Struct Writer

pub struct Writer<W, F>
where
    W: Write,
    F: JsonFormat,
{
    writer: W,
    started: bool,
    finished: bool,
    format: F,
    options: EncoderOptions,
}

A JSON writer which serializes [RecordBatch]es to a stream of u8 encoded JSON objects.

See the module level documentation for detailed usage and examples. The specific format of the stream is controlled by the JsonFormat type parameter.

By default the writer will skip writing keys with null values for backward compatibility. See WriterBuilder on how to customize this behaviour when creating a new writer.

Fields

writer: W

Underlying writer to use to write bytes

started: bool

Has the writer output any records yet?

finished: bool

Is the writer finished?

format: F

Determines how the byte stream is formatted

options: EncoderOptions

Controls how JSON should be encoded, e.g. whether to write explicit nulls or skip them

Implementations

impl<W, F> Writer<W, F>

where W: Write, F: JsonFormat,

pub fn new(writer: W) -> Self

Construct a new writer

pub fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError>

Serialize batch to JSON output

pub fn write_batches( &mut self, batches: &[&RecordBatch], ) -> Result<(), ArrowError>

Serialize batches to JSON output

pub fn finish(&mut self) -> Result<(), ArrowError>

Finishes the output stream. This function must be called after all record batches have been produced. (e.g. producing the final ']' if writing arrays.

pub fn into_inner(self) -> W

Unwraps this Writer<W>, returning the underlying writer

Trait Implementations

impl<W, F> Debug for Writer<W, F>

where W: Write + Debug, F: JsonFormat + Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<W, F> RecordBatchWriter for Writer<W, F>

where W: Write, F: JsonFormat,

fn write(&mut self, batch: &RecordBatch) -> Result<(), ArrowError>

Write a single batch to the writer.

fn close(self) -> Result<(), ArrowError>

Write footer or termination data, then mark the writer as done.