Method encode

arrow-ipc/src/writer.rs:470–498

Encodes a batch to a number of [EncodedData] items (dictionary batches + the record batch). The [DictionaryTracker] keeps track of dictionaries with new `dict_id`s (so they are only sent once) Make sure the [DictionaryTracker] is initialized at the start of the stream.

(
        &self,
        batch: &RecordBatch,
        dictionary_tracker: &mut DictionaryTracker,
        write_options: &IpcWriteOptions,
        compression_context: &mut CompressionContext,
    )

    /// The [DictionaryTracker] keeps track of dictionaries with new `dict_id`s  (so they are only sent once)
    /// Make sure the [DictionaryTracker] is initialized at the start of the stream.
    pub fn encode(
        &self,
        batch: &RecordBatch,
        dictionary_tracker: &mut DictionaryTracker,
        write_options: &IpcWriteOptions,
        compression_context: &mut CompressionContext,
    ) -> Result<(Vec<EncodedData>, EncodedData), ArrowError> {
        let schema = batch.schema();
        let mut encoded_dictionaries = Vec::with_capacity(schema.flattened_fields().len());

        let mut dict_id = dictionary_tracker.dict_ids.clone().into_iter();

        for (i, field) in schema.fields().iter().enumerate() {
            let column = batch.column(i);
            self.encode_dictionaries(
                field,
                column,
                &mut encoded_dictionaries,
                dictionary_tracker,
                write_options,
                &mut dict_id,
                compression_context,
            )?;
        }

        let encoded_message =
            self.record_batch_to_bytes(batch, write_options, compression_context)?;
        Ok((encoded_dictionaries, encoded_message))
    }

    /// Encodes a batch to a number of [EncodedData] items (dictionary batches + the record batch).
    /// The [DictionaryTracker] keeps track of dictionaries with new `dict_id`s  (so they are only sent once)