git.maemo.org Git - cinaest/blob - src/imdb/gzip-input-stream.vala

   1 /* This file is part of Cinaest.
   2  *
   3  * Copyright (C) 2009 Philipp Zabel
   4  *
   5  * Cinaest is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, either version 3 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * Cinaest is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with Cinaest. If not, see <http://www.gnu.org/licenses/>.
  17  */
  18
  19 using GLib;
  20 using ZLib;
  21
  22 class GzipInputStream : FilterInputStream {
  23         // 256KB buffer size
  24         const int CHUNK = 256*1024;
  25
  26         InflateStream strm;
  27         public uchar[] buf_in;
  28
  29         public GzipInputStream (GLib.InputStream _base_stream) {
  30                 Object (base_stream: _base_stream);
  31                 strm = InflateStream.full (15 | 32);
  32         }
  33
  34         construct {
  35                 buf_in = new uchar[CHUNK];
  36         }
  37
  38         public async override ssize_t read_async (void *buffer, size_t count, int io_priority, Cancellable? cancellable) throws Error {
  39                 int ret = Status.OK;
  40                 ssize_t n;
  41
  42                 if (strm.avail_in == 0) {
  43                         n = yield base_stream.read_async (buf_in, CHUNK, io_priority, cancellable);
  44                         strm.avail_in = (uint) n;
  45                         if (strm.avail_in == 0)
  46                                 return -1;
  47                         strm.next_in = buf_in;
  48                 }
  49
  50                 strm.avail_out = (int) count;
  51                 strm.next_out = buffer;
  52
  53                 ret = strm.inflate (Flush.NO_FLUSH);
  54                 assert (ret != Status.STREAM_ERROR);
  55                 if (ret == Status.NEED_DICT)
  56                         ret = Status.DATA_ERROR;
  57                 switch (ret) {
  58                 case Status.DATA_ERROR:
  59                 case Status.MEM_ERROR:
  60                         throw new IOError.FAILED("Error in gzip stream");
  61                 }
  62
  63                 return (ssize_t) count - strm.avail_out;
  64         }
  65
  66         public override ssize_t read_fn (void *buffer, size_t count, Cancellable? cancellable) throws Error {
  67                 int ret = Status.OK;
  68
  69                 if (strm.avail_in == 0) {
  70                         strm.avail_in = (int) base_stream.read (buf_in, CHUNK, cancellable);
  71                         if (strm.avail_in == 0)
  72                                 return -1;
  73                         strm.next_in = buf_in;
  74                 }
  75
  76                 strm.avail_out = (int) count;
  77                 strm.next_out = buffer;
  78
  79                 ret = strm.inflate (Flush.NO_FLUSH);
  80                 assert (ret != Status.STREAM_ERROR);
  81                 if (ret == Status.NEED_DICT)
  82                         ret = Status.DATA_ERROR;
  83                 switch (ret) {
  84                 case Status.DATA_ERROR:
  85                 case Status.MEM_ERROR:
  86                         return -1;
  87                 }
  88
  89                 return (ssize_t) count - strm.avail_out;
  90         }
  91
  92         public ulong total_in () {
  93                 return strm.total_in;
  94         }
  95 }