GH-41726: [C++][Parquet] Minor: moving EncodedStats by default rather than copying

cpp/src/parquet/arrow/writer.cc

@@ -547,8 +547,8 @@ Status GetSchemaMetadata(const ::arrow::Schema& schema, ::arrow::MemoryPool* poo
  // The serialized schema is not UTF-8, which is required for Thrift
  std::string schema_as_string = serialized->ToString();
  std::string schema_base64 = ::arrow::util::base64_encode(schema_as_string);
- result->Append(kArrowSchemaKey, schema_base64);
- *out = result;
+ result->Append(kArrowSchemaKey, std::move(schema_base64));
+ *out = std::move(result);
  return Status::OK();
 }
 

cpp/src/parquet/column_page.h

@@ -75,13 +75,13 @@ class DataPage : public Page {
  protected:
  DataPage(PageType::type type, const std::shared_ptr<Buffer>& buffer, int32_t num_values,
  Encoding::type encoding, int64_t uncompressed_size,
- const EncodedStatistics& statistics = EncodedStatistics(),
+ EncodedStatistics statistics = EncodedStatistics(),
  std::optional<int64_t> first_row_index = std::nullopt)
  : Page(buffer, type),
  num_values_(num_values),
  encoding_(encoding),
  uncompressed_size_(uncompressed_size),
- statistics_(statistics),
+ statistics_(std::move(statistics)),
  first_row_index_(std::move(first_row_index)) {}
 
  int32_t num_values_;
@@ -97,10 +97,10 @@ class DataPageV1 : public DataPage {
  DataPageV1(const std::shared_ptr<Buffer>& buffer, int32_t num_values,
  Encoding::type encoding, Encoding::type definition_level_encoding,
  Encoding::type repetition_level_encoding, int64_t uncompressed_size,
- const EncodedStatistics& statistics = EncodedStatistics(),
+ EncodedStatistics statistics = EncodedStatistics(),
  std::optional<int64_t> first_row_index = std::nullopt)
  : DataPage(PageType::DATA_PAGE, buffer, num_values, encoding, uncompressed_size,
- statistics, std::move(first_row_index)),
+ std::move(statistics), std::move(first_row_index)),
  definition_level_encoding_(definition_level_encoding),
  repetition_level_encoding_(repetition_level_encoding) {}
 
@@ -119,10 +119,10 @@ class DataPageV2 : public DataPage {
  int32_t num_rows, Encoding::type encoding,
  int32_t definition_levels_byte_length, int32_t repetition_levels_byte_length,
  int64_t uncompressed_size, bool is_compressed = false,
- const EncodedStatistics& statistics = EncodedStatistics(),
+ EncodedStatistics statistics = EncodedStatistics(),
  std::optional<int64_t> first_row_index = std::nullopt)
  : DataPage(PageType::DATA_PAGE_V2, buffer, num_values, encoding, uncompressed_size,
- statistics, std::move(first_row_index)),
+ std::move(statistics), std::move(first_row_index)),
  num_nulls_(num_nulls),
  num_rows_(num_rows),
  definition_levels_byte_length_(definition_levels_byte_length),

cpp/src/parquet/column_reader.cc

@@ -534,11 +534,11 @@ std::shared_ptr<Page> SerializedPageReader::NextPage() {
  page_buffer =
  DecompressIfNeeded(std::move(page_buffer), compressed_len, uncompressed_len);
 
- return std::make_shared<DataPageV1>(page_buffer, header.num_values,
-   LoadEnumSafe(&header.encoding),
-  LoadEnumSafe(&header.definition_level_encoding),
-  LoadEnumSafe(&header.repetition_level_encoding),
-  uncompressed_len, data_page_statistics);
+ return std::make_shared<DataPageV1>(
+ page_buffer, header.num_values, LoadEnumSafe(&header.encoding),
+ LoadEnumSafe(&header.definition_level_encoding),
+ LoadEnumSafe(&header.repetition_level_encoding), uncompressed_len,
+ std::move(data_page_statistics));
  } else if (page_type == PageType::DATA_PAGE_V2) {
  ++page_ordinal_;
  const format::DataPageHeaderV2& header = current_page_header_.data_page_header_v2;
@@ -565,7 +565,7 @@ std::shared_ptr<Page> SerializedPageReader::NextPage() {
  page_buffer, header.num_values, header.num_nulls, header.num_rows,
  LoadEnumSafe(&header.encoding), header.definition_levels_byte_length,
  header.repetition_levels_byte_length, uncompressed_len, is_compressed,
- data_page_statistics);
+ std::move(data_page_statistics));
  } else {
  throw ParquetException(
  "Internal error, we have already skipped non-data pages in ShouldSkipPage()");

cpp/src/parquet/column_writer.cc

@@ -379,6 +379,11 @@ class SerializedPageWriter : public PageWriter {
 
  int64_t WriteDataPage(const DataPage& page) override {
  const int64_t uncompressed_size = page.uncompressed_size();
+ if (uncompressed_size > std::numeric_limits<int32_t>::max()) {
+ throw ParquetException("Uncompressed data page size overflows INT32_MAX. Size:",
+ uncompressed_size);
+ }
+
  std::shared_ptr<Buffer> compressed_data = page.buffer();
  const uint8_t* output_data_buffer = compressed_data->data();
  int64_t output_data_len = compressed_data->size();
@@ -399,11 +404,6 @@ class SerializedPageWriter : public PageWriter {
  }
 
  format::PageHeader page_header;
-
- if (uncompressed_size > std::numeric_limits<int32_t>::max()) {
- throw ParquetException("Uncompressed data page size overflows INT32_MAX. Size:",
- uncompressed_size);
- }
  page_header.__set_uncompressed_page_size(static_cast<int32_t>(uncompressed_size));
  page_header.__set_compressed_page_size(static_cast<int32_t>(output_data_len));
 
@@ -1018,13 +1018,13 @@ void ColumnWriterImpl::BuildDataPageV1(int64_t definition_levels_rle_size,
  compressed_data->CopySlice(0, compressed_data->size(), allocator_));
  std::unique_ptr<DataPage> page_ptr = std::make_unique<DataPageV1>(
  compressed_data_copy, num_values, encoding_, Encoding::RLE, Encoding::RLE,
- uncompressed_size, page_stats, first_row_index);
+ uncompressed_size, std::move(page_stats), first_row_index);
  total_compressed_bytes_ += page_ptr->size() + sizeof(format::PageHeader);
 
  data_pages_.push_back(std::move(page_ptr));
  } else { // Eagerly write pages
  DataPageV1 page(compressed_data, num_values, encoding_, Encoding::RLE, Encoding::RLE,
- uncompressed_size, page_stats, first_row_index);
+ uncompressed_size, std::move(page_stats), first_row_index);
  WriteDataPage(page);
  }
 }