commit 689caf046cb99efda4462183eeaacb11a6119adb
author David Sehr <sehr@google.com> Fri Jun 29 09:31:30 2018 -0700
committer David Sehr <sehr@google.com> Fri Jun 29 09:50:55 2018 -0700
tree d318dd6e64269150bd3844b94ebb75dc8abf8ea2
parent 04a4f20f26b0935a43f74269f68ddfd67335afb8

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

libdexfile/dex/dex_file.cc

diff --git a/libdexfile/dex/dex_file.cc b/libdexfile/dex/dex_file.cc
index c2b478a..47a6c1b 100644
--- a/libdexfile/dex/dex_file.cc
+++ b/libdexfile/dex/dex_file.cc
@@ -99,6 +99,11 @@
                  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 @@
   // 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 @@
                  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 @@
   // 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();
 }
 

libdexfile/dex/dex_file.h

diff --git a/libdexfile/dex/dex_file.h b/libdexfile/dex/dex_file.h
index c94c786..714e42c 100644
--- a/libdexfile/dex/dex_file.h
+++ b/libdexfile/dex/dex_file.h
@@ -966,19 +966,19 @@
   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 @@
   void InitializeSectionsFromMapList();
 
   // The container for the header and fixed portions.
-  std::unique_ptr<DexFileContainer> main_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
-  std::unique_ptr<DexFileContainer> data_section_;
+  // 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.
   //