[snapshot] introduce SnapshotCreator API.

include/v8.h

 // Copyright 2012 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.
 
 /** \mainpage V8 API Reference Guide
  *
  * V8 is Google's open source JavaScript engine.
  *
  * This set of documents provides reference material generated from the
  * V8 header file, include/v8.h.
@@ skipping 6751 matching lines @@
   template <class T>
   friend class Maybe;
   template <class T>
   friend class WeakCallbackInfo;
   template <class T> friend class Eternal;
   template <class T> friend class PersistentBase;
   template <class T, class M> friend class Persistent;
   friend class Context;
 };
 
+/**
+ * Helper class to create a snapshot data blob.
+ */
+class SnapshotCreator {
+ public:
+  enum class FunctionCodeHandling { kClear, kKeep };
+
+  /**
+   * Create and enter an isolate, and set it up for serialization.
+   * The isolate is either created from scratch or from an existing snapshot.
+   * The caller keeps ownership of the argument snapshot.
+   */
+  explicit SnapshotCreator(StartupData* existing_blob = nullptr);
+
+  ~SnapshotCreator();
+
+  /**
+   * \returns the isolate prepared by the snapshot creator.
+   */
+  Isolate* GetIsolate();
+
+  /**
+   * Add a context to be included in the snapshot blob.
+   */
+  void AddContext(Local<Context> context);
+
+  /**
+   * Created a snapshot data blob.
+   * \param function_code_handling whether to include compiled function code
+   *        in the snapshot.
+   * \returns { nullptr, 0 } on failure, and a startup snapshot on success. The
+   *        caller acquires ownership of the data array in the return value.
+   */
+  StartupData CreateBlob(FunctionCodeHandling function_code_handling);
+
+ private:
+  void* data_;
+
+  // Disallow copying and assigning.
+  SnapshotCreator(const SnapshotCreator&);
+  void operator=(const SnapshotCreator&);
+};
 
 /**
  * A simple Maybe type, representing an object which may or may not have a
  * value, see https://hackage.haskell.org/package/base/docs/Data-Maybe.html.
  *
  * If an API method returns a Maybe<>, the API method can potentially fail
  * either because an exception is thrown, or because an exception is pending,
  * e.g. because a previous API call threw an exception that hasn't been caught
  * yet, or because a TerminateExecution exception was thrown. In that case, a
  * "Nothing" value is returned.
@@ skipping 2032 matching lines @@
  */
 
 
 }  // namespace v8
 
 
 #undef TYPE_CHECK
 
 
 #endif  // INCLUDE_V8_H_