commit d91d6d6a80748f277fd938a412211e5af28913b1
author Ian Rogers <irogers@google.com> Wed Sep 25 20:26:14 2013 -0700
committer Ian Rogers <irogers@google.com> Thu Sep 26 21:08:25 2013 -0700
tree 5c45f4ae53aab3f530284a97dc328b4e38ce7c94
parent 9c11b56296b8cffc94b0b854ce6cff7e014b8d57

Introduce Signature type to avoid string comparisons.

Method resolution currently creates strings to then compare with strings formed
from methods in other dex files. The temporary strings are purely created for
the sake of comparisons. This change creates a new Signature type that
represents a method signature but not as a string. This type supports
comparisons and so can be used when searching for methods in resolution.

With this change malloc is no longer the hottest method during dex2oat (now its
memset) and allocations during verification have been reduced. The verifier is
commonly what is populating the dex cache for methods and fields not declared
in the dex file itself.

Change-Id: I5ef0542823fbcae868aaa4a2457e8da7df0e9dae

runtime/dex_file_test.cc

diff --git a/runtime/dex_file_test.cc b/runtime/dex_file_test.cc
index 32a8354..1b40529 100644
--- a/runtime/dex_file_test.cc
+++ b/runtime/dex_file_test.cc
@@ -137,14 +137,14 @@
   EXPECT_STREQ("LNested;", raw->GetClassDescriptor(c1));
 }
 
-TEST_F(DexFileTest, CreateMethodSignature) {
+TEST_F(DexFileTest, GetMethodSignature) {
   ScopedObjectAccess soa(Thread::Current());
-  const DexFile* raw(OpenTestDexFile("CreateMethodSignature"));
+  const DexFile* raw(OpenTestDexFile("GetMethodSignature"));
   ASSERT_TRUE(raw != NULL);
   EXPECT_EQ(1U, raw->NumClassDefs());
 
   const DexFile::ClassDef& class_def = raw->GetClassDef(0);
-  ASSERT_STREQ("LCreateMethodSignature;", raw->GetClassDescriptor(class_def));
+  ASSERT_STREQ("LGetMethodSignature;", raw->GetClassDescriptor(class_def));
 
   const byte* class_data = raw->GetClassData(class_def);
   ASSERT_TRUE(class_data != NULL);
@@ -156,11 +156,9 @@
   {
     ASSERT_EQ(1U, it.NumDirectMethods());
     const DexFile::MethodId& method_id = raw->GetMethodId(it.GetMemberIndex());
-    uint32_t proto_idx = method_id.proto_idx_;
     const char* name = raw->StringDataByIdx(method_id.name_idx_);
     ASSERT_STREQ("<init>", name);
-    int32_t length;
-    std::string signature(raw->CreateMethodSignature(proto_idx, &length));
+    std::string signature(raw->GetMethodSignature(method_id).ToString());
     ASSERT_EQ("()V", signature);
   }
 
@@ -173,9 +171,7 @@
     const char* name = raw->StringDataByIdx(method_id.name_idx_);
     ASSERT_STREQ("m1", name);
 
-    uint32_t proto_idx = method_id.proto_idx_;
-    int32_t length;
-    std::string signature(raw->CreateMethodSignature(proto_idx, &length));
+    std::string signature(raw->GetMethodSignature(method_id).ToString());
     ASSERT_EQ("(IDJLjava/lang/Object;)Ljava/lang/Float;", signature);
   }
 
@@ -186,20 +182,18 @@
     const char* name = raw->StringDataByIdx(method_id.name_idx_);
     ASSERT_STREQ("m2", name);
 
-    uint32_t proto_idx = method_id.proto_idx_;
-    int32_t length;
-    std::string signature(raw->CreateMethodSignature(proto_idx, &length));
-    ASSERT_EQ("(ZSC)LCreateMethodSignature;", signature);
+    std::string signature(raw->GetMethodSignature(method_id).ToString());
+    ASSERT_EQ("(ZSC)LGetMethodSignature;", signature);
   }
 }
 
 TEST_F(DexFileTest, FindStringId) {
   ScopedObjectAccess soa(Thread::Current());
-  const DexFile* raw(OpenTestDexFile("CreateMethodSignature"));
+  const DexFile* raw(OpenTestDexFile("GetMethodSignature"));
   ASSERT_TRUE(raw != NULL);
   EXPECT_EQ(1U, raw->NumClassDefs());
 
-  const char* strings[] = { "LCreateMethodSignature;", "Ljava/lang/Float;", "Ljava/lang/Object;",
+  const char* strings[] = { "LGetMethodSignature;", "Ljava/lang/Float;", "Ljava/lang/Object;",
       "D", "I", "J", NULL };
   for (size_t i = 0; strings[i] != NULL; i++) {
     const char* str = strings[i];
@@ -245,11 +239,10 @@
     const DexFile::StringId& name = java_lang_dex_file_->GetStringId(to_find.name_idx_);
     const DexFile::ProtoId& signature = java_lang_dex_file_->GetProtoId(to_find.proto_idx_);
     const DexFile::MethodId* found = java_lang_dex_file_->FindMethodId(klass, name, signature);
-    int32_t length;
     ASSERT_TRUE(found != NULL) << "Didn't find method " << i << ": "
         << java_lang_dex_file_->StringByTypeIdx(to_find.class_idx_) << "."
         << java_lang_dex_file_->GetStringData(name)
-        << java_lang_dex_file_->CreateMethodSignature(to_find.proto_idx_, &length);
+        << java_lang_dex_file_->GetMethodSignature(to_find);
     EXPECT_EQ(java_lang_dex_file_->GetIndexForMethodId(*found), i);
   }
 }