1 files changed, 71 insertions, 0 deletions
diff --git a/xfa/fxbarcode/common/BC_CommonBitSource.cpp b/xfa/fxbarcode/common/BC_CommonBitSource.cpp
new file mode 100644
index 0000000000..af91d5e0bd
--- /dev/null
+++ b/xfa/fxbarcode/common/BC_CommonBitSource.cpp
@@ -0,0 +1,71 @@
+// Copyright 2014 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
+// Original code is licensed as follows:
+/*
+ * Copyright 2007 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "xfa/fxbarcode/common/BC_CommonBitSource.h"
+
+CBC_CommonBitSource::CBC_CommonBitSource(CFX_ByteArray* bytes) {
+  m_bytes.Copy((*bytes));
+  m_bitOffset = 0;
+  m_byteOffset = 0;
+}
+CBC_CommonBitSource::~CBC_CommonBitSource() {}
+int32_t CBC_CommonBitSource::ReadBits(int32_t numBits, int32_t& e) {
+  if (numBits < 1 || numBits > 32) {
+    e = BCExceptionIllegalArgument;
+    return 0;
+  }
+  int32_t result = 0;
+  if (m_bitOffset > 0) {
+    int32_t bitsLeft = 8 - m_bitOffset;
+    int32_t toRead = numBits < bitsLeft ? numBits : bitsLeft;
+    int32_t bitsToNotRead = bitsLeft - toRead;
+    int32_t mask = (0xff >> (8 - toRead)) << bitsToNotRead;
+    result = (m_bytes[m_byteOffset] & mask) >> bitsToNotRead;
+    numBits -= toRead;
+    m_bitOffset += toRead;
+    if (m_bitOffset == 8) {
+      m_bitOffset = 0;
+      m_byteOffset++;
+    }
+  }
+  if (numBits > 0) {
+    while (numBits >= 8) {
+      result = (result << 8) | (m_bytes[m_byteOffset] & 0xff);
+      m_byteOffset++;
+      numBits -= 8;
+    }
+    if (numBits > 0) {
+      int32_t bitsToNotRead = 8 - numBits;
+      int32_t mask = (0xff >> bitsToNotRead) << bitsToNotRead;
+      result = (result << numBits) |
+               ((m_bytes[m_byteOffset] & mask) >> bitsToNotRead);
+      m_bitOffset += numBits;
+    }
+  }
+  return result;
+}
+int32_t CBC_CommonBitSource::Available() {
+  return 8 * (m_bytes.GetSize() - m_byteOffset) - m_bitOffset;
+}
+int32_t CBC_CommonBitSource::getByteOffset() {
+  return m_byteOffset;
+}