Struct ReadStatWriter 

pub struct ReadStatWriter {
    pub(crate) wtr: Option<ReadStatWriterFormat>,
    pub(crate) wrote_header: bool,
    pub(crate) wrote_start: bool,
}

Manages writing Arrow [RecordBatch] data to the configured output format.

Supports streaming writes across multiple batches. The writer is created lazily on the first call to write and finalized via finish.

Fields

wtr: Option<ReadStatWriterFormat>

The format-specific writer, created on first write.

wrote_header: bool

Whether the CSV header row has been written.

wrote_start: bool

Whether any data has been written (controls file creation vs. append).

Implementations

impl ReadStatWriter

pub const fn new() -> Self

Creates a new ReadStatWriter with no active writer.

fn open_output(&self, path: &Path) -> Result<File, ReadStatError>

Opens an output file: creates or truncates on first write, appends on subsequent writes.

pub fn write_batch_to_parquet( batch: &RecordBatch, schema: &Schema, output_path: &Path, compression: Option<ParquetCompression>, compression_level: Option<u32>, buffer_size_bytes: usize, ) -> Result<(), ReadStatError>

Write a single batch to a Parquet file (for parallel writes). Uses SpooledTempFile to keep data in memory until buffer_size_bytes threshold.

Errors

Returns an error if compression configuration is invalid, writing fails, or the output file cannot be created.

pub fn merge_parquet_files( temp_files: &[PathBuf], output_path: &Path, schema: &Schema, compression: Option<ParquetCompression>, compression_level: Option<u32>, ) -> Result<(), ReadStatError>

Merge multiple Parquet files into one by reading and rewriting all batches.

Errors

Returns an error if any temp file cannot be read, the output file cannot be created, or writing fails.

fn resolve_compression( compression: Option<ParquetCompression>, compression_level: Option<u32>, ) -> Result<ParquetCompressionCodec, ReadStatError>

pub fn finish( &mut self, d: &ReadStatData, wc: &WriteConfig, in_path: &Path, ) -> Result<(), ReadStatError>

Finalizes the writer, flushing any remaining data and printing a summary.

in_path is used for display messages showing the source file name.

Errors

Returns an error if the underlying writer fails to flush or close, or if the output format is not enabled.

fn print_finish_message( &self, d: &ReadStatData, wc: &WriteConfig, in_path: &Path, )

fn finish_feather(&mut self) -> Result<(), ReadStatError>

fn finish_parquet(&mut self) -> Result<(), ReadStatError>

pub fn write( &mut self, d: &ReadStatData, wc: &WriteConfig, ) -> Result<(), ReadStatError>

Writes a single batch of data in the format determined by wc.

Handles writer initialization on first call and CSV header writing.

Errors

Returns an error if the output file cannot be opened, writing fails, or the output format is not enabled.

fn write_data_to_csv( &mut self, d: &ReadStatData, wc: &WriteConfig, ) -> Result<(), ReadStatError>

fn write_data_to_feather( &mut self, d: &ReadStatData, wc: &WriteConfig, ) -> Result<(), ReadStatError>

fn write_data_to_ndjson( &mut self, d: &ReadStatData, wc: &WriteConfig, ) -> Result<(), ReadStatError>

fn write_data_to_parquet( &mut self, d: &ReadStatData, wc: &WriteConfig, ) -> Result<(), ReadStatError>

fn write_data_to_stdout( &mut self, d: &ReadStatData, ) -> Result<(), ReadStatError>

fn write_header_to_stdout( &mut self, d: &ReadStatData, ) -> Result<(), ReadStatError>

pub fn write_metadata( &self, md: &ReadStatMetadata, rsp: &ReadStatPath, as_json: bool, ) -> Result<(), ReadStatError>

Writes metadata to stdout (pretty-printed) or as JSON.

Errors

Returns an error if JSON serialization fails.

pub fn write_metadata_to_json( &self, md: &ReadStatMetadata, ) -> Result<(), ReadStatError>

Serializes metadata as pretty-printed JSON and writes to stdout.

Errors

Returns an error if JSON serialization fails.

pub fn write_metadata_to_stdout( &self, md: &ReadStatMetadata, rsp: &ReadStatPath, ) -> Result<(), ReadStatError>

Writes metadata to stdout in a human-readable format.

Errors

This method currently always succeeds but returns Result for consistency with other writer methods.

Trait Implementations

impl Default for ReadStatWriter

fn default() -> ReadStatWriter

Returns the “default value” for a type.