GZ Filter.
This filter GZ encodes files before being sent out, resulting in less
bytes on the network.
It has been coded only to work on HTML files (some browsers don't like
JS/CSS files gziped)
you can set the compression options (defaults to min CPU/max mem/max
speed), and
it has the option of setting a note saying what compression level it
achieved.
It has been tested on W2K, and on linux (functionailty only, didn't
stress it) and it appears
to work ok.
2 Questions/Comments:
* Currently you can enable the GZ Filter at the serverr level,
should this be directory specific ?
(mainly to get around Filters lack of being able to be turned
off once set)
* It uses a AP_FTYPE_HTTP_HEADER, as it needs to run after all
content has been created,
and before Transcoding begins.
I'll create a document page later, but briefly some notes on config.
(Settings are server-wide)
<IfModule mod_gz.c>
GZFilter on #enable GZ filtering on this server
GZWindowSize 15 # zlib option
GZMemLevel 9 # Zlib option
GZFilterNote COMPRESS #note to add to the custom log to show
compression level
</IfModule>
<Location />
SetOutputFilter GZ
</Location>
..Ian
(oh. I ran the code through indent with the 'approved' options as per
the web page.. so the code should
follow the guidelines)
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact [EMAIL PROTECTED]
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* Portions of this software are based upon public domain software
* (zlib functions gz_open and gzwrite)
*/
/*
* mod_gz.c: GZip's HTML content on the fly
*
* Written by Ian Holsman ([EMAIL PROTECTED])
*
*/
#include "zlib.h"
#include "zutil.h"
#include "httpd.h"
#include "http_config.h"
#include "http_log.h"
#include "apr_strings.h"
#include "apr_general.h"
#include "util_filter.h"
#include "apr_buckets.h"
#include "http_request.h"
static const char s_szGZFilterName[] = "GZ";
module AP_MODULE_DECLARE_DATA gz_module;
typedef struct
{
int bEnabled;
int windowSize;
int memlevel;
char*noteName;
}
GZFilterConfig;
#define GZFILTER_DEFAULT_WINDOWSIZE -15 /* windowsize is negative to suppress Zlib
header */
#define GZFILTER_DEFAULT_MEMLEVEL 9
#define GZFILTER_BUFFERSIZE 8096
/*#define GZFILTER_COMPRESSION "GZCOMPRESSION" */
typedef struct gz_ctx
{
z_stream strm;
char buffer[GZFILTER_BUFFERSIZE];
unsigned long crc;
}
gz_ctx;
/* ===========================================================================
Outputs a long in LSB order to the given file
*/
static void putLong(char *string, unsigned long x)
{
int n;
for (n = 0; n < 4; n++) {
string[n] = (int) (x & 0xff);
x >>= 8;
}
}
static void *GZFilterCreateServerConfig(apr_pool_t * p, server_rec * s)
{
GZFilterConfig *pConfig = apr_pcalloc(p, sizeof *pConfig);
pConfig->bEnabled = 0;
pConfig->memlevel = GZFILTER_DEFAULT_MEMLEVEL;
pConfig->windowSize = GZFILTER_DEFAULT_WINDOWSIZE;
return pConfig;
}
static const char *GZSetWindowSize(cmd_parms * cmd, void *dummy, const char* arg)
{
GZFilterConfig *pConfig = ap_get_module_config(cmd->server->module_config,
&gz_module);
int iWindowSize;
iWindowSize = atoi(arg);
if (iWindowSize <1 || iWindowSize >15)
return "GZWindowSize must be between 1 and 15";
pConfig->windowSize = iWindowSize *-1;
return NULL;
}
static const char *GZSetNote(cmd_parms * cmd, void *dummy, const char* arg)
{
GZFilterConfig *pConfig = ap_get_module_config(cmd->server->module_config,
&gz_module);
pConfig->noteName=apr_pstrdup(cmd->pool,arg);
return NULL;
}
static const char *GZSetMemLevel(cmd_parms * cmd, void *dummy, const char* arg)
{
GZFilterConfig *pConfig = ap_get_module_config(cmd->server->module_config,
&gz_module);
int iMemLevel;
iMemLevel = atoi(arg);
if (iMemLevel <1 || iMemLevel >9)
return "GZMemLevel must be between 1 and 9";
pConfig->memlevel = iMemLevel;
return NULL;
}
static const char *GZFilterEnable(cmd_parms * cmd, void *dummy, int arg)
{
GZFilterConfig *pConfig = ap_get_module_config(cmd->server->module_config,
&gz_module);
pConfig->bEnabled = arg;
return NULL;
}
static void GZFilterInsertFilter(request_rec * r)
{
GZFilterConfig *pConfig = ap_get_module_config(r->server->module_config,
&gz_module);
if (!pConfig->bEnabled)
return;
ap_add_output_filter(s_szGZFilterName, NULL, r, r->connection);
}
static int gz_magic[2] = { 0x1f, 0x8b }; /* gzip magic header */
static apr_status_t GZFilterOutFilter(ap_filter_t * f,
apr_bucket_brigade * pbbIn)
{
apr_bucket *pbktIn;
apr_bucket_brigade *pbbOut;
apr_bucket *pbktOut;
char *buf;
const char *accepts;
request_rec *r = f->r;
gz_ctx *ctx;
char *token = NULL;
char *state = NULL;
int zRC;
GZFilterConfig *pConfig = ap_get_module_config(r->server->module_config,
&gz_module);
if ( pConfig->bEnabled != 1 )
return ap_pass_brigade(f->next, pbbIn);
/* only work on main request/no subrequests */
if (r->main)
return ap_pass_brigade(f->next, pbbIn);
/* only compress text/html files */
if (strncmp(r->content_type, "text/html", 9))
return ap_pass_brigade(f->next, pbbIn);
/* GETs only (for the moment) */
if (r->method_number != M_GET) {
return ap_pass_brigade(f->next, pbbIn);
}
/* some browsers might have problems, so set no-gzip (with browsermatch) for them
*/
if (apr_table_get(r->subprocess_env, "no-gzip")) {
return ap_pass_brigade(f->next, pbbIn);
}
accepts = apr_table_get(r->headers_in, "Accept-Encoding");
/* if they don't have the line, then they can't play */
if (accepts == NULL) {
return ap_pass_brigade(f->next, pbbIn);
}
token = ap_get_token(r->pool, &accepts, 0);
while (token && token[0] && strcmp(token, "gzip")) {
accepts++; /* skip token */
token = ap_get_token(r->pool, &accepts, 0);
}
if (token == NULL || token[0] == '\0') {
return ap_pass_brigade(f->next, pbbIn);
}
pbbOut = apr_brigade_create(f->r->pool);
if (!f->ctx) {
f->ctx = apr_pcalloc(f->c->pool, sizeof(*ctx));
ctx = f->ctx;
ctx->strm.zalloc = (alloc_func) 0;
ctx->strm.zfree = (free_func) 0;
ctx->strm.opaque = (voidpf) 0;
ctx->crc = 0L;
zRC = deflateInit2(&ctx->strm, Z_BEST_SPEED, Z_DEFLATED,
pConfig->windowSize, pConfig->memlevel,
Z_DEFAULT_STRATEGY);
if (zRC != Z_OK) {
f->ctx = NULL;
ap_log_rerror(APLOG_MARK, APLOG_ERR | APLOG_NOERRNO, 0, r,
"unable to init Zlib: deflateInit2 returned %d: URL %s",
zRC, r->uri);
return ap_pass_brigade(f->next, pbbIn);
}
buf =
apr_psprintf(r->pool, "%c%c%c%c%c%c%c%c%c%c", gz_magic[0],
gz_magic[1], Z_DEFLATED, 0 /*flags */ , 0, 0, 0,
0 /*time */ , 0 /*xflags */ , OS_CODE);
pbktOut = apr_bucket_pool_create(buf, 10, r->pool);
APR_BRIGADE_INSERT_TAIL(pbbOut, pbktOut);
apr_table_setn(r->headers_out, "Content-Encoding", "gzip");
apr_table_setn(r->headers_out, "Vary", "Accept-Encoding");
}
else {
ctx = f->ctx;
}
APR_BRIGADE_FOREACH(pbktIn, pbbIn) {
const char *data;
apr_size_t lenin;
unsigned int len;
char *buf;
char szCRC[4];
char szLen[4];
apr_size_t e_wrt;
int done = 0;
if (APR_BUCKET_IS_EOS(pbktIn)) {
apr_bucket *pbktEOS = apr_bucket_eos_create();
ctx->strm.avail_in = 0; /* should be zero already anyway */
for (;;) {
len = GZFILTER_BUFFERSIZE - ctx->strm.avail_out;
if (len != 0) {
pbktOut =
apr_bucket_heap_create(ctx->buffer, len, 1, &e_wrt);
APR_BRIGADE_INSERT_TAIL(pbbOut, pbktOut);
ctx->strm.next_out = ctx->buffer;
ctx->strm.avail_out = GZFILTER_BUFFERSIZE;
}
if (done)
break;
zRC = deflate(&ctx->strm, Z_FINISH);
if (len == 0 && zRC == Z_BUF_ERROR)
zRC = Z_OK;
done = (ctx->strm.avail_out != 0 || zRC == Z_STREAM_END);
if (zRC != Z_OK && zRC != Z_STREAM_END)
break;
}
putLong(szCRC, ctx->crc);
putLong(szLen, ctx->strm.total_in);
buf =
apr_psprintf(r->pool, "%c%c%c%c%c%c%c%c", szCRC[0], szCRC[1],
szCRC[2], szCRC[3], szLen[0], szLen[1], szLen[2],
szLen[3]);
pbktOut = apr_bucket_pool_create(buf, 8, r->pool);
APR_BRIGADE_INSERT_TAIL(pbbOut, pbktOut);
ap_log_rerror(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, 0, r,
"Zlib: Compressed %d to %d : URL %s",
ctx->strm.total_in, ctx->strm.total_out, r->uri);
if (pConfig->noteName) {
if (ctx->strm.total_in >0) {
apr_table_setn(r->notes,pConfig->noteName,apr_itoa(r->pool,
(ctx->strm.total_out*100/ctx->strm.total_in)));
} else {
apr_table_setn(r->notes,pConfig->noteName,"-");
}
}
deflateEnd(&ctx->strm);
f->ctx = NULL;
APR_BRIGADE_INSERT_TAIL(pbbOut, pbktOut);
APR_BRIGADE_INSERT_TAIL(pbbOut, pbktEOS);
break;
}
if (APR_BUCKET_IS_FLUSH(pbktIn)) {
/* XXX FIX: do we need the Content-Size set, or can we stream? we should
be able to stream */
/* ignore flush buckets for the moment.. we can't stream as we need the
size ;( */
continue;
}
/* read */
apr_bucket_read(pbktIn, &data, &lenin, APR_BLOCK_READ);
ctx->crc = crc32(ctx->crc, (const Bytef *) data, lenin);
/* write */
ctx->strm.next_in = (char *) data;
ctx->strm.avail_in = lenin;
ctx->strm.next_out = ctx->buffer;
ctx->strm.avail_out = GZFILTER_BUFFERSIZE;
while (ctx->strm.avail_in != 0) {
if (ctx->strm.avail_out == 0) {
ctx->strm.next_out = ctx->buffer;
len = GZFILTER_BUFFERSIZE - ctx->strm.avail_out;
pbktOut = apr_bucket_heap_create(ctx->buffer, len, 1, &e_wrt);
APR_BRIGADE_INSERT_TAIL(pbbOut, pbktOut);
ctx->strm.avail_out = GZFILTER_BUFFERSIZE;
}
zRC = deflate(&(ctx->strm), Z_NO_FLUSH);
if (zRC != Z_OK)
break;
}
}
return ap_pass_brigade(f->next, pbbOut);
}
static void GZFilterRegisterHooks(apr_pool_t * p)
{
// static const char * const aszPost[] = { "CHUNK", NULL };
// ap_hook_insert_filter(GZFilterInsertFilter, NULL, aszPost, APR_HOOK_LAST);
ap_register_output_filter(s_szGZFilterName, GZFilterOutFilter,
AP_FTYPE_HTTP_HEADER);
}
static const command_rec GZFilterCmds[] = {
AP_INIT_FLAG("GZFilter", GZFilterEnable, NULL, RSRC_CONF,
"Run a GZ filter on this host"),
AP_INIT_TAKE1("GZFilterNote", GZSetNote, NULL, RSRC_CONF,
"Set a note to report on compression ratio"),
AP_INIT_TAKE1("GZWindowSize", GZSetWindowSize, NULL, RSRC_CONF,
"Set the Zlib window size (1-15)"),
AP_INIT_TAKE1("GZMemLevel", GZSetMemLevel, NULL, RSRC_CONF,
"Set the Zlib Memory Level (1-9)"),
{NULL}
};
module AP_MODULE_DECLARE_DATA gz_module = {
STANDARD20_MODULE_STUFF,
NULL,
NULL,
GZFilterCreateServerConfig,
NULL,
GZFilterCmds,
GZFilterRegisterHooks
};
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APACHE_MODPATH_INIT(gz)
APACHE_MODULE(gz, GZip encoding support, "mod_gz.lo", , no, [
AC_MSG_CHECKING(for Zlib library)
AC_ARG_WITH(z, [ --with-z=DIR use a specific zlib library],
[
if test x"$withval" = x"yes"; then
for dir in /usr /usr/local/
do
if test -d $dir && test -f $dir/lib/libz.a; then
withval=$dir
break
fi
done
if test x"$withval" = x"yes"; then
AC_MSG_ERROR(Use --with-z=DIR to specify the location of your Zlib
installation)
fi
fi
z_lib=unknown
for params in \
"zlib|/include/|/lib|-lz "
do
prod=`IFS="|"; set -- $params; echo $1`
incdir=`IFS="|"; set -- $params; echo $2`
libdir=`IFS="|"; set -- $params; echo $3`
libs=`IFS="|"; set -- $params; echo $4`
searchfile="${withval}${incdir}/zlib.h"
if test -f ${searchfile} ; then
APR_ADDTO(INCLUDES, [-I${withval}${incdir}])
APR_ADDTO(LIBS, [-L${withval}${libdir} ${libs}])
z_lib="${prod}"
break
fi
done
if test x"${z_lib}" = x"unknown"; then
AC_MSG_ERROR(--with-z given but no appropriate lib found)
else
AC_MSG_RESULT(found $z_lib)
fi
],[
AC_MSG_ERROR(--with-z not given)
] ) ] )
APACHE_MODPATH_FINISH
# a modules Makefile has no explicit targets -- they will be defined by
# whatever modules are enabled. just grab special.mk to deal with this.
include $(top_srcdir)/build/special.mk
