Struct Hasher 

pub struct Hasher { /* private fields */ }

An incremental hasher, implemented by the VM.

A value of this type is meaningful only in the current contract invocation, so it can’t be stored.

Implementations

impl Hasher

pub fn new() -> Hasher

Get a hasher.

Throws a syscall exception if the VM refuses the stream — its live-stream cap (the chain’s max_sha256_buffers network config parameter) is reached.

pub fn try_new() -> SysResult<Hasher>

Get a hasher if the VM has a free stream, or the refusing syscall’s error.

pub fn update<I: AsRef<[u8]>>(&mut self, input: &I)

Append data to the hasher input.

Throws a syscall exception (aborting the frame) if the host call fails.

pub fn fork(&self) -> Hasher

Fork the hasher: a new hasher with a copy of the absorbed state, after which the two diverge independently. The copy is constant-time in the VM, so absorb a shared prefix once and fork per suffix.

Throws a syscall exception if the VM refuses the stream.

pub fn try_fork(&self) -> SysResult<Hasher>

Fork the hasher if the VM has a free stream (see fork), or the refusing syscall’s error.

pub fn finish(self) -> SHA256Hash

Consume the hasher and return the SHA256 hash of the prior input, freeing its VM-side stream.

Throws a syscall exception (aborting the frame) if the host call fails.

Trait Implementations

impl Debug for Hasher

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

Formats the value using the given formatter.

impl Default for Hasher

fn default() -> Self

Returns the “default value” for a type.

impl Drop for Hasher

fn drop(&mut self)

Executes the destructor for this type.

fn pin_drop(self: Pin<&mut Self>)

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

Execute the destructor for this type, but different to Drop::drop, it requires self to be pinned.