Method decode

arrow-json/src/reader/binary_array.rs:91–118

(&mut self, tape: &Tape<'_>, pos: &[u32])

impl<O: OffsetSizeTrait> ArrayDecoder for BinaryArrayDecoder<O> {
    fn decode(&mut self, tape: &Tape<'_>, pos: &[u32]) -> Result<ArrayRef, ArrowError> {
        let data_capacity = estimate_data_capacity(tape, pos)?;

        if O::from_usize(data_capacity).is_none() {
            return Err(ArrowError::JsonError(format!(
                "offset overflow decoding {}",
                GenericStringArray::<O>::DATA_TYPE
            )));
        }

        let mut builder = GenericBinaryBuilder::<O>::with_capacity(pos.len(), data_capacity);

        for p in pos {
            match tape.get(*p) {
                TapeElement::String(idx) => {
                    let string = tape.get_string(idx);
                    // Decode directly into the builder for performance. If decoding fails,
                    // the error is terminal and the builder is discarded by the caller.
                    decode_hex_to_writer(string, &mut builder)?;
                    builder.append_value(b"");
                }
                TapeElement::Null => builder.append_null(),
                _ => unreachable!(),
            }
        }

        Ok(Arc::new(builder.finish()))
    }
}

#[derive(Default)]