Struct IpcWriteContext 

pub struct IpcWriteContext {
    scratch: Vec<u8>,
    reserve_scratch: bool,
    fbb: FlatBufferBuilder<'static>,
    compressor: Option<Compressor<'static>>,
    lz4_compressor: Option<Lz4Compressor>,
}

Additional context that may be needed for compression.

In the case of zstd, this will contain the zstd context, which can be reused between subsequent compression calls to avoid the performance overhead of initialising a new context for every compression. In the case of lz4, this will contain the lz4 frame encoder, whose hash table and block buffers are likewise reused. Also holds a [FlatBufferBuilder] that is reused across IPC writes.

Fields

scratch: Vec<u8>

reserve_scratch: bool

fbb: FlatBufferBuilder<'static>

compressor: Option<Compressor<'static>>

lz4_compressor: Option<Lz4Compressor>

Implementations

impl IpcWriteContext

pub(crate) fn mut_fbb(&mut self) -> &mut FlatBufferBuilder<'static>

Get a mutable reference to the [FlatBufferBuilder] that is reused across IPC writes.

pub fn set_reserve_scratch(&mut self, reserve: bool)

Set whether the scratch buffer capacity should be reserved after each encode for reuse on the next call. Set to false for the final batch in a sequence to avoid a pointless allocation. by default, this is set to false.

pub(crate) fn reserve_scratch_with_capacity(&mut self, additional: usize)

Reserve the scratch buffer capacity for reuse on the next call. This is a no-op if reserve_scratch is set to false.

pub(crate) fn scratch(&mut self) -> Vec<u8>

fn zstd_compressor(&mut self, level: i32) -> &mut Compressor<'static>

fn lz4_compressor(&mut self) -> &mut Lz4Compressor

Trait Implementations

impl Debug for IpcWriteContext

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

Formats the value using the given formatter.

impl Default for IpcWriteContext

fn default() -> Self

Returns the “default value” for a type.