Parquet doc tweaks (#4680)

* Parquet doc tweaks

* Update parquet/src/arrow/mod.rs

parquet/src/arrow/arrow_reader/mod.rs

@@ -304,6 +304,8 @@ pub struct SyncReader<T: ChunkReader>(T);
 /// A synchronous builder used to construct [`ParquetRecordBatchReader`] for a file
 ///
 /// For an async API see [`crate::arrow::async_reader::ParquetRecordBatchStreamBuilder`]
+///
+/// See [`ArrowReaderBuilder`] for additional member functions
 pub type ParquetRecordBatchReaderBuilder<T> = ArrowReaderBuilder<SyncReader<T>>;
 
 impl<T: ChunkReader + 'static> ParquetRecordBatchReaderBuilder<T> {

parquet/src/arrow/async_reader/mod.rs

@@ -22,13 +22,13 @@
 //! # #[tokio::main(flavor="current_thread")]
 //! # async fn main() {
 //! #
-//! use arrow_array::RecordBatch;
-//! use arrow::util::pretty::pretty_format_batches;
-//! use futures::TryStreamExt;
-//! use tokio::fs::File;
-//!
-//! use parquet::arrow::{ParquetRecordBatchStreamBuilder, ProjectionMask};
-//!
+//! # use arrow_array::RecordBatch;
+//! # use arrow::util::pretty::pretty_format_batches;
+//! # use futures::TryStreamExt;
+//! # use tokio::fs::File;
+//! #
+//! # use parquet::arrow::{ParquetRecordBatchStreamBuilder, ProjectionMask};
+//! #
 //! # fn assert_batches_eq(batches: &[RecordBatch], expected_lines: &[&str]) {
 //! #     let formatted = pretty_format_batches(batches).unwrap().to_string();
 //! #     let actual_lines: Vec<_> = formatted.trim().lines().collect();
@@ -38,7 +38,7 @@
 //! #          expected_lines, actual_lines
 //! #      );
 //! #  }
-//!
+//! #
 //! let testdata = arrow::util::test_util::parquet_test_data();
 //! let path = format!("{}/alltypes_plain.parquet", testdata);
 //! let file = File::open(path).await.unwrap();
@@ -241,6 +241,8 @@ pub struct AsyncReader<T>(T);
 /// In particular, this handles reading the parquet file metadata, allowing consumers
 /// to use this information to select what specific columns, row groups, etc...
 /// they wish to be read by the resulting stream
+///
+/// See [`ArrowReaderBuilder`] for additional member functions
 pub type ParquetRecordBatchStreamBuilder<T> = ArrowReaderBuilder<AsyncReader<T>>;
 
 impl<T: AsyncFileReader + Send + 'static> ParquetRecordBatchStreamBuilder<T> {
@@ -263,6 +265,39 @@ impl<T: AsyncFileReader + Send + 'static> ParquetRecordBatchStreamBuilder<T> {
     ///
     /// This allows loading metadata once and using it to create multiple builders with
     /// potentially different settings
+    ///
+    /// ```
+    /// # use std::fs::metadata;
+    /// # use std::sync::Arc;
+    /// # use bytes::Bytes;
+    /// # use arrow_array::{Int32Array, RecordBatch};
+    /// # use arrow_schema::{DataType, Field, Schema};
+    /// # use parquet::arrow::arrow_reader::ArrowReaderMetadata;
+    /// # use parquet::arrow::{ArrowWriter, ParquetRecordBatchStreamBuilder};
+    /// # use tempfile::tempfile;
+    /// # use futures::StreamExt;
+    /// # #[tokio::main(flavor="current_thread")]
+    /// # async fn main() {
+    /// #
+    /// let mut file = tempfile().unwrap();
+    /// # let schema = Arc::new(Schema::new(vec![Field::new("i32", DataType::Int32, false)]));
+    /// # let mut writer = ArrowWriter::try_new(&mut file, schema.clone(), None).unwrap();
+    /// # let batch = RecordBatch::try_new(schema, vec![Arc::new(Int32Array::from(vec![1, 2, 3]))]).unwrap();
+    /// # writer.write(&batch).unwrap();
+    /// # writer.close().unwrap();
+    /// #
+    /// let mut file = tokio::fs::File::from_std(file);
+    /// let meta = ArrowReaderMetadata::load_async(&mut file, Default::default()).await.unwrap();
+    /// let mut a = ParquetRecordBatchStreamBuilder::new_with_metadata(
+    ///     file.try_clone().await.unwrap(),
+    ///     meta.clone()
+    /// ).build().unwrap();
+    /// let mut b = ParquetRecordBatchStreamBuilder::new_with_metadata(file, meta).build().unwrap();
+    ///
+    /// // Should be able to read from both in parallel
+    /// assert_eq!(a.next().await.unwrap().unwrap(), b.next().await.unwrap().unwrap());
+    /// # }
+    /// ```
     pub fn new_with_metadata(input: T, metadata: ArrowReaderMetadata) -> Self {
         Self::new_builder(AsyncReader(input), metadata)
     }

parquet/src/arrow/mod.rs

@@ -25,47 +25,40 @@
 //!# Example of writing Arrow record batch to Parquet file
 //!
 //!```rust
-//! use arrow_array::{Int32Array, ArrayRef};
-//! use arrow_array::RecordBatch;
-//! use parquet::arrow::arrow_writer::ArrowWriter;
-//! use parquet::file::properties::WriterProperties;
-//! use std::fs::File;
-//! use std::sync::Arc;
+//! # use arrow_array::{Int32Array, ArrayRef};
+//! # use arrow_array::RecordBatch;
+//! # use parquet::arrow::arrow_writer::ArrowWriter;
+//! # use parquet::file::properties::WriterProperties;
+//! # use tempfile::tempfile;
+//! # use std::sync::Arc;
+//! # use parquet::basic::Compression;
 //! let ids = Int32Array::from(vec![1, 2, 3, 4]);
 //! let vals = Int32Array::from(vec![5, 6, 7, 8]);
 //! let batch = RecordBatch::try_from_iter(vec![
 //!   ("id", Arc::new(ids) as ArrayRef),
 //!   ("val", Arc::new(vals) as ArrayRef),
 //! ]).unwrap();
 //!
-//! let file = File::create("data.parquet").unwrap();
+//! let file = tempfile().unwrap();
 //!
-//! let mut writer = ArrowWriter::try_new(file, batch.schema(), None).unwrap();
+//! // WriterProperties can be used to set Parquet file options
+//! let props = WriterProperties::builder()
+//!     .set_compression(Compression::SNAPPY)
+//!     .build();
+//!
+//! let mut writer = ArrowWriter::try_new(file, batch.schema(), Some(props)).unwrap();
 //!
 //! writer.write(&batch).expect("Writing batch");
 //!
 //! // writer must be closed to write footer
 //! writer.close().unwrap();
 //! ```
 //!
-//! `WriterProperties` can be used to set Parquet file options
-//! ```rust
-//! use parquet::file::properties::WriterProperties;
-//! use parquet::basic::{ Compression, Encoding };
-//! use parquet::file::properties::WriterVersion;
-//!
-//! // File compression
-//! let props = WriterProperties::builder()
-//!     .set_compression(Compression::SNAPPY)
-//!     .build();
-//! ```
-//!
 //! # Example of reading parquet file into arrow record batch
 //!
 //! ```rust
-//! use std::fs::File;
-//! use parquet::arrow::arrow_reader::ParquetRecordBatchReaderBuilder;
-//!
+//! # use std::fs::File;
+//! # use parquet::arrow::arrow_reader::ParquetRecordBatchReaderBuilder;
 //! # use std::sync::Arc;
 //! # use arrow_array::Int32Array;
 //! # use arrow::datatypes::{DataType, Field, Schema};
@@ -88,7 +81,7 @@
 //! #     writer.write(&batch).expect("Writing batch");
 //! # }
 //! # writer.close().unwrap();
-//!
+//! #
 //! let file = File::open("data.parquet").unwrap();
 //!
 //! let builder = ParquetRecordBatchReaderBuilder::try_new(file).unwrap();