Struct ClassicLayout 

pub struct ClassicLayout<I>
where
    I: MachineId,
{ /* private fields */ }

A Layout implementation for the classic snowflake layout introduced by Twitter.

Snowflakes constructed with this layout consist of a leading 0 bit, 41 bits for a timestamp in milliseconds, 10 bits for an instance ID, and 12 bits for the sequence number. The leading 0 bit guarantees that snowflakes with this layout keep their properties (namely, monotonicity) when converted into signed 64-bit integers.

Note that this layout doesn’t specify the snowflake’s epoch, however. Even when using this layout, you’ll have to specify your own epoch by implementing Epoch.

Example

use snowdon::{
    ClassicLayout, ClassicLayoutSnowflakeExtension, Epoch, Generator,
    MachineId, Snowflake,
};

struct SnowflakeParams;

impl Epoch for SnowflakeParams {
    fn millis_since_unix() -> u64 {
        // The epoch used by Twitter for their snowflake IDs
        1288834974657
    }
}

impl MachineId for SnowflakeParams {
    fn machine_id() -> u64 {
        // Somehow obtain this machine's ID (e.g. from the private IP
        // address or a configuration file)
    }
}

// Make our snowflake specification available to the rest of the application
type MySnowflake =
    Snowflake<ClassicLayout<SnowflakeParams>, SnowflakeParams>;
type MySnowflakeGenerator =
    Generator<ClassicLayout<SnowflakeParams>, SnowflakeParams>;

// Use our snowflake format
let snowflake = MySnowflake::from_raw(1541815603606036480).unwrap();
assert_eq!(367597485448, snowflake.timestamp_raw());
assert_eq!(0x017A, snowflake.machine_id());
assert_eq!(0, snowflake.sequence_number());

Implementations

impl<I> ClassicLayout<I>

where I: MachineId,

pub fn machine_id(input: u64) -> u64

Returns the machine ID of the given snowflake.

Usually, you shouldn’t call this function directly. Instead, use machine_id directly on the snowflake by importing ClassicLayoutSnowflakeExtension.

Trait Implementations

impl<I> Debug for ClassicLayout<I>

where I: MachineId + Debug,

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

Formats the value using the given formatter.

impl<I> Layout for ClassicLayout<I>

where I: MachineId,

fn construct_snowflake(timestamp: u64, sequence_number: u64) -> u64

Combines the given timestamp and sequence number into a 64-bit snowflake integer.

fn timestamp(input: u64) -> u64

Returns the timestamp stored in the given snowflake.

fn exceeds_timestamp(input: u64) -> bool

Returns whether the given timestamp exceeds the number of bits dedicated to timestamps in this layout.

fn sequence_number(input: u64) -> u64

Returns the sequence number of the given snowflake.

fn exceeds_sequence_number(input: u64) -> bool

Returns whether the given sequence number exceeds the number of bits dedicated in this layout.

fn is_valid_snowflake(input: u64) -> bool

Returns whether the given snowflake is a valid integer representation of a snowflake.