1 files changed, 47 insertions, 0 deletions
diff --git a/core/fxcrt/cfx_utf8decoder.cpp b/core/fxcrt/cfx_utf8decoder.cpp
new file mode 100644
index 0000000000..bee5e16da4
--- /dev/null
+++ b/core/fxcrt/cfx_utf8decoder.cpp
@@ -0,0 +1,47 @@
+// Copyright 2017 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "core/fxcrt/cfx_utf8decoder.h"
+
+void CFX_UTF8Decoder::Clear() {
+  m_Buffer.Clear();
+  m_PendingBytes = 0;
+}
+
+void CFX_UTF8Decoder::AppendCodePoint(uint32_t ch) {
+  m_Buffer.AppendChar(static_cast<wchar_t>(ch));
+}
+
+void CFX_UTF8Decoder::Input(uint8_t byte) {
+  if (byte < 0x80) {
+    m_PendingBytes = 0;
+    m_Buffer.AppendChar(byte);
+  } else if (byte < 0xc0) {
+    if (m_PendingBytes == 0) {
+      return;
+    }
+    m_PendingBytes--;
+    m_PendingChar |= (byte & 0x3f) << (m_PendingBytes * 6);
+    if (m_PendingBytes == 0) {
+      AppendCodePoint(m_PendingChar);
+    }
+  } else if (byte < 0xe0) {
+    m_PendingBytes = 1;
+    m_PendingChar = (byte & 0x1f) << 6;
+  } else if (byte < 0xf0) {
+    m_PendingBytes = 2;
+    m_PendingChar = (byte & 0x0f) << 12;
+  } else if (byte < 0xf8) {
+    m_PendingBytes = 3;
+    m_PendingChar = (byte & 0x07) << 18;
+  } else if (byte < 0xfc) {
+    m_PendingBytes = 4;
+    m_PendingChar = (byte & 0x03) << 24;
+  } else if (byte < 0xfe) {
+    m_PendingBytes = 5;
+    m_PendingChar = (byte & 0x01) << 30;
+  }
+}