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Posted to cvs@httpd.apache.org by rb...@locus.apache.org on 2000/07/28 22:31:16 UTC

cvs commit: apache-2.0/src/main util_filter.c Makefile.in http_protocol.c http_request.c

rbb         00/07/28 13:31:15

  Modified:    src/include httpd.h
               src/main Makefile.in http_protocol.c http_request.c
  Added:       src/include util_filter.h
               src/main util_filter.c
  Log:
  Add the ability to register filters.  This commit introduces a warning
  into the build.  This warning will be removed automatically, as soon as
  we decide on a prototype for the function causing the warning.  That
  decision is tied to which filtering mechanism we decide on.
  Submitted by:	Ryan Bloom and Greg Stein
  
  Revision  Changes    Path
  1.65      +3 -1      apache-2.0/src/include/httpd.h
  
  Index: httpd.h
  ===================================================================
  RCS file: /home/cvs/apache-2.0/src/include/httpd.h,v
  retrieving revision 1.64
  retrieving revision 1.65
  diff -u -r1.64 -r1.65
  --- httpd.h	2000/06/30 21:18:13	1.64
  +++ httpd.h	2000/07/28 20:30:52	1.65
  @@ -731,7 +731,9 @@
   #ifdef APACHE_XLATE
       struct ap_rr_xlate *rrx;
   #endif /*APACHE_XLATE*/
  -    
  +
  +    struct ap_filter_t *filters;
  +
   /* Things placed at the end of the record to avoid breaking binary
    * compatibility.  It would be nice to remember to reorder the entire
    * record to improve 64bit alignment the next time we need to break
  
  
  
  1.1                  apache-2.0/src/include/util_filter.h
  
  Index: util_filter.h
  ===================================================================
  /* ====================================================================
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2000 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 apache@apache.org.
   *
   * 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/>.
   */
  
  #ifndef AP_FILTER_H
  #define AP_FILTER_H
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #ifdef APR_HAVE_STDARG_H
  #include <stdarg.h>
  #endif
  
  #include "httpd.h"
  #include "apr.h"
  
  /*
   * FILTER CHAIN
   *
   * Filters operate using a "chaining" mechanism. The filters are chained
   * together into a sequence. When output is generated, it is passed through
   * each of the filters on this chain, until it reaches the end (or "bottom")
   * and is placed onto the network.
   *
   * The top of the chain, the code generating the output, is typically called
   * a "content generator." The content generator's output is fed into the
   * filter chain using the standard Apache output mechanisms: ap_rputs(),
   * ap_rprintf(), ap_rwrite(), etc.
   *
   * Each filter is defined by a callback. This callback takes the output from
   * the previous filter (or the content generator if there is no previous
   * filter), operates on it, and passes the result to the next filter in the
   * chain. This pass-off is performed using the ap_fc_* functions, such as
   * ap_fc_puts(), ap_fc_printf(), ap_fc_write(), etc.
   *
   * When content generation is complete, the system will pass an "end of
   * stream" marker into the filter chain. The filters will use this to flush
   * out any internal state and to detect incomplete syntax (for example, an
   * unterminated SSI directive).
   */
  
  /* forward declare the filter type */
  typedef struct ap_filter_t ap_filter_t;
  
  /*
   * ap_filter_func:
   *
   * This function type is used for filter callbacks. It will be passed a
   * pointer to "this" filter, and a "bucket" containing the content to be
   * filtered.
   *
   * In filter->ctx, the callback will find its context. This context is
   * provided here, so that a filter may be installed multiple times, each
   * receiving its own per-install context pointer.
   *
   * Callbacks are associated with a filter definition, which is specified
   * by name. See ap_register_filter() for setting the association between
   * a name for a filter and its associated callback (and other information).
   *
   * The *bucket structure (and all those referenced by ->next and ->prev)
   * should be considered "const". The filter is allowed to modify the
   * next/prev to insert/remove/replace elements in the bucket list, but
   * the types and values of the individual buckets should not be altered.
   */
  typedef ap_status_t (*ap_filter_func)();
  
  /*
   * ap_filter_type:
   *
   * Filters have different types/classifications. These are used to group
   * and sort the filters to properly sequence their operation.
   *
   * AP_FTYPE_CONTENT:
   *     These filters are used to alter the content that is passed through
   *     them. Examples are SSI or PHP.
   *
   * AP_FTYPE_CONNECTION:
   *     These filters will alter the content, but in ways that are more
   *     strongly associated with the output connection. Examples are
   *     compression, character recoding, or chunked transfer coding.
   *
   *     It is important to note that these types of filters are not allowed
   *     in a sub-request. A sub-requests output can certainly be filtered
   *     by AP_FTYPE_CONTENT filters, but all of the "final processing" is
   *     determined by the main request.
   *
   * The types have a particular sort order, which allows us to insert them
   * into the filter chain in a determistic order. Within a particular grouping,
   * the ordering is equivalent to the order of calls to ap_add_filter().
   */
  typedef enum {
      AP_FTYPE_CONTENT,
      AP_FTYPE_CONNECTION
  } ap_filter_type;
  
  /*
   * ap_filter_t:
   *
   * This is the request-time context structure for an installed filter (in
   * the output filter chain). It provides the callback to use for filtering,
   * the request this filter is associated with (which is important when
   * an output chain also includes sub-request filters), the context for this
   * installed filter, and the filter ordering/chaining fields.
   *
   * Filter callbacks are free to use ->ctx as they please, to store context
   * during the filter process. Generally, this is superior over associating
   * the state directly with the request. A callback should not change any of
   * the other fields.
   */
  struct ap_filter_t {
      ap_filter_func filter_func;
  
      void *ctx;
  
      ap_filter_type ftype;
      ap_filter_t *next;
  };
  
  /*
   * ap_register_filter():
   *
   * This function is used to register a filter with the system. After this
   * registration is performed, then a filter may be added into the filter
   * chain by using ap_add_filter() and simply specifying the name.
   *
   * The filter's callback and type should be passed.
   */
  API_EXPORT(void) ap_register_filter(const char *name,
                                      ap_filter_func filter_func,
                                      ap_filter_type ftype);
  
  /*
   * ap_add_filter():
   *
   * Adds a named filter into the filter chain on the specified request record.
   * The filter will be installed with the specified context pointer.
   *
   * Filters added in this way will always be placed at the end of the filters
   * that have the same type (thus, the filters have the same order as the
   * calls to ap_add_filter). If the current filter chain contains filters
   * from another request, then this filter will be added before those other
   * filters.
   */
  API_EXPORT(void) ap_add_filter(const char *name, void *ctx, request_rec *r);
  
  
  /*
   * Things to do later:
   * Add parameters to ap_filter_func type.  Those parameters will be something
   *     like:
   *         (request_rec *r, ap_filter_t *filter, ap_data_list *the_data)
   *      obviously, the request_rec is the current request, and the filter
   *      is the current filter stack.  The data_list is a bucket list or
   *      bucket_brigade, but I am trying to keep this patch neutral.  (If this
   *      comment breaks that, well sorry, but the information must be there
   *      somewhere.  :-)
   *
   * Add a function like ap_pass_data.  This function will basically just
   * call the next filter in the chain, until the current filter is NULL.  If the
   * current filter is NULL, that means that nobody wrote to the network, and
   * we have a HUGE bug, so we need to return an error and log it to the 
   * log file.
   */
  #ifdef __cplusplus
  }
  #endif
  
  #endif	/* !AP_FILTER_H */
  
  
  
  1.17      +2 -1      apache-2.0/src/main/Makefile.in
  
  Index: Makefile.in
  ===================================================================
  RCS file: /home/cvs/apache-2.0/src/main/Makefile.in,v
  retrieving revision 1.16
  retrieving revision 1.17
  diff -u -r1.16 -r1.17
  --- Makefile.in	2000/07/01 14:14:15	1.16
  +++ Makefile.in	2000/07/28 20:31:00	1.17
  @@ -8,7 +8,8 @@
   	http_protocol.c http_request.c http_vhost.c util.c util_date.c \
   	util_script.c util_uri.c util_md5.c util_cfgtree.c util_ebcdic.c \
   	rfc1413.c http_connection.c iol_file.c iol_socket.c listen.c \
  -        mpm_common.c util_charset.c util_debug.c util_xml.c
  +        mpm_common.c util_charset.c util_debug.c util_xml.c \
  +	util_filter.c
   
   include $(top_srcdir)/build/ltlib.mk
   
  
  
  
  1.99      +13 -6     apache-2.0/src/main/http_protocol.c
  
  Index: http_protocol.c
  ===================================================================
  RCS file: /home/cvs/apache-2.0/src/main/http_protocol.c,v
  retrieving revision 1.98
  retrieving revision 1.99
  diff -u -r1.98 -r1.99
  --- http_protocol.c	2000/07/26 14:29:34	1.98
  +++ http_protocol.c	2000/07/28 20:31:00	1.99
  @@ -1278,8 +1278,19 @@
       rnew->main = (request_rec *) r;
   }
   
  +static void end_output_stream(request_rec *r)
  +{
  +    /*
  +    ** ### place holder to tell filters that no more content will be
  +    ** ### arriving. typically, they will flush any pending content
  +    */
  +}
  +
   void ap_finalize_sub_req_protocol(request_rec *sub)
   {
  +    /* tell the filter chain there is no more content coming */
  +    end_output_stream(sub);
  +
       SET_BYTES_SENT(sub->main);
   }
   
  @@ -1833,11 +1844,6 @@
   #endif /*APACHE_XLATE*/
   }
   
  -static void flush_filters(request_rec *r)
  -{
  -    /* ### place holder to flush pending content through the filters */
  -}
  -
   /* finalize_request_protocol is called at completion of sending the
    * response.  It's sole purpose is to send the terminating protocol
    * information for any wrappers around the response message body
  @@ -1845,7 +1851,8 @@
    */
   API_EXPORT(void) ap_finalize_request_protocol(request_rec *r)
   {
  -    flush_filters(r);
  +    /* tell the filter chain there is no more content coming */
  +    end_output_stream(r);
   
       if (r->chunked && !r->connection->aborted) {
   #ifdef APACHE_XLATE
  
  
  
  1.37      +20 -8     apache-2.0/src/main/http_request.c
  
  Index: http_request.c
  ===================================================================
  RCS file: /home/cvs/apache-2.0/src/main/http_request.c,v
  retrieving revision 1.36
  retrieving revision 1.37
  diff -u -r1.36 -r1.37
  --- http_request.c	2000/07/21 19:50:47	1.36
  +++ http_request.c	2000/07/28 20:31:01	1.37
  @@ -770,6 +770,9 @@
       rnew->htaccess       = r->htaccess;
       rnew->per_dir_config = r->server->lookup_defaults;
   
  +    /* start with the same set of output filters */
  +    rnew->filters = r->filters;
  +
       ap_set_sub_req_protocol(rnew, r);
   
       /* would be nicer to pass "method" to ap_set_sub_req_protocol */
  @@ -858,6 +861,9 @@
       rnew->htaccess       = r->htaccess;
       rnew->chunked        = r->chunked;
   
  +    /* start with the same set of output filters */
  +    rnew->filters = r->filters;
  +
       ap_set_sub_req_protocol(rnew, r);
       fdir = ap_make_dirstr_parent(rnew->pool, r->filename);
   
  @@ -961,16 +967,22 @@
   
   API_EXPORT(int) ap_run_sub_req(request_rec *r)
   {
  -#ifndef APACHE_XLATE
  -    int retval = ap_invoke_handler(r);
  -#else /*APACHE_XLATE*/
  -    /* Save the output conversion setting of the caller across subrequests */
       int retval;
  -    ap_xlate_t *saved_xlate;
   
  -    ap_bgetopt(r->connection->client, BO_WXLATE, &saved_xlate);
  -    retval  = ap_invoke_handler(r);
  -    ap_bsetopt(r->connection->client, BO_WXLATE, &saved_xlate);
  +    /* see comments in process_request_internal() */
  +    ap_run_insert_filter(r);
  +
  +#ifndef APACHE_XLATE
  +    retval = ap_invoke_handler(r);
  +#else /*APACHE_XLATE*/
  +    {
  +        /* Save the output conversion setting across subrequests */
  +        ap_xlate_t *saved_xlate;
  +
  +        ap_bgetopt(r->connection->client, BO_WXLATE, &saved_xlate);
  +        retval  = ap_invoke_handler(r);
  +        ap_bsetopt(r->connection->client, BO_WXLATE, &saved_xlate);
  +    }
   #endif /*APACHE_XLATE*/
       ap_finalize_sub_req_protocol(r);
       return retval;
  
  
  
  1.1                  apache-2.0/src/main/util_filter.c
  
  Index: util_filter.c
  ===================================================================
  /* ====================================================================
   * The Apache Software License, Version 1.1
   *
   * Copyright (c) 2000 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 apache@apache.org.
   *
   * 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/>.
   */
  
  #include "util_filter.h"
  
  /*
   * ap_filter_rec_t:
   *
   * This (internal) structure is used for recording information about the
   * registered filters. It associates a name with the filter's callback
   * and filter type.
   *
   * At the moment, these are simply linked in a chain, so a ->next pointer
   * is available.
   */
  typedef struct ap_filter_rec_t {
      const char *name;
      ap_filter_func filter_func;
      ap_filter_type ftype;
  
      struct ap_filter_rec_t *next;
  } ap_filter_rec_t;
  
  /* ### make this visible for direct manipulation?
     ### use a hash table
  */
  static ap_filter_rec_t *registered_filters = NULL;
  
  /* NOTE: Apache's current design doesn't allow a pool to be passed thu,
     so we depend on a global to hold the correct pool
  */
  #define FILTER_POOL     ap_global_hook_pool
  #include "ap_hooks.h"   /* for ap_global_hook_pool */
  
  /*
  ** This macro returns true/false if a given filter should be inserted BEFORE
  ** another filter. This will happen when one of: 1) there isn't another
  ** filter; 2) that filter has a higher filter type (class); 3) that filter
  ** corresponds to a different request.
  */
  #define INSERT_BEFORE(f, before_this) ((before_this) == NULL \
                                         || (before_this)->ftype > (f)->ftype)
  
  
  static ap_status_t filter_cleanup(void *ctx)
  {
      registered_filters = NULL;
      return APR_SUCCESS;
  }
  
  API_EXPORT(void) ap_register_filter(const char *name,
                                      ap_filter_func filter_func,
                                      ap_filter_type ftype)
  {
      ap_filter_rec_t *frec = ap_palloc(FILTER_POOL, sizeof(*frec));
  
      frec->name = name;
      frec->filter_func = filter_func;
      frec->ftype = ftype;
  
      frec->next = registered_filters;
      registered_filters = frec;
  
      ap_register_cleanup(FILTER_POOL, NULL, filter_cleanup, NULL);
  }
  
  API_EXPORT(void) ap_add_filter(const char *name, void *ctx, request_rec *r)
  {
      ap_filter_rec_t *frec = registered_filters;
  
      for (; frec != NULL; frec = frec->next) {
          if (!strcasecmp(name, frec->name)) {
              ap_filter_t *f = ap_pcalloc(r->pool, sizeof(*f));
  
              f->filter_func = frec->filter_func;
              f->ctx = ctx;
              f->ftype = frec->ftype;
  
              if (INSERT_BEFORE(f, r->filters)) {
                  f->next = r->filters;
                  r->filters = f;
              }
              else {
                  ap_filter_t *fscan = r->filters;
                  while (!INSERT_BEFORE(f, fscan->next))
                      fscan = fscan->next;
                  f->next = fscan->next;
                  fscan->next = f;
              }
  
              break;
          }
      }
  }