Class: Liquidbook::PidManager

Inherits:
Object
  • Object
show all
Defined in:
lib/liquidbook/pid_manager.rb

Constant Summary collapse

PID_FILE_NAME = 
"server.pid"

Instance Method Summary collapse

Constructor Details

#initialize(theme_root:) ⇒ PidManager

Returns a new instance of PidManager.



7
8
9
 
# File 'lib/liquidbook/pid_manager.rb', line 7

def initialize(theme_root:)
  @theme_root = theme_root
end

Instance Method Details

#ensure_can_start! ⇒ Object

Check the current state and ensure it’s safe to start Returns :ok, :stale_pid_cleaned, or raises an error



48
49
50
51
52
53
54
55
56
57
58
 
# File 'lib/liquidbook/pid_manager.rb', line 48

def ensure_can_start!
  pid = read_pid
  return :ok if pid.nil?

  if process_alive?(pid)
    raise Error, "Server is already running (PID: #{pid}). Run `liquidbook stop` to stop it."
  end

  remove_pid
  :stale_pid_cleaned
end

#pid_file_path ⇒ Object 



11
12
13
 
# File 'lib/liquidbook/pid_manager.rb', line 11

def pid_file_path
  File.join(@theme_root, ".liquid-preview", PID_FILE_NAME)
end

#process_alive?(pid) ⇒ Boolean

Check if a process with the given PID is alive

Returns:

  • (Boolean) 


36
37
38
39
40
41
42
43
44
 
# File 'lib/liquidbook/pid_manager.rb', line 36

def process_alive?(pid)
  Process.kill(0, pid)
  true
rescue Errno::ESRCH
  false
rescue Errno::EPERM
  # Process exists but we don't have permission to signal it
  true
end

#read_pid ⇒ Object

Read the PID from the PID file, returns nil if not found



23
24
25
26
27
28
 
# File 'lib/liquidbook/pid_manager.rb', line 23

def read_pid
  return nil unless File.exist?(pid_file_path)

  pid = File.read(pid_file_path).strip.to_i
  pid.positive? ? pid : nil
end

#remove_pid ⇒ Object

Remove the PID file



31
32
33
 
# File 'lib/liquidbook/pid_manager.rb', line 31

def remove_pid
  File.delete(pid_file_path) if File.exist?(pid_file_path)
end

#stop! ⇒ Object

Stop the running server process Returns :stopped, :not_running, or :stale_pid_cleaned



62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
 
# File 'lib/liquidbook/pid_manager.rb', line 62

def stop!
  pid = read_pid

  if pid.nil?
    return :not_running
  end

  unless process_alive?(pid)
    remove_pid
    return :stale_pid_cleaned
  end

  Process.kill("TERM", pid)
  remove_pid
  :stopped
rescue Errno::EPERM
  raise Error, "Permission denied: cannot stop process (PID: #{pid})."
end

#write_pid ⇒ Object

Write the current process PID to the PID file



16
17
18
19
20
 
# File 'lib/liquidbook/pid_manager.rb', line 16

def write_pid
  dir = File.dirname(pid_file_path)
  FileUtils.mkdir_p(dir) unless File.directory?(dir)
  File.write(pid_file_path, Process.pid.to_s)
end