Move staging value application logic to persistent_properties and add
unit tests
1, Previous implementation has the staged prop application done in
property_service, which caused a number of unnecessary changes which
including exposing apis like AddPersistentProperty. In addition, it made
the property_service logic complicated. A better design is to have the
staged value application done while reading the persistent properties
from file. This way, no change to property service. In addition, unit
test is much cleaner and efficient.
2, add a unit test to lock down the behavior. Specifically, it locks down that when a prop is staged, it should be applied the next time when the persistent prop is loaded. In addition, it should lock down that other persistent props are not overwritten.
Bug: b/307752841, b/300111812, b/306062513
Change-Id: I43c603efbb803195065dda3f0bc2145716302bbc
diff --git a/init/persistent_properties.cpp b/init/persistent_properties.cpp
index e89244f..6f8a4de 100644
--- a/init/persistent_properties.cpp
+++ b/init/persistent_properties.cpp
@@ -46,6 +46,13 @@
constexpr const char kLegacyPersistentPropertyDir[] = "/data/property";
+void AddPersistentProperty(const std::string& name, const std::string& value,
+ PersistentProperties* persistent_properties) {
+ auto persistent_property_record = persistent_properties->add_properties();
+ persistent_property_record->set_name(name);
+ persistent_property_record->set_value(value);
+}
+
Result<PersistentProperties> LoadLegacyPersistentProperties() {
std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(kLegacyPersistentPropertyDir), closedir);
if (!dir) {
@@ -146,13 +153,6 @@
} // namespace
-void AddPersistentProperty(const std::string& name, const std::string& value,
- PersistentProperties* persistent_properties) {
- auto persistent_property_record = persistent_properties->add_properties();
- persistent_property_record->set_name(name);
- persistent_property_record->set_value(value);
-}
-
Result<PersistentProperties> LoadPersistentPropertyFile() {
auto file_contents = ReadPersistentPropertyFile();
if (!file_contents.ok()) return file_contents.error();
@@ -266,8 +266,57 @@
}
}
- return *persistent_properties;
+ // loop over to find all staged props
+ auto const staged_prefix = std::string_view("next_boot.");
+ auto staged_props = std::unordered_map<std::string, std::string>();
+ for (const auto& property_record : persistent_properties->properties()) {
+ auto const& prop_name = property_record.name();
+ auto const& prop_value = property_record.value();
+ if (StartsWith(prop_name, staged_prefix)) {
+ auto actual_prop_name = prop_name.substr(staged_prefix.size());
+ staged_props[actual_prop_name] = prop_value;
+ }
+ }
+
+ if (staged_props.empty()) {
+ return *persistent_properties;
+ }
+
+ // if has staging, apply staging and perserve the original prop order
+ PersistentProperties updated_persistent_properties;
+ for (const auto& property_record : persistent_properties->properties()) {
+ auto const& prop_name = property_record.name();
+ auto const& prop_value = property_record.value();
+
+ // don't include staged props anymore
+ if (StartsWith(prop_name, staged_prefix)) {
+ continue;
+ }
+
+ auto iter = staged_props.find(prop_name);
+ if (iter != staged_props.end()) {
+ AddPersistentProperty(prop_name, iter->second, &updated_persistent_properties);
+ staged_props.erase(iter);
+ } else {
+ AddPersistentProperty(prop_name, prop_value, &updated_persistent_properties);
+ }
+ }
+
+ // add any additional staged props
+ for (auto const& [prop_name, prop_value] : staged_props) {
+ AddPersistentProperty(prop_name, prop_value, &updated_persistent_properties);
+ }
+
+ // write current updated persist prop file
+ auto result = WritePersistentPropertyFile(updated_persistent_properties);
+ if (!result.ok()) {
+ LOG(ERROR) << "Could not store persistent property: " << result.error();
+ }
+
+ return updated_persistent_properties;
}
+
+
} // namespace init
} // namespace android
diff --git a/init/persistent_properties.h b/init/persistent_properties.h
index 7e9d438..11083da 100644
--- a/init/persistent_properties.h
+++ b/init/persistent_properties.h
@@ -25,8 +25,6 @@
namespace android {
namespace init {
-void AddPersistentProperty(const std::string& name, const std::string& value,
- PersistentProperties* persistent_properties);
PersistentProperties LoadPersistentProperties();
void WritePersistentProperty(const std::string& name, const std::string& value);
PersistentProperties LoadPersistentPropertiesFromMemory();
diff --git a/init/persistent_properties_test.cpp b/init/persistent_properties_test.cpp
index e5d26db..5763050 100644
--- a/init/persistent_properties_test.cpp
+++ b/init/persistent_properties_test.cpp
@@ -178,5 +178,37 @@
EXPECT_FALSE(it == read_back_properties.properties().end());
}
+TEST(persistent_properties, StagedPersistProperty) {
+ TemporaryFile tf;
+ ASSERT_TRUE(tf.fd != -1);
+ persistent_property_filename = tf.path;
+
+ std::vector<std::pair<std::string, std::string>> persistent_properties = {
+ {"persist.sys.locale", "en-US"},
+ {"next_boot.persist.test.numbers", "54321"},
+ {"persist.sys.timezone", "America/Los_Angeles"},
+ {"persist.test.numbers", "12345"},
+ {"next_boot.persist.test.extra", "abc"},
+ };
+
+ ASSERT_RESULT_OK(
+ WritePersistentPropertyFile(VectorToPersistentProperties(persistent_properties)));
+
+ std::vector<std::pair<std::string, std::string>> expected_persistent_properties = {
+ {"persist.sys.locale", "en-US"},
+ {"persist.sys.timezone", "America/Los_Angeles"},
+ {"persist.test.numbers", "54321"},
+ {"persist.test.extra", "abc"},
+ };
+
+ // lock down that staged props are applied
+ auto first_read_back_properties = LoadPersistentProperties();
+ CheckPropertiesEqual(expected_persistent_properties, first_read_back_properties);
+
+ // lock down that other props are not overwritten
+ auto second_read_back_properties = LoadPersistentProperties();
+ CheckPropertiesEqual(expected_persistent_properties, second_read_back_properties);
+}
+
} // namespace init
} // namespace android
diff --git a/init/property_service.cpp b/init/property_service.cpp
index b08a904..87fc4c7 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -1396,33 +1396,12 @@
switch (init_message.msg_case()) {
case InitMessage::kLoadPersistentProperties: {
load_override_properties();
- // Read persistent properties after all default values have been loaded.
- // Apply staged and persistent properties
- bool has_staged_prop = false;
- auto const staged_prefix = std::string_view("next_boot.");
auto persistent_properties = LoadPersistentProperties();
for (const auto& property_record : persistent_properties.properties()) {
auto const& prop_name = property_record.name();
auto const& prop_value = property_record.value();
-
- if (StartsWith(prop_name, staged_prefix)) {
- has_staged_prop = true;
- auto actual_prop_name = prop_name.substr(staged_prefix.size());
- InitPropertySet(actual_prop_name, prop_value);
- } else {
- InitPropertySet(prop_name, prop_value);
- }
- }
-
- // Update persist prop file if there are staged props
- if (has_staged_prop) {
- PersistentProperties props = LoadPersistentPropertiesFromMemory();
- // write current updated persist prop file
- auto result = WritePersistentPropertyFile(props);
- if (!result.ok()) {
- LOG(ERROR) << "Could not store persistent property: " << result.error();
- }
+ InitPropertySet(prop_name, prop_value);
}
// Apply debug ramdisk special settings after persistent properties are loaded.