| // 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/src/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; |
| } |