I was using GZipStream for some time without any problems. I didn't change any code at my function but now the compress and decompress doesn't work. I have extracted the following simple example (maybe I do something wrong generally...).
public static class ZipLib
{
#region Public Methods
public static string Unzip(byte[] compressedText)
{
try {
byte[] gzBuffer = compressedText;
int msgLength = BitConverter.ToInt32(gzBuffer, 0);
byte[] buffer = new byte[msgLength];
using (MemoryStream ms = new MemoryStream()) {
ms.Write(gzBuffer, 4, gzBuffer.Length - 4);
using (GZipStream zip = new GZipStream(ms, CompressionMode.Decompress, true)) {
zip.Read(buffer, 0, buffer.Length);
}
}
return Encoding.UTF8.GetString(buffer);
}
catch (Exception ex) {
Debug.WriteLine(ex.Message);
}
return "";
}
public static byte[] Zip(string text)
{
byte[] buffer = Encoding.UTF8.GetBytes(text);
MemoryStream ms = new MemoryStream();
using (GZipStream zip = new GZipStream(ms, CompressionMode.Compress, true)) {
zip.Write(buffer, 0, buffer.Length);
}
ms.Position = 0;
byte[] compressed = new byte[ms.Length];
ms.Read(compressed, 0, compressed.Length);
byte[] gzBuffer = new byte[compressed.Length + 4];
Buffer.BlockCopy(compressed, 0, gzBuffer, 4, compressed.Length);
Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gzBuffer, 0, 4);
return gzBuffer;
}
#endregion
}
internal class Program
{
#region Private Methods
private static void Main(string[] args)
{
string uncompressedIn = "Hallo Welt";
var compressed = ZipLib.Zip(uncompressedIn);
var uncompressed = ZipLib.Unzip(compressed);
Console.WriteLine("Uncompressed Input: " + uncompressedIn);
Console.WriteLine("Compressed value: " + string.Join(" | ", compressed));
Console.WriteLine("Uncompressed from compressed: " + string.Join(" | ", uncompressed.ToCharArray()));
Console.ReadKey();
}
#endregion
}
The value of uncompressed is "\0\0\0\0"...
In Unzip, you Write to a MemoryStream, then give it to the GZipStream to read from, but: it is still at the end of the stream, you didn't rewind it. Try adding:
ms.Position = 0;
after the Write. Note, however, that it might be more efficient to do:
using(MemoryStream ms = new MemoryStream(gzBuffer, 4, gzBuffer.Length - 4))
{
//...
}
this avoids duplicating any memory
Related
When I am trying to deflate one string to XML getting the error. can anyone help me out, if the string is wrong or any other thing I need to consider?
string output = DecompressString("H4sIAAAAAAAAAO1ay3LbIBTd9ys83hOcZrrxKP6CZpUuusUStulIoAFkxfn6XpCQ0NvWTDt+ZBUJ7vtwEQcneHv7ReN3Ko8spGrxkcRcrT8Ue10etE7XGOd5/pS/PAm5x99Xq2f8++3ne3igCUGMK014SJeFVqWRSfZEtWJWh+85TokkicIghRVLFPiCl5Cky823xSIIRZLGVFMkJNszTjTje8QiyjXTJ5RKquARRgU34qAwKbcgoWZH+rrUMqNL7NRSKokWctrPgmT6AFKfNCptFCbACEhpyUIjhcSRSgkGNu4BcaFR4TvAvZLOTEjimEoUMZXG5IQ4SaiLYGMcBnhMosgHn5+QrTO+rNATuHjpnQuLr1NBtCOxmoNR05iHV2GwqnQioOxgNSEcVANs33vQ3EC9wQE7EsiY8Z0ADTPeAPLyyrfrNIVCW7yShock4ywsrEZQO6nqiAZmm41Qp53FEKF2bZtJvmZU79ZFn65heA2bgLEJxlIRs/BUKZfqCwalNmsUQaVyIiOTRcZDwSNmYiAx2p7QEfISnqqNtJRQ/rABikaMzN9JrCuA11hpWTbxoojaWgC60WwnuJEJ7k8lIBY95QnDGoIQZlWQZBH7TxW0rm6+gttMne596YFhk+YNoHDPy/f6UeACvidp/Aj9AKkSrnIqbwSOO2+MW4ADzjYZOLSHdgk1OJAtVOMRWsXL9xbxufveuR58ijfgCo75jNOQihcN8pFhotZUkcB5eMGdOdCxoyjGN2FMSdt8QwKJXe2vHe+Q1ZoPuvn8QMu4LT+T9A8NAWREdDkKz1rYBbqB2oJQRs0AAdKuPUUjYCjkHLsuKi00kAGeJVvoBj89ZdoFmaXSrMjmeRXgy7UqJEAUqhO5qmmWQDQvYLN/ph/BZidX375CZdVGZlTaD4zD2XK3g5RqQ93RNk0fWbUeIR+TGhDKCTM49rLwcm7qpmNAafAGymyTbmVBlUIKxpXZJNnOGTkwhexuCn9dhNZ7ca00Q3u8oJ7UYDl9mQGRg4ij8eoYiW5p8KhjZ3XI65ZIWafIgIAnpkC9Qv/4PqX0YrrV1r+KBd7UvZ9Mpr5RrSCgJCKfn17ZDtZKM4qOu+ETyyRe93xSuRG8OieY8Q53+0+m9+JKtoE6lq9t4GqW1UV4fW0DV4UX45pKTh7jZwp7pvHy/UL9EX5aeWjUO5/88a95m3JMUYBe+uEbmDo8XMZfvChrCpNQpcieOlblcfJ2MMOS04GMe/EJFQfuTXlIu/TNzYww2oR8eIIIVoRmIUsJ1/YiY2S6S0v9QBolbUxU43Y7Hom/PT8vix8XJdEXk5dK73SdaKY0rN5Pc6UUl5dMWvAuMANyPTd0neU54sILpLxoODugCflzApt0GeDGfzttvv0F8ylWAP4kAAA=");
public static string DecompressString(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);
}
public static string DecodeGzip(string str)
{
byte[] gzBuffer = Convert.FromBase64String(str);
using (MemoryStream ms = new MemoryStream())
{
int msgLength = BitConverter.ToInt32(gzBuffer, 0);
ms.Write(gzBuffer, 0, gzBuffer.Length);
byte[] buffer = new byte[msgLength];
ms.Position = 0;
int length;
using (GZipStream zip = new GZipStream(ms, CompressionMode.Decompress))
{
length = zip.Read(buffer, 0, buffer.Length);
}
var data = new byte[length];
Array.Copy(buffer, data, length);
return Encoding.UTF8.GetString(data);
}
}
I have this function that splits a serialized byte array into pieces based on a max length:
public static List<byte[]> ZipStringList(List<string> curSpawn, int maxSize = -1) {
Environment.SetEnvironmentVariable("MONO_REFLECTION_SERIALIZER", "yes");
MemoryStream o = new MemoryStream();
BinaryFormatter bf = new BinaryFormatter();
bf.Serialize(o, curSpawn);
byte[] buffer = o.GetBuffer();
o.Close();
MemoryStream memoryStream = new MemoryStream();
using (GZipStream gZipStream = new GZipStream(memoryStream, CompressionMode.Compress, true))
{
gZipStream.Write(buffer, 0, buffer.Length);
}
memoryStream.Position = 0;
if (maxSize > 0 && memoryStream.Length > maxSize) {
int pieces = Mathf.CeilToInt (memoryStream.Length / (float)maxSize);
List<byte[]> listByte = new List<byte[]> ();
for (int i = 0; i < pieces; ++i) {
int curLength = (int)Mathf.Min (maxSize, memoryStream.Length - (i * maxSize));
byte[] compressedData = new byte[curLength];
memoryStream.Read (compressedData, 0, compressedData.Length);
if (i == pieces - 1) {
byte[] gZipBuffer = new byte[compressedData.Length + 4];
Buffer.BlockCopy (compressedData, 0, gZipBuffer, 4, compressedData.Length);
Buffer.BlockCopy (BitConverter.GetBytes (buffer.Length), 0, gZipBuffer, 0, 4);
listByte.Add (gZipBuffer);
}//if last piece
else {
listByte.Add (compressedData);
}//else normal
}//for each piece
return listByte;
} else {
byte[] compressedData = new byte[memoryStream.Length];
memoryStream.Read (compressedData, 0, compressedData.Length);
byte[] gZipBuffer = new byte[compressedData.Length + 4];
Buffer.BlockCopy (compressedData, 0, gZipBuffer, 4, compressedData.Length);
Buffer.BlockCopy (BitConverter.GetBytes (buffer.Length), 0, gZipBuffer, 0, 4);
List<byte[]> retList = new List<byte[]> ();
retList.Add (gZipBuffer);
return retList;
}
}//ZipStringList()
Then this function that deserializes it:
public static List<string> UnzipStringList(List<byte[]> byteList) {
byte[] gZipBuffer = byteList.SelectMany(b => b).ToArray();
Environment.SetEnvironmentVariable("MONO_REFLECTION_SERIALIZER", "yes");
byte[] buffer;
using (MemoryStream memoryStream = new MemoryStream())
{
int dataLength = BitConverter.ToInt32(gZipBuffer, 0);
memoryStream.Write(gZipBuffer, 4, gZipBuffer.Length - 4);
buffer = new byte[dataLength];
memoryStream.Position = 0;
using (GZipStream gZipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
{
gZipStream.Read(buffer, 0, buffer.Length);
}
}
MemoryStream o = new MemoryStream(buffer);
BinaryFormatter bf = new BinaryFormatter();
return (List<string>)bf.Deserialize(o);
}//UnzipStringList()
When I run it though, I'm getting a "corrupted gzip header" error, so there's some simple thing I'm missing. What is it?
More details: there aren't really, I'm likely positioning the buffer wrong. Fun fact: I searched google for the error message and the only result was this question.
Here's some code you can test with. Make it a large enough file (like at least a kilobyte). My file is full of JSON arrays.
string[] allLines = File.ReadAllLines ("path_to_file.txt");
List<byte[]> byteArray = Utility.ZipStringList(new List<string>(allLines), 60000);
List<string> stringList = Utility.UnzipStringList (byteArray);
Utility.LogRealError ("I unzipped it?", stringList.Count, stringList [4]);
I was searching for the correct solution to decompress the string in java coming from c# code.I tried myself with lot of techniques in java like(gzip,inflatter etc.).but didn't get the solution.i got some error while trying to decompress the string in java from compressed string from c# code.
My C# code to compress the string is,
public static string CompressString(string text)
{
byte[] byteArray = Encoding.GetEncoding(1252).GetBytes(text);// Encoding.ASCII.GetBytes(text);
using (var ms = new MemoryStream())
{
// Compress the text
using (var ds = new DeflateStream(ms, CompressionMode.Compress))
{
ds.Write(byteArray, 0, byteArray.Length);
}
return Convert.ToBase64String(ms.ToArray());
}
}
And decompress the string in java using,
private static void compressAndDecompress(){
try {
// Encode a String into bytes
String string = "xxxxxxSAMPLECOMPRESSEDSTRINGxxxxxxxxxx";
// // Compress the bytes
byte[] decoded = Base64.decodeBase64(string.getBytes());
byte[] output = new byte[4096];
// Decompress the bytes
Inflater decompresser = new Inflater();
decompresser.setInput(decoded);
int resultLength = decompresser.inflate(output);
decompresser.end();
// Decode the bytes into a String
String outputString = new String(output, 0, resultLength, "UTF-8");
System.out.println(outputString);
} catch(java.io.UnsupportedEncodingException ex) {
ex.printStackTrace();
} catch (java.util.zip.DataFormatException ex) {
ex.printStackTrace();
}
}
I get this exception when running the above code:
java.util.zip.DataFormatException: incorrect header check
Kindly give me the sample code in java to decompress the string java.Thanks
My C# code to compress is
private string Compress(string text)
{
byte[] buffer = Encoding.UTF8.GetBytes(text);
MemoryStream ms = new MemoryStream();
using (GZipStream zip = new GZipStream(ms, CompressionMode.Compress, true))
{
zip.Write(buffer, 0, buffer.Length);
}
ms.Position = 0;
MemoryStream outStream = new MemoryStream();
byte[] compressed = new byte[ms.Length];
ms.Read(compressed, 0, compressed.Length);
byte[] gzBuffer = new byte[compressed.Length + 4];
System.Buffer.BlockCopy(compressed, 0, gzBuffer, 4, compressed.Length);
System.Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gzBuffer, 0, 4);
return Convert.ToBase64String(gzBuffer);
}
Java code to decompress the text is
private String Decompress(String compressedText)
{
byte[] compressed = compressedText.getBytes("UTF8");
compressed = org.apache.commons.codec.binary.Base64.decodeBase64(compressed);
byte[] buffer=new byte[compressed.length-4];
buffer = copyForDecompression(compressed,buffer, 4, 0);
final int BUFFER_SIZE = 32;
ByteArrayInputStream is = new ByteArrayInputStream(buffer);
GZIPInputStream gis = new GZIPInputStream(is, BUFFER_SIZE);
StringBuilder string = new StringBuilder();
byte[] data = new byte[BUFFER_SIZE];
int bytesRead;
while ((bytesRead = gis.read(data)) != -1)
{
string.append(new String(data, 0, bytesRead));
}
gis.close();
is.close();
return string.toString();
}
private byte[] copyForDecompression(byte[] b1,byte[] b2,int srcoffset,int dstoffset)
{
for(int i=0;i<b2.length && i<b1.length;i++)
{
b2[i]=b1[i+4];
}
return b2;
}
This code works perfectly fine for me.
Had exactly the same issue. Could solve it via
byte[] compressed = Base64Utils.decodeFromString("mybase64encodedandwithc#zippedcrap");
Inflater decompresser = new Inflater(true);
decompresser.setInput(compressed);
byte[] result = new byte[4096];
decompresser.inflate(result);
decompresser.end();
System.out.printf(new String(result));
The magic happens with the boolen parameter on instantiating the Inflator
BW Hubert
For beloved googlers,
As #dbw mentioned,
according to post How to decompress stream deflated with java.util.zip.Deflater in .NET?,
java.util.zip.deflater equivalent in c# the default deflater used in C#
is not having any java equivalent that's why users prefer Gzip, Ziplib
or some other zip techniques.
a relatively simple method would be using GZip.
And for the accepted answer, one problem is that in this method you should append the data size to the compressed string yourself, and more importantly as per my own experience in our production app, It is buggy when the string reaches ~2000 chars!
the bug is in the System.io.Compression.GZipStream
any way using SharpZipLib in c# the problem goes away and everything would be as simple as following snippets:
JAVA:
import android.util.Base64;
import com.google.android.gms.common.util.IOUtils;
import org.jetbrains.annotations.Nullable;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.GZIPInputStream;
import java.util.zip.GZIPOutputStream;
public class CompressionHelper {
#Nullable
public static String compress(#Nullable String data) {
if(data == null || data.length() == 0)
return null;
try {
// Create an output stream, and a gzip stream to wrap over.
ByteArrayOutputStream bos = new ByteArrayOutputStream(data.length());
GZIPOutputStream gzip = new GZIPOutputStream(bos);
// Compress the input string
gzip.write(data.getBytes());
gzip.close();
byte[] compressed;
// Convert to base64
compressed = Base64.encode(bos.toByteArray(),Base64.NO_WRAP);
bos.close();
// return the newly created string
return new String(compressed);
} catch(IOException e) {
return null;
}
}
#Nullable
public static String decompress(#Nullable String compressedText) {
if(compressedText == null || compressedText.length() == 0)
return null;
try {
// get the bytes for the compressed string
byte[] compressed = compressedText.getBytes("UTF-8");
// convert the bytes from base64 to normal string
compressed = Base64.decode(compressed, Base64.NO_WRAP);
ByteArrayInputStream bis = new ByteArrayInputStream(compressed);
GZIPInputStream gis = new GZIPInputStream(bis);
byte[] bytes = IOUtils.toByteArray(gis);
return new String(bytes, "UTF-8");
}catch (IOException e){
e.printStackTrace();
}
return null;
}
}
and c#:
using ICSharpCode.SharpZipLib.GZip; //PM> Install-Package SharpZipLib
using System;
using System.Collections.Generic;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace GeneralTools
{
public static class CompressionTools
{
public static string CompressString(string text)
{
if (string.IsNullOrEmpty(text))
return null;
byte[] buffer = Encoding.UTF8.GetBytes(text);
using (var compressedStream = new MemoryStream())
{
GZip.Compress(new MemoryStream(buffer), compressedStream, false);
byte[] compressedData = compressedStream.ToArray();
return Convert.ToBase64String(compressedData);
}
}
public static string DecompressString(string compressedText)
{
if (string.IsNullOrEmpty(compressedText))
return null;
byte[] gZipBuffer = Convert.FromBase64String(compressedText);
using (var memoryStream = new MemoryStream())
{
using (var compressedStream = new MemoryStream(gZipBuffer))
{
var decompressedStream = new MemoryStream();
GZip.Decompress(compressedStream, decompressedStream, false);
return Encoding.UTF8.GetString(decompressedStream.ToArray()).Trim();
}
}
}
}
}
you may also find the codes here
If anyone still interested, here's my full solution with outputstream to handle unknown string size. Using C# DeflateStream and Java Inflater (based on Hubert Ströbitzer answer).
C# Compression:
string CompressString(string raw)
{
byte[] uncompressedData = Encoding.UTF8.GetBytes(raw);
MemoryStream output = new MemoryStream();
using (DeflateStream dStream = new DeflateStream(output, CompressionLevel.Optimal))
{
dStream.Write(uncompressedData, 0, uncompressedData.Length);
}
string compressedString = Convert.ToBase64String(output.ToArray());
return compressedString;
}
Java decompress:
String decompressString(String compressedString) {
byte[] compressed = Base64Utils.decodeFromString(compressedString);
Inflater inflater = new Inflater(true);
inflater.setInput(compressed);
//Using output stream to handle unknown size of decompressed string
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
try {
while(!inflater.finished()){
int count = inflater.inflate(buffer);
outputStream.write(buffer, 0, count);
}
inflater.end();
outputStream.close();
} catch (DataFormatException e) {
//Handle DataFormatException
} catch (IOException e) {
//Handle IOException
}
return outputStream.toString();
}
How can I get rid of the CA2202 warning (CA2202 : Microsoft.Usage : Object 'compressedStream' can be disposed more than once in method 'Compression.InternalDecompress(byte[])'. To avoid generating a System.ObjectDisposedException you should not call Dispose more than one time on an object) from the following code:
using (var compressedStream = new MemoryStream(inputData))
using (var zipStream = new GZipStream(compressedStream, CompressionMode.Decompress))
using (var resultStream = new MemoryStream())
{
zipStream.CopyTo(resultStream);
return resultStream.ToArray();
}
I have tried getting rid of the "using" statement and replacing it with try/finally pattern but then I get CA2000 (CA2000 : Microsoft.Reliability : In method 'Compression.InternalDecompress(byte[])', call System.IDisposable.Dispose on object 'stream' before all references to it are out of scope). I have tried replacing the above code like this:
MemoryStream decompressedData = null;
MemoryStream stream = null;
GZipStream decompressor = null;
try
{
decompressedData = new MemoryStream();
stream = new MemoryStream(inputData);
decompressor = new GZipStream(stream, CompressionMode.Decompress, false);
stream = null;
int bytesRead = 1;
int chunkSize = 4096;
byte[] chunk = new byte[chunkSize];
while ((bytesRead = decompressor.Read(chunk, 0, chunkSize)) > 0)
{
decompressedData.Write(chunk, 0, bytesRead);
}
decompressor = null;
return decompressedData.ToArray();
}
finally
{
if (stream != null)
{
stream.Dispose();
}
if (decompressor != null)
{
decompressor.Dispose();
}
if (decompressedData != null)
{
decompressedData.Dispose();
}
}
This is what i use:
public class Compression
{
public Compression()
{
}
public byte[] Compress(byte[] buffer)
{
byte[] gzBuffer;
using (MemoryStream ms = new MemoryStream())
{
using (GZipStream zip = new GZipStream(ms, CompressionMode.Compress, true))
{
zip.Write(buffer, 0, buffer.Length);
zip.Close();
}
ms.Position = 0;
MemoryStream outStream = new MemoryStream();
byte[] compressed = new byte[ms.Length];
ms.Read(compressed, 0, compressed.Length);
gzBuffer = new byte[compressed.Length + 4];
Buffer.BlockCopy(compressed, 0, gzBuffer, 4, compressed.Length);
Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gzBuffer, 0, 4);
}
return gzBuffer;
}
public byte[] Decompress(byte[] gzBuffer)
{
byte[] buffer;
using (MemoryStream ms = new MemoryStream())
{
int msgLength = BitConverter.ToInt32(gzBuffer, 0);
ms.Write(gzBuffer, 4, gzBuffer.Length - 4);
buffer = new byte[msgLength];
ms.Position = 0;
using (GZipStream zip = new GZipStream(ms, CompressionMode.Decompress))
{
zip.Read(buffer, 0, buffer.Length);
}
}
return buffer;
}
}
Or you can just add a pragma statement to your class
#pragma warning disable 2202
namespace Your.Namespace
{
...
}
#pragma warning restore 2202
This is what I ended up using - gets rid of both CA2000 and CA2202:
private static MemoryStream GetMemoryStream()
{
return new MemoryStream();
}
private static byte[] InternalDecompress(byte[] inputData)
{
Debug.Assert(inputData != null, "inputData cannot be null");
MemoryStream decompressedData = GetMemoryStream();
MemoryStream inputDataMemoryStream = GetMemoryStream();
GZipStream decompressor = null;
try
{
inputDataMemoryStream.Write(inputData, 0, inputData.Length);
inputDataMemoryStream.Position = 0;
decompressor = new GZipStream(inputDataMemoryStream, CompressionMode.Decompress, false);
int bytesRead;
int chunkSize = 4096;
byte[] chunk = new byte[chunkSize];
while ((bytesRead = decompressor.Read(chunk, 0, chunkSize)) > 0)
{
decompressedData.Write(chunk, 0, bytesRead);
}
}
finally
{
if (decompressor != null)
{
decompressor.Dispose();
}
}
return decompressedData.ToArray();
}
This is my attempt. It works and it avoids CA2202
/// <summary>
/// Compresses byte array to new byte array.
/// </summary>
public byte[] Compress(byte[] raw)
{
MemoryStream outStream = null;
GZipStream tinyStream = null;
byte[] retValue = null;
try
{
outStream = new MemoryStream();
tinyStream = new GZipStream(outStream, CompressionMode.Compress);
using (var mStream = new MemoryStream(raw))
mStream.CopyTo(tinyStream);
}
finally
{
if (tinyStream != null)
{
tinyStream.Dispose();
retValue = outStream.ToArray();
}
else if (outStream != null)
{
retValue = outStream.ToArray();
outStream.Dispose();
}
}
return retValue;
}
I am writing a C# assembly to take advantage of the GZip functionality in newer versions of the .NET framework, and I am copying code I have used successfully elsewhere.
The way this works is that an application we are using feeds a stream to the assembly, the assembly reads it, compresses it, then returns the compressed result as a string. That string is then put back into the assembly through a stream to uncompress it (normally it will be stored, but I am simply running a basic test).
However, when I feed the string back to the assembly, it errors out while reading it from a byte array that is read from the application's stream. Here is the code:
private void ReadStream(IStream stream, out byte[] data)
{
using (MemoryStream writer = new MemoryStream())
{
IntPtr rwBytes = Marshal.AllocHGlobal(4);
int _rwBytes = 0;
data = new byte[0xafc8];
do
{
stream.Read(data, 0xafc8, rwBytes);
_rwBytes = Marshal.ReadInt32(rwBytes);
writer.Write(data, 0, _rwBytes);
}
while (_rwBytes > 0);
writer.Close();
Marshal.FreeHGlobal(rwBytes);
}
}
public string CompressString([In, MarshalAs(UnmanagedType.AsAny)] object appStream)
{
byte[] buffer = null;
ReadStream(appStream as IStream, out buffer);
MemoryStream ms = new MemoryStream();
using (GZipStream zip = new GZipStream(ms, CompressionMode.Compress, true))
{
zip.Write(buffer, 0, buffer.Length);
}
ms.Position = 0;
MemoryStream outStream = new MemoryStream();
byte[] compressed = new byte[ms.Length];
ms.Read(compressed, 0, compressed.Length);
byte[] gzBuffer = new byte[compressed.Length + 4];
System.Buffer.BlockCopy(compressed, 0, gzBuffer, 4, compressed.Length);
System.Buffer.BlockCopy(BitConverter.GetBytes(buffer.Length), 0, gzBuffer, 0, 4);
string str = Convert.ToBase64String(gzBuffer);
gzBuffer = Convert.FromBase64String(str);
return str;
}
public string DecompressString([In, MarshalAs(UnmanagedType.AsAny)] object appStream)
{
byte[] buffer = null;
ReadStream(appStream as IStream, out buffer);
string compressedText = Encoding.UTF8.GetString(buffer);
byte[] gzBuffer = Convert.FromBase64String(compressedText);
using (MemoryStream ms = new MemoryStream())
{
int msgLength = BitConverter.ToInt32(gzBuffer, 0);
ms.Write(gzBuffer, 4, gzBuffer.Length - 4);
buffer = new byte[msgLength];
ms.Position = 0;
using (GZipStream zip = new GZipStream(ms, CompressionMode.Decompress))
{
zip.Read(buffer, 0, buffer.Length);
}
}
return Encoding.UTF8.GetString(buffer);
}
The string is returned from the CompressString function as:
yK8AAB+LCAAAAAAABADtvQdgHEmWJSYvbcp7f0r1StfgdKEIgGATJNiQQBDswYjN5pLsHWlHIymrKoHKZVZlXWYWQMztnbz33nvvvffee++997o7nU4n99//P1xmZAFs9s5K2smeIYCqyB8/fnwfPyK+ndd5WjRplk6rxarOm6aolmmbN+04TZ/n7cdN2uTU4jwt2vSqqt8241/jR8+Pnh89P3p+9Pzo+dHzo+dHz4+eHz0/en70/Oj50fOj50fPj54fPT96fvT86PnR86PnR8+Pnh89P3p+9Pzo+dHz/67nR9j86PnR86PnR8+Pnh89P3p+9Pzo+dHzo+dHz4+eHz0/en70/Oj50fOj50fPj54fPT96fvT86PnR86PnR8+Pnh89/99/fjSCHz0/en70/Oj50fOj50fPj54fPT96fvT86PnR86PnR8+Pnh89P3p+9Pzo+dHzo+dHz4+eHz0/en70/Oj50fOj5//7z49G8KPnR8+Pnh89P3p+9Pzo+dHzo+dHz4+eHz0/en70/Oj50fOj50fPj54fPT96fvT86PnR86PnR8+Pnh89P3p+9Px///nRCH70/Oj50fOj50fPj54fPT96fvT86PnR86PnR8+Pnh89P3p+9Pzo+dHzo+dHz4+eHz0/en70/Oj50fOj50fPj57/7z8/GsGPnh89P3p+9Pzo+dHzo+dHz4+eHz0/en70/Oj50fP/nef/AYk/UbjIrwAA
When it is read back from the stream in the Encoding.UTF8.GetString call, it is:
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
These strings are identical. I can even convert it back and forth in the CompressString function with no problem. Any thoughts out there? This is very strange.
Don't use UTF8, you should use the ascii text encoding instead. When you get the bytes from your string, you'll end up with some extra bytes due to the way UTF strings are encoded.