1 # -*- encoding: binary -*-
2 require 'io_splice_ext'
7 # The maximum default capacity of the pipe in bytes.
8 # Under stock Linux, this is 65536 bytes as of 2.6.11, and 4096 before
9 # We detect this at runtime as it is easy to recompile the kernel
10 # and set a new value.
11 # Starting with Linux 2.6.35, pipe capacity will be tunable
12 # and this will only represent the default capacity of a
19 n += wr.write_nonblock(buf)
28 # copies the contents of the IO object given by +src+ to +dst+
29 # If +len+ is specified, then only +len+ bytes are copied and
30 # +EOFError+ is raised if fewer than +len+ bytes could be copied.
31 # Otherwise the copy will be until EOF is reached on the +src+.
32 # +src+ and +dst+ must be IO objects or respond to +to_io+
34 # This is nearly a drop-in replacement for IO.copy_stream (in Ruby 1.9)
35 # but does not take into account userspace I/O buffers nor IO-like
36 # objects with no underlying file descriptor (e.g. StringIO).
37 def self.copy_stream(src, dst, len = nil, src_offset = nil)
39 src.kind_of?(String) and close << (src = File.open(src))
40 dst.kind_of?(String) and close << (dst = File.open(dst, "w"))
41 src, dst = src.to_io, dst.to_io
44 if src.stat.pipe? || dst.stat.pipe?
46 len -= full(src, dst, len, src_offset) until len == 0
49 while n = partial(src, dst, PIPE_CAPA, src_offset)
51 src_offset += n if src_offset
58 while len != 0 && n = partial(src, w, len, src_offset)
59 src_offset += n if src_offset
60 len -= full(r, dst, n, nil)
64 while n = partial(src, w, PIPE_CAPA, src_offset)
65 src_offset += n if src_offset
66 rv += full(r, dst, n, nil)
73 close.each { |io| io.close }
76 # splice the full amount specified from +src+ to +dst+
77 # Either +dst+ or +src+ must be a pipe. +dst+ and +src+
78 # may BOTH be pipes in Linux 2.6.31 or later.
79 # This will block and wait for IO completion of +len+
80 # Raises +EOFError+ if end of file is reached.
81 # bytes. Returns the number of bytes actually spliced (always +len+)
82 def self.full(src, dst, len, src_offset)
83 IO.splice(src, src_offset, dst, nil, len, F_MOVE | WAITALL)
86 # splice up to +len+ bytes from +src+ to +dst+.
87 # Either +dst+ or +src+ must be a pipe. +dst+ and +src+
88 # may BOTH be pipes in Linux 2.6.31 or later.
89 # Returns the number of bytes actually spliced.
90 # Like IO#readpartial, this never returns Errno::EAGAIN
91 def self.partial(src, dst, len, src_offset)
92 IO.splice(src, src_offset, dst, nil, len, F_MOVE)
99 rv = IO.trysplice(src, src_offset, dst, nil, len, F_MOVE)
100 end while rv == :EAGAIN