Cache DexFile begin and size

Avoid virtual function invocations in DexFile Begin() and Size() methods
by caching duplicate copies of the beginning address and size at construction.

Bug: 110980617
Test: make -j 50 test-art-host
Change-Id: I70867bcd69e30a93b91873171d365a916b76bc96

2 files changed, 23 insertions, 13 deletions

diff --git a/libdexfile/dex/dex_file.cc b/libdexfile/dex/dex_file.cc
index c2b478aded..47a6c1b6b7 100644
--- a/libdexfile/dex/dex_file.cc
+++ b/libdexfile/dex/dex_file.cc
@@ -99,6 +99,11 @@ DexFile::DexFile(std::unique_ptr<DexFileContainer> main_section,
                  const OatDexFile* oat_dex_file,
                  bool is_compact_dex)
     : main_section_(std::move(main_section)),
+      main_begin_(main_section_->Begin()),
+      main_size_(main_section_->Size()),
+      data_section_(std::move(data_section)),
+      data_begin_(data_section_->Begin()),
+      data_size_(data_section_->Size()),
       location_(location),
       location_checksum_(location_checksum),
       header_(reinterpret_cast<const Header*>(main_section_->Begin())),
@@ -127,8 +132,6 @@ DexFile::DexFile(std::unique_ptr<DexFileContainer> main_section,
   // any of the sections via a pointer.
   CHECK_ALIGNED(main_section_->Begin(), alignof(Header));
 
-  data_section_ = std::move(data_section);
-
   InitializeSectionsFromMapList();
 }
 
@@ -138,6 +141,12 @@ DexFile::DexFile(std::unique_ptr<DexFileContainer> main_section,
                  const OatDexFile* oat_dex_file,
                  bool is_compact_dex)
     : main_section_(std::move(main_section)),
+      main_begin_(main_section_->Begin()),
+      main_size_(main_section_->Size()),
+      data_section_(std::make_unique<NonOwningDexFileContainer>(main_section_->Begin(),
+                                                                main_section_->Size())),
+      data_begin_(data_section_->Begin()),
+      data_size_(data_section_->Size()),
       location_(location),
       location_checksum_(location_checksum),
       header_(reinterpret_cast<const Header*>(main_section_->Begin())),
@@ -166,9 +175,6 @@ DexFile::DexFile(std::unique_ptr<DexFileContainer> main_section,
   // any of the sections via a pointer.
   CHECK_ALIGNED(main_section_->Begin(), alignof(Header));
 
-  data_section_ = std::make_unique<NonOwningDexFileContainer>(main_section_->Begin(),
-                                                              main_section_->Size());
-
   InitializeSectionsFromMapList();
 }
 
diff --git a/libdexfile/dex/dex_file.h b/libdexfile/dex/dex_file.h
index c94c786699..714e42cb3c 100644
--- a/libdexfile/dex/dex_file.h
+++ b/libdexfile/dex/dex_file.h
@@ -966,19 +966,19 @@ class DexFile {
   bool DisableWrite() const;
 
   const uint8_t* Begin() const {
-    return main_section_->Begin();
+    return main_begin_;
   }
 
   size_t Size() const {
-    return main_section_->Size();
+    return main_size_;
   }
 
   const uint8_t* DataBegin() const {
-    return data_section_->Begin();
+    return data_begin_;
   }
 
   size_t DataSize() const {
-    return data_section_->Size();
+    return data_size_;
   }
 
   template <typename T>
@@ -1089,10 +1089,14 @@ class DexFile {
   void InitializeSectionsFromMapList();
 
   // The container for the header and fixed portions.
-  std::unique_ptr<DexFileContainer> main_section_;
-
-  // The container for the data section
-  std::unique_ptr<DexFileContainer> data_section_;
+  const std::unique_ptr<DexFileContainer> main_section_;
+  const uint8_t* const main_begin_;
+  const size_t main_size_;
+
+  // The container for the data section.
+  const std::unique_ptr<DexFileContainer> data_section_;
+  const uint8_t* const data_begin_;
+  const size_t data_size_;
 
   // Typically the dex file name when available, alternatively some identifying string.
   //