Nagoya

A multithreading helper library for nushell.

The goal here is not to recreate tokio, but to create smaller-scale helpers like locking and message-channel systems.

numng package name: jan9103/nagoya.

Documentation

The documentation is formatted as usage-examples with additional information were needed.

Lock

A filebased lock, which can be shared across threads.

# import library
use nagoya/lock.nu *

# select a lockfile-path (`mktemp` + delete)
let lockfile: path = (create_lockfile)

# wait until the lock is released, and then lock it
await_lock $lockfile

do_something

# release the lock
unlock $lockfile

# await_lock, run the code, unlock
# but with handling for errors, etc
with_lock $lockfile {
  do_something
}

FGQ: Fifo Global Queue

A filebased cross-thread queue with locking.

# import library
use nagoya/fgq.nu

# create a fgq-que
let que: path = (fgq create)

fgq push $que {"name": "alice"}
fgq push_all $que [{"name": "bob"}, {"name": "eve"}, {"name": "mallory"}]

let value = (fgq pop $que)
if $value != null {  # "pop" returns null if the que is empty
  print $"Hello, ($value.name)!"
}

for value in (fgq pop_all $que) {
  print $"Hello, ($value.name)!"
}

# delete the que when we no longer need it
fgq delete $que

Mutex

A data-wrapper, which allows multiple threads to read-write access the same variable safely.

# import library
use nagoya/mutex.nu

# create a new mutex with a initial value
let mutex_variable = (mutex new "World")

# change the value
let name = (input "What is your name? ")
mutex set $mutex_variable $name

# change the value while blocking all other access to it between the read and write
mutex change $mutex_variable {|current_value| $current_value | str pascal-case}

# read the current value
print $"Hello, (mutex get $mutex_variable)!"

# clean up and delete the mutex
mutex delete $mutex_variable

Versions

changelog

Version system

scheme: major.minor.patch:

• patch: non-breaking changes
  • fixes for not working things
  • new features
• minor: breaking changes to the API
• major: rewrites, or similar drastic changes

recommended version to specify in numng: ~1.0.0