1 files changed, 44 insertions, 7 deletions

diff --git a/modules/session/mod_session.c b/modules/session/mod_session.c
index 64e6e4a..fa8d406 100644
--- a/modules/session/mod_session.c
+++ b/modules/session/mod_session.c
@@ -128,7 +128,7 @@ static apr_status_t ap_session_load(request_rec * r, session_rec ** z)
     now = apr_time_now();
 
     if (zz) {
-        /* load the session attibutes */
+        /* load the session attributes */
         rv = ap_run_session_decode(r, zz);
  
         /* having a session we cannot decode is just as good as having
@@ -142,6 +142,7 @@ static apr_status_t ap_session_load(request_rec * r, session_rec ** z)
 
        /* invalidate session if session is expired */
         if (zz && zz->expiry && zz->expiry < now) {
+            ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "session is expired");
             zz = NULL;
         }
     }
@@ -180,6 +181,7 @@ static apr_status_t ap_session_save(request_rec * r, session_rec * z)
 {
     if (z) {
         apr_time_t now = apr_time_now();
+        apr_time_t initialExpiry = z->expiry;
         int rv = 0;
 
         session_dir_conf *dconf = ap_get_module_config(r->per_dir_config,
@@ -210,6 +212,17 @@ static apr_status_t ap_session_save(request_rec * r, session_rec * z)
             z->expiry = now + z->maxage * APR_USEC_PER_SEC;
         } 
 
+        /* don't save if the only change is the expiry by a small amount */
+        if (!z->dirty && dconf->expiry_update_time
+                && (z->expiry - initialExpiry < dconf->expiry_update_time)) {
+            return APR_SUCCESS;
+        }
+
+        /* also don't save sessions that didn't change at all */
+        if (!z->dirty && !z->maxage) {
+            return APR_SUCCESS;
+        }
+
         /* encode the session */
         rv = ap_run_session_encode(r, z);
         if (OK != rv) {
@@ -304,15 +317,17 @@ static apr_status_t ap_session_set(request_rec * r, session_rec * z,
 
 static int identity_count(void *v, const char *key, const char *val)
 {
-    int *count = v;
-    *count += strlen(key) * 3 + strlen(val) * 3 + 1;
+    apr_size_t *count = v;
+
+    *count += strlen(key) * 3 + strlen(val) * 3 + 2;
     return 1;
 }
 
 static int identity_concat(void *v, const char *key, const char *val)
 {
     char *slider = v;
-    int length = strlen(slider);
+    apr_size_t length = strlen(slider);
+
     slider += length;
     if (length) {
         *slider = '&';
@@ -341,9 +356,9 @@ static int identity_concat(void *v, const char *key, const char *val)
  */
 static apr_status_t session_identity_encode(request_rec * r, session_rec * z)
 {
-
     char *buffer = NULL;
-    int length = 0;
+    apr_size_t length = 0;
+
     if (z->expiry) {
         char *expiry = apr_psprintf(z->pool, "%" APR_INT64_T_FMT, z->expiry);
         apr_table_setn(z->entries, SESSION_EXPIRY, expiry);
@@ -392,8 +407,8 @@ static apr_status_t session_identity_decode(request_rec * r, session_rec * z)
         char *plast = NULL;
         const char *psep = "=";
         char *key = apr_strtok(pair, psep, &plast);
-        char *val = apr_strtok(NULL, psep, &plast);
         if (key && *key) {
+            char *val = apr_strtok(NULL, sep, &plast);
             if (!val || !*val) {
                 apr_table_unset(z->entries, key);
             }
@@ -556,6 +571,10 @@ static void *merge_session_dir_config(apr_pool_t * p, void *basev, void *addv)
     new->env_set = add->env_set || base->env_set;
     new->includes = apr_array_append(p, base->includes, add->includes);
     new->excludes = apr_array_append(p, base->excludes, add->excludes);
+    new->expiry_update_time = (add->expiry_update_set == 0)
+                                ? base->expiry_update_time
+                                : add->expiry_update_time;
+    new->expiry_update_set = add->expiry_update_set || base->expiry_update_set;
 
     return new;
 }
@@ -625,6 +644,21 @@ static const char *add_session_exclude(cmd_parms * cmd, void *dconf, const char
     return NULL;
 }
 
+static const char *
+     set_session_expiry_update(cmd_parms * parms, void *dconf, const char *arg)
+{
+    session_dir_conf *conf = dconf;
+
+    conf->expiry_update_time = atoi(arg);
+    if (conf->expiry_update_time < 0) {
+        return "SessionExpiryUpdateInterval must be zero (disable) or a positive value";
+    }
+    conf->expiry_update_time = apr_time_from_sec(conf->expiry_update_time);
+    conf->expiry_update_set = 1;
+
+    return NULL;
+}
+
 
 static const command_rec session_cmds[] =
 {
@@ -640,6 +674,9 @@ static const command_rec session_cmds[] =
                   "URL prefixes to include in the session. Defaults to all URLs"),
     AP_INIT_TAKE1("SessionExclude", add_session_exclude, NULL, RSRC_CONF|OR_AUTHCFG,
                   "URL prefixes to exclude from the session. Defaults to no URLs"),
+    AP_INIT_TAKE1("SessionExpiryUpdateInterval", set_session_expiry_update, NULL, RSRC_CONF|OR_AUTHCFG,
+                  "time interval for which a session's expiry time may change "
+                  "without having to be rewritten. Zero to disable"),
     {NULL}
 };