parquet_derive for the new RecordWriter trait

.gitignore

@@ -1,3 +1,3 @@
 Cargo.lock
-/target
+target
 **/*.rs.bk

.travis.yml

@@ -44,6 +44,11 @@ script:
   - cargo build
   - cargo test
   - cargo doc --no-deps
+  - cd parquet_derive_test
+  - cargo fmt --all -- --check
+  - cargo test
+  - cargo doc --no-deps
+  - cd ..
 
 after_success:
   - if [ "$TRAVIS_RUST_VERSION" == "nightly" ]; then

Cargo.toml

@@ -42,7 +42,12 @@ lz4 = "1.23"
 zstd = "0.4"
 chrono = "0.4"
 num-bigint = "0.2"
+syn = "0.15.21"
+quote = "0.6.10"
 
 [dev-dependencies]
 lazy_static = "1"
 rand = "0.5"
+
+[workspace]
+members = ["parquet_derive", "parquet_derive_test"]

appveyor.yml

@@ -28,3 +28,6 @@ install:
 build: false
 test_script:
   - cargo test --verbose --jobs 4
+  - cd parquet_derive_test
+  - cargo test
+  - cd ..

parquet_derive/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "parquet_derive"
+version = "0.1.0"
+authors = ["Xavier Lange <xrlange@gmail.com>"]
+edition = "2018"
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "0.4"
+quote = "0.6.10"
+syn = { version = "0.15.22", features = ["extra-traits"] }
+parquet = { path = ".." }

parquet_derive/README.md

@@ -0,0 +1,91 @@
+<!---
+  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.
+-->
+
+# parquet_derive-rs
+
+A create for automatically deriving `RecordWriter` for arbitrary, _simple_ structs. This does not generate writers for nested structures but it will work great for shallow structures.
+
+## Usage
+Add this to your Cargo.toml:
+```toml
+[dependencies]
+parquet = "0.4"
+parquet_derive = "0.4"
+```
+
+and this to your crate root:
+```rust
+extern crate parquet;
+#[macro_use] extern crate parquet_derive;
+```
+
+Example usage of deriving a `RecordWriter` for your struct:
+
+```rust
+use parquet;
+use parquet::file::writer::RecordWriter;
+
+#[derive(ParquetRecordWriter)]
+struct ACompleteRecord<'a> {
+    pub a_bool: bool,
+    pub a_str: &'a str,
+    pub a_string: String,
+    pub a_borrowed_string: &'a String,
+    pub maybe_a_str: Option<&'a str>,
+    pub magic_number: i32,
+    pub low_quality_pi: f32,
+    pub high_quality_pi: f64,
+    pub maybe_pi: Option<f32>,
+    pub maybe_best_pi: Option<f64>,
+}
+
+// Initialize your parquet file
+let mut writer = SerializedFileWriter::new(file, schema, props).unwrap();
+let mut row_group = writer.next_row_group().unwrap();
+
+// Build up your records
+let chunks = ...
+
+// The derived `RecordWriter` takes over here
+chunks.write_to_row_group(&mut row_group);
+
+writer.close_row_group(row_group).unwrap();
+writer.close().unwrap();
+```
+
+## Features
+- [X] Support writing `String`, `&str`, `bool`, `i32`, `f32`, `f64`
+- [ ] Support writing dictionaries
+- [ ] Support writing logical types like timestamp
+- [X] Derive definition_levels for `Option`
+- [ ] Derive definition levels for nested structures
+
+## Requirements
+- Same as `parquet-rs`
+
+## Test
+Testing a `*_derive` crate requires an intermediate crate. Go to `parquet_derive_test` and run `cargo test` for
+unit tests.
+
+## Docs
+To build documentation, run `cargo doc --no-deps`.
+To compile and view in the browser, run `cargo doc --no-deps --open`.
+
+## License
+Licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0.