Igosuki commented on a change in pull request #910: URL: https://github.com/apache/arrow-datafusion/pull/910#discussion_r696540252
########## File path: datafusion/src/datasource/avro.rs ########## @@ -0,0 +1,420 @@ +// 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. + +//! Line-delimited Avro data source +//! +//! This data source allows Line-delimited Avro records or files to be used as input for queries. +//! + +use std::{ + any::Any, + io::{Read, Seek}, + sync::{Arc, Mutex}, +}; + +use arrow::datatypes::SchemaRef; + +use crate::physical_plan::avro::{AvroExec, AvroReadOptions}; +use crate::{ + datasource::{Source, TableProvider}, + error::{DataFusionError, Result}, + physical_plan::{common, ExecutionPlan}, +}; + +use super::datasource::Statistics; + +trait SeekRead: Read + Seek {} + +impl<T: Seek + Read> SeekRead for T {} + +/// Represents a line-delimited Avro file with a provided schema +pub struct AvroFile { + source: Source<Box<dyn SeekRead + Send + Sync + 'static>>, + schema: SchemaRef, + file_extension: String, + statistics: Statistics, +} + +impl AvroFile { + /// Attempt to initialize a `AvroFile` from a path. The schema can be inferred automatically. + pub fn try_new(path: &str, options: AvroReadOptions) -> Result<Self> { + let schema = if let Some(schema) = options.schema { + schema + } else { + let filenames = + common::build_checked_file_list(path, options.file_extension)?; + Arc::new(AvroExec::try_infer_schema(&filenames)?) + }; + + Ok(Self { + source: Source::Path(path.to_string()), + schema, + file_extension: options.file_extension.to_string(), + statistics: Statistics::default(), + }) + } + + /// Attempt to initialize a `AvroFile` from a reader. The schema MUST be provided in options + pub fn try_new_from_reader<R: Read + Seek + Send + Sync + 'static>( + reader: R, + options: AvroReadOptions, + ) -> Result<Self> { + let schema = match options.schema { + Some(s) => s, + None => { + return Err(DataFusionError::Execution( + "Schema must be provided to CsvRead".to_string(), + )); + } + }; + Ok(Self { + source: Source::Reader(Mutex::new(Some(Box::new(reader)))), + schema, + statistics: Statistics::default(), + file_extension: String::new(), + }) + } + + /// Attempt to initialize an AvroFile from a reader impls Seek. The schema can be inferred automatically. + pub fn try_new_from_reader_infer_schema<R: Read + Seek + Send + Sync + 'static>( + mut reader: R, + options: AvroReadOptions, + ) -> Result<Self> { + let schema = { + if let Some(schema) = options.schema { + schema + } else { + Arc::new(crate::avro_to_arrow::infer_avro_schema_from_reader( + &mut reader, + )?) + } + }; + + Ok(Self { + source: Source::Reader(Mutex::new(Some(Box::new(reader)))), + schema, + statistics: Statistics::default(), + file_extension: String::new(), + }) + } + + /// Get the path for Avro file(s) represented by this AvroFile instance + pub fn path(&self) -> &str { + match &self.source { + Source::Reader(_) => "", + Source::Path(path) => path, + } + } + + /// Get the file extension for the Avro file(s) represented by this AvroFile instance + pub fn file_extension(&self) -> &str { + &self.file_extension + } +} + +impl TableProvider for AvroFile { + fn as_any(&self) -> &dyn Any { + self + } + + fn schema(&self) -> SchemaRef { + self.schema.clone() + } + + fn scan( + &self, + projection: &Option<Vec<usize>>, + batch_size: usize, + _filters: &[crate::logical_plan::Expr], + limit: Option<usize>, + ) -> Result<Arc<dyn ExecutionPlan>> { + let opts = AvroReadOptions { + schema: Some(self.schema.clone()), + file_extension: self.file_extension.as_str(), + }; + let batch_size = limit + .map(|l| std::cmp::min(l, batch_size)) + .unwrap_or(batch_size); + + let exec = match &self.source { + Source::Reader(maybe_reader) => { + if let Some(rdr) = maybe_reader.lock().unwrap().take() { + AvroExec::try_new_from_reader( + rdr, + opts, + projection.clone(), + batch_size, + limit, + )? + } else { + return Err(DataFusionError::Execution( + "You can only read once if the data comes from a reader" + .to_string(), + )); + } + } + Source::Path(p) => { + AvroExec::try_from_path(p, opts, projection.clone(), batch_size, limit)? + } + }; + Ok(Arc::new(exec)) + } + + fn statistics(&self) -> Statistics { + self.statistics.clone() + } +} + +#[cfg(test)] +mod tests { + use arrow::array::{ + BinaryArray, BooleanArray, Float32Array, Float64Array, Int32Array, + TimestampMicrosecondArray, + }; + use arrow::record_batch::RecordBatch; + use futures::StreamExt; + + use super::*; + + #[tokio::test] + async fn read_small_batches() -> Result<()> { + let table = load_table("alltypes_plain.avro")?; + let projection = None; + let exec = table.scan(&projection, 2, &[], None)?; + let stream = exec.execute(0).await?; + + let _ = stream + .map(|batch| { + let batch = batch.unwrap(); + assert_eq!(11, batch.num_columns()); + assert_eq!(2, batch.num_rows()); + }) + .fold(0, |acc, _| async move { acc + 1i32 }) + .await; + + Ok(()) + } + + #[tokio::test] + async fn read_alltypes_plain_avro() -> Result<()> { + let table = load_table("alltypes_plain.avro")?; + + let x: Vec<String> = table + .schema() + .fields() + .iter() + .map(|f| format!("{}: {:?}", f.name(), f.data_type())) + .collect(); + let y = x.join("\n"); + assert_eq!( + "id: Int32\n\ + bool_col: Boolean\n\ + tinyint_col: Int32\n\ + smallint_col: Int32\n\ + int_col: Int32\n\ + bigint_col: Int64\n\ + float_col: Float32\n\ + double_col: Float64\n\ + date_string_col: Binary\n\ + string_col: Binary\n\ + timestamp_col: Timestamp(Microsecond, None)", + y + ); + + let projection = None; + let batch = get_first_batch(table, &projection).await?; + + assert_eq!(11, batch.num_columns()); + assert_eq!(8, batch.num_rows()); Review comment: Thanks for pointing that out -- This is an automated message from the Apache Git Service. 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