[hunchentoot-devel] Hunchentoot data-transfers seem slow

[Edi Weitz]

On Wed, 21 Mar 2007 20:57:12 +0000, "Robert Synnott" <rsynnott at gmail.com> wrote:

> The function which just sent back a big file was simply:
>
> (defun speedtest () *big-string*)
>
> where *big-string* contained the contents of a 700kb text file.

OK, I see.  The culprit /is/ FLEXI-STREAMS, but there's not much to do
about it in the general case.  Its WRITE-SEQUENCE function gets a
string and loops through it element by element calling WRITE-CHAR for
each one in turn.  This is necessary because a) the sequences you can
output with FLEXI-STREAMS can be almost anything, even lists or
vectors containing a mixture of octets and characters and b) you can't
know in advance whether you'll have encoding errors further down the
string.

I have a crude optimization for some special cases which I'll release
one of these days, but it is just that - a crude optimization for
special cases.

To solve your problem there are at least two ways, though:

1. To output a static file you shouldn't keep the file in memory
   anyway - use CREATE-STATIC-FILE-DISPATCHER-AND-HANDLER instead (or
   see HANDLE-STATIC-FILE).

2. If you insist on using a variable like above and you know its
   contents in advance, convert it to an array of element type
   FLEX:OCTET, i.e. (UNSIGNED-BYTE 8), and let the handler return this
   array.  (This is the only "optimization" that'll always work with
   FLEXI-STREAMS.)

In both cases, the transfer rate should be in the ballpark of Apache
handling static files.  Let us know if it's not.

HTH,
Edi.