libs/httpclient/luasrc/httpclient/receiver.lua

   1 --[[
   2 LuCI - Lua Development Framework
   3
   4 Copyright 2009 Steven Barth <steven@midlink.org>
   5
   6 Licensed under the Apache License, Version 2.0 (the "License");
   7 you may not use this file except in compliance with the License.
   8 You may obtain a copy of the License at
   9
  10         http://www.apache.org/licenses/LICENSE-2.0
  11
  12 $Id$
  13 ]]--
  14
  15 require "nixio.util"
  16 local nixio = require "nixio"
  17 local httpc = require "luci.httpclient"
  18 local ltn12 = require "luci.ltn12"
  19
  20 local print, tonumber, require, unpack = print, tonumber, require, unpack
  21
  22 module "luci.httpclient.receiver"
  23
  24 local function prepare_fd(target)
  25         -- Open fd for appending
  26         local oflags = nixio.open_flags("wronly", "creat")
  27         local file, code, msg = nixio.open(target, oflags)
  28         if not file then
  29                 return file, code, msg
  30         end
  31
  32         -- Acquire lock
  33         local stat, code, msg = file:lock("tlock")
  34         if not stat then
  35                 return stat, code, msg
  36         end
  37
  38         file:seek(0, "end")
  39
  40         return file
  41 end
  42
  43 local function splice_async(sock, pipeout, pipein, file, cb)
  44         local ssize = 65536
  45         local smode = nixio.splice_flags("move", "more", "nonblock")
  46
  47         -- Set pipe non-blocking otherwise we might end in a deadlock
  48         local stat, code, msg = pipein:setblocking(false)
  49         if stat then
  50                 stat, code, msg = pipeout:setblocking(false)
  51         end
  52         if not stat then
  53                 return stat, code, msg
  54         end
  55
  56
  57         local pollsock = {
  58                 {fd=sock, events=nixio.poll_flags("in")}
  59         }
  60
  61         local pollfile = {
  62                 {fd=file, events=nixio.poll_flags("out")}
  63         }
  64
  65         local done
  66         local active -- Older splice implementations sometimes don't detect EOS
  67
  68         repeat
  69                 active = false
  70
  71                 -- Socket -> Pipe
  72                 repeat
  73                         nixio.poll(pollsock, 15000)
  74
  75                         stat, code, msg = nixio.splice(sock, pipeout, ssize, smode)
  76                         if stat == nil then
  77                                 return stat, code, msg
  78                         elseif stat == 0 then
  79                                 done = true
  80                                 break
  81                         elseif stat then
  82                                 active = true
  83                         end
  84                 until stat == false
  85
  86                 -- Pipe -> File
  87                 repeat
  88                         nixio.poll(pollfile, 15000)
  89
  90                         stat, code, msg = nixio.splice(pipein, file, ssize, smode)
  91                         if stat == nil then
  92                                 return stat, code, msg
  93                         elseif stat then
  94                                 active = true
  95                         end
  96                 until stat == false
  97
  98                 if cb then
  99                         cb(file)
 100                 end
 101
 102                 if not active then
 103                         -- We did not splice any data, maybe EOS, fallback to default
 104                         return false
 105                 end
 106         until done
 107
 108         pipein:close()
 109         pipeout:close()
 110         sock:close()
 111         file:close()
 112         return true
 113 end
 114
 115 local function splice_sync(sock, pipeout, pipein, file, cb)
 116         local os = require "os"
 117         local ssize = 65536
 118         local smode = nixio.splice_flags("move", "more")
 119         local stat
 120
 121         -- This is probably the only forking http-client ;-)
 122         local pid, code, msg = nixio.fork()
 123         if not pid then
 124                 return pid, code, msg
 125         elseif pid == 0 then
 126                 pipein:close()
 127                 file:close()
 128
 129                 repeat
 130                         stat, code = nixio.splice(sock, pipeout, ssize, smode)
 131                 until not stat or stat == 0
 132
 133                 pipeout:close()
 134                 sock:close()
 135                 os.exit(stat or code)
 136         else
 137                 pipeout:close()
 138                 sock:close()
 139
 140                 repeat
 141                         stat, code, msg = nixio.splice(pipein, file, ssize, smode)
 142                         if cb then
 143                                 cb(file)
 144                         end
 145                 until not stat or stat == 0
 146
 147                 pipein:close()
 148                 file:close()
 149
 150                 if not stat then
 151                         nixio.kill(pid, 15)
 152                         nixio.wait(pid)
 153                         return stat, code, msg
 154                 else
 155                         pid, msg, code = nixio.wait(pid)
 156                         if msg == "exited" then
 157                                 if code == 0 then
 158                                         return true
 159                                 else
 160                                         return nil, code, nixio.strerror(code)
 161                                 end
 162                         else
 163                                 return nil, -0x11, "broken pump"
 164                         end
 165                 end
 166         end
 167 end
 168
 169 function request_to_file(uri, target, options, cbs)
 170         options = options or {}
 171         cbs = cbs or {}
 172         options.headers = options.headers or {}
 173         local hdr = options.headers
 174         local file, code, msg
 175
 176         if target then
 177                 file, code, msg = prepare_fd(target)
 178                 if not file then
 179                         return file, code, msg
 180                 end
 181
 182                 local off = file:tell()
 183
 184                 -- Set content range
 185                 if off > 0 then
 186                         hdr.Range = hdr.Range or ("bytes=" .. off .. "-")
 187                 end
 188         end
 189
 190         local code, resp, buffer, sock = httpc.request_raw(uri, options)
 191         if not code then
 192                 -- No success
 193                 if file then
 194                         file:close()
 195                 end
 196                 return code, resp, buffer
 197         elseif hdr.Range and code ~= 206 then
 198                 -- We wanted a part but we got the while file
 199                 sock:close()
 200                 if file then
 201                         file:close()
 202                 end
 203                 return nil, -4, code, resp
 204         elseif not hdr.Range and code ~= 200 then
 205                 -- We encountered an error
 206                 sock:close()
 207                 if file then
 208                         file:close()
 209                 end
 210                 return nil, -4, code, resp
 211         end
 212
 213         if cbs.on_header then
 214                 local stat = {cbs.on_header(file, code, resp)}
 215                 if stat[1] == false then
 216                         if file then
 217                                 file:close()
 218                         end
 219                         sock:close()
 220                         return unpack(stat)
 221                 elseif stat[2] then
 222                         file = file and stat[2]
 223                 end
 224         end
 225
 226         if not file then
 227                 return nil, -5, "no target given"
 228         end
 229
 230         local chunked = resp.headers["Transfer-Encoding"] == "chunked"
 231         local stat
 232
 233         -- Write the buffer to file
 234         file:writeall(buffer)
 235
 236         repeat
 237                 if not options.splice or not sock:is_socket() or chunked then
 238                         break
 239                 end
 240
 241                 -- This is a plain TCP socket and there is no encoding so we can splice
 242
 243                 local pipein, pipeout, msg = nixio.pipe()
 244                 if not pipein then
 245                         sock:close()
 246                         file:close()
 247                         return pipein, pipeout, msg
 248                 end
 249
 250
 251                 -- Adjust splice values
 252                 local ssize = 65536
 253                 local smode = nixio.splice_flags("move", "more")
 254
 255                 -- Splicing 512 bytes should never block on a fresh pipe
 256                 local stat, code, msg = nixio.splice(sock, pipeout, 512, smode)
 257                 if stat == nil then
 258                         break
 259                 end
 260
 261                 -- Now do the real splicing
 262                 local cb = cbs.on_write
 263                 if options.splice == "asynchronous" then
 264                         stat, code, msg = splice_async(sock, pipeout, pipein, file, cb)
 265                 elseif options.splice == "synchronous" then
 266                         stat, code, msg = splice_sync(sock, pipeout, pipein, file, cb)
 267                 else
 268                         break
 269                 end
 270
 271                 if stat == false then
 272                         break
 273                 end
 274
 275                 return stat, code, msg
 276         until true
 277
 278         local src = chunked and httpc.chunksource(sock) or sock:blocksource()
 279         local snk = file:sink()
 280
 281         if cbs.on_write then
 282                 src = ltn12.source.chain(src, function(chunk)
 283                         cbs.on_write(file)
 284                         return chunk
 285                 end)
 286         end
 287
 288         -- Fallback to read/write
 289         stat, code, msg = ltn12.pump.all(src, snk)
 290
 291         file:close()
 292         sock:close()
 293         return stat and true, code, msg
 294 end
 295