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Posted to dev@httpd.apache.org by Dean Gaudet <dg...@arctic.org> on 1998/02/09 07:20:28 UTC
[contrib] mod_mmap_static.c v0.03
v0.02 assumed that if it found a file during the translate_name phase that
the file would stay constant all the way to the run_request phase... not
true, consider mod_negotiation. There were a few other minor logic bugs
in the mmap_static_handler that were fixed.
Note the "Known Problems", there's an API deficiency... I'd really love a
get_metadata() phase which does the r->finfo and r->path_info processing.
Dean
/*
* mod_mmap_static: mmap a config-time list of files for faster serving
*
* v0.03
*
* Author: Dean Gaudet <dg...@arctic.org>
*
* This code would be available under the same license as the Apache server
* itself, but unfortunately that license doesn't really allow for third
* parties to distribute code under it. So since I'm just too plain
* lazy to copy another license in here, I'll just have to do this:
*
* Copyright (c) 1998 Dean Gaudet, all rights reserved.
*
* v0.01: initial implementation
* v0.02: get rid of the extra stat() in the core by filling in what we know
* v0.03: get rid of the cached match from the xlat routine since there are
* many cases where the request is modified between it and the
* handler... so we do the binary search twice, but the second time
* we can use st_ino and st_dev to speed it up.
*/
/*
Documentation:
The concept is simple. Some sites have a set of static files that are
really busy, and change infrequently (or even on a regular schedule).
Save time by mmap()ing these files into memory and avoid a lot of the
crap required to do normal file serving. Place directives such as:
mmapfile /path/to/file1
mmapfile /path/to/file2
...
into your configuration. These files are only mmap()d when the server
is restarted, so if you change the list, or if the files are changed,
then you'll need to restart the server.
To reiterate that point: if the files are modified *in place*
without restarting the server you may end up serving requests that
are completely bogus. You should update files by unlinking the old
copy and putting a new copy in place. Most tools such as rdist and
mv do this.
There's no such thing as inheriting these files across vhosts or
whatever... place the directives in the main server only.
Known problems:
Don't use Alias or RewriteRule to move these files around... unless
you feel like paying for an extra stat() on each request. This is
a deficiency in the Apache API that will hopefully be solved some day.
The file will be served out of the mmap cache, but there will be
an extra stat() that's a waste.
*/
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include "httpd.h"
#include "http_config.h"
#include "http_log.h"
#include "http_protocol.h"
#include "http_request.h"
module MODULE_VAR_EXPORT mmap_static_module;
typedef struct {
char *filename;
void *mm;
struct stat finfo;
} a_file;
typedef struct {
array_header *files;
array_header *inode_sorted;
} a_server_config;
static void *create_server_config(pool *p, server_rec *s)
{
a_server_config *sconf = palloc(p, sizeof(*sconf));
sconf->files = make_array(p, 20, sizeof(a_file));
sconf->inode_sorted = NULL;
return sconf;
}
static void cleanup_mmap(void *sconfv)
{
a_server_config *sconf = sconfv;
size_t n;
a_file *file;
n = sconf->files->nelts;
file = (a_file *)sconf->files->elts;
while(n) {
munmap(file->mm, file->finfo.st_size);
++file;
--n;
}
}
static const char *mmapfile(cmd_parms *cmd, void *dummy, char *filename)
{
a_server_config *sconf;
a_file *new_file;
a_file tmp;
int fd;
caddr_t mm;
if (stat(filename, &tmp.finfo) == -1) {
aplog_error(APLOG_MARK, APLOG_WARNING, cmd->server,
"mmap_static: unable to stat(%s), skipping", filename);
return NULL;
}
if ((tmp.finfo.st_mode & S_IFMT) != S_IFREG) {
aplog_error(APLOG_MARK, APLOG_WARNING, cmd->server,
"mmap_static: %s isn't a regular file, skipping", filename);
return NULL;
}
block_alarms();
fd = open(filename, O_RDONLY, 0);
if (fd == -1) {
aplog_error(APLOG_MARK, APLOG_WARNING, cmd->server,
"mmap_static: unable to open(%s, O_RDONLY), skipping", filename);
return NULL;
}
mm = mmap(NULL, tmp.finfo.st_size, PROT_READ, MAP_SHARED, fd, 0);
if (mm == (caddr_t)-1) {
int save_errno = errno;
close(fd);
unblock_alarms();
errno = save_errno;
aplog_error(APLOG_MARK, APLOG_WARNING, cmd->server,
"mmap_static: unable to mmap %s, skipping", filename);
return NULL;
}
close(fd);
tmp.mm = mm;
tmp.filename = pstrdup(cmd->pool, filename);
sconf = get_module_config(cmd->server->module_config, &mmap_static_module);
new_file = push_array(sconf->files);
*new_file = tmp;
if (sconf->files->nelts == 1) {
/* first one, register the cleanup */
register_cleanup(cmd->pool, sconf, cleanup_mmap, null_cleanup);
}
unblock_alarms();
return NULL;
}
static command_rec mmap_static_cmds[] =
{
{
"mmapfile", mmapfile, NULL, RSRC_CONF, ITERATE,
"A space separated list of files to mmap at config time"
},
{
NULL
}
};
static int file_compare(const void *av, const void *bv)
{
const a_file *a = av;
const a_file *b = bv;
return strcmp(a->filename, b->filename);
}
static int inode_compare(const void *av, const void *bv)
{
const a_file *a = *(a_file **)av;
const a_file *b = *(a_file **)bv;
long c;
c = a->finfo.st_ino - b->finfo.st_ino;
if (c == 0) {
return a->finfo.st_dev - b->finfo.st_dev;
}
return c;
}
static void mmap_init(server_rec *s, pool *p)
{
a_server_config *sconf;
array_header *inodes;
a_file *elts;
int nelts;
int i;
/* sort the elements of the main_server, by filename */
sconf = get_module_config(s->module_config, &mmap_static_module);
elts = (a_file *)sconf->files->elts;
nelts = sconf->files->nelts;
qsort(elts, nelts, sizeof(a_file), file_compare);
/* build an index by inode as well, speeds up the search in the handler */
inodes = make_array(p, nelts, sizeof(a_file *));
sconf->inode_sorted = inodes;
for (i = 0; i < nelts; ++i) {
*(a_file **)push_array(inodes) = &elts[i];
}
qsort(inodes->elts, nelts, sizeof(a_file *), inode_compare);
/* and make the virtualhosts share the same thing */
for (s = s->next; s; s = s->next) {
set_module_config(s->module_config, &mmap_static_module, sconf);
}
}
/* If it's one of ours, fill in r->finfo now to avoid extra stat()... this is a
* bit of a kludge, because we really want to run after core_translate runs.
*/
extern int core_translate(request_rec *r);
static int mmap_static_xlat(request_rec *r)
{
a_server_config *sconf;
a_file tmp;
a_file *match;
int res;
/* we require other modules to first set up a filename */
if (!r->filename) {
res = core_translate(r);
if (res == DECLINED || !r->filename) {
return res;
}
}
sconf = get_module_config(r->server->module_config, &mmap_static_module);
tmp.filename = r->filename;
match = bsearch(&tmp, sconf->files->elts, sconf->files->nelts,
sizeof(a_file), file_compare);
if (match == NULL) {
return DECLINED;
}
/* shortcircuit the get_path_info() stat() calls and stuff */
r->finfo = match->finfo;
return OK;
}
static int mmap_static_handler(request_rec *r)
{
a_server_config *sconf;
a_file tmp;
a_file *ptmp;
a_file **pmatch;
a_file *match;
int rangestatus, errstatus;
/* we don't handle anything but GET */
if (r->method_number != M_GET) return DECLINED;
/* file doesn't exist, we won't be dealing with it */
if (r->finfo.st_mode == 0) return DECLINED;
sconf = get_module_config(r->server->module_config, &mmap_static_module);
tmp.finfo.st_dev = r->finfo.st_dev;
tmp.finfo.st_ino = r->finfo.st_ino;
ptmp = &tmp;
pmatch = bsearch(&ptmp, sconf->inode_sorted->elts,
sconf->inode_sorted->nelts, sizeof(a_file *), inode_compare);
if (pmatch == NULL) {
return DECLINED;
}
match = *pmatch;
/* note that we would handle GET on this resource */
r->allowed |= (1 << M_GET);
/* This handler has no use for a request body (yet), but we still
* need to read and discard it if the client sent one.
*/
if ((errstatus = discard_request_body(r)) != OK)
return errstatus;
update_mtime(r, match->finfo.st_mtime);
set_last_modified(r);
set_etag(r);
if (((errstatus = meets_conditions(r)) != OK)
|| (errstatus = set_content_length (r, match->finfo.st_size))) {
return errstatus;
}
rangestatus = set_byterange(r);
send_http_header(r);
if (!r->header_only) {
if (!rangestatus) {
send_mmap (match->mm, r, 0, match->finfo.st_size);
}
else {
long offset, length;
while (each_byterange(r, &offset, &length)) {
send_mmap(match->mm, r, offset, length);
}
}
}
return OK;
}
static handler_rec mmap_static_handlers[] =
{
{ "*/*", mmap_static_handler },
{ NULL }
};
module MODULE_VAR_EXPORT mmap_static_module =
{
STANDARD_MODULE_STUFF,
mmap_init, /* initializer */
NULL, /* dir config creater */
NULL, /* dir merger --- default is to override */
create_server_config, /* server config */
NULL, /* merge server config */
mmap_static_cmds, /* command handlers */
mmap_static_handlers, /* handlers */
mmap_static_xlat, /* filename translation */
NULL, /* check_user_id */
NULL, /* check auth */
NULL, /* check access */
NULL, /* type_checker */
NULL, /* fixups */
NULL, /* logger */
NULL, /* header parser */
NULL, /* child_init */
NULL, /* child_exit */
NULL /* post read-request */
};
Re: [contrib] mod_mmap_static.c v0.03
Posted by Dean Gaudet <dg...@arctic.org>.
On Mon, 9 Feb 1998, Ben Laurie wrote:
> Sure. What I've done when I've had this problem is to simply replace
> _every_ occurence of "the Apache Group" with "Ben Laurie".
Yeah if I did that then folks would have to credit me if they shipped the
module and I really don't care about that... I'm actually a believer in
GPL rather than the apache license, but I'm not interested in pushing that
belief here. I can't GPL it because that would preclude us ever including
it with the server. So I put that statement in. I suppose I could just
do what you do.
Dean
Re: [contrib] mod_mmap_static.c v0.03
Posted by Ben Laurie <be...@algroup.co.uk>.
Marc Slemko wrote:
>
> On Mon, 9 Feb 1998, Ben Laurie wrote:
>
> > Dean Gaudet wrote:
> > > * This code would be available under the same license as the Apache server
> > > * itself, but unfortunately that license doesn't really allow for third
> > > * parties to distribute code under it.
> >
> > What do you mean by this?
>
> The below snips from the licence don't really fit with a third party
> having made the source; some of it is simply lies if you do that. Can
> something be copyright the Apache Group with the Apache Group knowing
> nothing about it?
Sure. What I've done when I've had this problem is to simply replace
_every_ occurence of "the Apache Group" with "Ben Laurie".
Cheers,
Ben.
--
Ben Laurie |Phone: +44 (181) 735 0686|Apache Group member
Freelance Consultant |Fax: +44 (181) 735 0689|http://www.apache.org
and Technical Director|Email: ben@algroup.co.uk |Apache-SSL author
A.L. Digital Ltd, |http://www.algroup.co.uk/Apache-SSL
London, England. |"Apache: TDG" http://www.ora.com/catalog/apache
Re: [contrib] mod_mmap_static.c v0.03
Posted by Marc Slemko <ma...@worldgate.com>.
On Mon, 9 Feb 1998, Ben Laurie wrote:
> Dean Gaudet wrote:
> > * This code would be available under the same license as the Apache server
> > * itself, but unfortunately that license doesn't really allow for third
> > * parties to distribute code under it.
>
> What do you mean by this?
The below snips from the licence don't really fit with a third party
having made the source; some of it is simply lies if you do that. Can
something be copyright the Apache Group with the Apache Group knowing
nothing about it?
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Group and was originally based
* on public domain software written at the National Center for
* Supercomputing Applications, University of Illinois, Urbana-Champaign.
* For more information on the Apache Group and the Apache HTTP server
* project, please see <http://www.apache.org/>.
* Copyright (c) 1995-1997 The Apache Group. All rights reserved.
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the Apache Group
* for use in the Apache HTTP server project (http://www.apache.org/)."
* 4. The names "Apache Server" and "Apache Group" must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 5. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the Apache Group
* for use in the Apache HTTP server project (http://www.apache.org/)."
Re: [contrib] mod_mmap_static.c v0.03
Posted by Ben Laurie <be...@algroup.co.uk>.
Dean Gaudet wrote:
> * This code would be available under the same license as the Apache server
> * itself, but unfortunately that license doesn't really allow for third
> * parties to distribute code under it.
What do you mean by this?
Cheers,
Ben.
--
Ben Laurie |Phone: +44 (181) 735 0686|Apache Group member
Freelance Consultant |Fax: +44 (181) 735 0689|http://www.apache.org
and Technical Director|Email: ben@algroup.co.uk |Apache-SSL author
A.L. Digital Ltd, |http://www.algroup.co.uk/Apache-SSL
London, England. |"Apache: TDG" http://www.ora.com/catalog/apache
Re: [contrib] mod_mmap_static.c v0.03
Posted by Dean Gaudet <dg...@arctic.org>.
Hey Ralf why does mod_rewrite do this?
/* if filename was not initially set,
* we start with the requested URI
*/
if (r->filename == NULL) {
r->filename = pstrdup(r->pool, r->uri);
rewritelog(r, 2, "init rewrite engine with requested uri %s",
r->filename);
}
?
I didn't expect r->filename to be set at this point, especially when no
RewriteRule was matched.
v0.04 of my module works around it... and rather than spam y'all with the
module again, just go to
<http://www.arctic.org/~dgaudet/apache/mod_mmap_static.c>.
Dean