Struct uuid::Uuid

pub struct Uuid(_);

A Universally Unique Identifier (UUID).

Methods

impl Uuid

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, Error>

Creates a UUID from four field values in big-endian order.

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);

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

Creates a UUID from four field values in little-endian order.

The bytes in the d1, d2 and d3 fields will be converted into big-endian order.

Examples

use uuid::Uuid;

let d1 = 0xAB3F1097u32;
let d2 = 0x501Eu16;
let d3 = 0xB736u16;
let d4 = [12, 3, 9, 56, 54, 43, 8, 9];

let uuid = Uuid::from_fields_le(d1, d2, d3, &d4);
let uuid = uuid.map(|uuid| uuid.to_hyphenated().to_string());

let expected_uuid =
    Ok(String::from("97103fab-1e50-36b7-0c03-0938362b0809"));

assert_eq!(expected_uuid, uuid);

pub const fn from_u128(v: u128) -> Self

Creates a UUID from a 128bit value in big-endian order.

pub const fn from_u128_le(v: u128) -> Self

Creates a UUID from a 128bit value in little-endian order.

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

Creates a UUID using the supplied big-endian 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::Uuid;

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

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

assert!(uuid.is_err());

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

Creates a UUID using the supplied big-endian bytes.

impl Uuid

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

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.

impl Uuid

pub const fn to_hyphenated(self) -> Hyphenated

Get a Hyphenated formatter.

pub const fn to_hyphenated_ref(&self) -> HyphenatedRef

Get a borrowed HyphenatedRef formatter.

pub const fn to_simple(self) -> Simple

Get a Simple formatter.

pub const fn to_simple_ref(&self) -> SimpleRef

Get a borrowed SimpleRef formatter.

pub const fn to_urn(self) -> Urn

Get a Urn formatter.

pub const fn to_urn_ref(&self) -> UrnRef

Get a borrowed UrnRef formatter.

impl Uuid

pub fn new_v1(ts: Timestamp, node_id: &[u8]) -> Result<Self, Error>

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

When generating Timestamps using a 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.

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

Examples

A UUID can be created from a unix Timestamp with a ClockSequence:

use uuid::v1::{Timestamp, Context};
use uuid::Uuid;

let context = Context::new(42);
let ts = Timestamp::from_unix(&context, 1497624119, 1234);
let uuid = Uuid::new_v1(ts, &[1, 2, 3, 4, 5, 6]).expect("failed to generate UUID");

assert_eq!(
    uuid.to_hyphenated().to_string(),
    "f3b4958c-52a1-11e7-802a-010203040506"
);

The timestamp can also be created manually as per RFC4122:

use uuid::v1::{Timestamp, Context};
use uuid::Uuid;

let context = Context::new(42);
let ts = Timestamp::from_rfc4122(1497624119, 0);
let uuid = Uuid::new_v1(ts, &[1, 2, 3, 4, 5, 6]).expect("failed to generate UUID");

assert_eq!(
    uuid.to_hyphenated().to_string(),
    "5943ee37-0000-1000-8000-010203040506"
);

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

Returns an optional Timestamp storing 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.

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 fn from_guid(guid: GUID) -> Result<Uuid, Error>

Attempts to create a Uuid from a little endian winapi GUID

pub fn to_guid(&self) -> GUID

Converts a Uuid into a little endian winapi GUID

impl Uuid

pub const NAMESPACE_DNS: Self

UUID namespace for Domain Name System (DNS).

pub const NAMESPACE_OID: Self

UUID namespace for ISO Object Identifiers (OIDs).

pub const NAMESPACE_URL: Self

UUID namespace for Uniform Resource Locators (URLs).

pub const NAMESPACE_X500: Self

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

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 const 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 in big-endian order.

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 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.

Examples

use uuid::Uuid;

let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8").unwrap();
assert_eq!(
    uuid.to_fields_le(),
    (
        0x1FA06D93,
        0xBD9A,
        0x9D4D,
        b"\x80\xC7\x02\xAF\x85\xC8\x22\xA8"
    )
);

pub fn as_u128(&self) -> u128

Returns a 128bit value containing the UUID data.

The bytes in the UUID will be packed into a u128, like the Uuid::as_bytes method.

Examples

use uuid::Uuid;

let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8").unwrap();
assert_eq!(
    uuid.as_u128(),
    0x936DA01F9ABD4D9D80C702AF85C822A8,
)

pub fn to_u128_le(&self) -> u128

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

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

use uuid::Uuid;

let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8").unwrap();

assert_eq!(
    uuid.to_u128_le(),
    0xA822C885AF02C7809D4DBD9A1FA06D93,
)

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

Returns an array of 16 octets containing the UUID data.

pub fn is_nil(&self) -> bool

Tests if the UUID is nil.

pub const fn encode_buffer() -> [u8; 45]

A buffer that can be used for encode_... calls, that is guaranteed to be long enough for any of the adapters.

Examples

use uuid::Uuid;

let uuid = Uuid::nil();

assert_eq!(
    uuid.to_simple().encode_lower(&mut Uuid::encode_buffer()),
    "00000000000000000000000000000000"
);

assert_eq!(
    uuid.to_hyphenated()
        .encode_lower(&mut Uuid::encode_buffer()),
    "00000000-0000-0000-0000-000000000000"
);

assert_eq!(
    uuid.to_urn().encode_lower(&mut Uuid::encode_buffer()),
    "urn:uuid:00000000-0000-0000-0000-000000000000"
);

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 Debug for Uuid

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

Formats the value using the given formatter.

impl PartialEq<Uuid> 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 Eq for Uuid

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.

fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialOrd<Uuid> 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.

impl FromStr for Uuid

type Err = Error

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 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 Copy for Uuid

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 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 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 dyn Serializer
) -> Result<(), Error>

Serialize self into Serializer