| // Copyright 2010-2015, Google Inc. |
| // All rights reserved. |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following disclaimer |
| // in the documentation and/or other materials provided with the |
| // distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "storage/louds/bit_vector_based_array.h" |
| |
| #include "base/logging.h" |
| |
| namespace mozc { |
| namespace storage { |
| namespace louds { |
| |
| namespace { |
| inline int ReadInt32(const uint8 *data) { |
| return *reinterpret_cast<const int32*>(data); |
| } |
| } // namespace |
| |
| void BitVectorBasedArray::Open(const uint8 *image) { |
| const int index_length = ReadInt32(image); |
| const int base_length = ReadInt32(image + 4); |
| const int step_length = ReadInt32(image + 8); |
| // Check 0 padding. |
| CHECK_EQ(ReadInt32(image + 12), 0); |
| |
| index_.Init(image + 16, index_length); |
| base_length_ = base_length; |
| step_length_ = step_length; |
| data_ = reinterpret_cast<const char*>(image + 16 + index_length); |
| } |
| |
| void BitVectorBasedArray::Close() { |
| index_.Reset(); |
| base_length_ = 0; |
| step_length_ = 0; |
| data_ = 0; |
| } |
| |
| const char *BitVectorBasedArray::Get(size_t index, size_t *length) const { |
| DCHECK(length); |
| const int bit_index = index_.Select0(index + 1); |
| const int data_index = |
| base_length_ * index + step_length_ * index_.Rank1(bit_index); |
| // Linear search. |
| int i = bit_index + 1; |
| while (index_.Get(i)) { |
| ++i; |
| } |
| *length = base_length_ + step_length_ * (i - bit_index - 1); |
| return data_ + data_index; |
| } |
| |
| } // namespace louds |
| } // namespace storage |
| } // namespace mozc |