liblp: Make kDefaultGroup a string_view
Changing the type of kDefaultGroup from std::string to std::string_view
allows us to make it a constexpr object. Since kDefaultGroup is the
only dirty object in liblp .bss at runtime, this change turns the .bss
page clean and thus saves 4KB per library load.
Bug: 138856262
Test: Boot cuttlefish and check liblp bss is clean for all 5 processes
that are using it.
Change-Id: I7d7c0992e0ab769f070807f24e1275ffed424b5b
diff --git a/fs_mgr/liblp/builder.cpp b/fs_mgr/liblp/builder.cpp
index 8797ea9..a434c93 100644
--- a/fs_mgr/liblp/builder.cpp
+++ b/fs_mgr/liblp/builder.cpp
@@ -19,6 +19,7 @@
#include <string.h>
#include <algorithm>
+#include <string_view>
#include <android-base/properties.h>
#include <android-base/unique_fd.h>
@@ -33,7 +34,7 @@
std::optional<bool> MetadataBuilder::sABOverride;
std::optional<bool> MetadataBuilder::sRetrofitDap;
-static const std::string kDefaultGroup = "default";
+static constexpr std::string_view kDefaultGroup = "default";
bool LinearExtent::AddTo(LpMetadata* out) const {
if (device_index_ >= out->block_devices.size()) {
@@ -414,7 +415,7 @@
geometry_.metadata_slot_count = metadata_slot_count;
geometry_.logical_block_size = logical_block_size;
- if (!AddGroup(kDefaultGroup, 0)) {
+ if (!AddGroup(std::string(kDefaultGroup), 0)) {
return false;
}
return true;
@@ -430,7 +431,7 @@
}
Partition* MetadataBuilder::AddPartition(const std::string& name, uint32_t attributes) {
- return AddPartition(name, kDefaultGroup, attributes);
+ return AddPartition(name, std::string(kDefaultGroup), attributes);
}
Partition* MetadataBuilder::AddPartition(const std::string& name, const std::string& group_name,