diff options
author | Eric Wong <normalperson@yhbt.net> | 2013-10-06 11:02:38 +0000 |
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committer | Eric Wong <normalperson@yhbt.net> | 2013-10-06 11:19:02 +0000 |
commit | 019543aa3a1074582a460b944ad5ebcddecd4394 (patch) | |
tree | bb24e015b373c5b9daca04e3497230058c8bcdf7 /lib | |
parent | b991345ff960229347b32eb1bfe9d7732441c19e (diff) | |
download | dtas-019543aa3a1074582a460b944ad5ebcddecd4394.tar.gz |
We do not need this for single sink situations (the common case) at all. We also do not need to check IO#nread for splice, either; we can just do non-blocking I/O. The only common path where we might still need it is the non-splice case with multiple sinks.
Diffstat (limited to 'lib')
-rw-r--r-- | lib/dtas/buffer.rb | 7 | ||||
-rw-r--r-- | lib/dtas/buffer/read_write.rb | 13 | ||||
-rw-r--r-- | lib/dtas/buffer/splice.rb | 21 |
3 files changed, 24 insertions, 17 deletions
diff --git a/lib/dtas/buffer.rb b/lib/dtas/buffer.rb index c9f096c..c0ba6a6 100644 --- a/lib/dtas/buffer.rb +++ b/lib/dtas/buffer.rb @@ -47,16 +47,13 @@ class DTAS::Buffer # :nodoc: # - some type of StandardError # - nil def broadcast(targets) - bytes = inflight - return :wait_readable if 0 == bytes # spurious wakeup - case targets.size when 0 :ignore # this will pause decoders when 1 - broadcast_one(targets, bytes) + broadcast_one(targets) else # infinity - broadcast_inf(targets, bytes) + broadcast_inf(targets) end end diff --git a/lib/dtas/buffer/read_write.rb b/lib/dtas/buffer/read_write.rb index 0044400..11d1a95 100644 --- a/lib/dtas/buffer/read_write.rb +++ b/lib/dtas/buffer/read_write.rb @@ -17,25 +17,30 @@ module DTAS::Buffer::ReadWrite # :nodoc: def discard(bytes) buf = _rbuf begin - @to_io.read(bytes, buf) or break # EOF + @to_io.readpartial(bytes, buf) bytes -= buf.bytesize + rescue EOFError + return end until bytes == 0 end # always block when we have a single target - def broadcast_one(targets, bytes) + def broadcast_one(targets) buf = _rbuf - @to_io.read(bytes, buf) + @to_io.readpartial(MAX_AT_ONCE, buf) n = targets[0].write(buf) # IO#write has write-in-full behavior @bytes_xfer += n :wait_readable + rescue EOFError + nil rescue Errno::EPIPE, IOError => e __dst_error(targets[0], e) targets.clear nil # do not return error here, we already spewed an error message end - def broadcast_inf(targets, bytes) + def broadcast_inf(targets) + bytes = inflight nr_nb = targets.count { |sink| sink.nonblock? } if nr_nb == 0 || nr_nb == targets.size # if all targets are full, don't start until they're all writable diff --git a/lib/dtas/buffer/splice.rb b/lib/dtas/buffer/splice.rb index 18dfd82..90c2e47 100644 --- a/lib/dtas/buffer/splice.rb +++ b/lib/dtas/buffer/splice.rb @@ -8,6 +8,7 @@ require_relative '../pipe' module DTAS::Buffer::Splice # :nodoc: MAX_AT_ONCE = 4096 # page size in Linux + MAX_AT_ONCE_1 = 65536 MAX_SIZE = File.read("/proc/sys/fs/pipe-max-size").to_i DEVNULL = File.open("/dev/null", "r+") F_MOVE = IO::Splice::F_MOVE @@ -28,9 +29,9 @@ module DTAS::Buffer::Splice # :nodoc: IO.splice(@to_io, nil, DEVNULL, nil, bytes) end - def broadcast_one(targets, bytes) + def broadcast_one(targets) # single output is always non-blocking - s = IO.trysplice(@to_io, nil, targets[0], nil, bytes, F_MOVE) + s = IO.trysplice(@to_io, nil, targets[0], nil, MAX_AT_ONCE_1, F_MOVE) if Symbol === s targets # our one and only target blocked on write else @@ -48,11 +49,14 @@ module DTAS::Buffer::Splice # :nodoc: most_teed = 0 targets.delete_if do |dst| begin - t = dst.nonblock? ? + t = (dst.nonblock? || most_teed == 0) ? IO.trytee(@to_io, dst, chunk_size) : IO.tee(@to_io, dst, chunk_size, WAITALL) if Integer === t - most_teed = t if t > most_teed + if t > most_teed + chunk_size = t if most_teed == 0 + most_teed = t + end else blocked << dst end @@ -65,7 +69,7 @@ module DTAS::Buffer::Splice # :nodoc: most_teed end - def broadcast_inf(targets, bytes) + def broadcast_inf(targets) if targets.none? { |sink| sink.nonblock? } # if all targets are blocking, don't start until they're all writable r = IO.select(nil, targets, nil, 0) or return targets @@ -80,9 +84,10 @@ module DTAS::Buffer::Splice # :nodoc: end # don't pin too much on one target - bytes = bytes > MAX_AT_ONCE ? MAX_AT_ONCE : bytes - + bytes = MAX_AT_ONCE last = targets.pop # we splice to the last one, tee to the rest + + # this may return zero if all targets were non-blocking most_teed = __broadcast_tee(blocked, targets, bytes) # don't splice more than the largest amount we successfully teed @@ -90,7 +95,7 @@ module DTAS::Buffer::Splice # :nodoc: begin targets << last - if last.nonblock? + if last.nonblock? || most_teed == 0 s = IO.trysplice(@to_io, nil, last, nil, bytes, F_MOVE) if Symbol === s blocked << last |