Joveler.ZLibWrapper 1.1.0

.NET Framework 4.0
There is a newer version of this package available.
See the version list below for details.
Install-Package Joveler.ZLibWrapper -Version 1.1.0
dotnet add package Joveler.ZLibWrapper --version 1.1.0
<PackageReference Include="Joveler.ZLibWrapper" Version="1.1.0" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add Joveler.ZLibWrapper --version 1.1.0
The NuGet Team does not provide support for this client. Please contact its maintainers for support.
#r "nuget: Joveler.ZLibWrapper, 1.1.0"
#r directive can be used in F# Interactive, C# scripting and .NET Interactive. Copy this into the interactive tool or source code of the script to reference the package.
// Install Joveler.ZLibWrapper as a Cake Addin
#addin nuget:?package=Joveler.ZLibWrapper&version=1.1.0

// Install Joveler.ZLibWrapper as a Cake Tool
#tool nuget:?package=Joveler.ZLibWrapper&version=1.1.0
The NuGet Team does not provide support for this client. Please contact its maintainers for support.



To let user to use custom zlibwapi.dll, ZLibWrapper internally loads zlib dynamically (using LoadLibrary and GetProcAddress).

Personal recommendation is case 2, since it provides newer version of zlib while convenient.

Case 1 : No Explicit Initialzation

Starting from .Net Framework 4.5, .Net has its own copy of zlib, named clrcompression.dll.
It is stripped version of zlib, which is used in System.IO.Compression.DeflateStream.

If ZLibWrapper is used in .Net Framework 4.5 or later without explicit initialization, clrcompression.dll is used by default.

  • Since clrcompression.dll does not expose adler32() and crc32(), checksum calculation feature will be disabled.
  • Application built for .Net Framework 4.0 cannot use this method.
  • clrcompression.dll is based on quite old version of zlib (at least in .Net Framework 4.7).

Case 2 : Embedded Precompiled zlib

ZLibWrapper contains zlibwapi.dll, precompiled binaries of zlib 1.2.11.
They will be copied into $(OutDir)\x86\zlibwpi.all and $(OutDir)\x64\zlibwpi.all at build.

To use zlibwapi.dll, call ZLibNative.AssemblyInit(path_to_zlibwapi_dll) explicitly at App's init code.

WARNING: Architecture of zlibwapi.dll must be matched with .Net Framework!

Put this snippet in Application's init code:

if (IntPtr.Size == 8) // This app is running on 64bit .Net Framework
    ZLibNative.AssemblyInit(Path.Combine("x64", "zlibwapi.dll"));
else // This app is running on 32bit .Net Framework
    ZLibNative.AssemblyInit(Path.Combine("x86", "zlibwapi.dll"));
Known Issue
  • x86 version of embedded zlibwapi.dll was compiled without assembly optimization, due to the bug

Case 3 : Custom zlib

You may want to use custom zlib because of several reasons.

In this case, call ZLibNative.AssemblyInit with path to custom zlibwapi.dll.

NOTE: ZLibWrapper can only recognize zlibwapi.dll, not zlib1.dll.
The difference is the calling convention: zlibwapi.dll uses stdcall, while zlib1.dll uses cdecl.

It is advised to prevent copy of package-embedded zlibwapi.dll in this case.
To do so, create empty file named Joveler.ZLibWrapper.Precompiled.Exclude in project directory.


To unload zlib dll explicitly, call ZLibNative.AssemblyCleanup().

NOTE: Loading and unloading dll too often can impact performance.



A stream to process a data format conforming RFC 1951.

Its API is similar to System.IO.Compression.DeflateStream.

Example of compression:

using (FileStream fsOrigin = new FileStream("file_origin.bin", FileMode.Open))
using (FileStream fsComp = new FileStream("test.deflate", FileMode.Create))
using (DeflateStream zs = new DeflateStream(fsComp, CompressionMode.Compress, CompressionLevel.Default, true))

ZLibWrapper.CompressionLevel has more option compared to System.IO.Compression.CompressionLevel:

public enum CompressionLevel : int
    NoCompression = 0,
    Fastest = 1,
    Best = 9,
    Default = -1,
    Level0 = 0,
    Level1 = 1,
    Level2 = 2,
    Level3 = 3,
    Level4 = 4,
    Level5 = 5,
    Level6 = 6,
    Level7 = 7,
    Level8 = 8,
    Level9 = 9,

Example of decompression:

using (FileStream fsComp = new FileStream("test.deflate", FileMode.Create))
using (FileStream fsDecomp = new FileStream("file_decomp.bin", FileMode.Open))
using (DeflateStream zs = new DeflateStream(fsComp, CompressionMode.Decompress, true))


A stream to process a data format conforming RFC 1950.

Same usage with DeflateStream.


A stream to process a data format conforming RFC 1952.

Same usage with DeflateStream.


A helper class for DeflateStream.

Example of DeflateCompressor.Compress(Stream stream):

using (FileStream fsOrigin = new FileStream("file_origin.bin", FileMode.Open))
using (MemoryStream msComp = DeflateCompressor.Compress(fsOrigin))
    // write msComp to file, or send through network, etc

Example of DeflateCompressor.Decompress(byte[] buffer):

byte[] input = new byte[] { 0x73, 0x74, 0x72, 0x76, 0x71, 0x75, 0x03, 0x00 };
byte[] decompBytes = DeflateCompressor.Decompress(input);
string decompText = Encoding.UTF8.GetString(decompBytes);
Console.WriteLine(decompText); // "ABCDEF"


A helper class for ZLibStream.

Same usage with DeflateCompressor.


A helper class for GZipStream.

Same usage with DeflateCompressor.


NOTE: To use checksum calculation, you MUST USE zlibwapi.dll.


A class to compute adler32 checksum.

Use Append() methods to compute checksum.
Use Checksum property to get checksum value.

Example of Append(Stream stream):

using (FileStream fs = new FileStream("read.txt", FileMode.Open))
    Adler32Checksum adler = new Adler32Checksum();
    Console.WriteLine("0x" + adler.Checksum.ToString("X8")); 

Example of Append(byte[] buffer) and Append(byte[] buffer, int offset, int count):

Adler32Checksum adler = new Adler32Checksum();
byte[] bin = Encoding.UTF8.GetBytes("ABCDEF");

Console.WriteLine("0x" + adler.Checksum.ToString("X8")); // 0x057E0196

adler.Append(bin, 2, 3);
Console.WriteLine("0x" + adler.Checksum.ToString("X8")); // 0x0BD60262

Static wrapper methods named Adler32Checksum.Adler32() behave just like zlib's adler32() function.

Example of static wrapper methods:

byte[] bin = Encoding.UTF8.GetBytes("ABCDEF");

// Call Adler32() without checksum to use initial state.
uint checksum = Adler32Checksum.Adler32(bin);
Console.WriteLine("0x" + checksum.ToString("X8")); // 0x057E0196

// Call Adler32() with checksum to set as current state.
checksum = Adler32Checksum.Adler32(checksum, bin, 2, 3);
Console.WriteLine("0x" + checksum.ToString("X8")); // 0x0BD60262


Same usage with Adler32Checksum.

To use static wrapper methods, call Crc32Checksum.Crc32() instead of Adler32Checksum.Adler32().


A stream designed to compute adler32 checksum on-the-fly.

Example of reading from AdlerStream:

using (FileStream fs = new FileStream("read.bin", FileMode.Open))
using (Adler32Stream adler = new Adler32Stream(fs))
    byte[] buffer = new byte[256];
    adler.Read(buffer, 0, 256);
    Console.WriteLine("0x" + adler.Checksum.ToString("X8"));

    adler.Read(buffer, 0, 128);
    Console.WriteLine("0x" + adler.Checksum.ToString("X8"));

Example of writing to AdlerStream:

using (FileStream fs = new FileStream("write.bin", FileMode.Create))
using (Adler32Stream adler = new Adler32Stream(fs))
    byte[] bin;

    bin = new byte[] { 0x01, 0x02, 0x03 };
    adler.Write(bin, 0, bin.Length);
    Console.WriteLine("0x" + adler.Checksum.ToString("X8")); // 0x000D0007

    bin = new byte[] { 0x04, 0x05, 0x06 };
    adler.Write(bin, 0, bin.Length);
    Console.WriteLine("0x" + adler.Checksum.ToString("X8")); // 0x003E0016


Same usage with Adler32Stream.

Product Versions
.NET Framework net40 net403 net45 net451 net452 net46 net461 net462 net463 net47 net471 net472 net48
Compatible target framework(s)
Additional computed target framework(s)
Learn more about Target Frameworks and .NET Standard.
  • .NETFramework 4.0

    • No dependencies.
  • .NETFramework 4.5

    • No dependencies.

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

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Version Downloads Last updated
1.3.1 1,321 9/6/2018
1.3.0 1,025 5/22/2018
1.2.0 1,342 1/20/2018
1.1.0 1,227 10/4/2017
1.0.0 892 10/3/2017

- Multi target .Net Framework 4.0 and .Net Framework 4.5
- Change namespace to 'Joveler.ZLibWrapper' from 'ZLibWrapper'
- Improved copy of embedded precompiled binaries