Struct uuid::Uuid

pub struct Uuid(_);

A Universally Unique Identifier (UUID).

Methods

impl Uuid

pub const fn to_hyphenated(self) -> Hyphenated

Creates a Hyphenated instance from a Uuid.

pub const fn to_hyphenated_ref(&self) -> HyphenatedRef

Creates a HyphenatedRef instance from a Uuid reference.

pub const fn to_simple(self) -> Simple

Creates a Simple instance from a Uuid.

pub const fn to_simple_ref(&self) -> SimpleRef

Creates a SimpleRef instance from a Uuid reference.

pub const fn to_urn(self) -> Urn

Creates a Urn instance from a Uuid.

pub const fn to_urn_ref(&self) -> UrnRef

Creates a UrnRef instance from a Uuid reference.

impl Uuid

pub fn new_v1<T>(     context: &T,     seconds: u64,     nano_seconds: u32,     node_id: &[u8] ) -> Result<Self, BytesError> where     T: ClockSequence,

Create a new Uuid (version 1) using a time value + sequence + NodeId.

This expects two values representing a monotonically increasing value as well as a unique 6 byte NodeId, and an implementation of ClockSequence. This function is only guaranteed to produce unique values if the following conditions hold:

1. The NodeId is unique for this process,
2. The Context is shared across all threads which are generating v1 Uuids,
3. The ClockSequence implementation reliably returns unique clock sequences (this crate provides Context for this purpose. However you can create your own ClockSequence implementation, if Context does not meet your needs).

The NodeID must be exactly 6 bytes long. If the NodeID is not a valid length this will return a ParseError::InvalidLength.

The function is not guaranteed to produce monotonically increasing values however. There is a slight possibility that two successive equal time values could be supplied and the sequence counter wraps back over to 0.

If uniqueness and monotonicity is required, the user is responsible for ensuring that the time value always increases between calls (including between restarts of the process and device).

Note that usage of this method requires the v1 feature of this crate to be enabled.

Examples

Basic usage:

use uuid::v1::Context;
use uuid::Uuid;

let context = Context::new(42);
if let Ok(uuid) =
    Uuid::new_v1(&context, 1497624119, 1234, &[1, 2, 3, 4, 5, 6])
{
    assert_eq!(
        uuid.to_hyphenated().to_string(),
        "f3b4958c-52a1-11e7-802a-010203040506"
    )
} else {
    panic!()
}

impl Uuid

pub fn from_u128(quad: u128) -> Self

Creates a new Uuid from a u128 value.

To create a Uuid from u128s, you need u128 feature enabled for this crate.

impl Uuid

pub fn new_v3(namespace: &Uuid, name: &[u8]) -> Uuid

Creates a Uuid using a name from a namespace, based on the MD5 hash.

A number of namespaces are available as constants in this crate:

• NAMESPACE_DNS
• NAMESPACE_OID
• NAMESPACE_URL
• NAMESPACE_X500

Note that usage of this method requires the v3 feature of this crate to be enabled.

impl Uuid

pub fn new_v4() -> Self

Creates a random Uuid.

This uses the rand crate's default task RNG as the source of random numbers. If you'd like to use a custom generator, don't use this method: use the rand::Rand trait's rand() method instead.

Note that usage of this method requires the v4 feature of this crate to be enabled.

Examples

Basic usage:

use uuid::Uuid;

let uuid = Uuid::new_v4();

impl Uuid

pub fn new_v5(namespace: &Uuid, name: &[u8]) -> Uuid

Creates a UUID using a name from a namespace, based on the SHA-1 hash.

A number of namespaces are available as constants in this crate:

• NAMESPACE_DNS
• NAMESPACE_OID
• NAMESPACE_URL
• NAMESPACE_X500

Note that usage of this method requires the v5 feature of this crate to be enabled.

impl Uuid

pub const NAMESPACE_DNS: Self

NAMESPACE_DNS: Self = Uuid([107, 167, 184, 16, 157, 173, 17, 209, 128, 180, 0, 192, 79, 212, 48,
      200])

Uuid namespace for Domain Name System (DNS).

pub const NAMESPACE_OID: Self

NAMESPACE_OID: Self = Uuid([107, 167, 184, 18, 157, 173, 17, 209, 128, 180, 0, 192, 79, 212, 48,
      200])

Uuid namespace for ISO Object Identifiers (OIDs).

pub const NAMESPACE_URL: Self

NAMESPACE_URL: Self = Uuid([107, 167, 184, 17, 157, 173, 17, 209, 128, 180, 0, 192, 79, 212, 48,
      200])

Uuid namespace for Uniform Resource Locators (URLs).

pub const NAMESPACE_X500: Self

NAMESPACE_X500: Self = Uuid([107, 167, 184, 20, 157, 173, 17, 209, 128, 180, 0, 192, 79, 212, 48,
      200])

Uuid namespace for X.500 Distinguished Names (DNs).

pub const fn nil() -> Self

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.

Examples

Basic usage:

use uuid::Uuid;

let uuid = Uuid::nil();

assert_eq!(
    uuid.to_hyphenated().to_string(),
    "00000000-0000-0000-0000-000000000000"
);

pub fn from_fields(     d1: u32,     d2: u16,     d3: u16,     d4: &[u8] ) -> Result<Uuid, BytesError>

Creates a Uuid from four field values.

Errors

This function will return an error if d4's length is not 8 bytes.

Examples

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.to_hyphenated().to_string());

let expected_uuid =
    Ok(String::from("0000002a-000c-0005-0c03-0938362b0809"));

assert_eq!(expected_uuid, uuid);

An invalid length:

use uuid::prelude::*;

let d4 = [12];

let uuid = uuid::Uuid::from_fields(42, 12, 5, &d4);

let expected_uuid = Err(uuid::BytesError::new(8, d4.len()));

assert_eq!(expected_uuid, uuid);

pub fn from_slice(b: &[u8]) -> Result<Uuid, BytesError>

Creates a Uuid using the supplied bytes.

Errors

This function will return an error if b has any length other than 16.

Examples

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_slice(&bytes);
let uuid = uuid.map(|uuid| uuid.to_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::prelude::*;

let bytes = [4, 54, 67, 12, 43, 2, 98, 76];

let uuid = Uuid::from_slice(&bytes);

let expected_uuid = Err(uuid::BytesError::new(16, 8));

assert_eq!(expected_uuid, uuid);

pub const fn from_bytes(bytes: Bytes) -> Uuid

Creates a Uuid using the supplied bytes.

Examples

Basic usage:

use uuid::Bytes;
use uuid::Uuid;

let bytes: Bytes = [
    70, 235, 208, 238, 14, 109, 67, 201, 185, 13, 204, 195, 90, 145, 63,
    62,
];

let uuid = Uuid::from_bytes(bytes);
let uuid = uuid.to_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::Bytes;
use uuid::Uuid;

let bytes: Bytes = [4, 54, 67, 12, 43, 2, 98, 76]; // doesn't compile

let uuid = Uuid::from_bytes(bytes);

pub fn from_random_bytes(bytes: Bytes) -> Uuid

Creates a v4 Uuid from random bytes (e.g. bytes supplied from Rand crate)

Examples

Basic usage:

use uuid::Bytes;
use uuid::Uuid;

let bytes: Bytes = [
    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.to_hyphenated().to_string();

let expected_uuid = String::from("46ebd0ee-0e6d-43c9-b90d-ccc35a913f3e");

assert_eq!(expected_uuid, uuid);

pub fn get_variant(&self) -> Option<Variant>

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.

• Variant Reference

pub fn get_version_num(&self) -> usize

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.

• Version Reference

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

Returns the version of the Uuid.

This represents the algorithm used to generate the contents

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 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

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"
    )
);

pub const fn as_bytes(&self) -> &Bytes

Returns an array of 16 octets containing the UUID data.

Examples

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,
    ]
);

pub fn to_timestamp(&self) -> Option<(u64, u16)>

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

pub fn parse_str(input: &str) -> Result<Uuid, ParseError>

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.

pub fn is_nil(&self) -> bool

Tests if the UUID is nil

Trait Implementations

impl From<Uuid> for Hyphenated

fn from(f: Uuid) -> Self

Performs the conversion.

impl<'a> From<&'a Uuid> for HyphenatedRef<'a>

fn from(f: &'a Uuid) -> Self

Performs the conversion.

impl From<Uuid> for Simple

fn from(f: Uuid) -> Self

Performs the conversion.

impl<'a> From<&'a Uuid> for SimpleRef<'a>

fn from(f: &'a Uuid) -> Self

Performs the conversion.

impl From<Uuid> for Urn

fn from(f: Uuid) -> Self

Performs the conversion.

impl<'a> From<&'a Uuid> for UrnRef<'a>

fn from(f: &'a Uuid) -> Self

Performs the conversion.

impl Display for Uuid

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

Formats the value using the given formatter.

impl LowerHex for Uuid

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

Formats the value using the given formatter.

impl UpperHex for Uuid

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

Formats the value using the given formatter.

impl FromStr for Uuid

type Err = ParseError

The associated error which can be returned from parsing.

fn from_str(uuid_str: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Default for Uuid

fn default() -> Self

Returns the "default value" for a type.

impl Serialize for Uuid

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serialize this value into the given Serde serializer.

impl<'de> Deserialize<'de> for Uuid

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl Value for Uuid

fn serialize(     &self,     _: &Record,     key: Key,     serializer: &mut Serializer ) -> Result<(), Error>

Serialize self into Serializer

impl From<u128> for Uuid

fn from(f: u128) -> Self

Performs the conversion.

impl Clone for Uuid

fn clone(&self) -> Uuid

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Uuid

impl Debug for Uuid

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

Formats the value using the given formatter.

impl Eq for Uuid

impl Hash for Uuid

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given [Hasher].

fn hash_slice<H>(data: &[Self], state: &mut H) where     H: Hasher,

Feeds a slice of this type into the given [Hasher].

impl Ord for Uuid

fn cmp(&self, other: &Uuid) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

impl PartialEq for Uuid

fn eq(&self, other: &Uuid) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Uuid) -> bool

This method tests for !=.

impl PartialOrd for Uuid

fn partial_cmp(&self, other: &Uuid) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Uuid) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Uuid) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Uuid) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Uuid) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.