bionic: add __system_property_foreach
find_nth() will be inefficient on a trie. Since find_nth() is only used
internally and only for enumerating properties, we can add a foreach()
function to do this directly.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
(cherry picked from commit 577418403d68e663fb33c7b0c8a90d862d9c00cf)
Change-Id: Iaca97d1182ce2c28863ba85241cbb5cf6185eb2f
diff --git a/libc/bionic/system_properties.c b/libc/bionic/system_properties.c
index d969507..5197ef3 100644
--- a/libc/bionic/system_properties.c
+++ b/libc/bionic/system_properties.c
@@ -159,6 +159,22 @@
return result;
}
+int __system_property_foreach(
+ void (*propfn)(const prop_info *pi, void *cookie),
+ void *cookie)
+{
+ prop_area *pa = __system_property_area__;
+ unsigned i;
+
+ for (i = 0; i < pa->count; i++) {
+ unsigned entry = pa->toc[i];
+ prop_info *pi = TOC_TO_INFO(pa, entry);
+ propfn(pi, cookie);
+ }
+
+ return 0;
+}
+
const prop_info *__system_property_find_nth(unsigned n)
{
prop_area *pa = __system_property_area__;
diff --git a/libc/include/sys/system_properties.h b/libc/include/sys/system_properties.h
index 85915b2..01c3db3 100644
--- a/libc/include/sys/system_properties.h
+++ b/libc/include/sys/system_properties.h
@@ -76,13 +76,26 @@
** there is no nth property. Use __system_property_read() to
** read the value of this property.
**
-** This method is for inspecting and debugging the property
+** Please do not call this method. It only exists to provide
+** backwards compatibility to NDK apps. Its implementation
+** is inefficient and order of results may change from call
+** to call.
+*/
+const prop_info *__system_property_find_nth(unsigned n);
+
+/* Pass a prop_info for each system property to the provided
+** callback. Use __system_property_read() to read the value
+** of this property.
+**
+** This method is for inspecting and debugging the property
** system. Please use __system_property_find() instead.
**
** Order of results may change from call to call. This is
** not a bug.
-*/
-const prop_info *__system_property_find_nth(unsigned n);
+*/
+int __system_property_foreach(
+ void (*propfn)(const prop_info *pi, void *cookie),
+ void *cookie);
__END_DECLS
diff --git a/tests/system_properties_test.cpp b/tests/system_properties_test.cpp
index 60188f4..70ff1d6 100644
--- a/tests/system_properties_test.cpp
+++ b/tests/system_properties_test.cpp
@@ -125,6 +125,25 @@
}
}
+static void foreach_test_callback(const prop_info *pi, void* cookie) {
+ size_t *count = static_cast<size_t *>(cookie);
+
+ ASSERT_NE((prop_info *)NULL, pi);
+ (*count)++;
+}
+
+TEST(properties, foreach) {
+ LocalPropertyTestState pa;
+ size_t count = 0;
+
+ ASSERT_EQ(0, __system_property_add("property", 8, "value1", 6));
+ ASSERT_EQ(0, __system_property_add("other_property", 14, "value2", 6));
+ ASSERT_EQ(0, __system_property_add("property_other", 14, "value3", 6));
+
+ ASSERT_EQ(0, __system_property_foreach(foreach_test_callback, &count));
+ ASSERT_EQ(3U, count);
+}
+
TEST(properties, find_nth) {
LocalPropertyTestState pa;