Struct Uuid 

pub struct Uuid(/* private fields */);

A Universally Unique Identifier (UUID).

Implementations

impl Uuid

pub const fn nil() -> Uuid

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) -> Uuid

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

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

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: [u8; 16]) -> 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_v4() -> Uuid

Creates a random UUID.

This uses the getrandom crate to utilise the operating system’s RNG as the source of random numbers. If you’d like to use a custom generator, don’t use this method: generate random bytes using your custom generator and pass them to the uuid::Builder::from_bytes function 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 const NAMESPACE_DNS: Uuid

UUID namespace for Domain Name System (DNS).

pub const NAMESPACE_OID: Uuid

UUID namespace for ISO Object Identifiers (OIDs).

pub const NAMESPACE_URL: Uuid

UUID namespace for Uniform Resource Locators (URLs).

pub const NAMESPACE_X500: Uuid

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;

fn main() -> Result<(), uuid::Error> {
    let uuid = Uuid::nil();
    assert_eq!(uuid.as_fields(), (0, 0, 0, &[0u8; 8]));

    let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8")?;
    assert_eq!(
        uuid.as_fields(),
        (
            0x936DA01F,
            0x9ABD,
            0x4D9D,
            b"\x80\xC7\x02\xAF\x85\xC8\x22\xA8"
        )
    );

    Ok(())
}

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;

fn main() -> Result<(), uuid::Error> {
    let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8")?;
    assert_eq!(
        uuid.to_fields_le(),
        (
            0x1FA06D93,
            0xBD9A,
            0x9D4D,
            b"\x80\xC7\x02\xAF\x85\xC8\x22\xA8"
        )
    );
    Ok(())
}

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;

fn main() -> Result<(), uuid::Error> {
    let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8")?;
    assert_eq!(
        uuid.as_u128(),
        0x936DA01F9ABD4D9D80C702AF85C822A8,
    );
    Ok(())
}

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;

fn main() -> Result<(), uuid::Error> {
    let uuid = Uuid::parse_str("936DA01F-9ABD-4D9D-80C7-02AF85C822A8")?;

    assert_eq!(
        uuid.to_u128_le(),
        0xA822C885AF02C7809D4DBD9A1FA06D93,
    );
    Ok(())
}

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

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 Clone for Uuid

fn clone(&self) -> Uuid

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Uuid

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

Formats the value using the given formatter.

impl Decode<'_, Sqlite> for Uuid

fn decode( value: SqliteValueRef<'_>, ) -> Result<Uuid, Box<dyn Error + Send + Sync>>

Decode a new value of this type using a raw value from the database.

impl Default for Uuid

fn default() -> Uuid

Returns the “default value” for a type.

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

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

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Display for Uuid

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

Formats the value using the given formatter.

impl<'q> Encode<'q, Sqlite> for Uuid

fn encode_by_ref(&self, args: &mut Vec<SqliteArgumentValue<'q>>) -> IsNull

Writes the value of self into buf without moving self.

fn encode(self, buf: &mut <DB as HasArguments<'q>>::ArgumentBuffer) -> IsNull

where Self: Sized,

Writes the value of self into buf in the expected format for the database.

fn produces(&self) -> Option<<DB as Database>::TypeInfo>

fn size_hint(&self) -> usize

impl FromStr for Uuid

type Err = Error

The associated error which can be returned from parsing.

fn from_str(uuid_str: &str) -> Result<Uuid, <Uuid as FromStr>::Err>

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

impl Hash for Uuid

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

where __H: Hasher,

Feeds this value into the given Hasher.

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

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl InputType for Uuid

type RawValueType = Uuid

The raw type used for validator.

fn type_name() -> Cow<'static, str>

Type the name.

fn create_type_info(registry: &mut Registry) -> String

Create type information in the registry and return qualified typename.

fn parse(value: Option<ConstValue>) -> Result<Uuid, InputValueError<Uuid>>

Parse from Value. None represents undefined.

fn to_value(&self) -> ConstValue

Convert to a Value for introspection.

fn as_raw_value(&self) -> Option<&<Uuid as InputType>::RawValueType>

Returns a reference to the raw value.

fn qualified_type_name() -> String

Qualified typename.

impl LowerHex for Uuid

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

Formats the value using the given formatter.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

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

where Self: Sized,

Restrict a value to a certain interval.

impl OutputType for Uuid

fn type_name() -> Cow<'static, str>

Type the name.

fn create_type_info(registry: &mut Registry) -> String

Create type information in the registry and return qualified typename.

fn resolve<'life0, 'life1, 'life2, 'life3, 'async_trait>( &'life0 self, _: &'life1 ContextBase<'life2, &'life2 Positioned<SelectionSet>>, _field: &'life3 Positioned<Field>, ) -> Pin<Box<dyn Future<Output = Result<ConstValue, ServerError>> + Send + 'async_trait>>

where 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait, Uuid: 'async_trait,

Resolve an output value to async_graphql::Value.

fn qualified_type_name() -> String

Qualified typename.

fn introspection_type_name(&self) -> Cow<'static, str>

Introspection type name

impl PartialEq for Uuid

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

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: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl ScalarType for Uuid

A UUID is a unique 128-bit number, stored as 16 octets. UUIDs are parsed as Strings within GraphQL. UUIDs are used to assign unique identifiers to entities without requiring a central allocating authority.

References

• Wikipedia: Universally Unique Identifier
• RFC4122: A Universally Unique IDentifier (UUID) URN Namespace

fn parse(value: ConstValue) -> Result<Uuid, InputValueError<Uuid>>

Parse a scalar value.

fn to_value(&self) -> ConstValue

Convert the scalar to Value.

fn is_valid(_value: &ConstValue) -> bool

Checks for a valid scalar value.

impl Serialize for Uuid

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

where S: Serializer,

Serialize this value into the given Serde serializer.

impl TryFrom<ID> for Uuid

type Error = Error

The type returned in the event of a conversion error.

fn try_from(id: ID) -> Result<Uuid, <Uuid as TryFrom<ID>>::Error>

Performs the conversion.

impl Type<Sqlite> for Uuid

fn type_info() -> SqliteTypeInfo

Returns the canonical SQL type for this Rust type.

fn compatible(ty: &SqliteTypeInfo) -> bool

Determines if this Rust type is compatible with the given SQL type.

impl UpperHex for Uuid

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

Formats the value using the given formatter.

impl Copy for Uuid

impl Eq for Uuid

impl StructuralPartialEq for Uuid