Struct WithUnit

pub struct WithUnit;

Default deserializer for Durations, ByteSizes and EtherAmounts.

Values can be deserialized from 2 formats:

• String consisting of a number, optional whitespace and a unit, such as “30 secs” or “500ms” (for Duration) / “4 MiB” (for ByteSize). The unit must correspond to a TimeUnit / SizeUnit / EtherUnit. Durations and EtherAmounts support decimal numbers, such as 3.5 sec or 1.5e-5 ether; ByteSizes only support integers.
• Object with a single key and a numeric value, such as { "hours": 3 } (for Duration) / { "kb": 512 } (for SizeUnit). To prevent precision loss, decimal values may be enclosed in a string (e.g., { "ether": "0.000123456" }).

Thanks to nesting of object params, the second approach automatically means that a duration can be parsed from a param name suffixed with a unit. For example, a value latency_ms: 500 for parameter latency will be recognized as 500 ms.

Examples

#[derive(DescribeConfig, DeserializeConfig)]
struct TestConfig {
    latency: Duration,
    disk: ByteSize,
    #[config(default)]
    fee: EtherAmount,
}

// Parsing from a string
let source = smart_config::config!(
    "latency": "30 secs",
    "disk": "256 MiB",
    "fee": "100 gwei",
);
let config: TestConfig = testing::test(source)?;
assert_eq!(config.latency, Duration::from_secs(30));
assert_eq!(config.disk, ByteSize(256 << 20));
assert_eq!(config.fee, EtherAmount(100_000_000_000));

// Parsing from an object
let source = smart_config::config!(
    "latency": serde_json::json!({ "hours": 3.5 }),
    "disk": serde_json::json!({ "gigabytes": 2 }),
    "fee": serde_json::json!({ "ether": "0.000125" }),
);
let config: TestConfig = testing::test(source)?;
assert_eq!(config.latency, Duration::from_secs(3_600 * 7 / 2));
assert_eq!(config.disk, ByteSize(2 << 30));
assert_eq!(config.fee, EtherAmount(125_000_000_000_000));

// Parsing from a suffixed parameter name
let source = Environment::from_iter("", [
    ("LATENCY_SEC", "1.5"),
    ("DISK_GB", "10"),
    ("FEE_IN_ETHER", "1.5e-5"),
]);
let config: TestConfig = testing::test(source)?;
assert_eq!(config.latency, Duration::from_millis(1_500));
assert_eq!(config.disk, ByteSize(10 << 30));
assert_eq!(config.fee, EtherAmount(15_000_000_000_000));

Trait Implementations

impl Clone for WithUnit

fn clone(&self) -> WithUnit

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WithUnit

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl DeserializeParam<ByteSize> for WithUnit

const EXPECTING: BasicTypes = Self::EXPECTED_TYPES

Describes which parameter this deserializer is expecting.

fn describe(&self, description: &mut TypeDescription)

Additional info about the deserialized type, e.g., extended description.

fn deserialize_param( &self, ctx: DeserializeContext<'_>, param: &'static ParamMetadata, ) -> Result<ByteSize, ErrorWithOrigin>

Performs deserialization given the context and param metadata.

fn serialize_param(&self, param: &ByteSize) -> Value

Serializes the provided parameter to the JSON model.

impl DeserializeParam<Duration> for WithUnit

const EXPECTING: BasicTypes = Self::EXPECTED_TYPES

Describes which parameter this deserializer is expecting.

fn describe(&self, description: &mut TypeDescription)

Additional info about the deserialized type, e.g., extended description.

fn deserialize_param( &self, ctx: DeserializeContext<'_>, param: &'static ParamMetadata, ) -> Result<Duration, ErrorWithOrigin>

Performs deserialization given the context and param metadata.

fn serialize_param(&self, param: &Duration) -> Value

Serializes the provided parameter to the JSON model.

impl DeserializeParam<EtherAmount> for WithUnit

const EXPECTING: BasicTypes = Self::EXPECTED_TYPES

Describes which parameter this deserializer is expecting.

fn describe(&self, description: &mut TypeDescription)

Additional info about the deserialized type, e.g., extended description.

fn deserialize_param( &self, ctx: DeserializeContext<'_>, param: &'static ParamMetadata, ) -> Result<EtherAmount, ErrorWithOrigin>

Performs deserialization given the context and param metadata.

fn serialize_param(&self, param: &EtherAmount) -> Value

Serializes the provided parameter to the JSON model.

impl DeserializeParam<Option<ByteSize>> for WithUnit

const EXPECTING: BasicTypes = Self::EXPECTED_TYPES

Describes which parameter this deserializer is expecting.

fn describe(&self, description: &mut TypeDescription)

Additional info about the deserialized type, e.g., extended description.

fn deserialize_param( &self, ctx: DeserializeContext<'_>, param: &'static ParamMetadata, ) -> Result<Option<ByteSize>, ErrorWithOrigin>

Performs deserialization given the context and param metadata.

fn serialize_param(&self, param: &Option<ByteSize>) -> Value

Serializes the provided parameter to the JSON model.

impl DeserializeParam<Option<Duration>> for WithUnit

const EXPECTING: BasicTypes = Self::EXPECTED_TYPES

Describes which parameter this deserializer is expecting.

fn describe(&self, description: &mut TypeDescription)

Additional info about the deserialized type, e.g., extended description.

fn deserialize_param( &self, ctx: DeserializeContext<'_>, param: &'static ParamMetadata, ) -> Result<Option<Duration>, ErrorWithOrigin>

Performs deserialization given the context and param metadata.

fn serialize_param(&self, param: &Option<Duration>) -> Value

Serializes the provided parameter to the JSON model.

impl DeserializeParam<Option<EtherAmount>> for WithUnit

const EXPECTING: BasicTypes = Self::EXPECTED_TYPES

Describes which parameter this deserializer is expecting.

fn describe(&self, description: &mut TypeDescription)

Additional info about the deserialized type, e.g., extended description.

fn deserialize_param( &self, ctx: DeserializeContext<'_>, param: &'static ParamMetadata, ) -> Result<Option<EtherAmount>, ErrorWithOrigin>

Performs deserialization given the context and param metadata.

fn serialize_param(&self, param: &Option<EtherAmount>) -> Value

Serializes the provided parameter to the JSON model.

impl Copy for WithUnit