Struct RegionBuffer 

pub struct RegionBuffer { /* private fields */ }

A low-level helper struct for writing data onto the current fiber’s region allocator.

Users of the picodata plugin API should use the higher-level constructs instead. For example see crate::transport::rpc::Response.

May be useful for passing data across the ABI boundary.

Is used in the plugin RPC API.

Implementations

impl RegionBuffer

pub fn new() -> Self

Construct the region buffer capturing the current state of the region allocator. The region will be automatically truncated when this struct is dropped.

pub fn push(&mut self, data: &[u8]) -> Result<(), BoxError>

Append the data onto the region allocator.

Note that the data may or may not be non-contiguous with the previous allocation. Use Self::into_raw_parts to get the guaranteed contiguous result.

Returns an error if the region allocation fails.

pub fn get(&self) -> &[u8]

👎Deprecated: no longer supported, consider using RegionBuffer::into_raw_parts instead

pub fn into_raw_parts(self) -> (&'static [u8], usize)

Consumes the slice of the region memory containing the written data contiguously. The second return values is the save point for the region allocator.

The caller is responsible for truncating the region afterwards. Also the caller must make sure data is not used after the region is truncated.

Note that if the code is executed in the context of a stored procedure call, then the region is automatically truncated after the handler returns, so no explicit truncation is required.

Panicking

Will panic if the region allocation fails. Consider using Self::try_into_raw_parts if this is an issue.

pub fn try_into_raw_parts( self, ) -> Result<(&'static [u8], usize), (BoxError, Self)>

Consumes the slice of the region memory containing the written data contiguously. The second return values is the save point for the region allocator.

The caller is responsible for truncating the region afterwards. Also the caller must make sure data is not used after the region is truncated.

Note that if the code is executed in the context of a stored procedure call, then the region is automatically truncated after the handler returns, so no explicit truncation is required.

Returns an error if the region allocation fails.

pub fn try_into_vec(self) -> Result<Vec<u8>, BoxError>

Copies the data from region buffer to rust allocated Vec. The region is automatically truncated to the point before self was created.

Trait Implementations

impl Debug for RegionBuffer

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

Formats the value using the given formatter.

impl Write for RegionBuffer

fn write(&mut self, data: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

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

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

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

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.