Function ParallelComputeV1

tensorflow/core/kernels/unique_ali_op_util.h:242–482

template<typename T, typename TIndex, class HashMap>
void ParallelComputeV1(OpKernelContext* context, const Tensor& input,
    Tensor* idx, int64 axis, int64* uniq_size, int num_sparse, 
     google::dense_hash_map<int, TIndex>* counter_map, Tensor* output) {
  // Struct INode was used to store an inverse mapping for each node in the
  // hash map container.
  struct INode {
    explicit INode(const TIndex index, const T& key)
      : owner_ptr_(nullptr), index_(index), key_(key) {}

    const INode* owner_ptr_;
    TIndex index_;
    const T key_;
  };

  // Struct UniqueSubMap is used to build and operate local hash map and keep
  // index mapping information.
  struct UniqueSubMap {
    public:
      inline void Init(int64 size) {
        next_index_ = 0;
        HashMapInitializer<HashMap>::InitSize(&uniq_, size);
        inodes_.reserve(size);
      }

      inline void UniqueInsert(const T& key) {
        auto it = uniq_.emplace(key, next_index_);
        if (it.second) {
          inodes_.emplace_back(INode(next_index_, key));
          ++next_index_;
        }
      }

      inline const INode* GetINodeByPos(const TIndex pos) const {
        const INode* inode = &inodes_[pos];
        return (inode->owner_ptr_ == nullptr) ? inode : inode->owner_ptr_;
      }

      inline const INode* GetINodeByKey(const T& key) const {
        auto item = uniq_.find(key);
        if (item != uniq_.end()) { return GetINodeByPos(item->second); }
        return nullptr;
      }

      bool DeDup(const TIndex pos, const UniqueSubMap& prior_map) {
        INode* my_inode = &inodes_[pos];
        if (my_inode->owner_ptr_ != nullptr) { return false; }
        const INode* prior_inode = prior_map.GetINodeByKey(my_inode->key_);
        if (prior_inode == nullptr) { return false; }
        my_inode->owner_ptr_ = prior_inode;
        return true;
      }

      bool TryIndexAndGetKey(const TIndex pos, const TIndex new_id, T* out) {
        INode* inode = &inodes_[pos];
        if (inode->owner_ptr_ != nullptr) { return false; }
        inode->index_ = new_id;
        *out = inode->key_;
        return true;