1 files changed, 86 insertions, 0 deletions
diff --git a/xfa/fde/css/cfde_csstextbuf.cpp b/xfa/fde/css/cfde_csstextbuf.cpp
new file mode 100644
index 0000000000..83b2899f19
--- /dev/null
+++ b/xfa/fde/css/cfde_csstextbuf.cpp
@@ -0,0 +1,86 @@
+// 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 "xfa/fde/css/cfde_csstextbuf.h"
+
+#include <algorithm>
+
+CFDE_CSSTextBuf::CFDE_CSSTextBuf()
+    : m_bExtBuf(false),
+      m_pBuffer(nullptr),
+      m_iBufLen(0),
+      m_iDatLen(0),
+      m_iDatPos(0) {}
+
+CFDE_CSSTextBuf::~CFDE_CSSTextBuf() {
+  Reset();
+}
+
+void CFDE_CSSTextBuf::Reset() {
+  if (!m_bExtBuf) {
+    FX_Free(m_pBuffer);
+    m_pBuffer = nullptr;
+  }
+  m_iDatPos = m_iDatLen = m_iBufLen;
+}
+
+bool CFDE_CSSTextBuf::AttachBuffer(const FX_WCHAR* pBuffer, int32_t iBufLen) {
+  Reset();
+  m_pBuffer = const_cast<FX_WCHAR*>(pBuffer);
+  m_iDatLen = m_iBufLen = iBufLen;
+  return m_bExtBuf = true;
+}
+
+bool CFDE_CSSTextBuf::EstimateSize(int32_t iAllocSize) {
+  ASSERT(iAllocSize > 0);
+  Clear();
+  m_bExtBuf = false;
+  return ExpandBuf(iAllocSize);
+}
+
+int32_t CFDE_CSSTextBuf::LoadFromStream(
+    const CFX_RetainPtr<IFGAS_Stream>& pTxtStream,
+    int32_t iStreamOffset,
+    int32_t iMaxChars,
+    bool& bEOS) {
+  ASSERT(iStreamOffset >= 0 && iMaxChars > 0);
+  Clear();
+  m_bExtBuf = false;
+  if (!ExpandBuf(iMaxChars))
+    return 0;
+
+  if (pTxtStream->GetPosition() != iStreamOffset)
+    pTxtStream->Seek(FX_STREAMSEEK_Begin, iStreamOffset);
+
+  m_iDatLen = pTxtStream->ReadString(m_pBuffer, iMaxChars, bEOS);
+  return m_iDatLen;
+}
+
+bool CFDE_CSSTextBuf::ExpandBuf(int32_t iDesiredSize) {
+  if (m_bExtBuf)
+    return false;
+  if (!m_pBuffer)
+    m_pBuffer = FX_Alloc(FX_WCHAR, iDesiredSize);
+  else if (m_iBufLen != iDesiredSize)
+    m_pBuffer = FX_Realloc(FX_WCHAR, m_pBuffer, iDesiredSize);
+  else
+    return true;
+
+  if (!m_pBuffer) {
+    m_iBufLen = 0;
+    return false;
+  }
+  m_iBufLen = iDesiredSize;
+  return true;
+}
+
+void CFDE_CSSTextBuf::Subtract(int32_t iStart, int32_t iLength) {
+  ASSERT(iStart >= 0 && iLength >= 0);
+
+  iLength = std::max(std::min(iLength, m_iDatLen - iStart), 0);
+  FXSYS_memmove(m_pBuffer, m_pBuffer + iStart, iLength * sizeof(FX_WCHAR));
+  m_iDatLen = iLength;
+}