Struct ofdb_entities::nonce::Nonce

This determines the interpretation of the structure of the UUID. This method simply reads the value of the variant byte. It doesn’t validate the rest of the UUID as conforming to that variant.

Examples

Basic usage:

let my_uuid = Uuid::parse_str("02f09a3f-1624-3b1d-8409-44eff7708208")?;

assert_eq!(Variant::RFC4122, my_uuid.get_variant());

pub fn get_version_num(&self) -> usize

Returns the version number of the UUID.

This represents the algorithm used to generate the value. This method is the future-proof alternative to Uuid::get_version.

Examples

Basic usage:

let my_uuid = Uuid::parse_str("02f09a3f-1624-3b1d-8409-44eff7708208")?;

assert_eq!(3, my_uuid.get_version_num());

pub fn get_version(&self) -> Option<Version>

Returns the version of the UUID.

This represents the algorithm used to generate the value. If the version field doesn’t contain a recognized version then None is returned. If you’re trying to read the version for a future extension you can also use Uuid::get_version_num to unconditionally return a number. Future extensions may start to return Some once they’re standardized and supported.

Examples

Basic usage:

let my_uuid = Uuid::parse_str("02f09a3f-1624-3b1d-8409-44eff7708208")?;

assert_eq!(Some(Version::Md5), my_uuid.get_version());

References

Version in RFC4122

source

pub fn as_fields(&self) -> (u32, u16, u16, &[u8; 8])

Returns the four field values of the UUID.

These values can be passed to the Uuid::from_fields method to get the original Uuid back.

The first field value represents the first group of (eight) hex digits, taken as a big-endian u32 value. For V1 UUIDs, this field represents the low 32 bits of the timestamp.
The second field value represents the second group of (four) hex digits, taken as a big-endian u16 value. For V1 UUIDs, this field represents the middle 16 bits of the timestamp.
The third field value represents the third group of (four) hex digits, taken as a big-endian u16 value. The 4 most significant bits give the UUID version, and for V1 UUIDs, the last 12 bits represent the high 12 bits of the timestamp.
The last field value represents the last two groups of four and twelve hex digits, taken in order. The first 1-3 bits of this indicate the UUID variant, and for V1 UUIDs, the next 13-15 bits indicate the clock sequence and the last 48 bits indicate the node ID.

Examples

let uuid = Uuid::nil();

assert_eq!(uuid.as_fields(), (0, 0, 0, &[0u8; 8]));

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.as_fields(),
    (
        0xa1a2a3a4,
        0xb1b2,
        0xc1c2,
        &[0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8],
    )
);

source

pub fn to_fields_le(&self) -> (u32, u16, u16, &[u8; 8])

Returns the four field values of the UUID in little-endian order.

The bytes in the returned integer fields will be converted from big-endian order. This is based on the endianness of the UUID, rather than the target environment so bytes will be flipped on both big and little endian machines.

Examples

use uuid::Uuid;

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.to_fields_le(),
    (
        0xa4a3a2a1,
        0xb2b1,
        0xc2c1,
        &[0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8],
    )
);

source

pub fn as_u128(&self) -> u128

Returns a 128bit value containing the value.

The bytes in the UUID will be packed directly into a u128.

Examples

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.as_u128(),
    0xa1a2a3a4b1b2c1c2d1d2d3d4d5d6d7d8,
);

source

pub fn to_u128_le(&self) -> u128

Returns a 128bit little-endian value containing the value.

The bytes in the u128 will be flipped to convert into big-endian order. This is based on the endianness of the UUID, rather than the target environment so bytes will be flipped on both big and little endian machines.

Note that this will produce a different result than Uuid::to_fields_le, because the entire UUID is reversed, rather than reversing the individual fields in-place.

Examples

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.to_u128_le(),
    0xd8d7d6d5d4d3d2d1c2c1b2b1a4a3a2a1,
);

source

pub fn as_u64_pair(&self) -> (u64, u64)

Returns two 64bit values containing the value.

The bytes in the UUID will be split into two u64. The first u64 represents the 64 most significant bits, the second one represents the 64 least significant.

Examples

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;
assert_eq!(
    uuid.as_u64_pair(),
    (0xa1a2a3a4b1b2c1c2, 0xd1d2d3d4d5d6d7d8),
);

source

pub fn as_bytes(&self) -> &[u8; 16]

Returns a slice of 16 octets containing the value.

This method borrows the underlying byte value of the UUID.

Examples

let bytes1 = [
    0xa1, 0xa2, 0xa3, 0xa4,
    0xb1, 0xb2,
    0xc1, 0xc2,
    0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8,
];
let uuid1 = Uuid::from_bytes_ref(&bytes1);

let bytes2 = uuid1.as_bytes();
let uuid2 = Uuid::from_bytes_ref(bytes2);

assert_eq!(uuid1, uuid2);

assert!(std::ptr::eq(
    uuid2 as *const Uuid as *const u8,
    &bytes1 as *const [u8; 16] as *const u8,
));

source

pub fn to_bytes_le(&self) -> [u8; 16]

Returns the bytes of the UUID in little-endian order.

The bytes will be flipped to convert into little-endian order. This is based on the endianness of the UUID, rather than the target environment so bytes will be flipped on both big and little endian machines.

Examples

use uuid::Uuid;

let uuid = Uuid::parse_str("a1a2a3a4-b1b2-c1c2-d1d2-d3d4d5d6d7d8")?;

assert_eq!(
    uuid.to_bytes_le(),
    ([
        0xa4, 0xa3, 0xa2, 0xa1, 0xb2, 0xb1, 0xc2, 0xc1, 0xd1, 0xd2,
        0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8
    ])
);

source

pub fn is_nil(&self) -> bool

Tests if the UUID is nil (all zeros).

source

pub fn is_max(&self) -> bool

Tests if the UUID is max (all ones).

source

pub fn get_timestamp(&self) -> Option<Timestamp>

If the UUID is the correct version (v1, v6, or v7) this will return the timestamp and counter portion parsed from a V1 UUID.

Returns None if the supplied UUID is not V1.

The V1 timestamp format defined in RFC4122 specifies a 60-bit integer representing the number of 100-nanosecond intervals since 00:00:00.00, 15 Oct 1582.

Timestamp offers several options for converting the raw RFC4122 value into more commonly-used formats, such as a unix timestamp.

Roundtripping

This method is unlikely to roundtrip a timestamp in a UUID due to the way UUIDs encode timestamps. The timestamp returned from this method will be truncated to 100ns precision for version 1 and 6 UUIDs, and to millisecond precision for version 7 UUIDs.