Class: Yahns::WbufLite

Inherits:
Object
  • Object
show all
Includes:
WbufCommon
Defined in:
lib/yahns/wbuf_lite.rb

Overview

This is only used for “proxy_buffering: false”

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from WbufCommon

#wbuf_close_common

Constructor Details

#initialize(req_res) ⇒ WbufLite

Returns a new instance of WbufLite.



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# File 'lib/yahns/wbuf_lite.rb', line 14

def initialize(req_res)
  @tmpio = nil
  @sf_offset = @sf_count = 0
  @wbuf_persist = :ignore
  @busy = false
  @req_res = req_res
end

Instance Attribute Details

#busy ⇒ Object (readonly)

Returns the value of attribute busy.



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# File 'lib/yahns/wbuf_lite.rb', line 11

def busy
  @busy
end

#req_res=(value) ⇒ Object (writeonly)

Sets the attribute req_res

Parameters:

  • value —

    the value to set the attribute req_res to.



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# File 'lib/yahns/wbuf_lite.rb', line 12

def req_res=(value)
  @req_res = value
end

Instance Method Details

#wbuf_abort ⇒ Object 



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# File 'lib/yahns/wbuf_lite.rb', line 104

def wbuf_abort
  @sf_offset = @sf_count = 0
  # we can safely truncate since this is a StringIO, we cannot do this
  # with a real file because zero-copy with sendfile means truncating
  # a while could clobber in-flight data
  @tmpio.truncate(0)
end

#wbuf_close(client) ⇒ Object

called by Yahns::HttpClient#step_write



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# File 'lib/yahns/wbuf_lite.rb', line 84

def wbuf_close(client)
  wbuf_abort if @tmpio

  # resume the event loop when @blocked is empty
  # The actual Yahns::ReqRes#yahns_step is actually read/write-event
  # agnostic, and we should actually watch for writability here since
  # the req_res socket itself could be completely drained of readable
  # data and just waiting for another request (which we don't support, yet)
  if @req_res
    @busy = false
    client.hijack_cleanup
    Thread.current[:yahns_queue].queue_mod(@req_res, Yahns::Queue::QEV_WR)
    return :ignore
  end
  @wbuf_persist
rescue
  @req_res = @req_res.close if @req_res
  raise
end

#wbuf_flush(client) ⇒ Object 



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# File 'lib/yahns/wbuf_lite.rb', line 63

def wbuf_flush(client)
  case rv = client.trysendio(@tmpio, @sf_offset, @sf_count)
  when Integer
    return wbuf_close(client) if (@sf_count -= rv) == 0 # all sent!
    @sf_offset += rv # keep going otherwise
  when :wait_writable, :wait_readable
    return rv
  else
    raise "BUG: #{rv.nil? ? 'EOF' : rv.inspect} on " \
          "tmpio.size=#{@tmpio.size} " \
          "sf_offset=#@sf_offset sf_count=#@sf_count"
  end while @sf_count > 0
  wbuf_close(client)
rescue
  @wbuf_persist = false # ensure a hijack response is not called
  @req_res = @req_res.close if @req_res
  wbuf_close(client)
  raise
end

#wbuf_write(c, buf) ⇒ Object 



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# File 'lib/yahns/wbuf_lite.rb', line 22

def wbuf_write(c, buf)
  buf = buf.join if Array === buf
  # try to bypass the VFS layer and write directly to the socket
  # if we're all caught up
  case rv = c.kgio_trywrite(buf)
  when String
    buf = rv # retry in loop
  when nil
    return # yay! hopefully we don't have to buffer again
  when :wait_writable, :wait_readable
    @busy = rv
  end until @busy

  @tmpio ||= StringIO.new(''.dup) # relies on encoding: binary above
  @tmpio.seek(0, 2) # fake O_APPEND behavior
  @sf_count += @tmpio.write(buf)

  # we spent some time copying to the FS, try to write to
  # the socket again in case some space opened up...
  case rv = c.trysendio(@tmpio, @sf_offset, @sf_count)
  when Integer
    @sf_count -= rv
    @sf_offset += rv
  when :wait_writable, :wait_readable
    @busy = rv
    return rv
  else
    raise "BUG: #{rv.nil? ? 'EOF' : rv.inspect} on " \
          "tmpio.size=#{@tmpio.size} " \
          "sf_offset=#@sf_offset sf_count=#@sf_count"
  end while @sf_count > 0

  # we're all caught up, try to save some memory if we can help it.
  wbuf_abort
  @busy = false
  nil
rescue
  @req_res = @req_res.close if @req_res
  raise
end