harshmotw-db commented on code in PR #7884: URL: https://github.com/apache/arrow-rs/pull/7884#discussion_r2195584723
########## parquet-variant-compute/src/from_json.rs: ########## @@ -0,0 +1,181 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +//! Module for transforming a batch of JSON strings into a batch of Variants represented as +//! STRUCT<metadata: BINARY, value: BINARY> + +use std::sync::Arc; + +use arrow::array::{Array, ArrayRef, BinaryArray, BooleanBufferBuilder, StringArray, StructArray}; +use arrow::buffer::{Buffer, NullBuffer, OffsetBuffer, ScalarBuffer}; +use arrow::datatypes::{DataType, Field}; +use arrow_schema::ArrowError; +use parquet_variant::{json_to_variant, VariantBuilder}; + +fn variant_arrow_repr() -> DataType { + // The subfields are expected to be non-nullable according to the parquet variant spec. + let metadata_field = Field::new("metadata", DataType::Binary, false); + let value_field = Field::new("value", DataType::Binary, false); + let fields = vec![metadata_field, value_field]; + DataType::Struct(fields.into()) +} + +/// Parse a batch of JSON strings into a batch of Variants represented as +/// STRUCT<metadata: BINARY, value: BINARY> where nulls are preserved. The JSON strings in the input +/// must be valid. +pub fn batch_json_string_to_variant(input: &ArrayRef) -> Result<StructArray, ArrowError> { + let input_string_array = match input.as_any().downcast_ref::<StringArray>() { + Some(string_array) => Ok(string_array), + None => Err(ArrowError::CastError( + "Expected reference to StringArray as input".into(), + )), + }?; + + // Zero-copy builders + let mut metadata_buffer: Vec<u8> = Vec::with_capacity(input.len() * 128); + let mut metadata_offsets: Vec<i32> = Vec::with_capacity(input.len() + 1); + let mut metadata_validity = BooleanBufferBuilder::new(input.len()); + let mut metadata_current_offset: i32 = 0; + metadata_offsets.push(metadata_current_offset); + + let mut value_buffer: Vec<u8> = Vec::with_capacity(input.len() * 128); + let mut value_offsets: Vec<i32> = Vec::with_capacity(input.len() + 1); + let mut value_validity = BooleanBufferBuilder::new(input.len()); + let mut value_current_offset: i32 = 0; + value_offsets.push(value_current_offset); + + let mut validity = BooleanBufferBuilder::new(input.len()); + for i in 0..input.len() { + if input.is_null(i) { + // The subfields are expected to be non-nullable according to the parquet variant spec. + metadata_validity.append(true); + value_validity.append(true); + metadata_offsets.push(metadata_current_offset); + value_offsets.push(value_current_offset); + validity.append(false); + } else { + let mut vb = VariantBuilder::new(); + json_to_variant(input_string_array.value(i), &mut vb)?; + let (metadata, value) = vb.finish(); + validity.append(true); + + metadata_current_offset += metadata.len() as i32; + metadata_buffer.extend(metadata); + metadata_offsets.push(metadata_current_offset); + metadata_validity.append(true); + + value_current_offset += value.len() as i32; + value_buffer.extend(value); + value_offsets.push(value_current_offset); + value_validity.append(true); + println!("{value_current_offset} {metadata_current_offset}"); Review Comment: This was some debugging code I forgot to remove. Thanks for catching it. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@arrow.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
