Rework scanner-character-streams.

src/parsing/parser.cc

 // 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.
 
 #include "src/parsing/parser.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/ast/ast-expression-rewriter.h"
@@ skipping 598 matching lines @@
     cached_parse_data_->Initialize();
   }
 
   DeserializeScopeChain(info, info->context(),
                         Scope::DeserializationMode::kKeepScopeInfo);
 
   source = String::Flatten(source);
   FunctionLiteral* result;
 
   {
-    std::unique_ptr<Utf16CharacterStream> stream;
-    if (source->IsExternalTwoByteString()) {
-      stream.reset(new ExternalTwoByteStringUtf16CharacterStream(
-          Handle<ExternalTwoByteString>::cast(source), 0, source->length()));
-    } else if (source->IsExternalOneByteString()) {
-      stream.reset(new ExternalOneByteStringUtf16CharacterStream(
-          Handle<ExternalOneByteString>::cast(source), 0, source->length()));
-    } else {
-      stream.reset(
-          new GenericStringUtf16CharacterStream(source, 0, source->length()));
-    }
+    std::unique_ptr<Utf16CharacterStream> stream(ScannerStream::For(source));
     scanner_.Initialize(stream.get());
     result = DoParseProgram(info);
   }
   if (result != NULL) {
     DCHECK_EQ(scanner_.peek_location().beg_pos, source->length());
   }
   HandleSourceURLComments(isolate, info->script());
 
   if (FLAG_trace_parse && result != NULL) {
     double ms = timer.Elapsed().InMillisecondsF();
@@ skipping 126 matching lines @@
     timer.Start();
   }
   Handle<SharedFunctionInfo> shared_info = info->shared_info();
   DeserializeScopeChain(info, info->context(),
                         Scope::DeserializationMode::kKeepScopeInfo);
 
   // Initialize parser state.
   source = String::Flatten(source);
   FunctionLiteral* result;
   {
-    std::unique_ptr<Utf16CharacterStream> stream;
-    if (source->IsExternalTwoByteString()) {
-      stream.reset(new ExternalTwoByteStringUtf16CharacterStream(
-          Handle<ExternalTwoByteString>::cast(source),
-          shared_info->start_position(), shared_info->end_position()));
-    } else if (source->IsExternalOneByteString()) {
-      stream.reset(new ExternalOneByteStringUtf16CharacterStream(
-          Handle<ExternalOneByteString>::cast(source),
-          shared_info->start_position(), shared_info->end_position()));
-    } else {
-      stream.reset(new GenericStringUtf16CharacterStream(
-          source, shared_info->start_position(), shared_info->end_position()));
-    }
+    std::unique_ptr<Utf16CharacterStream> stream(ScannerStream::For(
+        source, shared_info->start_position(), shared_info->end_position()));
     Handle<String> name(String::cast(shared_info->name()));
     result =
         DoParseLazy(info, ast_value_factory()->GetString(name), stream.get());
     if (result != nullptr) {
       Handle<String> inferred_name(shared_info->inferred_name());
       result->set_inferred_name(inferred_name);
     }
   }
 
   if (FLAG_trace_parse && result != NULL) {
@@ skipping 4116 matching lines @@
   CompleteParserRecorder recorder;
   if (produce_cached_parse_data()) log_ = &recorder;
 
   std::unique_ptr<Utf16CharacterStream> stream;
   Utf16CharacterStream* stream_ptr;
   if (info->character_stream()) {
     DCHECK(info->source_stream() == nullptr);
     stream_ptr = info->character_stream();
   } else {
     DCHECK(info->character_stream() == nullptr);
-    stream.reset(new ExternalStreamingStream(info->source_stream(),
-                                             info->source_stream_encoding()));
+    stream.reset(ScannerStream::For(info->source_stream(),
+                                    info->source_stream_encoding()));
     stream_ptr = stream.get();
   }
   DCHECK(info->context().is_null() || info->context()->IsNativeContext());
 
   DCHECK(original_scope_);
 
   // When streaming, we don't know the length of the source until we have parsed
   // it. The raw data can be UTF-8, so we wouldn't know the source length until
   // we have decoded it anyway even if we knew the raw data length (which we
   // don't). We work around this by storing all the scopes which need their end
@@ skipping 1516 matching lines @@
   node->Print(Isolate::Current());
 }
 #endif  // DEBUG
 
 #undef CHECK_OK
 #undef CHECK_OK_VOID
 #undef CHECK_FAILED
 
 }  // namespace internal
 }  // namespace v8