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Class: Kward::LocalCommandRunner

Inherits:
Object
  • Object
show all
Defined in:
lib/kward/local_command_runner.rb

Overview

Low-level local process runner with bounded capture, timeout, cancellation, and optional output streaming. Callers own command semantics and formatting.

Defined Under Namespace

Classes: Result

Constant Summary collapse

READ_SIZE = 
4096

Instance Method Summary collapse

Constructor Details

#initialize(timeout_seconds:, max_output_bytes:, terminate_on_output_limit: false) ⇒ LocalCommandRunner

Returns a new instance of LocalCommandRunner.



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# File 'lib/kward/local_command_runner.rb', line 15

def initialize(timeout_seconds:, max_output_bytes:, terminate_on_output_limit: false)
  @timeout_seconds = timeout_seconds.to_i.positive? ? timeout_seconds.to_i : 30
  @max_output_bytes = max_output_bytes.to_i.positive? ? max_output_bytes.to_i : 128 * 1024
  @terminate_on_output_limit = terminate_on_output_limit
end

Instance Method Details

#run(*command, env: {}, cwd: Dir.pwd, cancellation: nil, &block) ⇒ Object 



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# File 'lib/kward/local_command_runner.rb', line 21

def run(*command, env: {}, cwd: Dir.pwd, cancellation: nil, &block)
  cancellation&.raise_if_cancelled!
  stdout_buffer = +""
  stderr_buffer = +""
  captured_bytes = 0
  truncated = false
  timed_out = false
  queue = Queue.new

  Open3.popen3(env.to_h, *command, chdir: cwd.to_s, pgroup: true) do |stdin, stdout, stderr, wait_thread|
    stdin.close
    readers = [
      read_stream(stdout, :stdout, queue),
      read_stream(stderr, :stderr, queue)
    ]
    cancellation&.on_cancel { terminate_process_group(wait_thread.pid) }

    status = wait_for_process(wait_thread, readers, queue, cancellation: cancellation) do |stream, chunk|
      captured_bytes, truncated, captured_chunk = capture_chunk(
        stream,
        chunk,
        stdout_buffer,
        stderr_buffer,
        captured_bytes,
        truncated
      )
      block&.call(stream, captured_chunk) unless captured_chunk.empty?
      terminate_process_group(wait_thread.pid) if truncated && @terminate_on_output_limit
    end

    join_readers(readers)
    drain_queue(queue) do |stream, chunk|
      captured_bytes, truncated, captured_chunk = capture_chunk(
        stream,
        chunk,
        stdout_buffer,
        stderr_buffer,
        captured_bytes,
        truncated
      )
      block&.call(stream, captured_chunk) unless captured_chunk.empty?
    end

    Result.new(stdout: stdout_buffer, stderr: stderr_buffer, exit_status: status.exitstatus || 1, timed_out: false, truncated: truncated)
  rescue Timeout::Error
    timed_out = true
    terminate_process_group(wait_thread.pid)
    join_readers(readers)
    Result.new(stdout: stdout_buffer, stderr: stderr_buffer, exit_status: nil, timed_out: timed_out, truncated: truncated)
  ensure
    readers&.each { |reader| reader.kill if reader&.alive? }
  end
end