The 'nil UUID'.
The nil UUID is special form of UUID that is specified to have all
128 bits set to zero, as defined in IETF RFC 4122 Section 4.1.7.
Basic usage:
use uuid::Uuid;
let uuid = Uuid::nil();
assert_eq!(uuid.hyphenated().to_string(),
"00000000-0000-0000-0000-000000000000");
Creates a new Uuid
.
Note that not all versions can be generated currently and None
will be
returned if the specified version cannot be generated.
To generate a random UUID (UuidVersion::Md5
), then the v3
feature must be enabled for this crate.
To generate a random UUID (UuidVersion::Random
), then the v4
feature must be enabled for this crate.
To generate a random UUID (UuidVersion::Sha1
), then the v5
feature must be enabled for this crate.
Creates a Uuid
from four field values.
This function will return an error if d4
's length is not 8 bytes.
Basic usage:
use uuid::Uuid;
let d4 = [12, 3, 9, 56, 54, 43, 8, 9];
let uuid = Uuid::from_fields(42, 12, 5, &d4);
let uuid = uuid.map(|uuid| uuid.hyphenated().to_string());
let expected_uuid = Ok(String::from("0000002a-000c-0005-0c03-0938362b0809"));
assert_eq!(expected_uuid, uuid);
An invalid length:
use uuid::Uuid;
use uuid::ParseError;
let d4 = [12];
let uuid = Uuid::from_fields(42, 12, 5, &d4);
let expected_uuid = Err(ParseError::InvalidLength(1));
assert_eq!(expected_uuid, uuid);
Creates a Uuid
using the supplied bytes.
This function will return an error if b
has any length other than 16.
Basic usage:
use uuid::Uuid;
let bytes = [4, 54, 67, 12, 43, 2, 98, 76,
32, 50, 87, 5, 1, 33, 43, 87];
let uuid = Uuid::from_bytes(&bytes);
let uuid = uuid.map(|uuid| uuid.hyphenated().to_string());
let expected_uuid = Ok(String::from("0436430c-2b02-624c-2032-570501212b57"));
assert_eq!(expected_uuid, uuid);
An incorrect number of bytes:
use uuid::Uuid;
use uuid::ParseError;
let bytes = [4, 54, 67, 12, 43, 2, 98, 76];
let uuid = Uuid::from_bytes(&bytes);
let expected_uuid = Err(ParseError::InvalidLength(8));
assert_eq!(expected_uuid, uuid);
Creates a Uuid
using the supplied bytes.
Basic usage:
use uuid::Uuid;
use uuid::UuidBytes;
let bytes:UuidBytes = [70, 235, 208, 238, 14, 109, 67, 201, 185, 13, 204, 195, 90, 145, 63, 62];
let uuid = Uuid::from_uuid_bytes(bytes);
let uuid = uuid.hyphenated().to_string();
let expected_uuid = String::from("46ebd0ee-0e6d-43c9-b90d-ccc35a913f3e");
assert_eq!(expected_uuid, uuid);
An incorrect number of bytes:
use uuid::Uuid;
use uuid::UuidBytes;
let bytes:UuidBytes = [4, 54, 67, 12, 43, 2, 98, 76];
let uuid = Uuid::from_uuid_bytes(bytes);
Creates a v4 Uuid from random bytes (e.g. bytes supplied from Rand
crate)
Basic usage:
use uuid::Uuid;
use uuid::UuidBytes;
let bytes:UuidBytes = [70, 235, 208, 238, 14, 109, 67, 201, 185, 13, 204, 195, 90, 145, 63, 62];
let uuid = Uuid::from_random_bytes(bytes);
let uuid = uuid.hyphenated().to_string();
let expected_uuid = String::from("46ebd0ee-0e6d-43c9-b90d-ccc35a913f3e");
assert_eq!(expected_uuid, uuid);
Returns the variant of the Uuid
structure.
This determines the interpretation of the structure of the UUID.
Currently only the RFC4122 variant is generated by this module.
Returns the version number of the Uuid
.
This represents the algorithm used to generate the contents.
Currently only the Random (V4) algorithm is supported by this
module. There are security and privacy implications for using
older versions - see Wikipedia: Universally Unique Identifier for
details.
Returns the version of the Uuid
.
This represents the algorithm used to generate the contents
Returns the four field values of the UUID.
These values can be passed to the 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.
use uuid::Uuid;
let uuid = Uuid::nil();
assert_eq!(uuid.as_fields(), (0, 0, 0, &[0u8; 8]));
let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8").unwrap();
assert_eq!(uuid.as_fields(),
(0x936DA01F, 0x9ABD, 0x4D9D, b"\x80\xC7\x02\xAF\x85\xC8\x22\xA8"));
Returns an array of 16 octets containing the UUID data.
use uuid::Uuid;
let uuid = Uuid::nil();
assert_eq!(uuid.as_bytes(), &[0; 16]);
let uuid = Uuid::parse_str("936DA01F9ABD4d9d80C702AF85C822A8").unwrap();
assert_eq!(uuid.as_bytes(),
&[147, 109, 160, 31, 154, 189, 77, 157,
128, 199, 2, 175, 133, 200, 34, 168]);
Returns a wrapper which when formatted via fmt::Display
will format a
string of 32 hexadecimal digits.
use uuid::Uuid;
let uuid = Uuid::nil();
assert_eq!(uuid.simple().to_string(),
"00000000000000000000000000000000");
Returns a wrapper which when formatted via fmt::Display
will format a
string of hexadecimal digits separated into groups with a hyphen.
use uuid::Uuid;
let uuid = Uuid::nil();
assert_eq!(uuid.hyphenated().to_string(),
"00000000-0000-0000-0000-000000000000");
Returns a wrapper which when formatted via fmt::Display
will format a
string of the UUID as a full URN string.
use uuid::Uuid;
let uuid = Uuid::nil();
assert_eq!(uuid.urn().to_string(),
"urn:uuid:00000000-0000-0000-0000-000000000000");
Returns an Optional Tuple of (u64, u16) representing the timestamp and
counter portion of a V1 UUID. If the supplied UUID is not V1, this
will return None
Parses a Uuid
from a string of hexadecimal digits with optional hyphens.
Any of the formats generated by this module (simple, hyphenated, urn) are
supported by this parsing function.