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Zipping Two File with Same Content and Encoding them to base64 giving different response

I need to encode the zip file in base64 formats.
I followed the following approach
string text = File.ReadAllText("../../../SampleDat.dat");
byte[] compress0 = Compress(stringbyte);
string short_com0 = base64_encode(compress0);
public static byte[] Compress(byte[] data)
{
using (var compressedStream = new MemoryStream())
using (var zipStream = new GZipStream(compressedStream, CompressionMode.Compress))
{
zipStream.Write(data, 0, data.Length);
zipStream.Close();
return compressedStream.ToArray();
}
}
public string base64_encode(byte[] data)
{
if (data == null)
throw new ArgumentNullException("data");
return Convert.ToBase64String(data);
}
After using this I got this encoded string.
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
When I created zip manually and read file in the code and compress that file
//file zipped manually
string filePath1 = "../../../git_only/oraclehcm1/dbscripts/SampleDat.zip";
byte[] physicalfile1 = File.ReadAllBytes(filePath1);
string long_com1 = base64_encode(physicalfile1);
The response I get is
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
This is the actual response . I also noticed the two zip are of the different size and the zip I which I created programmatically , The files in this zip have no extensions.
Please help me to create the second encoding through program and > .NET version I am using is 4.5
and I cannot use Zip.createDirectory() method due to project dependencies.
Any help is appreaciated .
Thanks in Advnance!

The first one is a gzip file, the second one is a zip file. If you want to make a zip file, try the ZipFile class as opposed to the GZipStream class.

I wouldn't expect two different Zip algorithms/libraries to yield the same output. For one, in the programmatic way, the file metadata (name, modification date, attributes) are not set, while the command line version will include all that information for unzipping purposes.
Plus libraries update at different cadence than standalones, and you might not have the fixes synchronized to reliably match the outputs.

Stream video from RavenDB through ASP.Net MVC

I'm trying to stream a Video, that is saved as an attachment in a Ravendb-Database, through an ASP.NET MVC 5 Action to a WebBrowser. It is working with the following Code, but the Video gets fully downloaded before the Video starts. I don't get what I'm doing wrong.
I found some ways to do Streaming in MVC, but they seem to expect a Seekable Stream - but the stream I receive from Ravendb is not seekable; it even does not provide a length. So the only way of doing it would be to copy the ravendb-stream to a memorystream and provide a PartialContent or similar from there.
Does anybody have a better solution? I cannot be the only one that wants to stream a Video from a database without loading the full Video into Memory before sending it.
I'm fetching the attachment from ravendb like this:
public async Task<System.IO.Stream> GetAttachmentAsync(IAttachmentPossible attachedObject, string key)
{
using (var ds = InitDatabase())
{
using (var session = ds.OpenAsyncSession())
{
try
{
var result = await session.Advanced.Attachments.GetAsync(attachedObject.Id, key);
return result.Stream;
}
catch (Exception ex)
{
return null;
}
}
}
}
After that I send the stream to the browser like this:
var file = await _database.GetAttachmentAsync(entry, attachmentId);
HttpResponseMessage msg = new HttpResponseMessage(HttpStatusCode.OK);
msg.Content = new StreamContent(file);
msg.Content.Headers.ContentType = new MediaTypeHeaderValue("video/mp4");
return msg;
Any ideas? Thank you very much!

I think that it is correct to copy the stream into a memory stream. With the answer you linked (https://stackoverflow.com/a/39247028/10291808) you can do streaming.
Maybe could be an idea to think about the multiple calls that will done to retrieve the file from the db (maybe you could cache the file for a limited time to improve performance).

Using MemoryStream Send .txt attachment with email?

I have been looking through many answers on this I just can't quite seem to understand how to do it though, even if its glaringly obvious.
I want to write values from a table in my database to a text file and attach the text file to an email without storing it locally. I am using Sendgrid API to manage sending the email and I was attempting to use MemoryStream to store the data.
Below is what I have attempted
private MemoryStream WriteToTextFile(IEnumerable<Location> locations)
{
MemoryStream memoryStream = new MemoryStream();
using (StreamWriter streamWriter = new StreamWriter(memoryStream))
{
foreach (var location in locations)
{
streamWriter.WriteLine($"{location.Time},{location.Location},{ location.LocationAccuracy},{ location.IsAlertRaised}");
}
streamWriter.Flush();
}
return memoryStream;
}
Then my attempt to attach it to the email
memoryStream.Seek(0, SeekOrigin.Begin);
var message = MailHelper.CreateSingleEmail(from, to, subject, plainTextContent, htmlContent);
message.AddAttachment(memoryStream, fileName);
var response = await _client.SendEmailAsync(message);
memoryStream.Dispose();
The error is straightforward "cannot convert from 'System.IO.MemoryStream' to 'string'
The solution I was attempting was based on a question asked here.
AddAttachment from MemoryStream

There are two problems here.
The using block in the first sample will call streamWriter.Dispose() before returning the stream. The Dispose() operation will close your MemoryStream, leaving it unusable.
The example code from your link seems to be using a different, possibly older, version of the SendGrid API. Looking at the current API, the only overload from the AddAttachment() family that accepts a stream looks like this:
public async Task AddAttachmentAsync(string filename, Stream contentStream, string type = null, string disposition = null, string content_id = null, CancellationToken cancellationToken = default(CancellationToken))
All of the other options required a base64content string instead. You can also just read the code for the method in the API link above for a good example of how to convert that stream to base64.

Zip within a zip opens to undocumented System.IO.Compression.SubReadStream

I have a function I use for aggregating streams from a zip archive.
private void ExtractMiscellaneousFiles()
{
foreach (var miscellaneousFileName in _fileData.MiscellaneousFileNames)
{
var fileEntry = _archive.GetEntry(miscellaneousFileName);
if (fileEntry == null)
{
throw new ZipArchiveMissingFileException("Couldn't find " + miscellaneousFileName);
}
var stream = fileEntry.Open();
OtherFileStreams.Add(miscellaneousFileName, (DeflateStream) stream);
}
}
This works well in most cases. However, if I have a zip within a zip, I get an excpetion on casting the stream to a DeflateStream:
System.InvalidCastException: Unable to cast object of type 'System.IO.Compression.SubReadStream' to type 'System.IO.Compression.DeflateStream'.
I am unable to find Microsoft documentation for a SubReadStream. I would like my zip within a zip as a DeflateStream. Is this possible? If so how?
UPDATE
Still no success. I attempted #Sunshine's suggestion of copying the stream using the following code:
private void ExtractMiscellaneousFiles()
{
_logger.Log("Extracting misc files...");
foreach (var miscellaneousFileName in _fileData.MiscellaneousFileNames)
{
_logger.Log($"Opening misc file stream for {miscellaneousFileName}");
var fileEntry = _archive.GetEntry(miscellaneousFileName);
if (fileEntry == null)
{
throw new ZipArchiveMissingFileException("Couldn't find " + miscellaneousFileName);
}
var openStream = fileEntry.Open();
var deflateStream = openStream;
if (!(deflateStream is DeflateStream))
{
var memoryStream = new MemoryStream();
deflateStream.CopyTo(memoryStream);
memoryStream.Position = 0;
deflateStream = new DeflateStream(memoryStream, CompressionLevel.NoCompression, true);
}
OtherFileStreams.Add(miscellaneousFileName, (DeflateStream)deflateStream);
}
}
But I get a
System.NotSupportedException: Stream does not support reading.
I inspected deflateStream.CanRead and it is true.
I've discovered this happens not just on zips, but on files that are in the zip but are not compressed (because too small, for example). Surely there's a way to deal with this; surely someone has encountered this before. I'm opening a bounty on this question.
Here's the .NET source for SubReadStream, thanks to #Quantic.

The return type of ZipArchiveEntry.Open() is Stream. An abstract type, in practice it can be a DeflateStream (you'd be happy), a SubReadStream (boo) or a WrappedStream (boo). Woe be you if they decide to improve the class some day and use a ZopfliStream (boo). The workaround is not good, you are trying to deflate data that is not compressed (boo).
Too many boos.
Only good solution is to change the type of your OtherFileStreams member. We can't see it, smells like a List<DeflateStream>. It needs to be a List<Stream>.

So it looks like the when storing a zip file inside another zip it doesn't deflate the zip but rather just inlines the content of the zip with the rest of the files with some information that these entries are part of a sub zip file. Which makes sense because applying compression to something that is already compressed is a waste of time.
This zip file is marked as CompressionMethodValues.Stored in the archive, which causes .NET to just return the original stream it read instead to wrapping it in a DeflateStream.
Source here: https://github.com/dotnet/corefx/blob/master/src/System.IO.Compression/src/System/IO/Compression/ZipArchiveEntry.cs#L670
You could pass the stream into a ZipArchive, if it's not a DeflateStream (if you are interested in the file inside)
var stream = entry.Open();
if (!(stream is DeflateStream))
{
var subArchive = new ZipArchive(stream);
}
Or you can copy the stream to a FileStream (if you want to save it to disk)
var stream = entry.Open();
if (!(stream is DeflateStream))
{
var fs = File.Create(Path.GetTempFileName());
stream.CopyTo(fs);
fs.Close();
}
Or copy to any stream you are interested in using.
Note: This is also how .NET 4.6 behaves

AddAttachment from MemoryStream

The SendGrid API docs specify you can add attachments from a Stream. The example it gives uses a FileStream object.
I have some blobs in Azure Storage which I'd like to email as attachments. To achieve this I'm trying to use a MemoryStream:
var getBlob = blobContainer.GetBlobReferenceFromServer(fileUploadLink.Name);
if(getBlob != null)
{
// Get file as a stream
MemoryStream memoryStream = new MemoryStream();
getBlob.DownloadToStream(memoryStream);
emailMessage.AddAttachment(memoryStream, fileUploadLink.Name);
}
emailTransport.Deliver(emailMessage);
It sends fine but when the email arrives, the attachment appears to be there but it's actually empty. Looking at the email source, there is no content for the attachment.
Is using a MemoryStream a known limitation when using the SendGrid C# API to send attachments? Or should I be approaching this in some other way?

You probably just need to reset the stream position back to 0 after you call DownloadToStream:
var getBlob = blobContainer.GetBlobReferenceFromServer(fileUploadLink.Name);
if (getBlob != null)
{
var memoryStream = new MemoryStream();
getBlob.DownloadToStream(memoryStream);
memoryStream.Seek(0,SeekOrigin.Begin); // Reset stream back to beginning
emailMessage.AddAttachment(memoryStream, fileUploadLink.Name);
}
emailTransport.Deliver(emailMessage);
You might want to check who cleans up the stream as well and if they don't you should dispose of it after you've called Deliver().

According to their API, they have implemented void AddAttachment(Stream stream, String name).
You are probably using a MemoryStream which you have written to before. I suggest resetting the position inside the stream to the beginning, like:
memoryStream.Seek(0, SeekOrigin.Begin);

I ended up with the following which fixed the issue for me:
fileByteArray = new byte[getBlob.Properties.Length];
getBlob.DownloadToByteArray(fileByteArray, 0);
attachmentFileStream = new MemoryStream(fileByteArray);
emailMessage.AddAttachment(attachmentFileStream, fileUploadLink.Name);

The thread is a bit old, but I use a varient with NReco PDF converter:
private async Task SendGridasyncBid(string from, string to, string displayName, string subject, **byte[] PDFBody**, string TxtBody, string HtmlBody)
{
...
var myStream = new System.IO.MemoryStream(**PDFBody**);
myStream.Seek(0, SeekOrigin.Begin);
myMessage.AddAttachment(myStream, "NewBid.pdf");
...
}
convert the html to pdf and return it instead of writing it for download...
private byte[] getHTML(newBidViewModel model)
{
string strHtml = ...;
HtmlToPdfConverter pdfConverter = new HtmlToPdfConverter();
pdfConverter.CustomWkHtmlArgs = "--page-size Letter";
var pdfBytes = pdfConverter.GeneratePdf(strHtml);
return **pdfBytes**;
}
I am not sure how efficient this is, but it is working for me and I hope it helps someone else get their attachments figured out.