1 files changed, 56 insertions, 0 deletions
diff --git a/xfa/fxfa/cxfa_fileread.cpp b/xfa/fxfa/cxfa_fileread.cpp
new file mode 100644
index 0000000000..e2ecad2e93
--- /dev/null
+++ b/xfa/fxfa/cxfa_fileread.cpp
@@ -0,0 +1,56 @@
+// 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/fxfa/cxfa_fileread.h"
+
+#include <algorithm>
+
+#include "core/fpdfapi/parser/cpdf_stream_acc.h"
+#include "third_party/base/stl_util.h"
+
+CXFA_FileRead::CXFA_FileRead(const std::vector<CPDF_Stream*>& streams) {
+  for (CPDF_Stream* pStream : streams) {
+    m_Data.push_back(pdfium::MakeRetain<CPDF_StreamAcc>(pStream));
+    m_Data.back()->LoadAllData();
+  }
+}
+
+CXFA_FileRead::~CXFA_FileRead() {}
+
+FX_FILESIZE CXFA_FileRead::GetSize() {
+  uint32_t dwSize = 0;
+  for (const auto& acc : m_Data)
+    dwSize += acc->GetSize();
+  return dwSize;
+}
+
+bool CXFA_FileRead::ReadBlock(void* buffer, FX_FILESIZE offset, size_t size) {
+  int32_t iCount = pdfium::CollectionSize<int32_t>(m_Data);
+  int32_t index = 0;
+  while (index < iCount) {
+    const auto& acc = m_Data[index];
+    FX_FILESIZE dwSize = acc->GetSize();
+    if (offset < dwSize)
+      break;
+
+    offset -= dwSize;
+    index++;
+  }
+  while (index < iCount) {
+    const auto& acc = m_Data[index];
+    uint32_t dwSize = acc->GetSize();
+    size_t dwRead = std::min(size, static_cast<size_t>(dwSize - offset));
+    memcpy(buffer, acc->GetData() + offset, dwRead);
+    size -= dwRead;
+    if (size == 0)
+      return true;
+
+    buffer = static_cast<uint8_t*>(buffer) + dwRead;
+    offset = 0;
+    index++;
+  }
+  return false;
+}