Flat string reader

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 23bd4c0976651c66d6d89b6250facf489053b116..9f4f5cf41b271a7fb86585f98637ef1a08e94885 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -3501,6 +3501,57 @@ const unibrow::byte* String::ReadBlock(String* input,
 }
 
 
+FlatStringReader* FlatStringReader::top_ = NULL;

[Erik Corry, 2008/11/19 09:45:38]

Some people don't like static initializers.  Perhaps this should be in a
function called from v8::Initialize?

[Christian Plesner Hansen, 2008/11/19 10:15:26]

I don't think initialization of pointers to NULL are an issue.

+
+
+FlatStringReader::FlatStringReader(Handle<String> str)
+  : str_(str.location()),
+    length_(str->length()),
+    prev_(top_) {
+  top_ = this;
+  RefreshState();
+}
+
+
+FlatStringReader::FlatStringReader(Vector<const char> input)
+  : str_(NULL),
+    is_ascii_(true),
+    length_(input.length()),
+    start_(input.start()),
+    prev_(top_) {
+  top_ = this;
+}
+
+
+FlatStringReader::~FlatStringReader() {
+  ASSERT_EQ(top_, this);
+  top_ = prev_;
+}
+
+
+void FlatStringReader::RefreshState() {
+  if (str_ == NULL) return;
+  Handle<String> str(str_);
+  StringShape shape(*str);
+  ASSERT(str->IsFlat(shape));
+  is_ascii_ = shape.IsAsciiRepresentation();
+  if (is_ascii_) {
+    start_ = str->ToAsciiVector().start();
+  } else {
+    start_ = str->ToUC16Vector().start();
+  }
+}
+
+
+void FlatStringReader::PostGarbageCollectionProcessing() {
+  FlatStringReader* current = top_;
+  while (current != NULL) {
+    current->RefreshState();
+    current = current->prev_;
+  }
+}
+
+
 void StringInputBuffer::Seek(unsigned pos) {
   Reset(pos, input_);
 }