Struct snowflake::ProcessUniqueId

pub struct ProcessUniqueId { /* fields omitted */ }

Process unique IDs are guaranteed to be unique within the current process, for the lifetime of the current process.

1. ID creation should be highly performant even on highly concurrent systems. It's MUCH faster than using random/time based IDs (but, on the other hand, only unique within a process).
2. While this crate can run out of process unique IDs, this is very unlikely assuming a sane threading model and will panic rather than potentially reusing unique IDs.

Limits

The unique ID's are sizeof(usize) + 64 bits wide and are generated by combining a usize global counter value with a 64bit thread local offset. This is important because each thread that calls new() at least once will reserve at least 2^64 IDs. So, the only way to run out of IDs in a reasonable amount of time is to run a 32bit system, spawn 2^32 threads, and claim one ID on each thread. You might be able to do this on a 64bit system but it would take a while... TL; DR: Don't create unique IDs from over 4 billion different threads on a 32bit system.

Methods

impl ProcessUniqueId

pub fn new() -> Self

Create a new unique ID.

panics if there are no more unique IDs available. If this happens, go home and reevaluate your threading model!

Trait Implementations

impl Ord for ProcessUniqueId

fn cmp(&self, other: &ProcessUniqueId) -> 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 Copy for ProcessUniqueId

impl Clone for ProcessUniqueId

fn clone(&self) -> ProcessUniqueId

Returns a copy of the value.

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

Performs copy-assignment from source.

impl PartialOrd<ProcessUniqueId> for ProcessUniqueId

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

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

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

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

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

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

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

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

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

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

impl Eq for ProcessUniqueId

impl Default for ProcessUniqueId

fn default() -> Self

Returns the "default value" for a type.

impl PartialEq<ProcessUniqueId> for ProcessUniqueId

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

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

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

This method tests for !=.

impl Hash for ProcessUniqueId

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 Display for ProcessUniqueId

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

Formats the value using the given formatter.

impl Debug for ProcessUniqueId

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

Formats the value using the given formatter.