De-virtualize snapshot sink.

src/mksnapshot.cc

 // Copyright 2006-2008 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 <errno.h>
 #include <stdio.h>
 #ifdef COMPRESS_STARTUP_DATA_BZ2
 #include <bzlib.h>
 #endif
 #include <signal.h>
@@ skipping 60 matching lines @@
                       context_snapshot_data, context_serializer);
     MaybeWriteStartupBlob(snapshot_data, serializer,
                           context_snapshot_data, context_serializer);
   }
 
  private:
   void MaybeWriteStartupBlob(const i::List<i::byte>& snapshot_data,
                              const i::Serializer& serializer,
                              const i::List<i::byte>& context_snapshot_data,
                              const i::Serializer& context_serializer) const {
-    if (!startup_blob_file_)
-      return;
+    if (!startup_blob_file_) return;
 
-    i::List<i::byte> startup_blob;
-    i::ListSnapshotSink sink(&startup_blob);
+    i::SnapshotByteSink sink;
 
     int spaces[] = {i::NEW_SPACE,           i::OLD_POINTER_SPACE,
                     i::OLD_DATA_SPACE,      i::CODE_SPACE,
                     i::MAP_SPACE,           i::CELL_SPACE,
                     i::PROPERTY_CELL_SPACE, i::LO_SPACE};
 
     i::byte* snapshot_bytes = snapshot_data.begin();
     sink.PutBlob(snapshot_bytes, snapshot_data.length(), "snapshot");
     for (size_t i = 0; i < arraysize(spaces); ++i) {
       i::Vector<const uint32_t> chunks =
           serializer.FinalAllocationChunks(spaces[i]);
       // For the start-up snapshot, none of the reservations has more than
       // one chunk (reservation for each space fits onto a single page).
       CHECK_EQ(1, chunks.length());
       sink.PutInt(chunks[0], "spaces");
     }
 
     i::byte* context_bytes = context_snapshot_data.begin();
     sink.PutBlob(context_bytes, context_snapshot_data.length(), "context");
     for (size_t i = 0; i < arraysize(spaces); ++i) {
       i::Vector<const uint32_t> chunks =
           context_serializer.FinalAllocationChunks(spaces[i]);
       // For the context snapshot, none of the reservations has more than
       // one chunk (reservation for each space fits onto a single page).
       CHECK_EQ(1, chunks.length());
       sink.PutInt(chunks[0], "spaces");
     }
 
+    const i::List<i::byte>& startup_blob = sink.data();
     size_t written = fwrite(startup_blob.begin(), 1, startup_blob.length(),
                             startup_blob_file_);
-    if (written != (size_t)startup_blob.length()) {
+    if (written != static_cast<size_t>(startup_blob.length())) {
       i::PrintF("Writing snapshot file failed.. Aborting.\n");
       exit(1);
     }
   }
 
   void WriteSnapshotFile(const i::List<i::byte>& snapshot_data,
                          const i::Serializer& serializer,
                          const i::List<i::byte>& context_snapshot_data,
                          const i::Serializer& context_serializer) const {
     WriteFilePrefix();
@@ skipping 286 matching lines @@
       }
     }
     // If we don't do this then we end up with a stray root pointing at the
     // context even after we have disposed of the context.
     internal_isolate->heap()->CollectAllAvailableGarbage("mksnapshot");
     i::Object* raw_context = *v8::Utils::OpenPersistent(context);
     context.Reset();
 
     // This results in a somewhat smaller snapshot, probably because it gets
     // rid of some things that are cached between garbage collections.
-    i::List<i::byte> snapshot_data;
-    i::ListSnapshotSink snapshot_sink(&snapshot_data);
+    i::SnapshotByteSink snapshot_sink;
     i::StartupSerializer ser(internal_isolate, &snapshot_sink);
     ser.SerializeStrongReferences();
 
-    i::List<i::byte> context_data;
-    i::ListSnapshotSink contex_sink(&context_data);
-    i::PartialSerializer context_ser(internal_isolate, &ser, &contex_sink);
+    i::SnapshotByteSink context_sink;
+    i::PartialSerializer context_ser(internal_isolate, &ser, &context_sink);
     context_ser.Serialize(&raw_context);
     ser.SerializeWeakReferences();
 
     context_ser.FinalizeAllocation();
     ser.FinalizeAllocation();
 
     {
       SnapshotWriter writer(argv[1]);
       if (i::FLAG_raw_file && i::FLAG_raw_context_file)
         writer.SetRawFiles(i::FLAG_raw_file, i::FLAG_raw_context_file);
       if (i::FLAG_startup_blob)
         writer.SetStartupBlobFile(i::FLAG_startup_blob);
   #ifdef COMPRESS_STARTUP_DATA_BZ2
       BZip2Compressor bzip2;
       writer.SetCompressor(&bzip2);
   #endif
-      writer.WriteSnapshot(snapshot_data, ser, context_data, context_ser);
+      writer.WriteSnapshot(snapshot_sink.data(), ser, context_sink.data(),
+                           context_ser);
     }
   }
 
   isolate->Dispose();
   V8::Dispose();
   V8::ShutdownPlatform();
   delete platform;
   return 0;
 }