match: Support for both merging and replacing proplist updates.

This patch adds a new update mode specifier that can be optionally
given in match rules after the regexp. Property list updates triggered
by the rule will honour the given mode. The two allowed modes are 'merge'
and 'replace', corresponding to PA_UPDATE_MERGE and PA_UPDATE_REPLACE
respectively. If omitted, the mode defaults to PA_UPDATE_MERGE, ie. to
the original behavior.

For example, to force 'media.role' to be overwritten with 'bar' for
streams matching foo you can use an entry like this:

foo replace "bar"

This will really overwrite media.role to bar even if it has already been
set to something else by the application.

Thanks to Krisztian Litkey for the original patch and the description
above. In addition to implementing the new feature, this patch fixes
a number of bugs in the parsing code.

1 files changed, 60 insertions, 37 deletions

diff --git a/src/modules/module-match.c b/src/modules/module-match.c
index b3316d490..c94ef7901 100644
--- a/src/modules/module-match.c
+++ b/src/modules/module-match.c
@@ -60,6 +60,9 @@ PA_MODULE_USAGE("table=<filename> "
 #define DEFAULT_MATCH_TABLE_FILE PA_DEFAULT_CONFIG_DIR"/match.table"
 #define DEFAULT_MATCH_TABLE_FILE_USER "match.table"
 
+#define UPDATE_REPLACE "replace"
+#define UPDATE_MERGE "merge"
+
 static const char* const valid_modargs[] = {
     "table",
     "key",
@@ -70,6 +73,7 @@ struct rule {
     regex_t regex;
     pa_volume_t volume;
     pa_proplist *proplist;
+    pa_update_mode_t mode;
     struct rule *next;
 };
 
@@ -101,13 +105,14 @@ static int load_rules(struct userdata *u, const char *filename) {
     pa_lock_fd(fileno(f), 1);
 
     while (!feof(f)) {
-        char *d, *v;
+        char *token_end, *value_str;
         pa_volume_t volume = PA_VOLUME_NORM;
         uint32_t k;
         regex_t regex;
         char ln[256];
         struct rule *rule;
         pa_proplist *proplist = NULL;
+        pa_update_mode_t mode = (pa_update_mode_t) -1;
 
         if (!fgets(ln, sizeof(ln), f))
             break;
@@ -119,51 +124,72 @@ static int load_rules(struct userdata *u, const char *filename) {
         if (ln[0] == '#' || !*ln )
             continue;
 
-        d = ln+strcspn(ln, WHITESPACE);
-        v = d+strspn(d, WHITESPACE);
+        token_end = ln + strcspn(ln, WHITESPACE);
+        value_str = token_end + strspn(token_end, WHITESPACE);
+        *token_end = 0;
 
+        if (!*ln) {
+            pa_log("[%s:%u] failed to parse line - missing regexp", fn, n);
+            goto finish;
+        }
 
-        if (!*v) {
-            pa_log(__FILE__ ": [%s:%u] failed to parse line - too few words", filename, n);
+        if (!*value_str) {
+            pa_log("[%s:%u] failed to parse line - too few words", fn, n);
             goto finish;
         }
 
-        *d = 0;
-        if (pa_atou(v, &k) >= 0) {
+        if (pa_atou(value_str, &k) >= 0)
             volume = (pa_volume_t) PA_CLAMP_VOLUME(k);
-        } else if (*v == '"') {
-            char *e;
-
-            e = strchr(v+1, '"');
-            if (!e) {
-                pa_log(__FILE__ ": [%s:%u] failed to parse line - missing role closing quote", filename, n);
-                goto finish;
-            }
-
-            *e = '\0';
-            e = pa_sprintf_malloc("media.role=\"%s\"", v+1);
-            proplist = pa_proplist_from_string(e);
-            pa_xfree(e);
-        } else {
-            char *e;
-
-            e = v+strspn(v, WHITESPACE);
-            if (!*e) {
-                pa_log(__FILE__ ": [%s:%u] failed to parse line - missing end of property list", filename, n);
-                goto finish;
-            }
-            *e = '\0';
-            proplist = pa_proplist_from_string(v);
+        else {
+            size_t len;
+
+            token_end = value_str + strcspn(value_str, WHITESPACE);
+
+            len = token_end - value_str;
+            if (len == (sizeof(UPDATE_REPLACE) - 1) && !strncmp(value_str, UPDATE_REPLACE, len))
+                mode = PA_UPDATE_REPLACE;
+            else if (len == (sizeof(UPDATE_MERGE) - 1) && !strncmp(value_str, UPDATE_MERGE, len))
+                mode = PA_UPDATE_MERGE;
+
+            if (mode != (pa_update_mode_t) -1) {
+                value_str = token_end + strspn(token_end, WHITESPACE);
+
+                if (!*value_str) {
+                    pa_log("[%s:%u] failed to parse line - too few words", fn, n);
+                    goto finish;
+                }
+            } else
+                mode = PA_UPDATE_MERGE;
+
+            if (*value_str == '"') {
+                value_str++;
+
+                token_end = strchr(value_str, '"');
+                if (!token_end) {
+                    pa_log("[%s:%u] failed to parse line - missing role closing quote", fn, n);
+                    goto finish;
+                }
+            } else
+                token_end = value_str + strcspn(value_str, WHITESPACE);
+
+            *token_end = 0;
+
+            value_str = pa_sprintf_malloc("media.role=\"%s\"", value_str);
+            proplist = pa_proplist_from_string(value_str);
+            pa_xfree(value_str);
         }
 
         if (regcomp(&regex, ln, REG_EXTENDED|REG_NOSUB) != 0) {
-            pa_log("[%s:%u] invalid regular expression", filename, n);
+            pa_log("[%s:%u] invalid regular expression", fn, n);
+            if (proplist)
+                pa_proplist_free(proplist);
             goto finish;
         }
 
         rule = pa_xnew(struct rule, 1);
         rule->regex = regex;
         rule->proplist = proplist;
+        rule->mode = mode;
         rule->volume = volume;
         rule->next = NULL;
 
@@ -172,8 +198,6 @@ static int load_rules(struct userdata *u, const char *filename) {
         else
             u->rules = rule;
         end = rule;
-
-        *d = 0;
     }
 
     ret = 0;
@@ -184,8 +208,7 @@ finish:
         fclose(f);
     }
 
-    if (fn)
-        pa_xfree(fn);
+    pa_xfree(fn);
 
     return ret;
 }
@@ -206,7 +229,7 @@ static pa_hook_result_t sink_input_new_hook_callback(pa_core *c, pa_sink_input_n
         if (!regexec(&r->regex, n, 0, NULL, 0)) {
             if (r->proplist) {
                 pa_log_debug("updating proplist of sink input '%s'", n);
-                pa_proplist_update(si->proplist, PA_UPDATE_MERGE, r->proplist);
+                pa_proplist_update(si->proplist, r->mode, r->proplist);
             } else if (si->volume_writable) {
                 pa_cvolume cv;
                 pa_log_debug("changing volume of sink input '%s' to 0x%03x", n, r->volume);
@@ -231,7 +254,7 @@ int pa__init(pa_module*m) {
         goto fail;
     }
 
-    u = pa_xnew(struct userdata, 1);
+    u = pa_xnew0(struct userdata, 1);
     u->rules = NULL;
     m->userdata = u;