Results for: "to_proc"

Setter for to v.

Stores value in database with key as the index. value is converted to YAML before being stored.

Returns value

Substitution of getopts is possible as follows. Also see OptionParser#getopts.

def getopts(*args)
  ($OPT = ARGV.getopts(*args)).each do |opt, val|
    eval "$OPT_#{opt.gsub(/[^A-Za-z0-9_]/, '_')} = val"
  end
rescue OptionParser::ParseError
end

The top-level program node.

Like Enumerable#drop, but chains operation to be lazy-evaluated.

Examples

# Automatically freeing the pointer when the block is exited - recommended
Fiddle::Pointer.malloc(size, Fiddle::RUBY_FREE) do |pointer|
  ...
end

# Manually freeing but relying on the garbage collector otherwise
pointer = Fiddle::Pointer.malloc(size, Fiddle::RUBY_FREE)
...
pointer.call_free

# Relying on the garbage collector - may lead to unlimited memory allocated before freeing any, but safe
pointer = Fiddle::Pointer.malloc(size, Fiddle::RUBY_FREE)
...

# Only manually freeing
pointer = Fiddle::Pointer.malloc(size)
begin
  ...
ensure
  Fiddle.free pointer
end

# No free function and no call to free - the native memory will leak if the pointer is garbage collected
pointer = Fiddle::Pointer.malloc(size)
...

Allocate size bytes of memory and associate it with an optional freefunc.

If a block is supplied, the pointer will be yielded to the block instead of being returned, and the return value of the block will be returned. A freefunc must be supplied if a block is.

If a freefunc is supplied it will be called once, when the pointer is garbage collected or when the block is left if a block is supplied or when the user calls call_free, whichever happens first. freefunc must be an address pointing to a function or an instance of Fiddle::Function.

Allocates a C struct with the types provided.

See Fiddle::Pointer.malloc for memory management issues.

Wakes up all threads waiting for this lock.

Performs a Miller-Rabin probabilistic primality test for bn.

checks parameter is deprecated in version 3.0. It has no effect.

Returns the broadcast address of ifaddr. nil is returned if the flags doesn’t have IFF_BROADCAST.

Same as IO.

Same as IO.

Returns the number of native file system blocks allocated for this file, or nil if the operating system doesn’t support this feature.

File.stat("testfile").blocks   #=> 2

Returns true if stat is a zero-length file; false otherwise.

File.stat("testfile").zero?   #=> false

Returns true if stat is a socket, false if it isn’t or if the operating system doesn’t support this feature.

File.stat("testfile").socket?   #=> false

Returns true if the file is a block device, false if it isn’t or if the operating system doesn’t support this feature.

File.stat("testfile").blockdev?    #=> false
File.stat("/dev/hda1").blockdev?   #=> true

If the buffer is locked, meaning it is inside locked block execution. Locked buffer can’t be resized or freed, and another lock can’t be acquired on it.

Locking is not thread safe, but is a semantic used to ensure buffers don’t move while being used by a system call.

buffer.locked do
  buffer.write(io) # theoretical system call interface
end

If the buffer is private, meaning modifications to the buffer will not be replicated to the underlying file mapping.

# Create a test file:
File.write('test.txt', 'test')

# Create a private mapping from the given file. Note that the file here
# is opened in read-only mode, but it doesn't matter due to the private
# mapping:
buffer = IO::Buffer.map(File.open('test.txt'), nil, 0, IO::Buffer::PRIVATE)
# => #<IO::Buffer 0x00007fce63f11000+4 MAPPED PRIVATE>

# Write to the buffer (invoking CoW of the underlying file buffer):
buffer.set_string('b', 0)
# => 1

# The file itself is not modified:
File.read('test.txt')
# => "test"

Allows to process a buffer in exclusive way, for concurrency-safety. While the block is performed, the buffer is considered locked, and no other code can enter the lock. Also, locked buffer can’t be changed with resize or free.

The following operations acquire a lock: resize, free.

Locking is not thread safe. It is designed as a safety net around non-blocking system calls. You can only share a buffer between threads with appropriate synchronisation techniques.

buffer = IO::Buffer.new(4)
buffer.locked? #=> false

Fiber.schedule do
  buffer.locked do
    buffer.write(io) # theoretical system call interface
  end
end

Fiber.schedule do
  # in `locked': Buffer already locked! (IO::Buffer::LockedError)
  buffer.locked do
    buffer.set_string("test", 0)
  end
end

Read at least length bytes from the io starting at the specified from position, into the buffer starting at offset. If an error occurs, return -errno.

If length is not given or nil, it defaults to the size of the buffer minus the offset, i.e. the entire buffer.

If length is zero, exactly one pread operation will occur.

If offset is not given, it defaults to zero, i.e. the beginning of the buffer.

IO::Buffer.for('test') do |buffer|
  p buffer
  # =>
  # <IO::Buffer 0x00007fca40087c38+4 SLICE>
  # 0x00000000  74 65 73 74         test

  # take 2 bytes from the beginning of urandom,
  # put them in buffer starting from position 2
  buffer.pread(File.open('/dev/urandom', 'rb'), 0, 2, 2)
  p buffer
  # =>
  # <IO::Buffer 0x00007f3bc65f2a58+4 EXTERNAL SLICE>
  # 0x00000000  05 35 73 74         te.5
end

Sends a LOCK request to the server; returns an instance of a subclass of Net::HTTPResponse.

The request is based on the Net::HTTP::Lock object created from string path, string body, and initial headers hash initheader.

data = '{"userId": 1, "id": 1, "title": "delectus aut autem", "completed": false}'
http = Net::HTTP.new(hostname)
http.lock('/todos/1', data)

Sends an UNLOCK request to the server; returns an instance of a subclass of Net::HTTPResponse.

The request is based on the Net::HTTP::Unlock object created from string path, string body, and initial headers hash initheader.

data = '{"userId": 1, "id": 1, "title": "delectus aut autem", "completed": false}'
http = Net::HTTP.new(hostname)
http.unlock('/todos/1', data)

Sends a LOCK request to the server; returns an instance of a subclass of Net::HTTPResponse.

The request is based on the Net::HTTP::Lock object created from string path, string body, and initial headers hash initheader.

data = '{"userId": 1, "id": 1, "title": "delectus aut autem", "completed": false}'
http = Net::HTTP.new(hostname)
http.lock('/todos/1', data)