class Bakelite::SynchronizedIO

Overview

Thread-safe synchronized IO wrapper providing atomic seek-and-read operations for concurrent readers accessing the same container source.

Defined in:

bakelite/file_io.cr

Constructors

Instance Method Summary

Constructor Detail

def self.new(io : IO, mutex : Thread::Mutex = ::Thread::Mutex.new) #

Instance Method Detail

def close : Nil #
Description copied from class IO

Closes this IO.

IO defines this is a no-op method, but including types may override.


def closed? : Bool #
Description copied from class IO

Returns true if this IO is closed.

IO defines returns false, but including types may override.


def io : IO #

def mutex : Thread::Mutex #

def pos : Int64 #
Description copied from class IO

Returns the current position (in bytes) in this IO.

The IO class raises on this method, but some subclasses, notable IO::FileDescriptor and IO::Memory implement it.

File.write("testfile", "hello")

file = File.new("testfile")
file.pos     # => 0
file.gets(2) # => "he"
file.pos     # => 2

def read(slice : Bytes) : Int32 #
Description copied from class IO

Reads at most slice.size bytes from this IO into slice. Returns the number of bytes read, which is 0 if and only if there is no more data to read (so checking for 0 is the way to detect end of file).

io = IO::Memory.new "hello"
slice = Bytes.new(4)
io.read(slice) # => 4
slice          # => Bytes[104, 101, 108, 108]
io.read(slice) # => 1
slice          # => Bytes[111, 101, 108, 108]
io.read(slice) # => 0

def read_at(offset : Int64, slice : Bytes) : Nil #

Atomically seeks to offset and reads exact slice


def seek(offset : Int, whence : IO::Seek = IO::Seek::Set) : self #

def write(slice : Bytes) : Nil #
Description copied from class IO

Writes the contents of slice into this IO.

io = IO::Memory.new
slice = Bytes.new(4) { |i| ('a'.ord + i).to_u8 }
io.write(slice)
io.to_s # => "abcd"