Results for: "Logger"

Fiber#blocking?

Returns true if fiber is blocking and false otherwise. Fiber is non-blocking if it was created via passing blocking: false to Fiber.new, or via Fiber.schedule.

Note that, even if the method returns false, the fiber behaves differently only if Fiber.scheduler is set in the current thread.

See the “Non-blocking fibers” section in class docs for details.

Fiber#storage

Returns a copy of the storage hash for the fiber. The method can only be called on the Fiber.current.

Fiber#storage=

Sets the storage hash for the fiber. This feature is experimental and may change in the future. The method can only be called on the Fiber.current.

You should be careful about using this method as you may inadvertently clear important fiber-storage state. You should mostly prefer to assign specific keys in the storage using Fiber::[]=.

You can also use Fiber.new(storage: nil) to create a fiber with an empty storage.

Example:

while request = request_queue.pop
  # Reset the per-request state:
  Fiber.current.storage = nil
  handle_request(request)
end

Fiber#transfer

Transfer control to another fiber, resuming it from where it last stopped or starting it if it was not resumed before. The calling fiber will be suspended much like in a call to Fiber.yield.

The fiber which receives the transfer call treats it much like a resume call. Arguments passed to transfer are treated like those passed to resume.

The two style of control passing to and from fiber (one is resume and Fiber::yield, another is transfer to and from fiber) can’t be freely mixed.

If those rules are broken FiberError is raised.

For an individual Fiber design, yield/resume is easier to use (the Fiber just gives away control, it doesn’t need to think about who the control is given to), while transfer is more flexible for complex cases, allowing to build arbitrary graphs of Fibers dependent on each other.

Example:

manager = nil # For local var to be visible inside worker block

# This fiber would be started with transfer
# It can't yield, and can't be resumed
worker = Fiber.new { |work|
  puts "Worker: starts"
  puts "Worker: Performed #{work.inspect}, transferring back"
  # Fiber.yield     # this would raise FiberError: attempt to yield on a not resumed fiber
  # manager.resume  # this would raise FiberError: attempt to resume a resumed fiber (double resume)
  manager.transfer(work.capitalize)
}

# This fiber would be started with resume
# It can yield or transfer, and can be transferred
# back or resumed
manager = Fiber.new {
  puts "Manager: starts"
  puts "Manager: transferring 'something' to worker"
  result = worker.transfer('something')
  puts "Manager: worker returned #{result.inspect}"
  # worker.resume    # this would raise FiberError: attempt to resume a transferring fiber
  Fiber.yield        # this is OK, the fiber transferred from and to, now it can yield
  puts "Manager: finished"
}

puts "Starting the manager"
manager.resume
puts "Resuming the manager"
# manager.transfer  # this would raise FiberError: attempt to transfer to a yielding fiber
manager.resume

produces

Starting the manager
Manager: starts
Manager: transferring 'something' to worker
Worker: starts
Worker: Performed "something", transferring back
Manager: worker returned "Something"
Resuming the manager
Manager: finished

Fiber::blocking?

Returns false if the current fiber is non-blocking. Fiber is non-blocking if it was created via passing blocking: false to Fiber.new, or via Fiber.schedule.

If the current Fiber is blocking, the method returns 1. Future developments may allow for situations where larger integers could be returned.

Note that, even if the method returns false, Fiber behaves differently only if Fiber.scheduler is set in the current thread.

See the “Non-blocking fibers” section in class docs for details.

Fiber::scheduler

Returns the Fiber scheduler, that was last set for the current thread with Fiber.set_scheduler. Returns nil if no scheduler is set (which is the default), and non-blocking fibers’ behavior is the same as blocking. (see “Non-blocking fibers” section in class docs for details about the scheduler concept).

Dir#close

Closes the stream in self, if it is open, and returns nil; ignored if self is already closed:

dir = Dir.new('example')
dir.read     # => "."
dir.close     # => nil
dir.close     # => nil
dir.read # Raises IOError.

Dir::getwd

Returns the path to the current working directory:

Dir.chdir("/tmp") # => 0
Dir.pwd           # => "/tmp"

Dir::glob

Forms an array entry_names of the entry names selected by the arguments.

Argument patterns is a string pattern or an array of string patterns; note that these are not regexps; see below.

Notes for the following examples:

With no block, returns array entry_names; example (using the simple file tree):

Dir.glob('*') # => ["config.h", "lib", "main.rb"]

With a block, calls the block with each of the entry_names and returns nil:

Dir.glob('*') {|entry_name| puts entry_name } # => nil

Output:

config.h
lib
main.rb

If optional keyword argument flags is given, the value modifies the matching; see below.

If optional keyword argument base is given, its value specifies the base directory. Each pattern string specifies entries relative to the base directory; the default is '.'. The base directory is not prepended to the entry names in the result:

Dir.glob(pattern, base: 'lib').take(5)
# => ["abbrev.gemspec", "abbrev.rb", "base64.gemspec", "base64.rb", "benchmark.gemspec"]
Dir.glob(pattern, base: 'lib/irb').take(5)
# => ["cmd", "color.rb", "color_printer.rb", "completion.rb", "context.rb"]

If optional keyword sort is given, its value specifies whether the array is to be sorted; the default is true. Passing value false with that keyword disables sorting (though the underlying file system may already have sorted the array).

Patterns

Each pattern string is expanded according to certain metacharacters; examples below use the Ruby file tree:

More examples (using the simple file tree):

# We're in the example directory.
File.basename(Dir.pwd) # => "example"
Dir.glob('config.?')              # => ["config.h"]
Dir.glob('*.[a-z][a-z]')          # => ["main.rb"]
Dir.glob('*.[^r]*')               # => ["config.h"]
Dir.glob('*.{rb,h}')              # => ["main.rb", "config.h"]
Dir.glob('*')                     # => ["config.h", "lib", "main.rb"]
Dir.glob('*', File::FNM_DOTMATCH) # => [".", "config.h", "lib", "main.rb"]
Dir.glob(["*.rb", "*.h"])         # => ["main.rb", "config.h"]

Dir.glob('**/*.rb')
=> ["lib/song/karaoke.rb", "lib/song.rb", "main.rb"]

Dir.glob('**/*.rb', base: 'lib')  #   => ["song/karaoke.rb", "song.rb"]

Dir.glob('**/lib')                # => ["lib"]

Dir.glob('**/lib/**/*.rb')        # => ["lib/song/karaoke.rb", "lib/song.rb"]

Dir.glob('**/lib/*.rb')           # => ["lib/song.rb"]

Flags

If optional keyword argument flags is given (the default is zero – no flags), its value should be the bitwise OR of one or more of the constants defined in module File::Constants.

Example:

flags = File::FNM_EXTGLOB | File::FNM_DOTMATCH

Specifying flags can extend, restrict, or otherwise modify the matching.

The flags for this method (other constants in File::Constants do not apply):

File#flock

Locks or unlocks file self according to the given locking_constant, a bitwise OR of the values in the table below.

Not available on all platforms.

Returns false if File::LOCK_NB is specified and the operation would have blocked; otherwise returns 0.

Constant Lock Effect
File::LOCK_EX Exclusive Only one process may hold an exclusive lock for self at a time.
File::LOCK_NB Non-blocking No blocking; may be combined with File::LOCK_SH or File::LOCK_EX using the bitwise OR operator |.
File::LOCK_SH Shared Multiple processes may each hold a shared lock for self at the same time.
File::LOCK_UN Unlock Remove an existing lock held by this process.

Example:

# Update a counter using an exclusive lock.
# Don't use File::WRONLY because it truncates the file.
File.open('counter', File::RDWR | File::CREAT, 0644) do |f|
  f.flock(File::LOCK_EX)
  value = f.read.to_i + 1
  f.rewind
  f.write("#{value}\n")
  f.flush
  f.truncate(f.pos)
end

# Read the counter using a shared lock.
File.open('counter', 'r') do |f|
  f.flock(File::LOCK_SH)
  f.read
end

File::zero?

Returns true if the named file exists and has a zero size.

file_name can be an IO object.

File::blockdev?

Returns true if filepath points to a block device, false otherwise:

File.blockdev?('/dev/sda1')       # => true
File.blockdev?(File.new('t.tmp')) # => false

Object#Digest

Returns a Digest subclass by name in a thread-safe manner even when on-demand loading is involved.

require 'digest'

Digest("MD5")
# => Digest::MD5

Digest(:SHA256)
# => Digest::SHA256

Digest(:Foo)
# => LoadError: library not found for class Digest::Foo -- digest/foo

Exception#message

Returns to_s.

See Messages.

KeyError#receiver

Return the receiver associated with this KeyError exception.

NameError#receiver

Return the receiver associated with this NameError exception.

FrozenError#receiver

Return the receiver associated with this FrozenError exception.

SystemCallError#errno

Return this SystemCallError’s error number.

Module#autoload 

Registers _filename_ to be loaded (using Kernel::require)
the first time that _const_ (which may be a String or
a symbol) is accessed in the namespace of _mod_.

   module A
   end
   A.autoload(:B, "b")
   A::B.doit            # autoloads "b"

If const in mod is defined as autoload, the file name to be loaded is replaced with filename. If const is defined but not as autoload, does nothing.

Module#autoload?

Returns filename to be loaded if name is registered as autoload in the namespace of mod or one of its ancestors.

module A
end
A.autoload(:B, "b")
A.autoload?(:B)            #=> "b"

If inherit is false, the lookup only checks the autoloads in the receiver:

class A
  autoload :CONST, "const.rb"
end

class B < A
end

B.autoload?(:CONST)          #=> "const.rb", found in A (ancestor)
B.autoload?(:CONST, false)   #=> nil, not found in B itself

CGI#header

This method is an alias for http_header, when HTML5 tag maker is inactive.

NOTE: use http_header to create HTTP header blocks, this alias is only provided for backwards compatibility.

Using header with the HTML5 tag maker will create a <header> element.

Date::commercial

Returns a new Date object constructed from the arguments.

Argument cwyear gives the year, and should be an integer.

Argument cweek gives the index of the week within the year, and should be in range (1..53) or (-53..-1); in some years, 53 or -53 will be out-of-range; if negative, counts backward from the end of the year:

Date.commercial(2022, 1, 1).to_s  # => "2022-01-03"
Date.commercial(2022, 52, 1).to_s # => "2022-12-26"

Argument cwday gives the indes of the weekday within the week, and should be in range (1..7) or (-7..-1); 1 or -7 is Monday; if negative, counts backward from the end of the week:

Date.commercial(2022, 1, 1).to_s  # => "2022-01-03"
Date.commercial(2022, 1, -7).to_s # => "2022-01-03"

When cweek is 1:

See argument start.

Related: Date.jd, Date.new, Date.ordinal.

DateTime::commercial

Creates a DateTime object denoting the given week date.

DateTime.commercial(2001) #=> #<DateTime: 2001-01-01T00:00:00+00:00 ...>
DateTime.commercial(2002) #=> #<DateTime: 2001-12-31T00:00:00+00:00 ...>
DateTime.commercial(2001,5,6,4,5,6,'+7')
                          #=> #<DateTime: 2001-02-03T04:05:06+07:00 ...>

Time::local

Like Time.utc, except that the returned Time object has the local timezone, not the UTC timezone:

# With seven arguments.
Time.local(0, 1, 2, 3, 4, 5, 6)
# => 0000-01-02 03:04:05.000006 -0600
# With exactly ten arguments.
Time.local(0, 1, 2, 3, 4, 5, 6, 7, 8, 9)
# => 0005-04-03 02:01:00 -0600

Time#localtime

With no argument given:

With argument zone given, returns the new Time object created by converting self to the given time zone:

t = Time.utc(2000, 1, 1, 20, 15, 1) # => 2000-01-01 20:15:01 UTC
t.localtime("-09:00")               # => 2000-01-01 11:15:01 -0900

For forms of argument zone, see Timezone Specifiers.

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