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Class: Kward::PersistentShellSession

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

Overview

Owns one interactive shell process and serializes user and agent commands.

The process is kept alive between commands so shell variables, functions, aliases, directory changes, and child-shell state belong to one session.

Defined Under Namespace

Classes: CommandInterrupted, InteractiveResult

Constant Summary collapse

Result = 
Kwsh::Result
READ_SIZE = 
4_096
STARTUP_TIMEOUT_SECONDS = 
5
STTY_COMMAND = 
if File.executable?("/bin/stty")
  "/bin/stty"
elsif File.executable?("/usr/bin/stty")
  "/usr/bin/stty"
else
  "stty"
end.freeze
STATEFUL_COMMANDS = 
%w[alias cd export pwd unset unalias].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(cwd: Dir.pwd, env: ENV.to_h, shell: Kwsh::DEFAULT_SHELL, configured_env: {}, aliases: {}, timeout_seconds: Kwsh::DEFAULT_TIMEOUT_SECONDS, max_output_bytes: Kwsh::DEFAULT_MAX_OUTPUT_BYTES, window_size_provider: nil) ⇒ PersistentShellSession

Returns a new instance of PersistentShellSession.



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# File 'lib/kward/shell/persistent_session.rb', line 43

def initialize(cwd: Dir.pwd, env: ENV.to_h, shell: Kwsh::DEFAULT_SHELL, configured_env: {}, aliases: {}, timeout_seconds: Kwsh::DEFAULT_TIMEOUT_SECONDS, max_output_bytes: Kwsh::DEFAULT_MAX_OUTPUT_BYTES, window_size_provider: nil)
  @cwd = File.expand_path(cwd.to_s.empty? ? Dir.pwd : cwd.to_s)
  @base_env = env.to_h.transform_keys(&:to_s).transform_values(&:to_s)
  @configured_env = configured_env.to_h.transform_keys(&:to_s).transform_values(&:to_s)
  @aliases = aliases.to_h.transform_keys(&:to_s).transform_values(&:to_s)
  @shell = shell.to_s.empty? ? Kwsh::DEFAULT_SHELL : shell.to_s
  @timeout_seconds = timeout_seconds.to_i.positive? ? timeout_seconds.to_i : Kwsh::DEFAULT_TIMEOUT_SECONDS
  @max_output_bytes = max_output_bytes.to_i.positive? ? max_output_bytes.to_i : Kwsh::DEFAULT_MAX_OUTPUT_BYTES
  @window_size_provider = window_size_provider
  @last_command = nil
  @last_result = nil
  @command_mutex = Mutex.new
  @write_mutex = Mutex.new
  @marker_counter = 0
  @marker_prefix = "__KWARD_SHELL_#{SecureRandom.hex(16)}_"
  @closed = false
  @routing_shell = build_routing_shell
  @env = @routing_shell.child_env

  start_process
  initialize_protocol
rescue StandardError
  close
  raise
end

Instance Attribute Details

#cwd ⇒ Object (readonly)

Returns the value of attribute cwd.



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# File 'lib/kward/shell/persistent_session.rb', line 41

def cwd
  @cwd
end

#last_command ⇒ Object (readonly)

Returns the value of attribute last_command.



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# File 'lib/kward/shell/persistent_session.rb', line 41

def last_command
  @last_command
end

#timeout_seconds ⇒ Object (readonly)

Returns the value of attribute timeout_seconds.



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# File 'lib/kward/shell/persistent_session.rb', line 41

def timeout_seconds
  @timeout_seconds
end

Instance Method Details

#child_env(interactive: false) ⇒ Object 



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# File 'lib/kward/shell/persistent_session.rb', line 73

def child_env(interactive: false)
  @env.dup
end

#close ⇒ Object 



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# File 'lib/kward/shell/persistent_session.rb', line 180

def close
  return if @closed

  @closed = true
  begin
    terminate_process_group(@pid) if @pid
  ensure
    @write_mutex.synchronize do
      @reader&.close unless @reader&.closed?
      @writer&.close unless @writer&.closed?
    end
    @process_thread&.join(0.5)
    @process_thread&.kill if @process_thread&.alive?
    @pid = nil
  end
rescue StandardError
  nil
end

#command_shell ⇒ Object 



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# File 'lib/kward/shell/persistent_session.rb', line 69

def command_shell
  @shell
end

#complete(input, cursor) ⇒ Object 



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# File 'lib/kward/shell/persistent_session.rb', line 168

def complete(input, cursor)
  completion_shell.complete(input, cursor)
end

#context_snapshot(max_output_bytes: Kwsh::CONTEXT_OUTPUT_BYTES) ⇒ Object

Returns bounded shell state for an explicit shell-agent prompt.



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# File 'lib/kward/shell/persistent_session.rb', line 159

def context_snapshot(max_output_bytes: Kwsh::CONTEXT_OUTPUT_BYTES)
  {
    cwd: @cwd,
    last_command: @last_command,
    exit_status: @last_result&.exit_status,
    last_output: context_output(@last_result&.output, max_output_bytes)
  }
end

#editor_command_result(command, display_command: command) ⇒ Object 



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# File 'lib/kward/shell/persistent_session.rb', line 176

def editor_command_result(command, display_command: command)
  @routing_shell.editor_command_result(command, display_command: display_command)
end

#expand_alias(command, interactive: false) ⇒ Object 



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# File 'lib/kward/shell/persistent_session.rb', line 172

def expand_alias(command, interactive: false)
  @routing_shell.expand_alias(command, interactive: interactive)
end

#prompt_label ⇒ Object 



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# File 'lib/kward/shell/persistent_session.rb', line 77

def prompt_label
  "Shell #{display_cwd} $"
end

#record_interactive_result(output:, exit_status:) ⇒ Object

Records the safe output captured after an interactive terminal handoff.



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# File 'lib/kward/shell/persistent_session.rb', line 152

def record_interactive_result(output:, exit_status:)
  return unless @last_command

  @last_result = Result.new(output: ANSI.sanitize_transcript(output.to_s), exit_status: exit_status)
end

#run(input, cancellation: nil, &block) ⇒ Object 



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# File 'lib/kward/shell/persistent_session.rb', line 81

def run(input, cancellation: nil, &block)
  command = input.to_s.strip
  return Result.new(output: "", exit_status: 0) if command.empty?

  expanded_command = expand_alias(command)
  words = shell_words(expanded_command)
  sync_runtime_state(words)
  result = if words.empty?
    Result.new(output: "", exit_status: 0)
  elsif words.first == "clear"
    Result.new(output: "", exit_status: 0, clear: true)
  elsif %w[exit logout].include?(words.first)
    exit_result(command, words)
  elsif words.first == "capture"
    capture_result(command, expanded_command, cancellation: cancellation, &block)
  elsif words.first == "pty"
    interactive_result(command, expanded_command)
  elsif %w[source .].include?(words.first)
    source_result(command, words)
  elsif (editor_result = editor_command_result(command))
    editor_result
  elsif stateful_command?(words)
    execute_command(expanded_command, display_command: command, cancellation: cancellation, &block)
  else
    Result.new(output: command_echo(command), exit_status: 0, interactive_command: expanded_command)
  end
  remember_result(command, result)
  result
rescue ArgumentError => e
  result = Result.new(output: "#{command_echo(command)}kwsh: #{e.message}\n", exit_status: 2)
  remember_result(command, result)
  result
end

#run_for_agent(input, timeout_seconds: nil, cancellation: nil) ⇒ Object

Runs a command for the shell assistant without handing it the terminal.



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# File 'lib/kward/shell/persistent_session.rb', line 116

def run_for_agent(input, timeout_seconds: nil, cancellation: nil)
  command = input.to_s.strip
  return run(command, cancellation: cancellation) if command.empty?

  result = run(command, cancellation: cancellation)
  return result unless result.interactive_command

  result = execute_command(
    result.interactive_command,
    display_command: command,
    timeout_seconds: timeout_seconds,
    cancellation: cancellation,
    suppress_git_pager: true
  )
  remember_result(command, result)
  result
end

#run_interactive(command, input:, sink:, tab_action_handler: nil, on_detach: nil) ⇒ Object

Runs an external command through the same persistent shell process while the caller owns the terminal.



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# File 'lib/kward/shell/persistent_session.rb', line 136

def run_interactive(command, input:, sink:, tab_action_handler: nil, on_detach: nil)
  protocol = with_raw_input(input) do
    execute_protocol(command, input: input, sink: sink, tab_action_handler: tab_action_handler, on_detach: on_detach)
  end
  update_cwd(protocol[:cwd]) unless protocol[:background]
  InteractiveResult.new(
    exit_status: protocol[:status] || 1,
    input_forwarded: protocol[:input_forwarded],
    tab_action: protocol[:tab_action],
    background: protocol[:background]
  )
ensure
  sink.finish if sink.respond_to?(:finish)
end