Igosuki commented on a change in pull request #910: URL: https://github.com/apache/arrow-datafusion/pull/910#discussion_r701258301
########## File path: datafusion/src/avro_to_arrow/schema.rs ########## @@ -0,0 +1,452 @@ +// 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. + +use crate::arrow::datatypes::{DataType, IntervalUnit, Schema, TimeUnit}; +use crate::error::{DataFusionError, Result}; +use arrow::datatypes::Field; +use avro_rs::schema::Name; +use avro_rs::types::Value; +use avro_rs::Schema as AvroSchema; +use std::collections::BTreeMap; +use std::convert::TryFrom; + +/// Converts an avro schema to an arrow schema +pub fn to_arrow_schema(avro_schema: &avro_rs::Schema) -> Result<Schema> { + let mut schema_fields = vec![]; + match avro_schema { + AvroSchema::Record { fields, .. } => { + for field in fields { + schema_fields.push(schema_to_field_with_props( + &field.schema, + Some(&field.name), + false, + Some(&external_props(&field.schema)), + )?) + } + } + schema => schema_fields.push(schema_to_field(schema, Some(""), false)?), + } + + let schema = Schema::new(schema_fields); + Ok(schema) +} + +fn schema_to_field( + schema: &avro_rs::Schema, + name: Option<&str>, + nullable: bool, +) -> Result<Field> { + schema_to_field_with_props(schema, name, nullable, Some(&Default::default())) +} + +fn schema_to_field_with_props( + schema: &AvroSchema, + name: Option<&str>, + nullable: bool, + props: Option<&BTreeMap<String, String>>, +) -> Result<Field> { + let mut nullable = nullable; + let field_type: DataType = match schema { + AvroSchema::Null => DataType::Null, + AvroSchema::Boolean => DataType::Boolean, + AvroSchema::Int => DataType::Int32, + AvroSchema::Long => DataType::Int64, + AvroSchema::Float => DataType::Float32, + AvroSchema::Double => DataType::Float64, + AvroSchema::Bytes => DataType::Binary, + AvroSchema::String => DataType::Utf8, + AvroSchema::Array(item_schema) => DataType::List(Box::new( + schema_to_field_with_props(item_schema, None, false, None)?, + )), + AvroSchema::Map(value_schema) => { + let value_field = + schema_to_field_with_props(value_schema, Some("value"), false, None)?; + DataType::Dictionary( + Box::new(DataType::Utf8), + Box::new(value_field.data_type().clone()), + ) + } + AvroSchema::Union(us) => { + // If there are only two variants and one of them is null, set the other type as the field data type + let has_nullable = us.find_schema(&Value::Null).is_some(); + let sub_schemas = us.variants(); + if has_nullable && sub_schemas.len() == 2 { + nullable = true; + if let Some(schema) = sub_schemas + .iter() + .find(|&schema| !matches!(schema, AvroSchema::Null)) + { + schema_to_field_with_props(schema, None, has_nullable, None)? + .data_type() + .clone() + } else { + return Err(DataFusionError::AvroError( + avro_rs::Error::GetUnionDuplicate, + )); + } + } else { + let fields = sub_schemas + .iter() + .map(|s| schema_to_field_with_props(s, None, has_nullable, None)) + .collect::<Result<Vec<Field>>>()?; + DataType::Union(fields) + } + } + AvroSchema::Record { name, fields, .. } => { + let fields: Result<Vec<Field>> = fields + .iter() + .map(|field| { + let mut props = BTreeMap::new(); + if let Some(doc) = &field.doc { + props.insert("doc".to_string(), doc.clone()); + } + /*if let Some(aliases) = fields.aliases { + props.insert("aliases", aliases); + }*/ + schema_to_field_with_props( + &field.schema, + Some(&format!("{}.{}", name.fullname(None), field.name)), + false, + Some(&props), + ) + }) + .collect(); + DataType::Struct(fields?) + } + AvroSchema::Enum { symbols, name, .. } => { + return Ok(Field::new_dict( + &name.fullname(None), + index_type(symbols.len()), + false, + 0, + false, + )) + } + AvroSchema::Fixed { size, .. } => DataType::FixedSizeBinary(*size as i32), + AvroSchema::Decimal { + precision, scale, .. + } => DataType::Decimal(*precision, *scale), + AvroSchema::Uuid => DataType::Utf8, Review comment: https://github.com/Igosuki/arrow-datafusion/commit/94ec6e637c5a985bfc17618f9dda2cc342fa0381 -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
