From lispercat at gmail.com  Wed May 30 14:42:40 2007
From: lispercat at gmail.com (Andrei Stebakov)
Date: Wed, 30 May 2007 10:42:40 -0400
Subject: [cl-gd-devel] Image to array of bytes
Message-ID: <affe56e00705300742h495f9b1ei85dafd60e63ddde1@mail.gmail.com>

Instead of saving an image into a file using write-image-to-file I was
trying to provide a hunchentoot handler which outputs an array of bytes
(just like in the hunchentoot test.lisp image-ram-page example). For this I
thought write-jpeg-to-stream would be the best candidate so I did following:

  (let ((s (make-string-output-stream :element-type '(unsigned-byte 8))))
        (write-jpeg-to-stream s :image bg-image)
        (let ((image-data (make-array (image-size bg-image) :element-type
'(unsigned-byte 8))))
          (read-sequence image-data s)
          image-data)))))))

For which the SBCL complains:
#<SB-IMPL::STRING-OUTPUT-STREAM {CE6D171}> is not a binary output stream.

I am wondering if I am doing the right thing and choosing the right function
for the task. I also tried to create a stream with
flexi-stream:make-in-memory-output-stream
without any success.

Thank you,
Andrew
**
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.common-lisp.net/pipermail/cl-gd-devel/attachments/20070530/63df5895/attachment.html>

From edi at agharta.de  Wed May 30 15:10:40 2007
From: edi at agharta.de (Edi Weitz)
Date: Wed, 30 May 2007 17:10:40 +0200
Subject: [cl-gd-devel] Image to array of bytes
In-Reply-To: <affe56e00705300742h495f9b1ei85dafd60e63ddde1@mail.gmail.com>
	(Andrei Stebakov's message of "Wed, 30 May 2007 10:42:40 -0400")
References: <affe56e00705300742h495f9b1ei85dafd60e63ddde1@mail.gmail.com>
Message-ID: <ups4iwdn3.fsf@agharta.de>

On Wed, 30 May 2007 10:42:40 -0400, "Andrei Stebakov" <lispercat at gmail.com> wrote:

> Instead of saving an image into a file using write-image-to-file I
> was trying to provide a hunchentoot handler which outputs an array
> of bytes (just like in the hunchentoot test.lisp image-ram-page
> example). For this I thought write-jpeg-to-stream would be the best
> candidate so I did following:
>
>   (let ((s (make-string-output-stream :element-type '(unsigned-byte 8))))
>         (write-jpeg-to-stream s :image bg-image)
>         (let ((image-data (make-array (image-size bg-image) :element-type
> '(unsigned-byte 8))))
>           (read-sequence image-data s)
>           image-data)))))))
>
> For which the SBCL complains:
> #<SB-IMPL::STRING-OUTPUT-STREAM {CE6D171}> is not a binary output stream.
>
> I am wondering if I am doing the right thing and choosing the right
> function for the task. I also tried to create a stream with
> flexi-stream:make-in-memory-output-stream without any success.

MAKE-STRING-OUTPUT-STREAM can't work because it's a /string/ stream,
as the name says.  The FLEXI-STREAMS approach should work, though.  If
it doesn't, show us your code.

I wonder why you're doing all this, though.  Why don't you write
directly to the Hunchentoot stream?  (You know about SEND-HEADERS,
don't you?)

Cheers,
Edi.


From lispercat at gmail.com  Wed May 30 16:55:24 2007
From: lispercat at gmail.com (Andrei Stebakov)
Date: Wed, 30 May 2007 12:55:24 -0400
Subject: [cl-gd-devel] Image to array of bytes
In-Reply-To: <ups4iwdn3.fsf@agharta.de>
References: <affe56e00705300742h495f9b1ei85dafd60e63ddde1@mail.gmail.com>
	<ups4iwdn3.fsf@agharta.de>
Message-ID: <affe56e00705300955l6b1686d8w731fc136d55caddf@mail.gmail.com>

Thanks, Edi. I didn't know about send-headers. Now everything works.


On 5/30/07, Edi Weitz <edi at agharta.de> wrote:
>
> On Wed, 30 May 2007 10:42:40 -0400, "Andrei Stebakov" <lispercat at gmail.com>
> wrote:
>
> > Instead of saving an image into a file using write-image-to-file I
> > was trying to provide a hunchentoot handler which outputs an array
> > of bytes (just like in the hunchentoot test.lisp image-ram-page
> > example). For this I thought write-jpeg-to-stream would be the best
> > candidate so I did following:
> >
> >   (let ((s (make-string-output-stream :element-type '(unsigned-byte
> 8))))
> >         (write-jpeg-to-stream s :image bg-image)
> >         (let ((image-data (make-array (image-size bg-image)
> :element-type
> > '(unsigned-byte 8))))
> >           (read-sequence image-data s)
> >           image-data)))))))
> >
> > For which the SBCL complains:
> > #<SB-IMPL::STRING-OUTPUT-STREAM {CE6D171}> is not a binary output
> stream.
> >
> > I am wondering if I am doing the right thing and choosing the right
> > function for the task. I also tried to create a stream with
> > flexi-stream:make-in-memory-output-stream without any success.
>
> MAKE-STRING-OUTPUT-STREAM can't work because it's a /string/ stream,
> as the name says.  The FLEXI-STREAMS approach should work, though.  If
> it doesn't, show us your code.
>
> I wonder why you're doing all this, though.  Why don't you write
> directly to the Hunchentoot stream?  (You know about SEND-HEADERS,
> don't you?)
>
> Cheers,
> Edi.
> _______________________________________________
> cl-gd-devel site list
> cl-gd-devel at common-lisp.net
> http://common-lisp.net/mailman/listinfo/cl-gd-devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.common-lisp.net/pipermail/cl-gd-devel/attachments/20070530/2abf03c1/attachment.html>