iceberg/arrow/
delete_file_loader.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use std::sync::Arc;
19
20use futures::{StreamExt, TryStreamExt};
21
22use crate::arrow::ArrowReader;
23use crate::arrow::record_batch_transformer::RecordBatchTransformer;
24use crate::io::FileIO;
25use crate::scan::{ArrowRecordBatchStream, FileScanTaskDeleteFile};
26use crate::spec::{Schema, SchemaRef};
27use crate::{Error, ErrorKind, Result};
28
29/// Delete File Loader
30#[allow(unused)]
31#[async_trait::async_trait]
32pub trait DeleteFileLoader {
33    /// Read the delete file referred to in the task
34    ///
35    /// Returns the contents of the delete file as a RecordBatch stream. Applies schema evolution.
36    async fn read_delete_file(
37        &self,
38        task: &FileScanTaskDeleteFile,
39        schema: SchemaRef,
40    ) -> Result<ArrowRecordBatchStream>;
41}
42
43#[derive(Clone, Debug)]
44pub(crate) struct BasicDeleteFileLoader {
45    file_io: FileIO,
46}
47
48#[allow(unused_variables)]
49impl BasicDeleteFileLoader {
50    pub fn new(file_io: FileIO) -> Self {
51        BasicDeleteFileLoader { file_io }
52    }
53    /// Loads a RecordBatchStream for a given datafile.
54    pub(crate) async fn parquet_to_batch_stream(
55        &self,
56        data_file_path: &str,
57    ) -> Result<ArrowRecordBatchStream> {
58        /*
59           Essentially a super-cut-down ArrowReader. We can't use ArrowReader directly
60           as that introduces a circular dependency.
61        */
62        let record_batch_stream = ArrowReader::create_parquet_record_batch_stream_builder(
63            data_file_path,
64            self.file_io.clone(),
65            false,
66        )
67        .await?
68        .build()?
69        .map_err(|e| Error::new(ErrorKind::Unexpected, format!("{}", e)));
70
71        Ok(Box::pin(record_batch_stream) as ArrowRecordBatchStream)
72    }
73
74    /// Evolves the schema of the RecordBatches from an equality delete file
75    pub(crate) async fn evolve_schema(
76        record_batch_stream: ArrowRecordBatchStream,
77        target_schema: Arc<Schema>,
78    ) -> Result<ArrowRecordBatchStream> {
79        let eq_ids = target_schema
80            .as_ref()
81            .field_id_to_name_map()
82            .keys()
83            .cloned()
84            .collect::<Vec<_>>();
85
86        let mut record_batch_transformer =
87            RecordBatchTransformer::build(target_schema.clone(), &eq_ids);
88
89        let record_batch_stream = record_batch_stream.map(move |record_batch| {
90            record_batch.and_then(|record_batch| {
91                record_batch_transformer.process_record_batch(record_batch)
92            })
93        });
94
95        Ok(Box::pin(record_batch_stream) as ArrowRecordBatchStream)
96    }
97}
98
99#[async_trait::async_trait]
100impl DeleteFileLoader for BasicDeleteFileLoader {
101    async fn read_delete_file(
102        &self,
103        task: &FileScanTaskDeleteFile,
104        schema: SchemaRef,
105    ) -> Result<ArrowRecordBatchStream> {
106        let raw_batch_stream = self.parquet_to_batch_stream(&task.file_path).await?;
107
108        Self::evolve_schema(raw_batch_stream, schema).await
109    }
110}
111
112#[cfg(test)]
113mod tests {
114    use tempfile::TempDir;
115
116    use super::*;
117    use crate::arrow::delete_filter::tests::setup;
118
119    #[tokio::test]
120    async fn test_basic_delete_file_loader_read_delete_file() {
121        let tmp_dir = TempDir::new().unwrap();
122        let table_location = tmp_dir.path();
123        let file_io = FileIO::from_path(table_location.as_os_str().to_str().unwrap())
124            .unwrap()
125            .build()
126            .unwrap();
127
128        let delete_file_loader = BasicDeleteFileLoader::new(file_io.clone());
129
130        let file_scan_tasks = setup(table_location);
131
132        let result = delete_file_loader
133            .read_delete_file(
134                &file_scan_tasks[0].deletes[0],
135                file_scan_tasks[0].schema_ref(),
136            )
137            .await
138            .unwrap();
139
140        let result = result.try_collect::<Vec<_>>().await.unwrap();
141
142        assert_eq!(result.len(), 1);
143    }
144}
iceberg/arrow/delete_file_loader.rs

iceberg/arrow/
delete_file_loader.rs
