winval commented on code in PR #14191:
URL: https://github.com/apache/arrow/pull/14191#discussion_r977412990
##########
cpp/src/parquet/encoding.cc:
##########
@@ -2062,6 +2062,152 @@ class DictByteArrayDecoderImpl : public
DictDecoderImpl<ByteArrayType>,
}
};
+// ----------------------------------------------------------------------
+// DeltaBitPackEncoder
+
+template <typename DType>
+class DeltaBitPackEncoder : public EncoderImpl, virtual public
TypedEncoder<DType> {
+ public:
+ using T = typename DType::c_type;
+
+ explicit DeltaBitPackEncoder(const ColumnDescriptor* descr, MemoryPool* pool)
+ : EncoderImpl(descr, Encoding::DELTA_BINARY_PACKED, pool),
+ bits_buffer_(AllocateBuffer(pool, kInMemoryDefaultCapacity)),
+ sink_(pool),
+ bit_writer_(bits_buffer_->mutable_data(),
static_cast<int>(bits_buffer_->size())),
+ header_writer_(bits_buffer_->mutable_data(),
+ static_cast<int>(bits_buffer_->size())),
+ values_per_block_(256),
+ mini_blocks_per_block_(8),
+ values_per_mini_block_(values_per_block_ / mini_blocks_per_block_),
+ total_value_count_(0),
+ first_value_(0),
+ current_value_(0),
+ deltas_(std::vector<T>(values_per_mini_block_)) {}
+
+ int64_t EstimatedDataEncodedSize() override { return sink_.length(); }
+
+ std::shared_ptr<Buffer> FlushValues() override {
+ std::shared_ptr<Buffer> buffer;
+ // TODO: write total_value_count_
+ PARQUET_THROW_NOT_OK(sink_.Finish(&buffer));
+ return buffer;
+ }
+
+ using TypedEncoder<DType>::Put;
+
+ void Put(const T* buffer, int num_values) override;
+
+ void Put(const ::arrow::Array& values) override;
+
+ void PutSpaced(const T* src, int num_values, const uint8_t* valid_bits,
+ int64_t valid_bits_offset) override {
+ if (valid_bits != NULLPTR) {
+ PARQUET_ASSIGN_OR_THROW(auto buffer, ::arrow::AllocateBuffer(num_values
* sizeof(T),
+
this->memory_pool()));
+ T* data = reinterpret_cast<T*>(buffer->mutable_data());
+ int num_valid_values = ::arrow::util::internal::SpacedCompress<T>(
+ src, num_values, valid_bits, valid_bits_offset, data);
+ Put(data, num_valid_values);
+ } else {
+ Put(src, num_values);
+ }
+ }
+
+ void UnsafePutByteArray(const void* data, uint32_t length) {
+ DCHECK(length == 0 || data != nullptr) << "Value ptr cannot be NULL";
+ sink_.UnsafeAppend(&length, sizeof(uint32_t));
+ sink_.UnsafeAppend(data, static_cast<int64_t>(length));
+ }
+
+ protected:
+ std::shared_ptr<ResizableBuffer> bits_buffer_;
+ ::arrow::BufferBuilder sink_;
+ ::arrow::bit_util::BitWriter bit_writer_;
+ ::arrow::bit_util::BitWriter header_writer_;
+ uint32_t values_per_block_;
+ uint32_t mini_blocks_per_block_;
+ uint32_t values_per_mini_block_;
+ uint32_t total_value_count_;
+ T first_value_;
+ T current_value_;
+ uint64_t mini_block_bit_width_;
+ std::vector<T> deltas_;
+};
+
+template <typename DType>
+void DeltaBitPackEncoder<DType>::Put(const T* buffer, int num_values) {
+ first_value_ = current_value_ = buffer[0];
+
+ // <block size in values> <number of miniblocks in a block> <total value
count> <first
+ // value>
+ if (!header_writer_.PutVlqInt(values_per_block_) ||
Review Comment:
Put generate a block？ The block should be generated by FlushValues
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