libbinder: ParcelableHolder - avoid utf-8<->utf-16

Switching getParcelableDescriptor to String16:
- consistent w/ interfaces
- can use StaticString16 (no static dirty heap allocation)
- avoid converting these strings utf-8/utf-16

Bug: 170909836
Test: aidl_integration_test
Change-Id: I51f81fc89d95f2697524512b9d5cf3bd669dbb0e

2 files changed, 6 insertions, 5 deletions

diff --git a/libs/binder/ParcelableHolder.cpp b/libs/binder/ParcelableHolder.cpp
index b2b86716d5..2e86b7415a 100644
--- a/libs/binder/ParcelableHolder.cpp
+++ b/libs/binder/ParcelableHolder.cpp
@@ -37,7 +37,7 @@ status_t ParcelableHolder::writeToParcel(Parcel* p) const {
         size_t sizePos = p->dataPosition();
         RETURN_ON_FAILURE(p->writeInt32(0));
         size_t dataStartPos = p->dataPosition();
-        RETURN_ON_FAILURE(p->writeUtf8AsUtf16(this->mParcelableName));
+        RETURN_ON_FAILURE(p->writeString16(this->mParcelableName));
         this->mParcelable->writeToParcel(p);
         size_t dataSize = p->dataPosition() - dataStartPos;
 
diff --git a/libs/binder/include/binder/ParcelableHolder.h b/libs/binder/include/binder/ParcelableHolder.h
index ff0a6860f3..9e4475c947 100644
--- a/libs/binder/include/binder/ParcelableHolder.h
+++ b/libs/binder/include/binder/ParcelableHolder.h
@@ -18,6 +18,7 @@
 
 #include <binder/Parcel.h>
 #include <binder/Parcelable.h>
+#include <utils/String16.h>
 #include <mutex>
 #include <optional>
 #include <tuple>
@@ -72,7 +73,7 @@ public:
     template <typename T>
     status_t getParcelable(std::shared_ptr<T>* ret) const {
         static_assert(std::is_base_of<Parcelable, T>::value, "T must be derived from Parcelable");
-        const std::string& parcelableDesc = T::getParcelableDescriptor();
+        const String16& parcelableDesc = T::getParcelableDescriptor();
         if (!this->mParcelPtr) {
             if (!this->mParcelable || !this->mParcelableName) {
                 ALOGD("empty ParcelableHolder");
@@ -80,7 +81,7 @@ public:
                 return android::OK;
             } else if (parcelableDesc != *mParcelableName) {
                 ALOGD("extension class name mismatch expected:%s actual:%s",
-                      mParcelableName->c_str(), parcelableDesc.c_str());
+                      String8(*mParcelableName).c_str(), String8(parcelableDesc).c_str());
                 *ret = nullptr;
                 return android::BAD_VALUE;
             }
@@ -88,7 +89,7 @@ public:
             return android::OK;
         }
         this->mParcelPtr->setDataPosition(0);
-        status_t status = this->mParcelPtr->readUtf8FromUtf16(&this->mParcelableName);
+        status_t status = this->mParcelPtr->readString16(&this->mParcelableName);
         if (status != android::OK || parcelableDesc != this->mParcelableName) {
             this->mParcelableName = std::nullopt;
             *ret = nullptr;
@@ -130,7 +131,7 @@ public:
 
 private:
     mutable std::shared_ptr<Parcelable> mParcelable;
-    mutable std::optional<std::string> mParcelableName;
+    mutable std::optional<String16> mParcelableName;
     mutable std::unique_ptr<Parcel> mParcelPtr;
     Stability mStability;
 };