| // 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. |
| |
| //! [Apache Arrow](http://arrow.apache.org/) is a cross-language development platform for |
| //! in-memory data. |
| //! |
| //! This mod provides API for converting between arrow and parquet. |
| //! |
| //! # Example of reading parquet file into arrow record batch |
| //! |
| //! ```rust, no_run |
| //! use arrow::record_batch::RecordBatchReader; |
| //! use parquet::file::reader::SerializedFileReader; |
| //! use parquet::arrow::{ParquetFileArrowReader, ArrowReader}; |
| //! use std::sync::Arc; |
| //! use std::fs::File; |
| //! |
| //! let file = File::open("parquet.file").unwrap(); |
| //! let file_reader = SerializedFileReader::new(file).unwrap(); |
| //! let mut arrow_reader = ParquetFileArrowReader::new(Arc::new(file_reader)); |
| //! |
| //! println!("Converted arrow schema is: {}", arrow_reader.get_schema().unwrap()); |
| //! println!("Arrow schema after projection is: {}", |
| //! arrow_reader.get_schema_by_columns(vec![2, 4, 6], true).unwrap()); |
| //! |
| //! let mut record_batch_reader = arrow_reader.get_record_reader(2048).unwrap(); |
| //! |
| //! for maybe_record_batch in record_batch_reader { |
| //! let record_batch = maybe_record_batch.unwrap(); |
| //! if record_batch.num_rows() > 0 { |
| //! println!("Read {} records.", record_batch.num_rows()); |
| //! } else { |
| //! println!("End of file!"); |
| //! } |
| //!} |
| //! ``` |
| |
| pub mod array_reader; |
| pub mod arrow_array_reader; |
| pub mod arrow_reader; |
| pub mod arrow_writer; |
| pub mod converter; |
| pub(in crate::arrow) mod levels; |
| pub(in crate::arrow) mod record_reader; |
| pub mod schema; |
| |
| pub use self::arrow_reader::ArrowReader; |
| pub use self::arrow_reader::ParquetFileArrowReader; |
| pub use self::arrow_writer::ArrowWriter; |
| pub use self::schema::{ |
| arrow_to_parquet_schema, parquet_to_arrow_schema, parquet_to_arrow_schema_by_columns, |
| parquet_to_arrow_schema_by_root_columns, |
| }; |
| |
| /// Schema metadata key used to store serialized Arrow IPC schema |
| pub const ARROW_SCHEMA_META_KEY: &str = "ARROW:schema"; |