ceph/src/jaegertracing/thrift/lib/lua/TFramedTransport.lua

   1 --
   2 -- Licensed to the Apache Software Foundation (ASF) under one
   3 -- or more contributor license agreements. See the NOTICE file
   4 -- distributed with this work for additional information
   5 -- regarding copyright ownership. The ASF licenses this file
   6 -- to you under the Apache License, Version 2.0 (the
   7 -- "License"); you may not use this file except in compliance
   8 -- with the License. You may obtain a copy of the License at
   9 --
  10 --   http://www.apache.org/licenses/LICENSE-2.0
  11 --
  12 -- Unless required by applicable law or agreed to in writing,
  13 -- software distributed under the License is distributed on an
  14 -- "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  15 -- KIND, either express or implied. See the License for the
  16 -- specific language governing permissions and limitations
  17 -- under the License.
  18 --
  19
  20 require 'TTransport'
  21 require 'libluabpack'
  22
  23 TFramedTransport = TTransportBase:new{
  24   __type = 'TFramedTransport',
  25   doRead = true,
  26   doWrite = true,
  27   wBuf = '',
  28   rBuf = ''
  29 }
  30
  31 function TFramedTransport:new(obj)
  32   if ttype(obj) ~= 'table' then
  33     error(ttype(self) .. 'must be initialized with a table')
  34   end
  35
  36   -- Ensure a transport is provided
  37   if not obj.trans then
  38     error('You must provide ' .. ttype(self) .. ' with a trans')
  39   end
  40
  41   return TTransportBase.new(self, obj)
  42 end
  43
  44 function TFramedTransport:isOpen()
  45   return self.trans:isOpen()
  46 end
  47
  48 function TFramedTransport:open()
  49   return self.trans:open()
  50 end
  51
  52 function TFramedTransport:close()
  53   return self.trans:close()
  54 end
  55
  56 function TFramedTransport:read(len)
  57   if string.len(self.rBuf) == 0 then
  58     self:__readFrame()
  59   end
  60
  61   if self.doRead == false then
  62     return self.trans:read(len)
  63   end
  64
  65   if len > string.len(self.rBuf) then
  66     local val = self.rBuf
  67     self.rBuf = ''
  68     return val
  69   end
  70
  71   local val = string.sub(self.rBuf, 0, len)
  72   self.rBuf = string.sub(self.rBuf, len+1)
  73   return val
  74 end
  75
  76 function TFramedTransport:__readFrame()
  77   local buf = self.trans:readAll(4)
  78   local frame_len = libluabpack.bunpack('i', buf)
  79   self.rBuf = self.trans:readAll(frame_len)
  80 end
  81
  82
  83 function TFramedTransport:write(buf, len)
  84   if self.doWrite == false then
  85     return self.trans:write(buf, len)
  86   end
  87
  88   if len and len < string.len(buf) then
  89     buf = string.sub(buf, 0, len)
  90   end
  91   self.wBuf = self.wBuf .. buf
  92 end
  93
  94 function TFramedTransport:flush()
  95   if self.doWrite == false then
  96     return self.trans:flush()
  97   end
  98
  99   -- If the write fails we still want wBuf to be clear
 100   local tmp = self.wBuf
 101   self.wBuf = ''
 102   local frame_len_buf = libluabpack.bpack("i", string.len(tmp))
 103   tmp = frame_len_buf .. tmp
 104   self.trans:write(tmp)
 105   self.trans:flush()
 106 end
 107
 108 TFramedTransportFactory = TTransportFactoryBase:new{
 109   __type = 'TFramedTransportFactory'
 110 }
 111 function TFramedTransportFactory:getTransport(trans)
 112   if not trans then
 113     terror(TProtocolException:new{
 114       message = 'Must supply a transport to ' .. ttype(self)
 115     })
 116   end
 117   return TFramedTransport:new{trans = trans}
 118 end