string_decoder: reimplement in C++

Implement string decoder in C++. The perks are a decent speed boost
(for decoding, whereas creation show some performance degradation),
that this can now be used more easily to add native decoding support
to C++ streams and (arguably) more readable variable names.

PR-URL: https://github.com/nodejs/node/pull/18537
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

1 files changed, 38 insertions, 0 deletions

diff --git a/src/string_decoder-inl.h b/src/string_decoder-inl.h
new file mode 100644
index 00000000000..8a04211906f
--- /dev/null
+++ b/src/string_decoder-inl.h
@@ -0,0 +1,38 @@
+#ifndef SRC_STRING_DECODER_INL_H_
+#define SRC_STRING_DECODER_INL_H_
+
+#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#include "string_decoder.h"
+#include "util.h"
+
+namespace node {
+
+void StringDecoder::SetEncoding(enum encoding encoding) {
+  state_[kBufferedBytes] = 0;
+  state_[kMissingBytes] = 0;
+  state_[kEncodingField] = encoding;
+}
+
+enum encoding StringDecoder::Encoding() const {
+  return static_cast<enum encoding>(state_[kEncodingField]);
+}
+
+unsigned StringDecoder::BufferedBytes() const {
+  return state_[kBufferedBytes];
+}
+
+unsigned StringDecoder::MissingBytes() const {
+  return state_[kMissingBytes];
+}
+
+char* StringDecoder::IncompleteCharacterBuffer() {
+  return reinterpret_cast<char*>(state_ + kIncompleteCharactersStart);
+}
+
+
+}  // namespace node
+
+#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#endif   // SRC_STRING_DECODER_INL_H_