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Shared-memory writer for streaming collect()

Source: R/delarr-shard.R
shard_writer.Rd

Creates a writer object backed by shard::buffer() conforming to delarr's writer protocol. Pass to collect(x, into = shard_writer(...)) to stream results into shared memory.

Usage

shard_writer(nrow, ncol, backing = "auto")

Arguments

nrow, ncol

Dimensions of the output matrix.

backing

Backing type passed to shard::buffer().

Value

A writer list with $write(), $finalize(), $result(), and $close() methods.

Note

This writer supports 2D matrices only. N-d array collection does not currently support writer-style into targets.

Examples

if (requireNamespace("shard", quietly = TRUE)) {
  mat <- matrix(rnorm(20), 4, 5)
  darr <- delarr(mat)
  w <- shard_writer(4, 5)
  collect(darr |> d_map(~ .x * 2), into = w)
  w$result()
  w$close()
}