Commit 712f3cee authored by Justin Erenkrantz's avatar Justin Erenkrantz
Browse files

Make mod_include do lazy evaluation of potentially expensive to 

compute variables.

Tested with httpd-test's printenv.shtml.

(Justin threw in one or two unrelated formatting nits)
Submitted by:	Brian Pane <bpane@pacbell.net>
Reviewed by:	Justin Erenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90872 13f79535-47bb-0310-9956-ffa450edef68
parent 57407063

CHANGES

+3 −0
Original line number Diff line number Diff line 
Changes with Apache 2.0.26-dev



  *) Make mod_include do lazy evaluation of potentially expensive to

     compute variables.  [Brian Pane <bpane@pacbell.net>]



  *) Fix logging of bytes sent for HEAD requests.  %b and %B should

     log either - or 0, before this patch, they were both logging

     the file size.  [Taketo Kabe <kabe@sra-tohoku.co.jp>]

modules/filters/mod_include.c

+92 −42
Original line number Diff line number Diff line
@@ -96,32 +96,52 @@ module AP_MODULE_DECLARE_DATA include_module; 
static apr_hash_t *include_hash;

static APR_OPTIONAL_FN_TYPE(ap_register_include_handler) *ssi_pfn_register;



/*****************************************************************

 *

 * XBITHACK.  Sigh...  NB it's configurable per-directory; the compile-time

 * option only changes the default.

 */



module include_module;

enum xbithack {

    xbithack_off, xbithack_on, xbithack_full

};



typedef struct {

    char *default_error_msg;

    char *default_time_fmt;

    enum xbithack *xbithack;

} include_dir_config;



#ifdef XBITHACK

#define DEFAULT_XBITHACK xbithack_full

#else

#define DEFAULT_XBITHACK xbithack_off

#endif



#define BYTE_COUNT_THRESHOLD AP_MIN_BYTES_TO_WRITE



/* ------------------------ Environment function -------------------------- */



/* Sentinel value to store in subprocess_env for items that

 * shouldn't be evaluated until/unless they're actually used

 */

static char lazy_eval_sentinel;



/* XXX: could use ap_table_overlap here */

static void add_include_vars(request_rec *r, char *timefmt)

{

    char *pwname;

    apr_table_t *e = r->subprocess_env;

    char *t;

    apr_time_t date = r->request_time;



    apr_table_setn(e, "DATE_LOCAL", ap_ht_time(r->pool, date, timefmt, 0));

    apr_table_setn(e, "DATE_GMT", ap_ht_time(r->pool, date, timefmt, 1));

    apr_table_setn(e, "LAST_MODIFIED",

              ap_ht_time(r->pool, r->finfo.mtime, timefmt, 0));

    apr_table_setn(e, "DATE_LOCAL", &lazy_eval_sentinel);

    apr_table_setn(e, "DATE_GMT", &lazy_eval_sentinel);

    apr_table_setn(e, "LAST_MODIFIED", &lazy_eval_sentinel);

    apr_table_setn(e, "DOCUMENT_URI", r->uri);

    if (r->path_info && *r->path_info) {

        apr_table_setn(e, "DOCUMENT_PATH_INFO", r->path_info);

    }

    if (apr_get_username(&pwname, r->finfo.user, r->pool) == APR_SUCCESS) {

        apr_table_setn(e, "USER_NAME", pwname);

    }

    else {

        apr_table_setn(e, "USER_NAME", "<unknown>");

    }

    apr_table_setn(e, "USER_NAME", &lazy_eval_sentinel);

    if ((t = strrchr(r->filename, '/'))) {

        apr_table_setn(e, "DOCUMENT_NAME", ++t);

    }
@@ -137,6 +157,42 @@ static void add_include_vars(request_rec *r, char *timefmt) 
    }

}



static const char *add_include_vars_lazy(request_rec *r, const char *var)

{

    char *val;

    if (!strcasecmp(var, "DATE_LOCAL")) {

        include_dir_config *conf =

            (include_dir_config *)ap_get_module_config(r->per_dir_config,

                                                       &include_module);

        val = ap_ht_time(r->pool, r->request_time, conf->default_time_fmt, 0);

    }

    else if (!strcasecmp(var, "DATE_GMT")) {

        include_dir_config *conf =

            (include_dir_config *)ap_get_module_config(r->per_dir_config,

                                                       &include_module);

        val = ap_ht_time(r->pool, r->request_time, conf->default_time_fmt, 1);

    }

    else if (!strcasecmp(var, "LAST_MODIFIED")) {

        include_dir_config *conf =

            (include_dir_config *)ap_get_module_config(r->per_dir_config,

                                                       &include_module);

        val = ap_ht_time(r->pool, r->finfo.mtime, conf->default_time_fmt, 0);

    }

    else if (!strcasecmp(var, "USER_NAME")) {

        if (apr_get_username(&val, r->finfo.user, r->pool) != APR_SUCCESS) {

            val = "<unknown>";

        }

    }

    else {

        val = NULL;

    }



    if (val) {

        apr_table_setn(r->subprocess_env, var, val);

    }

    return val;

}



/* --------------------------- Parser functions --------------------------- */



/* This function returns either a pointer to the split bucket containing the
@@ -177,7 +233,6 @@ static apr_bucket *find_start_sequence(apr_bucket *dptr, include_ctx_t *ctx, 
        if (ctx->output_now) {

            apr_size_t start_index;

            apr_bucket *start_bucket;

            apr_bucket_brigade *remainder;

            if (ctx->head_start_index > 0) {

                start_bucket = ctx->head_start_bucket;

                apr_bucket_split(start_bucket, start_index);
@@ -716,6 +771,9 @@ static void ap_ssi_parse_string(request_rec *r, const char *in, char *out, 
                    tmp_store        = *end_of_var_name;

                    *end_of_var_name = '\0';

                    val = apr_table_get(r->subprocess_env, start_of_var_name);

                    if (val == &lazy_eval_sentinel) {

                        val = add_include_vars_lazy(r, start_of_var_name);

                    }

                    *end_of_var_name = tmp_store;



		    if (val) {
@@ -962,11 +1020,20 @@ static int handle_echo(include_ctx_t *ctx, apr_bucket_brigade **bb, request_rec 
            if (!strcmp(tag, "var")) {

                const char *val = apr_table_get(r->subprocess_env, tag_val);



                if (val == &lazy_eval_sentinel) {

                    val = add_include_vars_lazy(r, tag_val);

                }

                if (val) {

                    switch(encode) {

                    case E_NONE:   echo_text = val;                          break;

                    case E_URL:    echo_text = ap_escape_uri(r->pool, val);  break;

                    case E_ENTITY: echo_text = ap_escape_html(r->pool, val); break;

                    case E_NONE:   

                        echo_text = val;

                        break;

                    case E_URL:

                        echo_text = ap_escape_uri(r->pool, val);  

                        break;

                    case E_ENTITY: 

                        echo_text = ap_escape_html(r->pool, val); 

                        break;

                    }



                    e_len = strlen(echo_text);
@@ -2337,13 +2404,19 @@ static int handle_printenv(include_ctx_t *ctx, apr_bucket_brigade **bb, request_ 
            apr_array_header_t *arr = apr_table_elts(r->subprocess_env);

            apr_table_entry_t *elts = (apr_table_entry_t *)arr->elts;

            int i;

            char *key_text, *val_text;

            const char *key_text, *val_text;

            apr_size_t   k_len, v_len, t_wrt;



            *inserted_head = NULL;

            for (i = 0; i < arr->nelts; ++i) {

                key_text = ap_escape_html(r->pool, elts[i].key);

                if (elts[i].val == &lazy_eval_sentinel) {

                    val_text =

                        ap_escape_html(r->pool,

                                       add_include_vars_lazy(r, elts[i].key));

                } else {

                    val_text = ap_escape_html(r->pool, elts[i].val);

                }

                k_len = strlen(key_text);

                v_len = strlen(val_text);
@@ -2688,29 +2761,6 @@ static apr_status_t send_parsed_content(apr_bucket_brigade **bb, 
    return APR_SUCCESS;

}



/*****************************************************************

 *

 * XBITHACK.  Sigh...  NB it's configurable per-directory; the compile-time

 * option only changes the default.

 */



module include_module;

enum xbithack {

    xbithack_off, xbithack_on, xbithack_full

};



typedef struct {

    char *default_error_msg;

    char *default_time_fmt;

    enum xbithack *xbithack;

} include_dir_config;



#ifdef XBITHACK

#define DEFAULT_XBITHACK xbithack_full

#else

#define DEFAULT_XBITHACK xbithack_off

#endif



static void *create_includes_dir_config(apr_pool_t *p, char *dummy)

{

    include_dir_config *result =