[SOLVED] Ptr<Stream> arg to Blob constructor?

[ataylor]

I am trying to use a Blob to compress an existing file on disk:

Unigine::FilePtr fileIn = Unigine::File::create("someFile", "rb");
Unigine::FilePtr fileOut = Unigine::File::create("someOtherFile", "wb");
Unigine::BlobPtr blob=Unigine::Blob::create(fileIn->getStream());
blob->compress(fileOut->getStream(), 1);

But engine crashes inside Blob::compress function.

 

I see that there is another Blob constructor -- Blob::create(size_t size=0). If I use this function to create the Blob, there is no crash. fileOut is written successfully but of course has almost no content as the blob is empty. I assume I would need to manually read in the bytes of fileIn and write them to blob. This is OK, but if there is a way to have this done automatically I would prefer that.

Documentation for Blob class only shows a single create() function, and it seems wrong:

 

Ptr<Blob> create (const Ptr<Stream> & stream)

Blob constructor.

Arguments

• const Ptr<Stream> & stream - Size of the blob in bytes.

 

 

 

Is there a working example of initializing a Blob from a Stream?

[ded]

Hi,

 

I'm afraid there is flaw in the API.

Ptr<Blob> create (const Ptr<Stream> & stream);

Really should be declared as:

Ptr<Blob> create (const Ptr<Blob> & stream)

It's a copy constructor for a Blob.

 

 

Blob has no functionality to read all data from the another stream.

You'll have to read the file contents yourself, for example like this:

while (!fileIn->eof())
  fileIn->readStream(blob->getStream(), BUF_SIZE);

We'll fix the constructor signature, thank you for noticing the issue and sorry for the inconvenience caused.

[ataylor]

Okay, thanks, can mark as solved.