`class UNIXEndpoint`

This class doesn't exert ownership over the specified unix socket and ensures exclusive access by using flock where possible.

Definitions

`def self.short_path_for(path)`

Compute a stable temporary UNIX socket path for an overlong path.

Signature

parameter　path　String: The original (possibly overlong) path.
returns　String: A short, stable path suitable for Address.unix.

Implementation

def self.short_path_for(path)
	# We need to ensure the path is absolute and canonical, otherwise the SHA1 hash will not be consistent:
	path = File.expand_path(path)
	
	# We then use the SHA1 hash of the path to create a short, stable path:
	File.join(Dir.tmpdir, Digest::SHA1.hexdigest(path) + ".ipc")
end

`def initialize(path, type = Socket::SOCK_STREAM, **options)`

Initialize a new UNIX domain socket endpoint.

Signature

parameter　path　String: The path to the UNIX socket.
parameter　type　Integer: The socket type (defaults to Socket::SOCK_STREAM).
parameter　options　Hash: Additional options to pass to the parent class.

Implementation

def initialize(path, type = Socket::SOCK_STREAM, **options)
	@path = path
	
	begin
		address = Address.unix(path, type)
	rescue ArgumentError
		path = self.class.short_path_for(path)
		address = Address.unix(path, type)
	end
	
	super(address, **options)
end

`def to_s`

Get a string representation of the UNIX endpoint.

Signature

returns　String: A string representation showing the socket path.

Implementation

def to_s
	"unix:#{@path}"
end

`def inspect`

Get a detailed string representation of the UNIX endpoint.

Signature

returns　String: A detailed string representation including the path.

Implementation

def inspect
	target_path = @address.unix_path
	
	if @path == target_path
		"\#<#{self.class} path=#{@path.inspect}>"
	else
		"\#<#{self.class} path=#{@path.inspect} target=#{target_path.inspect}>"
	end
end

`def path`

Signature

attribute　String: The path to the UNIX socket.

Implementation

def path
	@path
end

`def symlink?`

Check if a symlink is used for this endpoint.

A symlink is created when the original path exceeds the system's maximum UNIX socket path length and a shorter temporary path is used for the actual socket.

Signature

returns　Boolean: True if the original path differs from the socket path, indicating a symlink is required.

Implementation

def symlink?
	File.symlink?(@path)
end

`def bound?`

Check if the socket is currently bound and accepting connections.

Signature

returns　Boolean: True if the socket is bound and accepting connections, false otherwise.

Implementation

def bound?
	self.connect do
		return true
	end
rescue Errno::ECONNREFUSED
	return false
rescue Errno::ENOENT
	return false
end

`def bind(...)`

Bind the UNIX socket, handling stale socket files.

Signature

yields　{|socket| ...}

If a block is given, yields the bound socket.

parameter　socket　Socket: The bound socket.

returns　Array(Socket)

The bound socket.

raises　Errno::EADDRINUSE

If the socket is still in use by another process.

Implementation

def bind(...)
	result = super
	create_symlink_if_required!
	return result
rescue Errno::EADDRINUSE
	# If you encounter EADDRINUSE from `bind()`, you can check if the socket is actually accepting connections by attempting to `connect()` to it. If the socket is still bound by an active process, the connection will succeed. Otherwise, it should be safe to `unlink()` the path and try again.
	if !bound?
		unlink_stale_paths!
		retry
	else
		raise
	end
end