[serializer] split up src/snapshot/serialize.*

src/snapshot/partial-serializer.cc

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/snapshot/partial-serializer.h"
+
+#include "src/objects-inl.h"
+
+namespace v8 {
+namespace internal {
+
+PartialSerializer::PartialSerializer(Isolate* isolate,
+                                     Serializer* startup_snapshot_serializer,
+                                     SnapshotByteSink* sink)
+    : Serializer(isolate, sink),
+      startup_serializer_(startup_snapshot_serializer),
+      global_object_(NULL) {
+  InitializeCodeAddressMap();
+}
+
+PartialSerializer::~PartialSerializer() {
+  OutputStatistics("PartialSerializer");
+}
+
+void PartialSerializer::Serialize(Object** o) {
+  if ((*o)->IsContext()) {
+    Context* context = Context::cast(*o);
+    global_object_ = context->global_object();
+    back_reference_map()->AddGlobalProxy(context->global_proxy());
+    // The bootstrap snapshot has a code-stub context. When serializing the
+    // partial snapshot, it is chained into the weak context list on the isolate
+    // and it's next context pointer may point to the code-stub context.  Clear
+    // it before serializing, it will get re-added to the context list
+    // explicitly when it's loaded.
+    if (context->IsNativeContext()) {
+      context->set(Context::NEXT_CONTEXT_LINK,
+                   isolate_->heap()->undefined_value());
+      DCHECK(!context->global_object()->IsUndefined());
+    }
+  }
+  VisitPointer(o);
+  SerializeDeferredObjects();
+  Pad();
+}
+
+void PartialSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
+                                        WhereToPoint where_to_point, int skip) {
+  if (obj->IsMap()) {
+    // The code-caches link to context-specific code objects, which
+    // the startup and context serializes cannot currently handle.
+    DCHECK(Map::cast(obj)->code_cache() == obj->GetHeap()->empty_fixed_array());
+  }
+
+  // Replace typed arrays by undefined.
+  if (obj->IsJSTypedArray()) obj = isolate_->heap()->undefined_value();
+
+  int root_index = root_index_map_.Lookup(obj);
+  if (root_index != RootIndexMap::kInvalidRootIndex) {
+    PutRoot(root_index, obj, how_to_code, where_to_point, skip);
+    return;
+  }
+
+  if (ShouldBeInThePartialSnapshotCache(obj)) {
+    FlushSkip(skip);
+
+    int cache_index = PartialSnapshotCacheIndex(obj);
+    sink_->Put(kPartialSnapshotCache + how_to_code + where_to_point,
+               "PartialSnapshotCache");
+    sink_->PutInt(cache_index, "partial_snapshot_cache_index");
+    return;
+  }
+
+  // Pointers from the partial snapshot to the objects in the startup snapshot
+  // should go through the root array or through the partial snapshot cache.
+  // If this is not the case you may have to add something to the root array.
+  DCHECK(!startup_serializer_->back_reference_map()->Lookup(obj).is_valid());
+  // All the internalized strings that the partial snapshot needs should be
+  // either in the root table or in the partial snapshot cache.
+  DCHECK(!obj->IsInternalizedString());
+
+  if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return;
+
+  FlushSkip(skip);
+
+  // Clear literal boilerplates.
+  if (obj->IsJSFunction()) {
+    FixedArray* literals = JSFunction::cast(obj)->literals();
+    for (int i = 0; i < literals->length(); i++) literals->set_undefined(i);
+  }
+
+  // Object has not yet been serialized.  Serialize it here.
+  ObjectSerializer serializer(this, obj, sink_, how_to_code, where_to_point);
+  serializer.Serialize();
+}
+
+int PartialSerializer::PartialSnapshotCacheIndex(HeapObject* heap_object) {
+  Isolate* isolate = this->isolate();
+  List<Object*>* cache = isolate->partial_snapshot_cache();
+  int new_index = cache->length();
+
+  int index = partial_cache_index_map_.LookupOrInsert(heap_object, new_index);
+  if (index == PartialCacheIndexMap::kInvalidIndex) {
+    // We didn't find the object in the cache.  So we add it to the cache and
+    // then visit the pointer so that it becomes part of the startup snapshot
+    // and we can refer to it from the partial snapshot.
+    cache->Add(heap_object);
+    startup_serializer_->VisitPointer(reinterpret_cast<Object**>(&heap_object));
+    // We don't recurse from the startup snapshot generator into the partial
+    // snapshot generator.
+    return new_index;
+  }
+  return index;
+}
+
+bool PartialSerializer::ShouldBeInThePartialSnapshotCache(HeapObject* o) {
+  // Scripts should be referred only through shared function infos.  We can't
+  // allow them to be part of the partial snapshot because they contain a
+  // unique ID, and deserializing several partial snapshots containing script
+  // would cause dupes.
+  DCHECK(!o->IsScript());
+  return o->IsName() || o->IsSharedFunctionInfo() || o->IsHeapNumber() ||
+         o->IsCode() || o->IsScopeInfo() || o->IsAccessorInfo() ||
+         o->map() ==
+             startup_serializer_->isolate()->heap()->fixed_cow_array_map();
+}
+
+}  // namespace internal
+}  // namespace v8