First step towards generation of application script snapshots

vm/dart_api_impl.cc

Index: vm/dart_api_impl.cc
===================================================================
--- vm/dart_api_impl.cc	(revision 2043)
+++ vm/dart_api_impl.cc	(working copy)
@@ -609,12 +609,12 @@
 }
 
 
-DART_EXPORT Dart_Handle Dart_CreateSnapshot(uint8_t** snapshot_buffer,
-                                            intptr_t* snapshot_size) {
+DART_EXPORT Dart_Handle Dart_CreateSnapshot(uint8_t** buffer,
+                                            intptr_t* size) {
   Isolate* isolate = Isolate::Current();
   DARTSCOPE(isolate);
-  if (snapshot_buffer == NULL || snapshot_size == NULL) {
-    return Api::Error("Invalid input parameters to Dart_CreateSnapshot");
+  if (buffer == NULL || size == NULL) {
+    return Api::Error("Invalid input parameters to %s", CURRENT_FUNC);

[turnidge, 2011/12/05 18:49:00]

If you are wanting to make this error message consistent with the wording of
other error messages in this file, it would look like:

if (buffer == NULL) {
  return Api::Error("%s expects the 'buffer' parameter to be non-NULL.",
CURRENT_FUNC);
}
if (size == NULL) {
  return Api::Error("%s expects the 'size' parameter to be non-NULL.",
CURRENT_FUNC);
}

[siva, 2011/12/05 21:35:37]

Done.

   }
   const char* msg = CheckIsolateState(isolate,
                                       ClassFinalizer::kGeneratingSnapshot);
@@ -623,13 +623,36 @@
   }
   // Since this is only a snapshot the root library should not be set.
   isolate->object_store()->set_root_library(Library::Handle());
-  SnapshotWriter writer(true, snapshot_buffer, ApiAllocator);
+  SnapshotWriter writer(Snapshot::kFull, buffer, ApiAllocator);
   writer.WriteFullSnapshot();
-  *snapshot_size = writer.Size();
+  *size = writer.Size();
   return Api::Success();
 }
 
 
+DART_EXPORT Dart_Handle Dart_CreateScriptSnapshot(Dart_Handle library,
+                                                  uint8_t** buffer,
+                                                  intptr_t* size) {
+  Isolate* isolate = Isolate::Current();
+  DARTSCOPE(isolate);
+  if (buffer == NULL || size == NULL) {
+    return Api::Error("Invalid input parameters to %s", CURRENT_FUNC);

[turnidge, 2011/12/05 18:49:00]

Ditto above.

[siva, 2011/12/05 21:35:37]

Done.

+  }
+  const Library& root_lib = Api::UnwrapLibraryHandle(library);
+  if (root_lib.IsNull()) {
+    RETURN_TYPE_ERROR(library, Library);
+  }
+  const char* msg = CheckIsolateState(isolate);
+  if (msg != NULL) {
+    return Api::Error(msg);
+  }
+  ScriptSnapshotWriter writer(root_lib, buffer, ApiAllocator);
+  writer.WriteScriptSnapshot();
+  *size = writer.Size();
+  return Api::Success();

[turnidge, 2011/12/05 18:49:00]

Once this works, it would be great to have a unit test for this in
dart_api_impl_test.cc

[siva, 2011/12/05 21:35:37]

I had already added a unit test in snapshot_test.cc and am currently skipping
it.

On 2011/12/05 18:49:00, turnidge wrote:

+}
+
+
 // --- Messages and Ports ---
 
 
@@ -648,7 +671,7 @@
 static RawInstance* DeserializeMessage(void* data) {
   // Create a snapshot object using the buffer.
   const Snapshot* snapshot = Snapshot::SetupFromBuffer(data);
-  ASSERT(snapshot->IsPartialSnapshot());
+  ASSERT(snapshot->IsMessageSnapshot());
 
   // Read object back from the snapshot.
   Isolate* isolate = Isolate::Current();
@@ -744,7 +767,7 @@
   DARTSCOPE_NOCHECKS(isolate);
   const Object& object = Object::Handle(Api::UnwrapHandle(handle));
   uint8_t* data = NULL;
-  SnapshotWriter writer(false, &data, &allocator);
+  SnapshotWriter writer(Snapshot::kMessage, &data, &allocator);
   writer.WriteObject(object.raw());
   writer.FinalizeBuffer();
   return PortMap::PostMessage(port_id, kNoReplyPort, Api::CastMessage(data));
@@ -2179,6 +2202,29 @@
 }
 
 
+DART_EXPORT Dart_Handle Dart_LoadScriptFromSnapshot(const uint8_t* data) {
+  Isolate* isolate = Isolate::Current();
+  DARTSCOPE(isolate);
+  if (data == NULL) {
+    return Api::Error("Invalid input parameters to %s", CURRENT_FUNC);

[turnidge, 2011/12/05 18:49:00]

Ditto above.

[siva, 2011/12/05 21:35:37]

Done.

+  }
+  const Snapshot* snapshot = Snapshot::SetupFromBuffer(data);
+  if (!snapshot->IsScriptSnapshot()) {
+    return Api::Error("Expected a script type snapshot to %s", CURRENT_FUNC);

[turnidge, 2011/12/05 18:49:00]

"%s expects parameter 'data' to be a script snapshot." or similar.

[siva, 2011/12/05 21:35:37]

Done.

+  }

[turnidge, 2011/12/05 18:49:00]

Should we check to see if a script has already been loaded, as we do in
Dart_LoadScript?

  Library& library = Library::Handle(isolate->object_store()->root_library());
  if (!library.IsNull()) {
    const String& library_url = String::Handle(library.url());
    return Api::Error("%s: A script has already been loaded from '%s'.",
                      CURRENT_FUNC, library_url.ToCString());
  }

[siva, 2011/12/05 21:35:37]

Good point.

On 2011/12/05 18:49:00, turnidge wrote:

+  SnapshotReader reader(snapshot, isolate->heap(), isolate->object_store());
+  const Object& tmp = Object::Handle(reader.ReadObject());
+  if (!tmp.IsLibrary()) {
+    return Api::Error("Unable to deserialize snapshot passed to %s correctly",
+                      CURRENT_FUNC);

[turnidge, 2011/12/05 18:49:00]

"%s: Unable to deserialize snapshot correctly.", CURRENT_FUNC

Generally, I always try to make the current function appear at the front of the
error message unless it is awkward.  Not sure why, but that's what I do.

[siva, 2011/12/05 21:35:37]

Done.

+  }
+  Library& lib = Library::Handle();
+  lib ^= tmp.raw();
+  isolate->object_store()->set_root_library(lib);
+  return Api::NewLocalHandle(lib);
+}
+
+
 DEFINE_FLAG(bool, compile_all, false, "Eagerly compile all code.");
 
 static void CompileAll(Isolate* isolate, Dart_Handle* result) {