ceph/src/jaegertracing/thrift/lib/lua/TMemoryBuffer.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
  22 TMemoryBuffer = TTransportBase:new{
  23   __type = 'TMemoryBuffer',
  24   buffer = '',
  25   bufferSize = 1024,
  26   wPos = 0,
  27   rPos = 0
  28 }
  29 function TMemoryBuffer:isOpen()
  30   return 1
  31 end
  32 function TMemoryBuffer:open() end
  33 function TMemoryBuffer:close() end
  34
  35 function TMemoryBuffer:peak()
  36   return self.rPos < self.wPos
  37 end
  38
  39 function TMemoryBuffer:getBuffer()
  40   return self.buffer
  41 end
  42
  43 function TMemoryBuffer:resetBuffer(buf)
  44   if buf then
  45     self.buffer = buf
  46     self.bufferSize = string.len(buf)
  47   else
  48     self.buffer = ''
  49     self.bufferSize = 1024
  50   end
  51   self.wPos = string.len(buf)
  52   self.rPos = 0
  53 end
  54
  55 function TMemoryBuffer:available()
  56   return self.wPos - self.rPos
  57 end
  58
  59 function TMemoryBuffer:read(len)
  60   local avail = self:available()
  61   if avail == 0 then
  62     return ''
  63   end
  64
  65   if avail < len then
  66     len = avail
  67   end
  68
  69   local val = string.sub(self.buffer, self.rPos + 1, self.rPos + len)
  70   self.rPos = self.rPos + len
  71   return val
  72 end
  73
  74 function TMemoryBuffer:readAll(len)
  75   local avail = self:available()
  76
  77   if avail < len then
  78     local msg = string.format('Attempt to readAll(%d) found only %d available',
  79                               len, avail)
  80     terror(TTransportException:new{message = msg})
  81   end
  82   -- read should block so we don't need a loop here
  83   return self:read(len)
  84 end
  85
  86 function TMemoryBuffer:write(buf)
  87   self.buffer = self.buffer .. buf
  88   self.wPos = self.wPos + string.len(buf)
  89 end
  90
  91 function TMemoryBuffer:flush() end