Implement external strings.

runtime/vm/raw_object_snapshot.cc

Index: runtime/vm/raw_object_snapshot.cc
diff --git a/runtime/vm/raw_object_snapshot.cc b/runtime/vm/raw_object_snapshot.cc
index 9a1be618eab884ab160b2025a087f5029beea9a7..bc7f122f2b33a28edeb4bd1c348927cb4e17f143 100644
--- a/runtime/vm/raw_object_snapshot.cc
+++ b/runtime/vm/raw_object_snapshot.cc
@@ -1134,6 +1134,108 @@ void RawFourByteString::WriteTo(SnapshotWriter* writer,
 }
 
 
+RawExternalOneByteString* ExternalOneByteString::ReadFrom(
+    SnapshotReader* reader,
+    intptr_t object_id,
+    bool classes_serialized) {
+  UNREACHABLE();
+  return ExternalOneByteString::null();
+}
+
+
+void RawExternalOneByteString::WriteTo(SnapshotWriter* writer,
+                                       intptr_t object_id,
+                                       bool serialize_classes) {
+  ASSERT(writer != NULL);
+  intptr_t len = Smi::Value(ptr()->length_);
+
+  // Write out the serialization header value for this object.
+  writer->WriteObjectHeader(kInlined, object_id);
+
+  // Write out the class information.
+  writer->WriteObjectHeader(kObjectId, ObjectStore::kOneByteStringClass);
+
+  // Write out the length field.
+  writer->Write<RawObject*>(ptr()->length_);
+
+  // Write out the hash field.
+  writer->Write<RawObject*>(ptr()->hash_);
+
+  // Write out the string.
+  for (int i = 0; i < len; i++) {
+    writer->Write<uint8_t>(ptr()->data_[i]);
+  }
+}
+
+
+RawExternalTwoByteString* ExternalTwoByteString::ReadFrom(
+    SnapshotReader* reader,
+    intptr_t object_id,
+    bool classes_serialized) {
+  UNREACHABLE();
+  return ExternalTwoByteString::null();
+}
+
+
+void RawExternalTwoByteString::WriteTo(SnapshotWriter* writer,
+                                       intptr_t object_id,
+                                       bool serialize_classes) {
+  ASSERT(writer != NULL);
+  intptr_t len = Smi::Value(ptr()->length_);
+
+  // Write out the serialization header value for this object.
+  writer->WriteObjectHeader(kInlined, object_id);
+
+  // Write out the class information.
+  writer->WriteObjectHeader(kObjectId, ObjectStore::kTwoByteStringClass);
+
+  // Write out the length field.
+  writer->Write<RawObject*>(ptr()->length_);
+
+  // Write out the hash field.
+  writer->Write<RawObject*>(ptr()->hash_);
+
+  // Write out the string.
+  for (int i = 0; i < len; i++) {
+    writer->Write<uint16_t>(ptr()->data_[i]);
+  }
+}
+
+
+RawExternalFourByteString* ExternalFourByteString::ReadFrom(
+    SnapshotReader* reader,
+    intptr_t object_id,
+    bool classes_serialized) {
+  UNREACHABLE();
+  return ExternalFourByteString::null();
+}
+
+
+void RawExternalFourByteString::WriteTo(SnapshotWriter* writer,
+                                        intptr_t object_id,
+                                        bool serialize_classes) {
+  ASSERT(writer != NULL);
+  intptr_t len = Smi::Value(ptr()->length_);
+
+  // Write out the serialization header value for this object.
+  writer->WriteObjectHeader(kInlined, object_id);
+
+  // Write out the class information.
+  writer->WriteObjectHeader(kObjectId, ObjectStore::kFourByteStringClass);
+
+  // Write out the length field.
+  writer->Write<RawObject*>(ptr()->length_);
+
+  // Write out the hash field.
+  writer->Write<RawObject*>(ptr()->hash_);
+
+  // Write out the string.
+  for (int i = 0; i < len; i++) {
+    writer->Write<uint32_t>(ptr()->data_[i]);
+  }
+}
+
+
 RawBool* Bool::ReadFrom(SnapshotReader* reader,
                           intptr_t object_id,
                           bool classes_serialized) {