commit 14e8ade9a91ea48cb65b3e14954e13a396e1a94d
author Ryan Mitchell <rtmitchell@google.com> Mon Jan 11 16:01:35 2021 -0800
committer Ryan Mitchell <rtmitchell@google.com> Wed Jan 13 21:14:31 2021 -0800
tree adbf03b67a1b60910948fa4fdc10726344eaf1ae
parent fb4d09cadd27a3fb1a2e268417f0f511aa92e344

Optimize FilterApkAssets by caching config

ResTable_config of every ResTable_type is read from device every time
AssetManager::RebuildFilterList is invoked. For large APKs (like
framework-res.apk), this causes a large number of page faults
when accessing the config from disk. The configs are also used in the
slow path of AssetManager::FindEntryInternal, which makes it even
slower. Instead cache the config on the TypeSpec of its ApkAsset.

Bug: 177247024
Test: libandroidfw_tests
Change-Id: I66d507c4eeb2399f7558f3d9dfc53c157129ada0

tools/aapt2/process/SymbolTable.cpp

diff --git a/tools/aapt2/process/SymbolTable.cpp b/tools/aapt2/process/SymbolTable.cpp
index ad716c7..daedc2a 100644
--- a/tools/aapt2/process/SymbolTable.cpp
+++ b/tools/aapt2/process/SymbolTable.cpp
@@ -227,8 +227,7 @@
       apk_assets.push_back(apk_asset.get());
     }
 
-    asset_manager_.SetApkAssets(apk_assets, true /* invalidate_caches */,
-                                false /* filter_incompatible_configs */);
+    asset_manager_.SetApkAssets(apk_assets);
     return true;
   }
   return false;
@@ -351,9 +350,9 @@
       return true;
     }
 
-    auto value = asset_manager_.GetResource(res_id.id, true /* may_be_bag */);
-    if (value.has_value()) {
-      type_spec_flags = value->flags;
+    auto flags = asset_manager_.GetResourceTypeSpecFlags(res_id.id);
+    if (flags.has_value()) {
+      type_spec_flags = *flags;
       found = true;
       return false;
     }
@@ -406,8 +405,8 @@
     return {};
   }
 
-  auto value = asset_manager_.GetResource(id.id, true /* may_be_bag */);
-  if (!value.has_value()) {
+  auto flags = asset_manager_.GetResourceTypeSpecFlags(id.id);
+  if (!flags.has_value()) {
     return {};
   }
 
@@ -422,7 +421,7 @@
   }
 
   if (s) {
-    s->is_public = (value->flags & android::ResTable_typeSpec::SPEC_PUBLIC) != 0;
+    s->is_public = (*flags & android::ResTable_typeSpec::SPEC_PUBLIC) != 0;
     return s;
   }
   return {};