convert C++ istringstream usage to C# - c#

I am rewriting some code and wondering how I can convert this from C++ to C#:
istringstream vertexString = new istringstream(s);
//number of vertices
int numVertices;
vertexString>>numVertices;

Add this to a static string utility class:
public static Stream ToStream(this string str)
{
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(str);
writer.Flush();
stream.Position = 0;
return stream;
}
Use like this. s must be string.
int numVertices;
using (var stringStream = s.ToStream())
{
stringStream>>numVertices;
}

Related

How to Serialize Avro to a byte array using Avro c# library?

I am looking for a way to serialize Avro to a byte array in Avro C# library. There is a link to do for Avro Java library as described in following link from Avro documentation:
https://cwiki.apache.org/confluence/display/AVRO/FAQ#FAQ-Serializingtoabytearray
Code copied from above link:
ByteArrayOutputStream out = new ByteArrayOutputStream();
BinaryEncoder encoder = EncoderFactory.get().binaryEncoder(out, null);
DatumWriter<User> writer = new SpecificDatumWriter<User>(User.getClassSchema());
writer.write(user, encoder);
encoder.flush();
out.close();
byte[] serializedBytes = out.toByteArray();
But I have not found a way to do in Avro c# library. I am basically looking for c# equivalent of above code.
You can use these methods to convert to and from an object to a byte array or vice-versa. Code extracted from https://stackoverflow.com/a/18205093/6138713
// Convert an object to a byte array
private byte[] ObjectToByteArray(Object obj)
{
if(obj == null)
return null;
BinaryFormatter bf = new BinaryFormatter();
MemoryStream ms = new MemoryStream();
bf.Serialize(ms, obj);
return ms.ToArray();
}
// Convert a byte array to an Object
private Object ByteArrayToObject(byte[] arrBytes)
{
MemoryStream memStream = new MemoryStream();
BinaryFormatter binForm = new BinaryFormatter();
memStream.Write(arrBytes, 0, arrBytes.Length);
memStream.Seek(0, SeekOrigin.Begin);
Object obj = (Object) binForm.Deserialize(memStream);
return obj;
}
Maybe something as follows, I used the following code to write to a Kineses Stream
public async Task RecordAsync(ISpecificRecord record, string partitionKey)
{
using (var ms = new MemoryStream())
{
var encoder = new BinaryEncoder(ms);
var writer = new SpecificDefaultWriter(record.Schema);
writer.Write(record, encoder);
// AWS Kineses
var putRecordRequest = new PutRecordRequest
{
StreamName = _streamName,
Data = ms,
PartitionKey = partitionKey
};
await _kinesis.PutRecordAsync(putRecordRequest);
}
}
or
public byte[] Serialize(ISpecificRecord record)
{
using (var ms = new MemoryStream())
{
var encoder = new BinaryEncoder(ms);
var writer = new SpecificDefaultWriter(record.Schema);
writer.Write(record, encoder);
return ms.ToArray();
}
}

Dispose writer after memoryStream

This is a piece of my code:
private static MemoryStream outputStream;
public static void ConvertMp3ToWavStream(string inputPath)
{
outputStream = new MemoryStream();
using (Mp3FileReader reader = new Mp3FileReader(inputPath))
{
using (WaveStream waveStream = WaveFormatConversionStream.CreatePcmStream(reader))
{
WaveFileWriter waveFileWriter = new WaveFileWriter(outputStream, waveStream.WaveFormat);
byte[] bytes = new byte[waveStream.Length];
waveStream.Position = 0;
waveStream.Read(bytes, 0, (int)waveStream.Length);
waveFileWriter.Write(bytes, 0, bytes.Length);
waveFileWriter.Flush();
}
}
}
This is my CloseAndDispose method, which I invoke after some manipulations:
private static void CloseAndDispose()
{
if (outputStream != null)
{
outputStream.Close();
outputStream.Dispose();
}
}
The problem: after all actions I've got some memory in memory stack, which wasn't disposed. As I understand, It's my writer. When I try to dispose writer, I get an exception. (can't read MemoryStream). When I try to close and dispose writer after CloseAndDispose() method, I get an exception. Where should I close waveFileWriter?
NAudio has a helper class called IgnoreDisposeStream in the NAudio.Utils namespace. Wrap your memory stream in one of those before passing it into the WaveFileWriter
using (var writer = new WaveFileWriter(new IgnoreDisposeStream(outputStream),
waveStream.WaveFormat))
{
...
}
You could pass a local MemoryStream to WaveFileWriter and copy it to the global one before it's disposed:
public static void ConvertMp3ToWavStream(string inputPath)
{
outputStream = new MemoryStream();
var outputStreamLocal = new MemoryStream();
using (...
{
using (var waveFileWriter = new WaveFileWriter(outputStreamLocal, ...
{
...
outputStreamLocal.CopyTo(outputStream);
}
}
}

How to merge two memory streams?

I have two MemoryStream instances.
How to merge them into one instance?
Well, now I can't copy from one MemoryStream to another.
Here is a method:
public static Stream ZipFiles(IEnumerable<FileToZip> filesToZip) {
ZipStorer storer = null;
MemoryStream result = null;
try {
MemoryStream memory = new MemoryStream(1024);
storer = ZipStorer.Create(memory, GetDateTimeInRuFormat());
foreach (var currentFilePath in filesToZip) {
string fileName = Path.GetFileName(currentFilePath.FullPath);
storer.AddFile(ZipStorer.Compression.Deflate, currentFilePath.FullPath, fileName,
GetDateTimeInRuFormat());
}
result = new MemoryStream((int) storer.ZipFileStream.Length);
storer.ZipFileStream.CopyTo(result); //Does not work!
//result's length will be zero
}
catch (Exception) {
}
finally {
if (storer != null)
storer.Close();
}
return result;
}
Spectacularly easy with CopyTo or CopyToAsync:
var streamOne = new MemoryStream();
FillThisStreamUp(streamOne);
var streamTwo = new MemoryStream();
DoSomethingToThisStreamLol(streamTwo);
streamTwo.CopyTo(streamOne); // streamOne holds the contents of both
The framework, people. The framework.
Based on the answer shared by #Will above, here is complete code:
void Main()
{
var s1 = GetStreamFromString("Hello");
var s2 = GetStreamFromString(" World");
var s3 = s1.Append(s2);
Console.WriteLine(Encoding.UTF8.GetString((s3 as MemoryStream).ToArray()));
}
public static Stream GetStreamFromString(string text)
{
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(text);
writer.Flush();
stream.Position = 0;
return stream;
}
public static class Extensions
{
public static Stream Append(this Stream destination, Stream source)
{
destination.Position = destination.Length;
source.CopyTo(destination);
return destination;
}
}
And merging stream collection with async:
async Task Main()
{
var list = new List<Task<Stream>> { GetStreamFromStringAsync("Hello"), GetStreamFromStringAsync(" World") };
Stream stream = await list
.Select(async item => await item)
.Aggregate((current, next) => Task.FromResult(current.Result.Append(next.Result)));
Console.WriteLine(Encoding.UTF8.GetString((stream as MemoryStream).ToArray()));
}
public static Task<Stream> GetStreamFromStringAsync(string text)
{
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(text);
writer.Flush();
stream.Position = 0;
return Task.FromResult(stream as Stream);
}
public static class Extensions
{
public static Stream Append(this Stream destination, Stream source)
{
destination.Position = destination.Length;
source.CopyTo(destination);
return destination;
}
}
Create third(let it be mergedStream) MemoryStream with length
equal to sum of first and second lengths
Write first MemoryStream to mergedStream (use GetBuffer() to
get byte[] from MemoryStream)
Write second MemoryStream to mergedStream(use GetBuffer())
Remember about offset while writing.
It's rather append, but it's totally unclear what is merge operation on MemoryStreams

Why StringWriter.ToString return `System.Byte[]` and not the data?

UnZipFile method writes the data from inputStream to outputWriter.
Why sr.ToString() returns System.Byte[] and not the data?
using (var sr = new StringWriter())
{
UnZipFile(response.GetResponseStream(), sr);
var content = sr.ToString();
}
public static void UnZipFile(Stream inputStream, TextWriter outputWriter)
{
using (var zipStream = new ZipInputStream(inputStream))
{
ZipEntry currentEntry;
if ((currentEntry = zipStream.GetNextEntry()) != null)
{
var size = 2048;
var data = new byte[size];
while (true)
{
size = zipStream.Read(data, 0, size);
if (size > 0)
{
outputWriter.Write(data);
}
else
{
break;
}
}
}
}
}
The problem is on the line:
outputWriter.Write(data);
StringWriter.Write has no overload expecting a byte[]. Therefore, Write(Object) is called instead. And according to MSDN:
Writes the text representation of an object to the text string or stream by calling the ToString method on that object.
Calling ToString on a byte array returns System.byte[], explaining how you get that string in your StringWriter.
The reason is simple:
data is of type byte[]. There is no overload for byte[] on StringWriter so it uses the overload for object. And then calls ToString() on the boxed byte array which simply prints the type.
Your code is equivalent to this:
outputWriter.Write(data.ToString());
theateist,
Looking at the other answers here, I am going to have to agree that the reason for the "ToString()" returning System.Byte[] is because that is what you are putting into it, and everything put into the StringWriter calls it's own "ToString" method when doing so. (i.e. byte[].toString() = "System.byte[]"). In fact the whole idea is that the StringWriter is only ment for writing into a string "buffer" (StringBuilder), so in theory if your file was large enough(bigger than 2048), your output would be "System.Byte[]System.Byte[]" (etc.). Try this to deflate into a memory stream and then read from that stream, may be a better understanding of what you are looking at. (Code not tested, just example).
using (Stream ms = new MemoryStream())
{
UnZipFile(response.GetResponseStream(), ms);
string content;
ms.Position = 0;
using(StreamReader s = new StreamReader(ms))
{
content = s.ReadToEnd();
}
}
public static void UnZipFile(Stream inputStream, Stream outputWriter)
{
using (var zipStream = new ZipInputStream(inputStream))
{
ZipEntry currentEntry;
if ((currentEntry = zipStream.GetNextEntry()) != null)
{
int size = 2048;
byte[] data = new byte[size];
while (true)
{
size = zipStream.Read(data, 0, size);
if (size > 0)
{
outputWriter.Write(data);
}
else
{
break;
}
}
}
}
}
Another idea would actually be to using the endcoding to get the string
public string UnZipFile(Stream inputStream)
{
string tmp;
using(Stream zipStream = new ZipInputStream(inputStream))
{
ZipEntry currentEntry;
if(currentEntry = zipStream.GetNextEntry()) != null)
{
using(Stream ms = new MemoryStream())
{
int size = 2048;
byte[] data = new byte[size];
while(true)
{
if((size = zipStream.Read(data,0,size)) > 0)
ms.Write(data);
else
break;
}
tmp = Encoding.Default.GetString(ms.ToByteArray());
}
}
}
}
return tmp;
}
Or as one last idea, you could actually change your original code to have
outputWriter.Write(Encoding.Default.GetString(data));
Instead of
outputWriter.Write(data);
By the way, please avoid the var keyword in posts, maybe just my pet peev, but code is less readable when utilizing weak types.
StringWriter.Write:MSDN
StringWriter.ToString:MSDN

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

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