
compressedBytes = outStream.ToArray();
}
Set the position of the stream to the 0 before copying it to the zip stream.
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
}
using (var fileStream = new FileStream(#"C:\Temp\test.zip", FileMode.Create))
{
memoryStream.Position=0;
memoryStream.WriteTo(fileStream);
}
}
Working solution for MVC
public ActionResult Index()
{
string fileName = "test.pdf";
string fileName1 = "test.vsix";
string fileNameZip = "Export_" + DateTime.Now.ToString("yyyyMMddhhmmss") + ".zip";
byte[] fileBytes = System.IO.File.ReadAllBytes(#"C:\test\test.pdf");
byte[] fileBytes1 = System.IO.File.ReadAllBytes(#"C:\test\test.vsix");
byte[] compressedBytes;
using (var outStream = new MemoryStream())
{
using (var archive = new ZipArchive(outStream, ZipArchiveMode.Create, true))
{
var fileInArchive = archive.CreateEntry(fileName, CompressionLevel.Optimal);
using (var entryStream = fileInArchive.Open())
using (var fileToCompressStream = new MemoryStream(fileBytes))
{
fileToCompressStream.CopyTo(entryStream);
}
var fileInArchive1 = archive.CreateEntry(fileName1, CompressionLevel.Optimal);
using (var entryStream = fileInArchive1.Open())
using (var fileToCompressStream = new MemoryStream(fileBytes1))
{
fileToCompressStream.CopyTo(entryStream);
}
}
compressedBytes = outStream.ToArray();
}
return File(compressedBytes, "application/zip", fileNameZip);
}
You need to finish writing the memory stream then read the buffer back.
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar!");
}
}
using (var fileStream = new FileStream(#"C:\Temp\test.zip", FileMode.Create))
{
var bytes = memoryStream.GetBuffer();
fileStream.Write(bytes,0,bytes.Length );
}
}
using System;
using System.IO;
using System.IO.Compression;
namespace ConsoleApplication
{
class Program`enter code here`
{
static void Main(string[] args)
{
using (FileStream zipToOpen = new FileStream(#"c:\users\exampleuser\release.zip", FileMode.Open))
{
using (ZipArchive archive = new ZipArchive(zipToOpen, ZipArchiveMode.Update))
{
ZipArchiveEntry readmeEntry = archive.CreateEntry("Readme.txt");
using (StreamWriter writer = new StreamWriter(readmeEntry.Open()))
{
writer.WriteLine("Information about this package.");
writer.WriteLine("========================");
}
}
}
}
}
}
Function to return stream that contain zip file
public static Stream ZipGenerator(List<string> files)
{
ZipArchiveEntry fileInArchive;
Stream entryStream;
int i = 0;
List<byte[]> byteArray = new List<byte[]>();
foreach (var file in files)
{
byteArray.Add(File.ReadAllBytes(file));
}
var outStream = new MemoryStream();
using (var archive = new ZipArchive(outStream, ZipArchiveMode.Create, true))
{
foreach (var file in files)
{
fileInArchive=(archive.CreateEntry(Path.GetFileName(file), CompressionLevel.Optimal));
using (entryStream = fileInArchive.Open())
{
using (var fileToCompressStream = new MemoryStream(byteArray[i]))
{
fileToCompressStream.CopyTo(entryStream);
}
i++;
}
}
}
outStream.Position = 0;
return outStream;
}
If you want , write zip to file stream.
using (var fileStream = new FileStream(#"D:\Tools\DBExtractor\DBExtractor\bin\Debug\test.zip", FileMode.Create))
{
outStream.Position = 0;
outStream.WriteTo(fileStream);
}
`
I'm late to the party, but there are scenarios where you can't access the ZipArchive's constructor to set the leaveOpen parameter and where you don't want the ZIP to be written to disk. In my case, the AsiceArchive class I'm using internally creates a ZipArchive but doesn't set leaveOpen to true.
I created a subclass of Stream that delegates all calls to an inner stream (a few clicks with ReSharper). This class is not disposable, so when the ZipArchive gets disposed, nothing happens to the inner stream.
public class NondisposingStreamWrapper : Stream
{
private readonly Stream _streamImplementation;
public NondisposingStreamWrapper(Stream inner) => _streamImplementation = inner;
public override void Flush() => _streamImplementation.Flush();
public override int Read(byte[] buffer, int offset, int count) => _streamImplementation.Read(buffer, offset, count);
public override long Seek(long offset, SeekOrigin origin) => _streamImplementation.Seek(offset, origin);
public override void SetLength(long value) => _streamImplementation.SetLength(value);
public override void Write(byte[] buffer, int offset, int count) => _streamImplementation.Write(buffer, offset, count);
public override bool CanRead => _streamImplementation.CanRead;
public override bool CanSeek => _streamImplementation.CanSeek;
public override bool CanWrite => _streamImplementation.CanWrite;
public override long Length => _streamImplementation.Length;
public override long Position
{
get => _streamImplementation.Position;
set => _streamImplementation.Position = value;
}
}
Use it like this:
using var memoryStream = new MemoryStream();
var output = new NondisposingStreamWrapper(memoryStream);
using (var archive = new ZipArchive(output, ZipArchiveMode.Create))
{
// add entries to archive
}
memoryStream.Flush();
memoryStream.Position = 0;
// write to file just for testing purposes
File.WriteAllBytes("out.zip", memoryStream.ToArray());
This is the way to convert a entity to XML File and then compress it:
private void downloadFile(EntityXML xml) {
string nameDownloadXml = "File_1.xml";
string nameDownloadZip = "File_1.zip";
var serializer = new XmlSerializer(typeof(EntityXML));
Response.Clear();
Response.ClearContent();
Response.ClearHeaders();
Response.AddHeader("content-disposition", "attachment;filename=" + nameDownloadZip);
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry(nameDownloadXml);
using (var entryStream = demoFile.Open())
using (StreamWriter writer = new StreamWriter(entryStream, System.Text.Encoding.UTF8))
{
serializer.Serialize(writer, xml);
}
}
using (var fileStream = Response.OutputStream)
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
Response.End();
}
Just in case, if anyone wants to save a dynamic zip file through SaveFileDialog.
var logFileName = "zip_filename.zip";
appLogSaver.FileName = logFileName;
appLogSaver.Filter = "LogFiles|*.zip";
appLogSaver.DefaultExt = "zip";
DialogResult resDialog = appLogSaver.ShowDialog();
if (resDialog.ToString() == "OK")
{
System.IO.FileStream fs = (System.IO.FileStream)appLogSaver.OpenFile();
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var demoFile = archive.CreateEntry("foo.txt");
using (var entryStream = demoFile.Open())
{
using (var streamWriter = new StreamWriter(entryStream))
{
//read your existing file and put the content here
streamWriter.Write("Bar!");
}
}
var demoFile2 = archive.CreateEntry("foo2.txt");
using (var entryStream = demoFile2.Open())
{
using (var streamWriter = new StreamWriter(entryStream))
{
streamWriter.Write("Bar2!");
}
}
}
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fs);
}
fs.Close();
}
For me something like this was ok:
using (var memoryStream = new MemoryStream())
{
using (var archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true))
{
var file = archive.CreateEntry("file.json");
using var entryStream = file.Open();
using var streamWriter = new StreamWriter(entryStream);
streamWriter.WriteLine(someJsonLine);
}
}
private void button6_Click(object sender, EventArgs e)
{
//create With Input FileNames
AddFileToArchive_InputByte(new ZipItem[]{ new ZipItem( #"E:\b\1.jpg",#"images\1.jpg"),
new ZipItem(#"E:\b\2.txt",#"text\2.txt")}, #"C:\test.zip");
//create with input stream
AddFileToArchive_InputByte(new ZipItem[]{ new ZipItem(File.ReadAllBytes( #"E:\b\1.jpg"),#"images\1.jpg"),
new ZipItem(File.ReadAllBytes(#"E:\b\2.txt"),#"text\2.txt")}, #"C:\test.zip");
//Create Archive And Return StreamZipFile
MemoryStream GetStreamZipFile = AddFileToArchive(new ZipItem[]{ new ZipItem( #"E:\b\1.jpg",#"images\1.jpg"),
new ZipItem(#"E:\b\2.txt",#"text\2.txt")});
//Extract in memory
ZipItem[] ListitemsWithBytes = ExtractItems(#"C:\test.zip");
//Choese Files For Extract To memory
List<string> ListFileNameForExtract = new List<string>(new string[] { #"images\1.jpg", #"text\2.txt" });
ListitemsWithBytes = ExtractItems(#"C:\test.zip", ListFileNameForExtract);
// Choese Files For Extract To Directory
ExtractItems(#"C:\test.zip", ListFileNameForExtract, "c:\\extractFiles");
}
public struct ZipItem
{
string _FileNameSource;
string _PathinArchive;
byte[] _Bytes;
public ZipItem(string __FileNameSource, string __PathinArchive)
{
_Bytes=null ;
_FileNameSource = __FileNameSource;
_PathinArchive = __PathinArchive;
}
public ZipItem(byte[] __Bytes, string __PathinArchive)
{
_Bytes = __Bytes;
_FileNameSource = "";
_PathinArchive = __PathinArchive;
}
public string FileNameSource
{
set
{
FileNameSource = value;
}
get
{
return _FileNameSource;
}
}
public string PathinArchive
{
set
{
_PathinArchive = value;
}
get
{
return _PathinArchive;
}
}
public byte[] Bytes
{
set
{
_Bytes = value;
}
get
{
return _Bytes;
}
}
}
public void AddFileToArchive(ZipItem[] ZipItems, string SeveToFile)
{
MemoryStream memoryStream = new MemoryStream();
//Create Empty Archive
ZipArchive archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true);
foreach (ZipItem item in ZipItems)
{
//Create Path File in Archive
ZipArchiveEntry FileInArchive = archive.CreateEntry(item.PathinArchive);
//Open File in Archive For Write
var OpenFileInArchive = FileInArchive.Open();
//Read Stream
FileStream fsReader = new FileStream(item.FileNameSource, FileMode.Open, FileAccess.Read);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0;
while (fsReader.Position != fsReader.Length)
{
//Read Bytes
ReadByte = fsReader.Read(ReadAllbytes, 0, ReadAllbytes.Length);
//Write Bytes
OpenFileInArchive.Write(ReadAllbytes, 0, ReadByte);
}
fsReader.Dispose();
OpenFileInArchive.Close();
}
archive.Dispose();
using (var fileStream = new FileStream(SeveToFile, FileMode.Create))
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
public MemoryStream AddFileToArchive(ZipItem[] ZipItems)
{
MemoryStream memoryStream = new MemoryStream();
//Create Empty Archive
ZipArchive archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true);
foreach (ZipItem item in ZipItems)
{
//Create Path File in Archive
ZipArchiveEntry FileInArchive = archive.CreateEntry(item.PathinArchive);
//Open File in Archive For Write
var OpenFileInArchive = FileInArchive.Open();
//Read Stream
FileStream fsReader = new FileStream(item.FileNameSource, FileMode.Open, FileAccess.Read);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0;
while (fsReader.Position != fsReader.Length)
{
//Read Bytes
ReadByte = fsReader.Read(ReadAllbytes, 0, ReadAllbytes.Length);
//Write Bytes
OpenFileInArchive.Write(ReadAllbytes, 0, ReadByte);
}
fsReader.Dispose();
OpenFileInArchive.Close();
}
archive.Dispose();
return memoryStream;
}
public void AddFileToArchive_InputByte(ZipItem[] ZipItems, string SeveToFile)
{
MemoryStream memoryStream = new MemoryStream();
//Create Empty Archive
ZipArchive archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true);
foreach (ZipItem item in ZipItems)
{
//Create Path File in Archive
ZipArchiveEntry FileInArchive = archive.CreateEntry(item.PathinArchive);
//Open File in Archive For Write
var OpenFileInArchive = FileInArchive.Open();
//Read Stream
// FileStream fsReader = new FileStream(item.FileNameSource, FileMode.Open, FileAccess.Read);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 4096 ;int TotalWrite=0;
while (TotalWrite != item.Bytes.Length)
{
if(TotalWrite+4096>item.Bytes.Length)
ReadByte=item.Bytes.Length-TotalWrite;
Array.Copy(item.Bytes, TotalWrite, ReadAllbytes, 0, ReadByte);
//Write Bytes
OpenFileInArchive.Write(ReadAllbytes, 0, ReadByte);
TotalWrite += ReadByte;
}
OpenFileInArchive.Close();
}
archive.Dispose();
using (var fileStream = new FileStream(SeveToFile, FileMode.Create))
{
memoryStream.Seek(0, SeekOrigin.Begin);
memoryStream.CopyTo(fileStream);
}
}
public MemoryStream AddFileToArchive_InputByte(ZipItem[] ZipItems)
{
MemoryStream memoryStream = new MemoryStream();
//Create Empty Archive
ZipArchive archive = new ZipArchive(memoryStream, ZipArchiveMode.Create, true);
foreach (ZipItem item in ZipItems)
{
//Create Path File in Archive
ZipArchiveEntry FileInArchive = archive.CreateEntry(item.PathinArchive);
//Open File in Archive For Write
var OpenFileInArchive = FileInArchive.Open();
//Read Stream
// FileStream fsReader = new FileStream(item.FileNameSource, FileMode.Open, FileAccess.Read);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 4096 ;int TotalWrite=0;
while (TotalWrite != item.Bytes.Length)
{
if(TotalWrite+4096>item.Bytes.Length)
ReadByte=item.Bytes.Length-TotalWrite;
Array.Copy(item.Bytes, TotalWrite, ReadAllbytes, 0, ReadByte);
//Write Bytes
OpenFileInArchive.Write(ReadAllbytes, 0, ReadByte);
TotalWrite += ReadByte;
}
OpenFileInArchive.Close();
}
archive.Dispose();
return memoryStream;
}
public void ExtractToDirectory(string sourceArchiveFileName, string destinationDirectoryName)
{
//Opens the zip file up to be read
using (ZipArchive archive = ZipFile.OpenRead(sourceArchiveFileName))
{
if (Directory.Exists(destinationDirectoryName)==false )
Directory.CreateDirectory(destinationDirectoryName);
//Loops through each file in the zip file
archive.ExtractToDirectory(destinationDirectoryName);
}
}
public void ExtractItems(string sourceArchiveFileName,List< string> _PathFilesinArchive, string destinationDirectoryName)
{
//Opens the zip file up to be read
using (ZipArchive archive = ZipFile.OpenRead(sourceArchiveFileName))
{
//Loops through each file in the zip file
foreach (ZipArchiveEntry file in archive.Entries)
{
int PosResult = _PathFilesinArchive.IndexOf(file.FullName);
if (PosResult != -1)
{
//Create Folder
if (Directory.Exists( destinationDirectoryName + "\\" +Path.GetDirectoryName( _PathFilesinArchive[PosResult])) == false)
Directory.CreateDirectory(destinationDirectoryName + "\\" + Path.GetDirectoryName(_PathFilesinArchive[PosResult]));
Stream OpenFileGetBytes = file.Open();
FileStream FileStreamOutput = new FileStream(destinationDirectoryName + "\\" + _PathFilesinArchive[PosResult], FileMode.Create);
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0; int TotalRead = 0;
while (TotalRead != file.Length)
{
//Read Bytes
ReadByte = OpenFileGetBytes.Read(ReadAllbytes, 0, ReadAllbytes.Length);
TotalRead += ReadByte;
//Write Bytes
FileStreamOutput.Write(ReadAllbytes, 0, ReadByte);
}
FileStreamOutput.Close();
OpenFileGetBytes.Close();
_PathFilesinArchive.RemoveAt(PosResult);
}
if (_PathFilesinArchive.Count == 0)
break;
}
}
}
public ZipItem[] ExtractItems(string sourceArchiveFileName)
{
List< ZipItem> ZipItemsReading = new List<ZipItem>();
//Opens the zip file up to be read
using (ZipArchive archive = ZipFile.OpenRead(sourceArchiveFileName))
{
//Loops through each file in the zip file
foreach (ZipArchiveEntry file in archive.Entries)
{
Stream OpenFileGetBytes = file.Open();
MemoryStream memstreams = new MemoryStream();
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0; int TotalRead = 0;
while (TotalRead != file.Length)
{
//Read Bytes
ReadByte = OpenFileGetBytes.Read(ReadAllbytes, 0, ReadAllbytes.Length);
TotalRead += ReadByte;
//Write Bytes
memstreams.Write(ReadAllbytes, 0, ReadByte);
}
memstreams.Position = 0;
OpenFileGetBytes.Close();
memstreams.Dispose();
ZipItemsReading.Add(new ZipItem(memstreams.ToArray(),file.FullName));
}
}
return ZipItemsReading.ToArray();
}
public ZipItem[] ExtractItems(string sourceArchiveFileName,List< string> _PathFilesinArchive)
{
List< ZipItem> ZipItemsReading = new List<ZipItem>();
//Opens the zip file up to be read
using (ZipArchive archive = ZipFile.OpenRead(sourceArchiveFileName))
{
//Loops through each file in the zip file
foreach (ZipArchiveEntry file in archive.Entries)
{
int PosResult = _PathFilesinArchive.IndexOf(file.FullName);
if (PosResult!= -1)
{
Stream OpenFileGetBytes = file.Open();
MemoryStream memstreams = new MemoryStream();
byte[] ReadAllbytes = new byte[4096];//Capcity buffer
int ReadByte = 0; int TotalRead = 0;
while (TotalRead != file.Length)
{
//Read Bytes
ReadByte = OpenFileGetBytes.Read(ReadAllbytes, 0, ReadAllbytes.Length);
TotalRead += ReadByte;
//Write Bytes
memstreams.Write(ReadAllbytes, 0, ReadByte);
}
//Create item
ZipItemsReading.Add(new ZipItem(memstreams.ToArray(),file.FullName));
OpenFileGetBytes.Close();
memstreams.Dispose();
_PathFilesinArchive.RemoveAt(PosResult);
}
if (_PathFilesinArchive.Count == 0)
break;
}
}
return ZipItemsReading.ToArray();
}

What is the fastest method to merge a number of files into a file in c#?

I handle with big files(of which capacities is minimum 500MB) to split and merge by c#.
I have to split the file into thousands of files, sort these files into some groups, and merge these by each group.
The minimum number of files are 10,000.
I implement the merge function by using the method Stream.CopyTo(). Here is the main part of that.
using (Stream writer = File.OpenWrite(outputFilePath))
{
int fileNum = filePaths.Count();
for (int i = 0; i < fileNum; i++)
{
using (Stream reader = File.OpenRead(filePaths.ElementAt(i)))
{ reader.CopyTo(writer); }
}
}
I've tested my program to split 500MB into 17000 files of 2 groups and to merge each group of 8500 files into one file.
The merging part takes about 80 seconds. I think it is pretty slow compared to splitting the same file which takes about 15~20 seconds
Is there any method which is faster than my code?
Your code looks fine but ElementAt is a code smell. Convert that to an array and use [i] instead. If you have 10K elements I'm positive you're wasting a lot of time.
Why not just use the Stream.CopyTo() method?
private static void CombineMultipleFilesIntoSingleFile(string inputDirectoryPath, string inputFileNamePattern, string outputFilePath)
{
string[] inputFilePaths = Directory.GetFiles(inputDirectoryPath, inputFileNamePattern);
Console.WriteLine("Number of files: {0}.", inputFilePaths.Length);
using (var outputStream = File.Create(outputFilePath))
{
foreach (var inputFilePath in inputFilePaths)
{
using (var inputStream = File.OpenRead(inputFilePath))
{
// Buffer size can be passed as the second argument.
inputStream.CopyTo(outputStream);
}
Console.WriteLine("The file {0} has been processed.", inputFilePath);
}
}
}
OR
Do it in chunks:
const int chunkSize = 2 * 1024; // 2KB
var inputFiles = new[] ;
using (var output = File.Create("output.dat"))
{
foreach (var file in inputFiles)
{
using (var input = File.OpenRead(file))
{
var buffer = new byte[chunkSize];
int bytesRead;
while ((bytesRead = input.Read(buffer, 0, buffer.Length)) > 0)
{
output.Write(buffer, 0, bytesRead);
}
}
}
}
Maybe try compressing the files?
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.IO.Compression;
class Program {
static void SaveCompressedFile(string filename, string data) {
FileStream fileStream = new FileStream(filename, FileMode.Create, FileAccess.Write);
GZipStream compressionStream = new GZipStream(fileStream, CompressionMode.Compress);
StreamWriter writer = new StreamWriter(compressionStream);
writer.Write(data);
writer.Close();
}
static string LoadCompressedFile(string filename) {
FileStream fileStream = new FileStream(filename, FileMode.Open, FileAccess.Read);
GZipStream compressionStream = new GZipStream(fileStream, CompressionMode.Decompress);
StreamReader reader = new StreamReader(compressionStream);
string data = reader.ReadToEnd();
reader.Close();
return data;
}
static void Main(string[] args) {
try {
string filename = "compressedFile.txt";
string sourceString = "Source String";
SaveCompressedFile(filename, sourceString);
FileInfo compressedFileData = new FileInfo(filename);
string recoveredString = LoadCompressedFile(filename);
} catch (IOException ex) {
Console.WriteLine(ex.ToString());
}
}
}
Source
Also check out the example of compressing a directory.
using System;
using System.Text;
using System.IO;
using System.IO.Compression;
namespace CmprDir
{
class Program
{
delegate void ProgressDelegate(string sMessage);
static void CompressFile(string sDir, string sRelativePath, GZipStream zipStream)
{
//Compress file name
char[] chars = sRelativePath.ToCharArray();
zipStream.Write(BitConverter.GetBytes(chars.Length), 0, sizeof(int));
foreach (char c in chars)
zipStream.Write(BitConverter.GetBytes(c), 0, sizeof(char));
//Compress file content
byte[] bytes = File.ReadAllBytes(Path.Combine(sDir, sRelativePath));
zipStream.Write(BitConverter.GetBytes(bytes.Length), 0, sizeof(int));
zipStream.Write(bytes, 0, bytes.Length);
}
static bool DecompressFile(string sDir, GZipStream zipStream, ProgressDelegate progress)
{
//Decompress file name
byte[] bytes = new byte[sizeof(int)];
int Readed = zipStream.Read(bytes, 0, sizeof(int));
if (Readed < sizeof(int))
return false;
int iNameLen = BitConverter.ToInt32(bytes, 0);
bytes = new byte[sizeof(char)];
StringBuilder sb = new StringBuilder();
for (int i = 0; i < iNameLen; i++)
{
zipStream.Read(bytes, 0, sizeof(char));
char c = BitConverter.ToChar(bytes, 0);
sb.Append(c);
}
string sFileName = sb.ToString();
if (progress != null)
progress(sFileName);
//Decompress file content
bytes = new byte[sizeof(int)];
zipStream.Read(bytes, 0, sizeof(int));
int iFileLen = BitConverter.ToInt32(bytes, 0);
bytes = new byte[iFileLen];
zipStream.Read(bytes, 0, bytes.Length);
string sFilePath = Path.Combine(sDir, sFileName);
string sFinalDir = Path.GetDirectoryName(sFilePath);
if (!Directory.Exists(sFinalDir))
Directory.CreateDirectory(sFinalDir);
using (FileStream outFile = new FileStream(sFilePath, FileMode.Create, FileAccess.Write, FileShare.None))
outFile.Write(bytes, 0, iFileLen);
return true;
}
static void CompressDirectory(string sInDir, string sOutFile, ProgressDelegate progress)
{
string[] sFiles = Directory.GetFiles(sInDir, "*.*", SearchOption.AllDirectories);
int iDirLen = sInDir[sInDir.Length - 1] == Path.DirectorySeparatorChar ? sInDir.Length : sInDir.Length + 1;
using (FileStream outFile = new FileStream(sOutFile, FileMode.Create, FileAccess.Write, FileShare.None))
using (GZipStream str = new GZipStream(outFile, CompressionMode.Compress))
foreach (string sFilePath in sFiles)
{
string sRelativePath = sFilePath.Substring(iDirLen);
if (progress != null)
progress(sRelativePath);
CompressFile(sInDir, sRelativePath, str);
}
}
static void DecompressToDirectory(string sCompressedFile, string sDir, ProgressDelegate progress)
{
using (FileStream inFile = new FileStream(sCompressedFile, FileMode.Open, FileAccess.Read, FileShare.None))
using (GZipStream zipStream = new GZipStream(inFile, CompressionMode.Decompress, true))
while (DecompressFile(sDir, zipStream, progress));
}
public static int Main(string[] argv)
{
if (argv.Length != 2)
{
Console.WriteLine("Usage: CmprDir.exe <in_dir compressed_file> | <compressed_file out_dir>");
return 1;
}
string sDir;
string sCompressedFile;
bool bCompress = false;
try
{
if (Directory.Exists(argv[0]))
{
sDir = argv[0];
sCompressedFile = argv[1];
bCompress = true;
}
else
if (File.Exists(argv[0]))
{
sCompressedFile = argv[0];
sDir = argv[1];
bCompress = false;
}
else
{
Console.Error.WriteLine("Wrong arguments");
return 1;
}
if (bCompress)
CompressDirectory(sDir, sCompressedFile, (fileName) => { Console.WriteLine("Compressing {0}...", fileName); });
else
DecompressToDirectory(sCompressedFile, sDir, (fileName) => { Console.WriteLine("Decompressing {0}...", fileName); });
return 0;
}
catch (Exception ex)
{
Console.Error.WriteLine(ex.Message);
return 1;
}
}
}
}
Source

Compress and decompress a Stream with Compression.DeflateStream

I am trying to compress and decompress a Stream using Compression.DeflateStream. Compressing seems to work correctly since the code below compresses my Stream to a 110 bytes long array. However, reading the decompressed Stream results in an empty string.
class Program
{
static void Main(string[] args)
{
// Compress a random string value
string value = Path.GetRandomFileName();
byte[] compressedBytes;
using (var writer = new StreamWriter(new MemoryStream()))
{
writer.Write(value);
writer.Flush();
writer.BaseStream.Position = 0;
compressedBytes = Compress(writer.BaseStream);
}
// Decompress compressed bytes
Stream decompressedStream = Decompress(compressedBytes);
// here already applies: decompressedStream.Length == 0
using (var reader = new StreamReader(decompressedStream))
{
string decompressedValue = reader.ReadToEnd();
if (value == decompressedValue)
Console.WriteLine("Success");
else
Console.WriteLine("Failed");
}
}
private static byte[] Compress(Stream input)
{
using (var compressStream = new MemoryStream())
using (var compressor = new DeflateStream(compressStream, CompressionMode.Compress))
{
input.CopyTo(compressor);
return compressStream.ToArray();
}
}
private static Stream Decompress(byte[] input)
{
var output = new MemoryStream();
using (var compressStream = new MemoryStream(input))
using (var decompressor = new DeflateStream(compressStream, CompressionMode.Decompress))
decompressor.CopyTo(output);
output.Position = 0;
return output;
}
}
Can anyone help me on this one?
Many thanks.
Fix your Compress function:
private static byte[] Compress(Stream input)
{
using(var compressStream = new MemoryStream())
using(var compressor = new DeflateStream(compressStream, CompressionMode.Compress))
{
input.CopyTo(compressor);
compressor.Close();
return compressStream.ToArray();
}
}
compressed stream was not flushed before returning the resulting byte array.
All those answers are far away from ideal form because all of you forgot that "using" disposing and closing streams its means that additional Close() is not needed. I think that ideal code will be like this:
public static class CompressionHelper
{
public static byte[] Compress(byte[] data)
{
byte[] compressArray = null;
try
{
using (MemoryStream memoryStream = new MemoryStream())
{
using (DeflateStream deflateStream = new DeflateStream(memoryStream, CompressionMode.Compress))
{
deflateStream.Write(data, 0, data.Length);
}
compressArray = memoryStream.ToArray();
}
}
catch (Exception exception)
{
// do something !
}
return compressArray;
}
public static byte[] Decompress(byte[] data)
{
byte[] decompressedArray = null;
try
{
using (MemoryStream decompressedStream = new MemoryStream())
{
using (MemoryStream compressStream = new MemoryStream(data))
{
using (DeflateStream deflateStream = new DeflateStream(compressStream, CompressionMode.Decompress))
{
deflateStream.CopyTo(decompressedStream);
}
}
decompressedArray = decompressedStream.ToArray();
}
}
catch (Exception exception)
{
// do something !
}
return decompressedArray;
}
}
Try closing the streams:
class Program
{
static void Main(string[] args)
{
// Compress a random string value
string value = DateTime.Now.ToLongTimeString();
byte[] compressedBytes;
using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(value)))
{
compressedBytes = Compress(stream);
}
// Decompress compressed bytes
using (var decompressedStream = Decompress(compressedBytes))
using (var reader = new StreamReader(decompressedStream))
{
string decompressedValue = reader.ReadToEnd();
if (value == decompressedValue)
Console.WriteLine("Success");
else
Console.WriteLine("Failed");
}
}
public static byte[] Compress(Stream input)
{
using (var compressedStream = new MemoryStream())
using (var zipStream = new GZipStream(compressedStream, CompressionMode.Compress))
{
input.CopyTo(zipStream);
zipStream.Close();
return compressedStream.ToArray();
}
}
public static Stream Decompress(byte[] data)
{
var output = new MemoryStream();
using(var compressedStream = new MemoryStream(data))
using(var zipStream = new GZipStream(compressedStream, CompressionMode.Decompress))
{
zipStream.CopyTo(output);
zipStream.Close();
output.Position = 0;
return output;
}
}
}

Compression/Decompression string with C#

I am newbie in .net. I am doing compression and decompression string in C#. There is a XML and I am converting in string and after that I am doing compression and decompression.There is no compilation error in my code except when I decompression my code and return my string, its returning only half of the XML.
Below is my code, please correct me where I am wrong.
Code:
class Program
{
public static string Zip(string value)
{
//Transform string into byte[]
byte[] byteArray = new byte[value.Length];
int indexBA = 0;
foreach (char item in value.ToCharArray())
{
byteArray[indexBA++] = (byte)item;
}
//Prepare for compress
System.IO.MemoryStream ms = new System.IO.MemoryStream();
System.IO.Compression.GZipStream sw = new System.IO.Compression.GZipStream(ms, System.IO.Compression.CompressionMode.Compress);
//Compress
sw.Write(byteArray, 0, byteArray.Length);
//Close, DO NOT FLUSH cause bytes will go missing...
sw.Close();
//Transform byte[] zip data to string
byteArray = ms.ToArray();
System.Text.StringBuilder sB = new System.Text.StringBuilder(byteArray.Length);
foreach (byte item in byteArray)
{
sB.Append((char)item);
}
ms.Close();
sw.Dispose();
ms.Dispose();
return sB.ToString();
}
public static string UnZip(string value)
{
//Transform string into byte[]
byte[] byteArray = new byte[value.Length];
int indexBA = 0;
foreach (char item in value.ToCharArray())
{
byteArray[indexBA++] = (byte)item;
}
//Prepare for decompress
System.IO.MemoryStream ms = new System.IO.MemoryStream(byteArray);
System.IO.Compression.GZipStream sr = new System.IO.Compression.GZipStream(ms,
System.IO.Compression.CompressionMode.Decompress);
//Reset variable to collect uncompressed result
byteArray = new byte[byteArray.Length];
//Decompress
int rByte = sr.Read(byteArray, 0, byteArray.Length);
//Transform byte[] unzip data to string
System.Text.StringBuilder sB = new System.Text.StringBuilder(rByte);
//Read the number of bytes GZipStream red and do not a for each bytes in
//resultByteArray;
for (int i = 0; i < rByte; i++)
{
sB.Append((char)byteArray[i]);
}
sr.Close();
ms.Close();
sr.Dispose();
ms.Dispose();
return sB.ToString();
}
static void Main(string[] args)
{
XDocument doc = XDocument.Load(#"D:\RSP.xml");
string val = doc.ToString(SaveOptions.DisableFormatting);
val = Zip(val);
val = UnZip(val);
}
}
My XML size is 63KB.
The code to compress/decompress a string
public static void CopyTo(Stream src, Stream dest) {
byte[] bytes = new byte[4096];
int cnt;
while ((cnt = src.Read(bytes, 0, bytes.Length)) != 0) {
dest.Write(bytes, 0, cnt);
}
}
public static byte[] Zip(string str) {
var bytes = Encoding.UTF8.GetBytes(str);
using (var msi = new MemoryStream(bytes))
using (var mso = new MemoryStream()) {
using (var gs = new GZipStream(mso, CompressionMode.Compress)) {
//msi.CopyTo(gs);
CopyTo(msi, gs);
}
return mso.ToArray();
}
}
public static string Unzip(byte[] bytes) {
using (var msi = new MemoryStream(bytes))
using (var mso = new MemoryStream()) {
using (var gs = new GZipStream(msi, CompressionMode.Decompress)) {
//gs.CopyTo(mso);
CopyTo(gs, mso);
}
return Encoding.UTF8.GetString(mso.ToArray());
}
}
static void Main(string[] args) {
byte[] r1 = Zip("StringStringStringStringStringStringStringStringStringStringStringStringStringString");
string r2 = Unzip(r1);
}
Remember that Zip returns a byte[], while Unzip returns a string. If you want a string from Zip you can Base64 encode it (for example by using Convert.ToBase64String(r1)) (the result of Zip is VERY binary! It isn't something you can print to the screen or write directly in an XML)
The version suggested is for .NET 2.0, for .NET 4.0 use the MemoryStream.CopyTo.
IMPORTANT: The compressed contents cannot be written to the output stream until the GZipStream knows that it has all of the input (i.e., to effectively compress it needs all of the data). You need to make sure that you Dispose() of the GZipStream before inspecting the output stream (e.g., mso.ToArray()). This is done with the using() { } block above. Note that the GZipStream is the innermost block and the contents are accessed outside of it. The same goes for decompressing: Dispose() of the GZipStream before attempting to access the data.
according to
this snippet
i use this code and it's working fine:
using System;
using System.IO;
using System.IO.Compression;
using System.Text;
namespace CompressString
{
internal static class StringCompressor
{
/// <summary>
/// Compresses the string.
/// </summary>
/// <param name="text">The text.</param>
/// <returns></returns>
public static string CompressString(string text)
{
byte[] buffer = Encoding.UTF8.GetBytes(text);
var memoryStream = new MemoryStream();
using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Compress, true))
{
gZipStream.Write(buffer, 0, buffer.Length);
}
memoryStream.Position = 0;
var compressedData = new byte[memoryStream.Length];
memoryStream.Read(compressedData, 0, compressedData.Length);
var gZipBuffer = new byte[compressedData.Length + 4];
Buffer.BlockCopy(compressedData, 0, gZipBuffer, 4, compressedData.Length);
Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gZipBuffer, 0, 4);
return Convert.ToBase64String(gZipBuffer);
}
/// <summary>
/// Decompresses the string.
/// </summary>
/// <param name="compressedText">The compressed text.</param>
/// <returns></returns>
public static string DecompressString(string compressedText)
{
byte[] gZipBuffer = Convert.FromBase64String(compressedText);
using (var memoryStream = new MemoryStream())
{
int dataLength = BitConverter.ToInt32(gZipBuffer, 0);
memoryStream.Write(gZipBuffer, 4, gZipBuffer.Length - 4);
var buffer = new byte[dataLength];
memoryStream.Position = 0;
using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
{
gZipStream.Read(buffer, 0, buffer.Length);
}
return Encoding.UTF8.GetString(buffer);
}
}
}
}
With the advent of .NET 4.0 (and higher) with the Stream.CopyTo() methods, I thought I would post an updated approach.
I also think the below version is useful as a clear example of a self-contained class for compressing regular strings to Base64 encoded strings, and vice versa:
public static class StringCompression
{
/// <summary>
/// Compresses a string and returns a deflate compressed, Base64 encoded string.
/// </summary>
/// <param name="uncompressedString">String to compress</param>
public static string Compress(string uncompressedString)
{
byte[] compressedBytes;
using (var uncompressedStream = new MemoryStream(Encoding.UTF8.GetBytes(uncompressedString)))
{
using (var compressedStream = new MemoryStream())
{
// setting the leaveOpen parameter to true to ensure that compressedStream will not be closed when compressorStream is disposed
// this allows compressorStream to close and flush its buffers to compressedStream and guarantees that compressedStream.ToArray() can be called afterward
// although MSDN documentation states that ToArray() can be called on a closed MemoryStream, I don't want to rely on that very odd behavior should it ever change
using (var compressorStream = new DeflateStream(compressedStream, CompressionLevel.Fastest, true))
{
uncompressedStream.CopyTo(compressorStream);
}
// call compressedStream.ToArray() after the enclosing DeflateStream has closed and flushed its buffer to compressedStream
compressedBytes = compressedStream.ToArray();
}
}
return Convert.ToBase64String(compressedBytes);
}
/// <summary>
/// Decompresses a deflate compressed, Base64 encoded string and returns an uncompressed string.
/// </summary>
/// <param name="compressedString">String to decompress.</param>
public static string Decompress(string compressedString)
{
byte[] decompressedBytes;
var compressedStream = new MemoryStream(Convert.FromBase64String(compressedString));
using (var decompressorStream = new DeflateStream(compressedStream, CompressionMode.Decompress))
{
using (var decompressedStream = new MemoryStream())
{
decompressorStream.CopyTo(decompressedStream);
decompressedBytes = decompressedStream.ToArray();
}
}
return Encoding.UTF8.GetString(decompressedBytes);
}
}
Here’s another approach using the extension methods technique to extend the String class to add string compression and decompression. You can drop the class below into an existing project and then use thusly:
var uncompressedString = "Hello World!";
var compressedString = uncompressedString.Compress();
and
var decompressedString = compressedString.Decompress();
To wit:
public static class Extensions
{
/// <summary>
/// Compresses a string and returns a deflate compressed, Base64 encoded string.
/// </summary>
/// <param name="uncompressedString">String to compress</param>
public static string Compress(this string uncompressedString)
{
byte[] compressedBytes;
using (var uncompressedStream = new MemoryStream(Encoding.UTF8.GetBytes(uncompressedString)))
{
using (var compressedStream = new MemoryStream())
{
// setting the leaveOpen parameter to true to ensure that compressedStream will not be closed when compressorStream is disposed
// this allows compressorStream to close and flush its buffers to compressedStream and guarantees that compressedStream.ToArray() can be called afterward
// although MSDN documentation states that ToArray() can be called on a closed MemoryStream, I don't want to rely on that very odd behavior should it ever change
using (var compressorStream = new DeflateStream(compressedStream, CompressionLevel.Fastest, true))
{
uncompressedStream.CopyTo(compressorStream);
}
// call compressedStream.ToArray() after the enclosing DeflateStream has closed and flushed its buffer to compressedStream
compressedBytes = compressedStream.ToArray();
}
}
return Convert.ToBase64String(compressedBytes);
}
/// <summary>
/// Decompresses a deflate compressed, Base64 encoded string and returns an uncompressed string.
/// </summary>
/// <param name="compressedString">String to decompress.</param>
public static string Decompress(this string compressedString)
{
byte[] decompressedBytes;
var compressedStream = new MemoryStream(Convert.FromBase64String(compressedString));
using (var decompressorStream = new DeflateStream(compressedStream, CompressionMode.Decompress))
{
using (var decompressedStream = new MemoryStream())
{
decompressorStream.CopyTo(decompressedStream);
decompressedBytes = decompressedStream.ToArray();
}
}
return Encoding.UTF8.GetString(decompressedBytes);
}
}
I like #fubo's answer the best but I think this is much more elegant.
This method is more compatible because it doesn't manually store the length up front.
Also I've exposed extensions to support compression for string to string, byte[] to byte[], and Stream to Stream.
public static class ZipExtensions
{
public static string CompressToBase64(this string data)
{
return Convert.ToBase64String(Encoding.UTF8.GetBytes(data).Compress());
}
public static string DecompressFromBase64(this string data)
{
return Encoding.UTF8.GetString(Convert.FromBase64String(data).Decompress());
}
public static byte[] Compress(this byte[] data)
{
using (var sourceStream = new MemoryStream(data))
using (var destinationStream = new MemoryStream())
{
sourceStream.CompressTo(destinationStream);
return destinationStream.ToArray();
}
}
public static byte[] Decompress(this byte[] data)
{
using (var sourceStream = new MemoryStream(data))
using (var destinationStream = new MemoryStream())
{
sourceStream.DecompressTo(destinationStream);
return destinationStream.ToArray();
}
}
public static void CompressTo(this Stream stream, Stream outputStream)
{
using (var gZipStream = new GZipStream(outputStream, CompressionMode.Compress))
{
stream.CopyTo(gZipStream);
gZipStream.Flush();
}
}
public static void DecompressTo(this Stream stream, Stream outputStream)
{
using (var gZipStream = new GZipStream(stream, CompressionMode.Decompress))
{
gZipStream.CopyTo(outputStream);
}
}
}
This is an updated version for .NET 4.5 and newer using async/await and IEnumerables:
public static class CompressionExtensions
{
public static async Task<IEnumerable<byte>> Zip(this object obj)
{
byte[] bytes = obj.Serialize();
using (MemoryStream msi = new MemoryStream(bytes))
using (MemoryStream mso = new MemoryStream())
{
using (var gs = new GZipStream(mso, CompressionMode.Compress))
await msi.CopyToAsync(gs);
return mso.ToArray().AsEnumerable();
}
}
public static async Task<object> Unzip(this byte[] bytes)
{
using (MemoryStream msi = new MemoryStream(bytes))
using (MemoryStream mso = new MemoryStream())
{
using (var gs = new GZipStream(msi, CompressionMode.Decompress))
{
// Sync example:
//gs.CopyTo(mso);
// Async way (take care of using async keyword on the method definition)
await gs.CopyToAsync(mso);
}
return mso.ToArray().Deserialize();
}
}
}
public static class SerializerExtensions
{
public static byte[] Serialize<T>(this T objectToWrite)
{
using (MemoryStream stream = new MemoryStream())
{
BinaryFormatter binaryFormatter = new BinaryFormatter();
binaryFormatter.Serialize(stream, objectToWrite);
return stream.GetBuffer();
}
}
public static async Task<T> _Deserialize<T>(this byte[] arr)
{
using (MemoryStream stream = new MemoryStream())
{
BinaryFormatter binaryFormatter = new BinaryFormatter();
await stream.WriteAsync(arr, 0, arr.Length);
stream.Position = 0;
return (T)binaryFormatter.Deserialize(stream);
}
}
public static async Task<object> Deserialize(this byte[] arr)
{
object obj = await arr._Deserialize<object>();
return obj;
}
}
With this you can serialize everything BinaryFormatter supports, instead only of strings.
Edit:
In case, you need take care of Encoding, you could just use Convert.ToBase64String(byte[])...
Take a look at this answer if you need an example!
For those who still getting The magic number in GZip header is not correct. Make sure you are passing in a GZip stream. ERROR
and if your string was zipped using php you'll need to do something like:
public static string decodeDecompress(string originalReceivedSrc) {
byte[] bytes = Convert.FromBase64String(originalReceivedSrc);
using (var mem = new MemoryStream()) {
//the trick is here
mem.Write(new byte[] { 0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00 }, 0, 8);
mem.Write(bytes, 0, bytes.Length);
mem.Position = 0;
using (var gzip = new GZipStream(mem, CompressionMode.Decompress))
using (var reader = new StreamReader(gzip)) {
return reader.ReadToEnd();
}
}
}
We can reduce code complexity by using StreamReader and StreamWriter rather than manually converting strings to byte arrays. Three streams is all you need:
public static byte[] Zip(string uncompressed)
{
byte[] ret;
using (var outputMemory = new MemoryStream())
{
using (var gz = new GZipStream(outputMemory, CompressionLevel.Optimal))
{
using (var sw = new StreamWriter(gz, Encoding.UTF8))
{
sw.Write(uncompressed);
}
}
ret = outputMemory.ToArray();
}
return ret;
}
public static string Unzip(byte[] compressed)
{
string ret = null;
using (var inputMemory = new MemoryStream(compressed))
{
using (var gz = new GZipStream(inputMemory, CompressionMode.Decompress))
{
using (var sr = new StreamReader(gz, Encoding.UTF8))
{
ret = sr.ReadToEnd();
}
}
}
return ret;
}
For .net6 cross platform Compression/Decompression string with C# using SharpZipLib library. Test for ubuntu(18.0.x) and windows.
#region helper
private byte[] Zip(string text)
{
if (text == null)
return null;
byte[] ret;
using (var outputMemory = new MemoryStream())
{
using (var gz = new GZipStream(outputMemory, CompressionLevel.Optimal))
{
using (var sw = new StreamWriter(gz, Encoding.UTF8))
{
sw.Write(text);
}
}
ret = outputMemory.ToArray();
}
return ret;
}
private string Unzip(byte[] bytes)
{
string ret = null;
using (var inputMemory = new MemoryStream(bytes))
{
using (var gz = new GZipStream(inputMemory, CompressionMode.Decompress))
{
using (var sr = new StreamReader(gz, Encoding.UTF8))
{
ret = sr.ReadToEnd();
}
}
}
return ret;
}
#endregion

Problem with decompress, GZipStream

I have problem with decomress gzip:
string fileData = string.Empty;
// byte[] starts with 31 and 139
var gzBuffer = entity.Data.Skip(pos).ToArray();
using (GZipStream stream = new GZipStream(new MemoryStream(gzBuffer),CompressionMode.Decompress))
{
const int size = 4096;
byte[] buffer = new byte[size];
using (MemoryStream memory = new MemoryStream())
{
int count = 0;
do
{
count = stream.Read(buffer, 0, size);
if (count > 0)
{
memory.Write(buffer, 0, count);
}
} while (count > 0);
fileData = Encoding.UTF8.GetString(memory.ToArray());
}
}
In the debugger, count allways equal 0. Where is the problem?
Thanks.
not sure if this will be of much help to you, but I will try. This is what I used in a sample project to compress/decompress files with GZIP. Maybe you can adapt this code for your needs?
public string Compress(FileInfo fi)
{
string outPath;
using (FileStream inFile = fi.OpenRead())
{
outPath = fi.FullName + ".gz";
using (FileStream outFile = File.Create(outPath))
{
using (var compress = new GZipStream(outFile,
CompressionMode.Compress))
{
inFile.CopyTo(compress);
}
}
}
return outPath;
}
public void Decompress(FileInfo fi)
{
using (FileStream inFile = fi.OpenRead())
{
string curFile = fi.FullName;
string origName = curFile.Remove(curFile.Length - fi.Extension.Length);
using (FileStream outFile = File.Create(origName))
{
using (var decompress = new GZipStream(inFile,
CompressionMode.Decompress))
{
decompress.CopyTo(outFile);
}
}
}
}

Categories