serde_amqp

A serde implementation of AMQP1.0 protocol.

Serializing and deserializing data structures

Any type that implement serde::Serialize and serde::Deserialize trait can be serialized/deserialized with the following convenience functions

Serialization:

Deserialization:

Primitive types

All primitive types defined in AMQP1.0 protocol can be found in mod [primitives].

Described types

AMQP1.0 specification allows annotating any AMQP type with a [descriptor::Descriptor], thus creating a described type. Though this can be constructed using [described::Described] and [Value], a much easier way to define a custom described type is to use the custom [SerializeComposite] and [DeserializeComposite] derive macros. Please be aware that the "derive" feature flag must be enabled.

You can read more about how to use the derive macros in the corresponding section.

Untyped AMQP1.0 values

Untyped AMQP1.0 values can be constructed as well as serialized/deserialized using [Value].

```rust use serdeamqp::{ SerializeComposite, DeserializeComposite, Value, tovec, from_slice, described::Described, descriptor::Descriptor, };

[derive(Debug, SerializeComposite, DeserializeComposite)]

[amqp_contract(code = 0x13, encoding = "list")]

struct Foo(Option, Option);

let foo = Foo(Some(true), Some(3)); let buf = tovec(&foo).unwrap(); let value: Value = fromslice(&buf).unwrap(); let expected = Value::from( Described { descriptor: Descriptor::Code(0x13), value: Value::List(vec![ Value::Bool(true), Value::Int(3) ]) } ); assert_eq!(value, expected); ```

Types that implements serde::Serialize and serde::Deserialize traits can also be converted into/from [Value] using the [to_value] and [from_value] functions.

WARNING enum

enum in serde data model can be categorized as below.

```rust use serde::{Serialize, Deserialize};

[derive(Serialize, Deserialize)]

enum Enumeration { UnitVariant, NewTypeVariant(u32), TupleVariant(bool, u64, String), StructVariant { id: u32, is_true: bool }, } ```

AMQP1.0 protocol doesn't natively support NewTypeVariant, TupleVariant or StructVariant. For the sake of completeness, serialization and deserialization for these variants are implemented as follows:

Feature flag

SerializeComposite and DeserializeComposite

The macro provides three types of encodings:

  1. "list": The struct will be serialized as a described list. A described list is an AMQP1.0 list with its descriptor prepended to the list itself. The deserialization will take either the "list" or the "map" encoded values.
  2. "map": The struct will be serialized as a described map. A described map is an AMQP1.0 map with its descriptor prepended to the map. The deserialization will take either the "list" or the "map" encoded values.
  3. "basic": The struct must be a thin wrapper (containing only one field) over another serializable/deserializable type. The inner struct will be serialized/deserialized with the descriptor prepended to the struct.

Details with the "list" encoding

Optinal fields

If a field is not marked with "mandatory" in the specification, the field can be an Option. During serialization, the optional fields may be skipped completely or encoded as an AMQP1.0 null primitive (0x40). During deserialization, an AMQP1.0 null primitive or an empty field will be decoded as a None.

Fields with default values:

For fields that have default values defined in the specification, the field type must implement both the Default and PartialEq trait. During serialization, if the field is equal to the default value of the field type, the field will be either ignored completely or encoded as an AMQP1.0 null primitive (0x40). During deserialization, an AMQP1.0 null primitive or an empty field will be decoded as the default value of the type.

Example of the derive macros

The "list" encoding will encode the Attach struct as a described list (a descriptor followed by a list of the fields).

```rust, ignore /// 2.7.3 Attach /// Attach a link to a session. /// ///

[derive(Debug, DeserializeComposite, SerializeComposite)]

[amqp_contract(

name = "amqp:attach:list",
code = 0x0000_0000_0000_0012,
encoding = "list",
rename_all = "kebab-case"

)] pub struct Attach { /// pub name: String,

/// <field name="handle" type="handle" mandatory="true"/>
pub handle: Handle,

/// <field name="role" type="role" mandatory="true"/>
pub role: Role,

/// <field name="snd-settle-mode" type="sender-settle-mode" default="mixed"/>
#[amqp_contract(default)]
pub snd_settle_mode: SenderSettleMode,

/// <field name="rcv-settle-mode" type="receiver-settle-mode" default="first"/>
#[amqp_contract(default)]
pub rcv_settle_mode: ReceiverSettleMode,

/// <field name="source" type="*" requires="source"/>
pub source: Option<Source>,

/// <field name="target" type="*" requires="target"/>
pub target: Option<Target>,

/// <field name="unsettled" type="map"/>
pub unsettled: Option<BTreeMap<DeliveryTag, DeliveryState>>,

/// <field name="incomplete-unsettled" type="boolean" default="false"/>
#[amqp_contract(default)]
pub incomplete_unsettled: Boolean,

/// <field name="initial-delivery-count" type="sequence-no"/>
pub initial_delivery_count: Option<SequenceNo>,

/// <field name="max-message-size" type="ulong"/>
pub max_message_size: Option<ULong>,

/// <field name="offered-capabilities" type="symbol" multiple="true"/>
pub offered_capabilities: Option<Array<Symbol>>,

/// <field name="desired-capabilities" type="symbol" multiple="true"/>
pub desired_capabilities: Option<Array<Symbol>>,

/// <field name="properties" type="fields"/>
pub properties: Option<Fields>,

} ```rust

```rust,ignore /// 3.2.5 Application Properties /// /// ///

[derive(Debug, Clone, SerializeComposite, DeserializeComposite)]

[amqp_contract(

name = "amqp:application-properties:map",
code = 0x0000_0000_0000_0074,
encoding = "basic"

)] pub struct ApplicationProperties(pub BTreeMap); ```

License: MIT/Apache-2.0