Elasticsearch Core Types

A high-level implementation of the core types in Elasticsearch documents.

Provides structs and traits for defining and deriving a correct Elasticsearch mapping definition from your Rust structures.

Usage

This crate is on crates.io.

There are two ways to reference elastic_types in your projects, depending on whether you're on the stable/beta or nightly channels.

Builds on nightly benefit from compile-time codegen for better performance and easier mapping definitions. The story on stable will be improved over time so it won't be a second-class citizen forever.

Nightly

To get started, add elastic_types and elastic_types_macros to your Cargo.toml:

[dependencies]
elastic_types = { version = "*", defeault-features = false, features = "nightly" }
elastic_types_macros = "*"

And reference it in your crate root:

#![feature(plugin)]
#![plugin(elastic_types_macros)]

extern crate elastic_types;

Stable

To get started, add elastic_types to your Cargo.toml:

[dependencies]
elastic_types = "*"

And reference it in your crate root:

extern crate elastic_types;

Any code examples that aren't compatible with both nightly and stable, like deriving mappings, have alternatives depending on the channel you're targeting.

Map Your Types

For mapping on stable, see here.

Derive ElasticType on your Elasticsearch-mappable types:

# #![feature(plugin, custom_derive)]
# #![plugin(json_str, elastic_types_macros)]
# #[macro_use]
# extern crate elastic_types;
# extern crate serde;
# use serde::{ Serialize, Deserialize };
# use elastic_types::mapping::prelude::*;
# use elastic_types::date::prelude::*;
#[derive(Serialize, Deserialize, ElasticType)]
pub struct MyType {
	pub my_date: ElasticDate<DefaultDateFormat>,
	pub my_num: i32
}

# impl serde::Serialize for MyType {
# 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: serde::Serializer {
# 		unimplemented!()
# 	}
# }
# impl serde::Deserialize for MyType {
# 	 fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error> where D: serde::Deserializer {
# 		unimplemented!()
# 	}
# }
# fn main() {
# }

This will generate a mapping type for you called {TypeName}Mapping, so in this case our mapping is called MyTypeMapping. You can then serialise the mapping as json:

# #![feature(plugin, custom_derive, custom_attribute)]
# #![plugin(json_str, elastic_types_macros)]
# #[macro_use]
# extern crate elastic_types;
# extern crate serde;
# use serde::{ Serialize, Deserialize };
# use elastic_types::mapping::prelude::*;
# use elastic_types::date::prelude::*;
# #[derive(Serialize, Deserialize, ElasticType)]
# pub struct MyType {
# 	pub my_date: ElasticDate<DefaultDateFormat>,
# 	pub my_string: String,
# 	pub my_num: i32
# }
# impl serde::Serialize for MyType {
# 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: serde::Serializer {
# 		unimplemented!()
# 	}
# }
# impl serde::Deserialize for MyType {
# 	 fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error> where D: serde::Deserializer {
# 		unimplemented!()
# 	}
# }
# fn main() {
let mapping = TypeMapper::to_string(MyTypeMapping).unwrap();
# }

Which will output the following json:

# #![feature(plugin, custom_derive, custom_attribute)]
# #![plugin(elastic_types_macros)]
# #[macro_use]
# extern crate json_str;
# extern crate elastic_types;
# extern crate serde;
# use serde::{ Serialize, Deserialize };
# use elastic_types::mapping::prelude::*;
# use elastic_types::date::prelude::*;
# #[derive(Serialize, Deserialize, ElasticType)]
# pub struct MyType {
# 	pub my_date: ElasticDate<DefaultDateFormat>,
# 	pub my_num: i32
# }
# impl serde::Serialize for MyType {
# 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: serde::Serializer {
# 		unimplemented!()
# 	}
# }
# impl serde::Deserialize for MyType {
# 	 fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error> where D: serde::Deserializer {
# 		unimplemented!()
# 	}
# }
# fn main() {
# let mapping = TypeMapper::to_string(MyTypeMapping).unwrap();
# let json = json_str!(
{
    "properties": {
        "my_date": {
            "type": "date",
            "format": "basic_date_time"
        },
        "my_num": {
            "type": "integer"
        }
    }
}
# );
# assert_eq!(json, mapping);
# }

Of course, structs that derive ElasticType can also be used as fields on other Elasticsearch types:

# #![feature(plugin, custom_derive, custom_attribute)]
# #![plugin(elastic_types_macros)]
# extern crate elastic_types;
# extern crate serde;
# use serde::{ Serialize, Deserialize };
# use elastic_types::mapping::prelude::*;
# use elastic_types::date::prelude::*;
# #[derive(Serialize, Deserialize, ElasticType)]
# pub struct MyType {
# 	pub my_date: ElasticDate<DefaultDateFormat>,
# 	pub my_num: i32
# }
# impl serde::Serialize for MyType {
# 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: serde::Serializer {
# 		unimplemented!()
# 	}
# }
# impl serde::Deserialize for MyType {
# 	 fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error> where D: serde::Deserializer {
# 		unimplemented!()
# 	}
# }
#[derive(Serialize, Deserialize, ElasticType)]
pub struct MyOtherType {
	pub my_type: MyType
}
# impl serde::Serialize for MyOtherType {
# 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: serde::Serializer {
# 		unimplemented!()
# 	}
# }
# impl serde::Deserialize for MyOtherType {
# 	 fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error> where D: serde::Deserializer {
# 		unimplemented!()
# 	}
# }
# fn main() {
# }

Our mapping for MyOtherType then looks like:

# #![feature(plugin, custom_derive, custom_attribute)]
# #![plugin(elastic_types_macros)]
# #[macro_use]
# extern crate json_str;
# extern crate elastic_types;
# extern crate serde;
# use serde::{ Serialize, Deserialize };
# use elastic_types::mapping::prelude::*;
# use elastic_types::date::prelude::*;
# #[derive(Serialize, Deserialize, ElasticType)]
# pub struct MyType {
# 	pub my_date: ElasticDate<DefaultDateFormat>,
# 	pub my_num: i32
# }
# impl Serialize for MyType {
# 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: serde::Serializer {
# 		unimplemented!()
# 	}
# }
# impl Deserialize for MyType {
# 	 fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error> where D: serde::Deserializer {
# 		unimplemented!()
# 	}
# }
# #[derive(Serialize, Deserialize, ElasticType)]
# pub struct MyOtherType {
# 	pub my_type: MyType
# }
# impl Serialize for MyOtherType {
# 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: serde::Serializer {
# 		unimplemented!()
# 	}
# }
# impl Deserialize for MyOtherType {
# 	 fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error> where D: serde::Deserializer {
# 		unimplemented!()
# 	}
# }
# fn main() {
# let mapping = TypeMapper::to_string(MyOtherTypeMapping).unwrap();
# let json = json_str!(
{
    "properties": {
        "my_type": {
            "type": "nested",
            "properties": {
                "my_date": {
                    "type": "date",
                    "format": "basic_date_time"
                },
                "my_num": {
                    "type": "integer"
                }
            }
        }
    }
}
# );
# assert_eq!(json, mapping);
# }

Elasticsearch doesn't differentiate between nullable types or collections, so it's also possible to derive mapping from Option or Vec types:

# #![feature(plugin, custom_derive)]
# #![plugin(json_str, elastic_types_macros)]
# #[macro_use]
# extern crate elastic_types;
# extern crate serde;
# use serde::{ Serialize, Deserialize };
# use elastic_types::mapping::prelude::*;
# use elastic_types::date::prelude::*;
#[derive(Serialize, Deserialize, ElasticType)]
pub struct MyType {
	pub my_date: Option<ElasticDate<DefaultDateFormat>>,
	pub my_num: Vec<i32>
}

# impl serde::Serialize for MyType {
# 	fn serialize<S>(&self, serializer: &mut S) -> Result<(), S::Error> where S: serde::Serializer {
# 		unimplemented!()
# 	}
# }
# impl serde::Deserialize for MyType {
# 	 fn deserialize<D>(deserializer: &mut D) -> Result<Self, D::Error> where D: serde::Deserializer {
# 		unimplemented!()
# 	}
# }
# fn main() {
# }

Which produces the same mapping as before. See the object mod for more mapping examples.

For mapping in rs-es, see the RsesMapper.

Types

Types in Elasticsearch are a combination of source and mapping. The source is the data (like 42 or "my string") and the mapping is metadata about how to interpret and use the data (like the format of a date string).

The approach elastic_types takes to types is to bundle the mapping up as a Zero Sized Type. This mapping type is then bound to a field as a generic parameter. For example:

ElasticString<DefaultStringMapping>

The source is a string and the mapping is DefaultStringMapping.

All Elasticsearch types implement the base ElasticType<M: ElasticFieldMapping<F>, F> trait where M is the mapping and F is a type-specific format.

The following table illustrates the types provided by elastic_types (links to the relevant mapping type):

The following sections explain this table.

Mapping

Having the mapping available at compile-time makes it easy to write efficient generic methods that use type mapping.

Where there's a std type that's equivalent to an Elasticsearch type (like i32 for integer), a default mapping is implemented for that type. That means you can use primitives in your structs and have them mapped to the correct type in Elasticsearch. If you want to provide your own mapping for a std type, there's also a struct provided by elastic_types that wraps the std type but also takes an explicit mapping (like ElasticInteger for i32).

Where there isn't a std type available (like date), an external crate is used and an implementation of that type is provided (like ElasticDate, which implements chrono::DateLike + chrono::TimeLike).

Formats

For some types (like ElasticDate), it's helpful to have an extra generic parameter that describes the format the data can take. For most types the format is (), because there aren't any alternative formats available.

Links

• Elasticsearch Mapping Concepts
• Elasticsearch Type Concepts
• Github