Struct WriteBatch 

pub struct WriteBatch<'db, K: StoreKey + Send, S: ParallelScheduler, const FAMILIES: usize> { /* private fields */ }

A write batch.

Implementations

impl<'db, K: StoreKey + Send + Sync, S: ParallelScheduler, const FAMILIES: usize> WriteBatch<'db, K, S, FAMILIES>

pub fn put(&self, family: u32, key: K, value: ValueBuffer<'_>) -> Result<()>

Puts a key-value pair into the write batch.

pub fn delete(&self, family: u32, key: K) -> Result<()>

Puts a delete operation into the write batch. This deletes all values for key.

Combining this with a WriteBatch::put of the same key in the same batch is not supported: which one wins is undefined, and callers are expected to resolve the intent themselves before writing.

pub fn delete_value( &self, family: u32, key: K, value: ValueBuffer<'_>, ) -> Result<()>

Deletes a single key-value pair, leaving any other values for key intact.

Only valid for FamilyKind::MultiValue families: in a SingleValue family a key has one value and WriteBatch::delete already removes it exactly.

Deleting a pair that is written in the same batch — by this or any other operation on the key — is not supported, for the reason given on WriteBatch::delete: which one wins is undefined, and it is the caller’s job to resolve that before writing.

Only values of at most MAX_INLINE_VALUE_SIZE bytes can be deleted this way. This is a simplifying limitation that could be relaxed if needed. Of course in general the storage overhead of deleting large values by value makes it apriori inefficient.

pub unsafe fn flush(&self, family: u32) -> Result<()>

Flushes a family of the write batch, reducing the amount of buffered memory used. Does not commit any data persistently.

Safety

Caller must ensure that no concurrent put or delete operation is happening on the flushed family.