datafusion_proto_common/
lib.rs

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// 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.
// Make cheap clones clear: https://github.com/apache/datafusion/issues/11143
#![deny(clippy::clone_on_ref_ptr)]

//! Serialize / Deserialize DataFusion Primitive Types to bytes
//!
//! This crate provides support for serializing and deserializing the
//! following structures to and from bytes:
//!
//! 1. [`ScalarValue`]'s
//!
//! [`ScalarValue`]: datafusion_common::ScalarValue
//!
//! Internally, this crate is implemented by converting the common types to [protocol
//! buffers] using [prost].
//!
//! [protocol buffers]: https://developers.google.com/protocol-buffers
//! [prost]: https://docs.rs/prost/latest/prost/
//!
//! # Version Compatibility
//!
//! The serialized form are not guaranteed to be compatible across
//! DataFusion versions. A plan serialized with one version of DataFusion
//! may not be able to deserialized with a different version.
//!
//! # See Also
//!
//! The binary format created by this crate supports the full range of DataFusion
//! plans, but is DataFusion specific. See [datafusion-substrait] for a crate
//! which can encode many DataFusion plans using the [substrait.io] standard.
//!
//! [datafusion-substrait]: https://docs.rs/datafusion-substrait/latest/datafusion_substrait
//! [substrait.io]: https://substrait.io
//!
//! # Example: Serializing [`ScalarValue`]s
//! ```
//! # use datafusion_common::{ScalarValue, Result};
//! # use prost::{bytes::{Bytes, BytesMut}};
//! # use datafusion_common::plan_datafusion_err;
//! # use datafusion_proto_common::protobuf_common;
//! # use prost::Message;
//! # fn main() -> Result<()>{
//!     // Create a new ScalarValue
//!     let val = ScalarValue::UInt64(Some(3));
//!     let mut buffer = BytesMut::new();
//!     let protobuf: protobuf_common::ScalarValue = match val {
//!         ScalarValue::UInt64(Some(val)) => {
//!             protobuf_common::ScalarValue{value: Some(protobuf_common::scalar_value::Value::Uint64Value(val))}
//!         }
//!         _ => unreachable!(),
//!     };
//!
//!     protobuf.encode(&mut buffer)
//!     .map_err(|e| plan_datafusion_err!("Error encoding protobuf as bytes: {e}"))?;
//!     // Convert it to bytes (for sending over the network, etc.)
//!     let bytes: Bytes = buffer.into();
//!
//!     let protobuf = protobuf_common::ScalarValue::decode(bytes).map_err(|e| plan_datafusion_err!("Error decoding ScalarValue as protobuf: {e}"))?;
//!     // Decode bytes from somewhere (over network, etc.) back to ScalarValue
//!     let decoded_val: ScalarValue = match protobuf.value {
//!         Some(protobuf_common::scalar_value::Value::Uint64Value(val)) => ScalarValue::UInt64(Some(val)),
//!         _ => unreachable!(),
//!     };
//!     assert_eq!(val, decoded_val);
//! # Ok(())
//! # }
//! ```

pub mod common;
pub mod from_proto;
pub mod generated;
pub mod to_proto;

pub use from_proto::Error as FromProtoError;
pub use generated::datafusion_proto_common as protobuf_common;
pub use generated::datafusion_proto_common::*;
pub use to_proto::Error as ToProtoError;

#[cfg(doctest)]
doc_comment::doctest!("../README.md", readme_example_test);