toolbox: reimplement watchprops using __system_property_foreach()
Internally, replace the watchlist array with a hashmap since the array
assumes properties are enumerated in a consistent order and foreach()
probably won't. (find_nth() never guaranteed this either but it usually
worked in practice.)
Signed-off-by: Greg Hackmann <ghackmann@google.com>
(cherry picked from commit 389e358017ad15485f2bd9120feebfffa489131b)
Change-Id: I1db3137b130474f4bb205f01f0bdcf37cf974764
diff --git a/toolbox/watchprops.c b/toolbox/watchprops.c
index 3418d62..bf82882 100644
--- a/toolbox/watchprops.c
+++ b/toolbox/watchprops.c
@@ -1,32 +1,30 @@
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
+#include <errno.h>
#include <cutils/properties.h>
+#include <cutils/hashmap.h>
#include <sys/atomics.h>
#define _REALLY_INCLUDE_SYS__SYSTEM_PROPERTIES_H_
#include <sys/_system_properties.h>
-typedef struct pwatch pwatch;
-
-struct pwatch
+static int str_hash(void *key)
{
- const prop_info *pi;
- unsigned serial;
-};
+ return hashmapHash(key, strlen(key));
+}
-static pwatch watchlist[1024];
-
-static void announce(const prop_info *pi)
+static bool str_equals(void *keyA, void *keyB)
{
- char name[PROP_NAME_MAX];
- char value[PROP_VALUE_MAX];
+ return strcmp(keyA, keyB) == 0;
+}
+
+static void announce(char *name, char *value)
+{
char *x;
- __system_property_read(pi, name, value);
-
for(x = value; *x; x++) {
if((*x < 32) || (*x > 127)) *x = '.';
}
@@ -34,42 +32,64 @@
fprintf(stderr,"%10d %s = '%s'\n", (int) time(0), name, value);
}
+static void add_to_watchlist(Hashmap *watchlist, const char *name,
+ const prop_info *pi)
+{
+ char *key = strdup(name);
+ unsigned *value = malloc(sizeof(unsigned));
+ if (!key || !value)
+ exit(1);
+
+ *value = __system_property_serial(pi);
+ hashmapPut(watchlist, key, value);
+}
+
+static void populate_watchlist(const prop_info *pi, void *cookie)
+{
+ Hashmap *watchlist = cookie;
+ char name[PROP_NAME_MAX];
+ char value_unused[PROP_VALUE_MAX];
+
+ __system_property_read(pi, name, value_unused);
+ add_to_watchlist(watchlist, name, pi);
+}
+
+static void update_watchlist(const prop_info *pi, void *cookie)
+{
+ Hashmap *watchlist = cookie;
+ char name[PROP_NAME_MAX];
+ char value[PROP_VALUE_MAX];
+ unsigned *serial;
+
+ __system_property_read(pi, name, value);
+ serial = hashmapGet(watchlist, name);
+ if (!serial) {
+ add_to_watchlist(watchlist, name, pi);
+ announce(name, value);
+ } else {
+ unsigned tmp = __system_property_serial(pi);
+ if (*serial != tmp) {
+ *serial = tmp;
+ announce(name, value);
+ }
+ }
+}
+
int watchprops_main(int argc, char *argv[])
{
unsigned serial = 0;
- unsigned count;
+ unsigned count = 0;
unsigned n;
- for(n = 0; n < 1024; n++) {
- watchlist[n].pi = __system_property_find_nth(n);
- if (watchlist[n].pi == 0)
- break;
- watchlist[n].serial = __system_property_serial(watchlist[n].pi);
- }
-
- count = n;
- if (count == 1024)
+ Hashmap *watchlist = hashmapCreate(1024, str_hash, str_equals);
+ if (!watchlist)
exit(1);
+ __system_property_foreach(populate_watchlist, watchlist);
+
for(;;) {
serial = __system_property_wait_any(serial);
- while(count < 1024){
- watchlist[count].pi = __system_property_find_nth(count);
- if (watchlist[count].pi == 0)
- break;
- watchlist[count].serial = __system_property_serial(watchlist[n].pi);
- announce(watchlist[count].pi);
- count++;
- if(count == 1024) exit(1);
- }
-
- for(n = 0; n < count; n++){
- unsigned tmp = __system_property_serial(watchlist[n].pi);
- if(watchlist[n].serial != tmp) {
- announce(watchlist[n].pi);
- watchlist[n].serial = tmp;
- }
- }
+ __system_property_foreach(update_watchlist, watchlist);
}
return 0;
}