Method FilterBlockReader

src/leveldb/table/filter_block.cc:77–88

}

FilterBlockReader::FilterBlockReader(const FilterPolicy* policy,
                                     const Slice& contents)
    : policy_(policy), data_(nullptr), offset_(nullptr), num_(0), base_lg_(0) {
  size_t n = contents.size();
  if (n < 5) return;  // 1 byte for base_lg_ and 4 for start of offset array
  base_lg_ = contents[n - 1];
  uint32_t last_word = DecodeFixed32(contents.data() + n - 5);
  if (last_word > n - 5) return;
  data_ = contents.data();
  offset_ = data_ + last_word;
  num_ = (n - 5 - last_word) / 4;
}

bool FilterBlockReader::KeyMayMatch(uint64_t block_offset, const Slice& key) {
  uint64_t index = block_offset >> base_lg_;