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Create the future argument of tar_resources() to specify optional high-performance computing settings for tar_make_future(). This is how to supply the resources argument of future::future() for targets. Resources supplied through future::plan() and future::tweak() are completely ignored. For details, see the documentation of the future R package and the corresponding argument names in this help file.

Usage

tar_resources_future(
  plan = NULL,
  resources = targets::tar_option_get("resources")$future$resources
)

Arguments

plan

A future::plan() object or NULL, a target-specific future plan. Defaults to NULL.

resources

Named list, resources argument to future::future(). This argument is not supported in some versions of future. For versions of future where resources is not supported, instead supply resources to future::tweak() and assign the returned plan to the plan argument of tar_resources_future(). The default value of resources in tar_resources_future() is an empty list.

Value

Object of class "tar_resources_future", to be supplied to the future argument of tar_resources().

Resources

Functions tar_target() and tar_option_set() each takes an optional resources argument to supply non-default settings of various optional backends for data storage and high-performance computing. The tar_resources() function is a helper to supply those settings in the correct manner.

In targets version 0.12.2 and above, resources are inherited one-by-one in nested fashion from tar_option_get("resources"). For example, suppose you set tar_option_set(resources = tar_resources(aws = my_aws)), where my_aws equals tar_resources_aws(bucket = "x", prefix = "y"). Then, tar_target(data, get_data() will have bucket "x" and prefix "y". In addition, if new_resources equals tar_resources(aws = tar_resources_aws(bucket = "z"))), then tar_target(data, get_data(), resources = new_resources) will use the new bucket "z", but it will still use the prefix "y" supplied through tar_option_set(). (In targets 0.12.1 and below, options like prefix do not carry over from tar_option_set() if you supply non-default resources to tar_target().)

Examples

# Somewhere in you target script file (usually _targets.R):
tar_target(
  name,
  command(),
  resources = tar_resources(
    future = tar_resources_future(resources = list(n_cores = 2))
  )
)
#> <tar_stem> 
#>   name: name 
#>   description:  
#>   command:
#>     command() 
#>   format: rds 
#>   repository: local 
#>   iteration method: vector 
#>   error mode: stop 
#>   memory mode: persistent 
#>   storage mode: main 
#>   retrieval mode: main 
#>   deployment mode: worker 
#>   priority: 0 
#>   resources:
#>     future: <environment> 
#>   cue:
#>     mode: thorough
#>     command: TRUE
#>     depend: TRUE
#>     format: TRUE
#>     repository: TRUE
#>     iteration: TRUE
#>     file: TRUE
#>     seed: TRUE 
#>   packages:
#>     targets
#>     stats
#>     graphics
#>     grDevices
#>     utils
#>     datasets
#>     methods
#>     base 
#>   library:
#>     NULL