1 files changed, 111 insertions, 0 deletions
diff --git a/deps/v8/src/snapshot/context-deserializer.cc b/deps/v8/src/snapshot/context-deserializer.cc
new file mode 100644
index 00000000000..2a3d77646a9
--- /dev/null
+++ b/deps/v8/src/snapshot/context-deserializer.cc
@@ -0,0 +1,111 @@
+// Copyright 2017 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/context-deserializer.h"
+
+#include "src/api/api-inl.h"
+#include "src/heap/heap-inl.h"
+#include "src/objects/slots.h"
+#include "src/snapshot/snapshot.h"
+
+namespace v8 {
+namespace internal {
+
+MaybeHandle<Context> ContextDeserializer::DeserializeContext(
+    Isolate* isolate, const SnapshotData* data, bool can_rehash,
+    Handle<JSGlobalProxy> global_proxy,
+    v8::DeserializeEmbedderFieldsCallback embedder_fields_deserializer) {
+  ContextDeserializer d(data);
+  d.SetRehashability(can_rehash);
+
+  MaybeHandle<Object> maybe_result =
+      d.Deserialize(isolate, global_proxy, embedder_fields_deserializer);
+
+  Handle<Object> result;
+  return maybe_result.ToHandle(&result) ? Handle<Context>::cast(result)
+                                        : MaybeHandle<Context>();
+}
+
+MaybeHandle<Object> ContextDeserializer::Deserialize(
+    Isolate* isolate, Handle<JSGlobalProxy> global_proxy,
+    v8::DeserializeEmbedderFieldsCallback embedder_fields_deserializer) {
+  Initialize(isolate);
+  if (!allocator()->ReserveSpace()) {
+    V8::FatalProcessOutOfMemory(isolate, "ContextDeserializer");
+  }
+
+  // Replace serialized references to the global proxy and its map with the
+  // given global proxy and its map.
+  AddAttachedObject(global_proxy);
+  AddAttachedObject(handle(global_proxy->map(), isolate));
+
+  Handle<Object> result;
+  {
+    DisallowHeapAllocation no_gc;
+    // Keep track of the code space start and end pointers in case new
+    // code objects were unserialized
+    CodeSpace* code_space = isolate->heap()->code_space();
+    Address start_address = code_space->top();
+    Object root;
+    VisitRootPointer(Root::kStartupObjectCache, nullptr, FullObjectSlot(&root));
+    DeserializeDeferredObjects();
+    DeserializeEmbedderFields(embedder_fields_deserializer);
+
+    allocator()->RegisterDeserializedObjectsForBlackAllocation();
+
+    // There's no code deserialized here. If this assert fires then that's
+    // changed and logging should be added to notify the profiler et al of the
+    // new code, which also has to be flushed from instruction cache.
+    CHECK_EQ(start_address, code_space->top());
+
+    if (FLAG_rehash_snapshot && can_rehash()) Rehash();
+    LogNewMapEvents();
+
+    result = handle(root, isolate);
+  }
+
+  SetupOffHeapArrayBufferBackingStores();
+
+  return result;
+}
+
+void ContextDeserializer::SetupOffHeapArrayBufferBackingStores() {
+  for (Handle<JSArrayBuffer> buffer : new_off_heap_array_buffers()) {
+    uint32_t store_index = buffer->GetBackingStoreRefForDeserialization();
+    auto bs = backing_store(store_index);
+    SharedFlag shared =
+        bs && bs->is_shared() ? SharedFlag::kShared : SharedFlag::kNotShared;
+    buffer->Setup(shared, bs);
+  }
+}
+
+void ContextDeserializer::DeserializeEmbedderFields(
+    v8::DeserializeEmbedderFieldsCallback embedder_fields_deserializer) {
+  if (!source()->HasMore() || source()->Get() != kEmbedderFieldsData) return;
+  DisallowHeapAllocation no_gc;
+  DisallowJavascriptExecution no_js(isolate());
+  DisallowCompilation no_compile(isolate());
+  DCHECK_NOT_NULL(embedder_fields_deserializer.callback);
+  for (int code = source()->Get(); code != kSynchronize;
+       code = source()->Get()) {
+    HandleScope scope(isolate());
+    int space = code & kSpaceMask;
+    DCHECK_LE(space, kNumberOfSpaces);
+    DCHECK_EQ(code - space, kNewObject);
+    Handle<JSObject> obj(JSObject::cast(GetBackReferencedObject(
+                             static_cast<SnapshotSpace>(space))),
+                         isolate());
+    int index = source()->GetInt();
+    int size = source()->GetInt();
+    // TODO(yangguo,jgruber): Turn this into a reusable shared buffer.
+    byte* data = new byte[size];
+    source()->CopyRaw(data, size);
+    embedder_fields_deserializer.callback(v8::Utils::ToLocal(obj), index,
+                                          {reinterpret_cast<char*>(data), size},
+                                          embedder_fields_deserializer.data);
+    delete[] data;
+  }
+}
+}  // namespace internal
+}  // namespace v8