[cleanup] Change native_groups_ to use unordered map.

Trying to reduce use of our self-baked data structures.

Bug: v8:7570
Change-Id: I419a932b6b8904810844d40a5636e423df832197
Reviewed-on: https://chromium-review.googlesource.com/1032739
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53033}

src/d8.h

@@ -14,6 +14,7 @@
 
 #include "src/allocation.h"
 #include "src/base/platform/time.h"
+#include "src/string-hasher.h"
 #include "src/utils.h"
 
 #include "src/base/once.h"
@@ -56,7 +57,7 @@ class CounterCollection {
   Counter counters_[kMaxCounters];
 };
 
-struct StringHasher {
+struct CStringHasher {
   std::size_t operator()(const char* name) const {
     size_t h = 0;
     size_t c;
@@ -68,13 +69,8 @@ struct StringHasher {
   }
 };
 
-struct StringEquals {
-  bool operator()(const char* name1, const char* name2) const {
-    return strcmp(name1, name2) == 0;
-  }
-};
-
-typedef std::unordered_map<const char*, Counter*, StringHasher, StringEquals>
+typedef std::unordered_map<const char*, Counter*, CStringHasher,
+                           i::StringEquals>
     CounterMap;
 
 class SourceGroup {

src/profiler/heap-snapshot-generator.cc

@@ -2141,13 +2141,38 @@ HeapEntry* EmbedderGraphEntriesAllocator::AllocateEntry(HeapThing ptr) {
       static_cast<int>(size), 0);
 }
 
+class NativeGroupRetainedObjectInfo : public v8::RetainedObjectInfo {
+ public:
+  explicit NativeGroupRetainedObjectInfo(const char* label)
+      : disposed_(false),
+        hash_(reinterpret_cast<intptr_t>(label)),
+        label_(label) {}
+
+  virtual ~NativeGroupRetainedObjectInfo() {}
+  virtual void Dispose() {
+    CHECK(!disposed_);
+    disposed_ = true;
+    delete this;
+  }
+  virtual bool IsEquivalent(RetainedObjectInfo* other) {
+    return hash_ == other->GetHash() && !strcmp(label_, other->GetLabel());
+  }
+  virtual intptr_t GetHash() { return hash_; }
+  virtual const char* GetLabel() { return label_; }
+
+ private:
+  bool disposed_;
+  intptr_t hash_;
+  const char* label_;
+};
+
 NativeObjectsExplorer::NativeObjectsExplorer(
     HeapSnapshot* snapshot, SnapshottingProgressReportingInterface* progress)
     : isolate_(snapshot->profiler()->heap_object_map()->heap()->isolate()),
       snapshot_(snapshot),
       names_(snapshot_->profiler()->names()),
       embedder_queried_(false),
-      native_groups_(StringsMatch),
+      native_groups_(0, SeededStringHasher(isolate_->heap()->HashSeed())),
       synthetic_entries_allocator_(
           new BasicHeapEntriesAllocator(snapshot, HeapEntry::kSynthetic)),
       native_entries_allocator_(
@@ -2163,10 +2188,8 @@ NativeObjectsExplorer::~NativeObjectsExplorer() {
     std::vector<HeapObject*>* objects = map_entry.second;
     delete objects;
   }
-  for (base::HashMap::Entry* p = native_groups_.Start(); p != nullptr;
-       p = native_groups_.Next(p)) {
-    v8::RetainedObjectInfo* info =
-        reinterpret_cast<v8::RetainedObjectInfo*>(p->value);
+  for (auto map_entry : native_groups_) {
+    NativeGroupRetainedObjectInfo* info = map_entry.second;
     info->Dispose();
   }
 }
@@ -2319,50 +2342,16 @@ bool NativeObjectsExplorer::IterateAndExtractReferences(
   return true;
 }
 
-
-class NativeGroupRetainedObjectInfo : public v8::RetainedObjectInfo {
- public:
-  explicit NativeGroupRetainedObjectInfo(const char* label)
-      : disposed_(false),
-        hash_(reinterpret_cast<intptr_t>(label)),
-        label_(label) {
-  }
-
-  virtual ~NativeGroupRetainedObjectInfo() {}
-  virtual void Dispose() {
-    CHECK(!disposed_);
-    disposed_ = true;
-    delete this;
-  }
-  virtual bool IsEquivalent(RetainedObjectInfo* other) {
-    return hash_ == other->GetHash() && !strcmp(label_, other->GetLabel());
-  }
-  virtual intptr_t GetHash() { return hash_; }
-  virtual const char* GetLabel() { return label_; }
-
- private:
-  bool disposed_;
-  intptr_t hash_;
-  const char* label_;
-};
-
-
 NativeGroupRetainedObjectInfo* NativeObjectsExplorer::FindOrAddGroupInfo(
     const char* label) {
   const char* label_copy = names_->GetCopy(label);
-  uint32_t hash = StringHasher::HashSequentialString(
-      label_copy,
-      static_cast<int>(strlen(label_copy)),
-      isolate_->heap()->HashSeed());
-  base::HashMap::Entry* entry =
-      native_groups_.LookupOrInsert(const_cast<char*>(label_copy), hash);
-  if (entry->value == nullptr) {
-    entry->value = new NativeGroupRetainedObjectInfo(label);
+  auto map_entry = native_groups_.find(label_copy);
+  if (map_entry == native_groups_.end()) {
+    native_groups_[label_copy] = new NativeGroupRetainedObjectInfo(label);
   }
-  return static_cast<NativeGroupRetainedObjectInfo*>(entry->value);
+  return native_groups_[label_copy];
 }
 
-
 void NativeObjectsExplorer::SetNativeRootReference(
     v8::RetainedObjectInfo* info) {
   HeapEntry* child_entry =
@@ -2398,10 +2387,8 @@ void NativeObjectsExplorer::SetWrapperNativeReferences(
 
 
 void NativeObjectsExplorer::SetRootNativeRootsReference() {
-  for (base::HashMap::Entry* entry = native_groups_.Start(); entry;
-       entry = native_groups_.Next(entry)) {
-    NativeGroupRetainedObjectInfo* group_info =
-        static_cast<NativeGroupRetainedObjectInfo*>(entry->value);
+  for (auto map_entry : native_groups_) {
+    NativeGroupRetainedObjectInfo* group_info = map_entry.second;
     HeapEntry* group_entry =
         filler_->FindOrAddEntry(group_info, native_entries_allocator_.get());
     DCHECK_NOT_NULL(group_entry);

src/profiler/heap-snapshot-generator.h

@@ -518,10 +518,6 @@ class NativeObjectsExplorer {
       return info1 == info2 || info1->IsEquivalent(info2);
     }
   };
-  INLINE(static bool StringsMatch(void* key1, void* key2)) {
-    return strcmp(reinterpret_cast<char*>(key1),
-                  reinterpret_cast<char*>(key2)) == 0;
-  }
 
   NativeGroupRetainedObjectInfo* FindOrAddGroupInfo(const char* label);
 
@@ -535,7 +531,9 @@ class NativeObjectsExplorer {
   std::unordered_map<v8::RetainedObjectInfo*, std::vector<HeapObject*>*,
                      RetainedInfoHasher, RetainedInfoEquals>
       objects_by_info_;
-  base::CustomMatcherHashMap native_groups_;
+  std::unordered_map<const char*, NativeGroupRetainedObjectInfo*,
+                     SeededStringHasher, StringEquals>
+      native_groups_;
   std::unique_ptr<HeapEntriesAllocator> synthetic_entries_allocator_;
   std::unique_ptr<HeapEntriesAllocator> native_entries_allocator_;
   std::unique_ptr<HeapEntriesAllocator> embedder_graph_entries_allocator_;

src/string-hasher-inl.h

@@ -142,6 +142,11 @@ void IteratingStringHasher::VisitTwoByteString(const uint16_t* chars,
   AddCharacters(chars, length);
 }
 
+std::size_t SeededStringHasher::operator()(const char* name) const {
+  return StringHasher::HashSequentialString(
+      name, static_cast<int>(strlen(name)), hashseed_);
+}
+
 }  // namespace internal
 }  // namespace v8
 

src/string-hasher.h

@@ -84,6 +84,21 @@ class IteratingStringHasher : public StringHasher {
   DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher);
 };
 
+// Useful for std containers that require something ()'able.
+struct SeededStringHasher {
+  explicit SeededStringHasher(uint32_t hashseed) : hashseed_(hashseed) {}
+  inline std::size_t operator()(const char* name) const;
+
+  uint32_t hashseed_;
+};
+
+// Useful for std containers that require something ()'able.
+struct StringEquals {
+  bool operator()(const char* name1, const char* name2) const {
+    return strcmp(name1, name2) == 0;
+  }
+};
+
 }  // namespace internal
 }  // namespace v8