methods/gzip.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: gzip.cc,v 1.17.2.1 2004/01/16 18:58:50 mdz Exp $
   4 /* ######################################################################
   5
   6    GZip method - Take a file URI in and decompress it into the target
   7    file.
   8
   9    ##################################################################### */
  10                                                                         /*}}}*/
  11 // Include Files                                                        /*{{{*/
  12 #include <config.h>
  13
  14 #include <apt-pkg/fileutl.h>
  15 #include <apt-pkg/error.h>
  16 #include <apt-pkg/acquire-method.h>
  17 #include <apt-pkg/strutl.h>
  18 #include <apt-pkg/hashes.h>
  19
  20 #include <sys/stat.h>
  21 #include <unistd.h>
  22 #include <stdio.h>
  23 #include <errno.h>
  24 #include <apti18n.h>
  25                                                                         /*}}}*/
  26
  27 const char *Prog;
  28
  29 class GzipMethod : public pkgAcqMethod
  30 {
  31    virtual bool Fetch(FetchItem *Itm);
  32
  33    public:
  34
  35    GzipMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {};
  36 };
  37
  38
  39 // GzipMethod::Fetch - Decompress the passed URI                        /*{{{*/
  40 // ---------------------------------------------------------------------
  41 /* */
  42 bool GzipMethod::Fetch(FetchItem *Itm)
  43 {
  44    URI Get = Itm->Uri;
  45    std::string Path = Get.Host + Get.Path; // To account for relative paths
  46
  47    FetchResult Res;
  48    Res.Filename = Itm->DestFile;
  49    URIStart(Res);
  50
  51    std::vector<APT::Configuration::Compressor> const compressors = APT::Configuration::getCompressors();
  52    std::vector<APT::Configuration::Compressor>::const_iterator compressor = compressors.begin();
  53    for (; compressor != compressors.end(); ++compressor)
  54       if (compressor->Name == Prog)
  55          break;
  56    if (compressor == compressors.end())
  57       return _error->Error("Extraction of file %s requires unknown compressor %s", Path.c_str(), Prog);
  58
  59    // Open the source and destination files
  60    FileFd From;
  61    From.Open(Path, FileFd::ReadOnly, *compressor);
  62
  63    if(From.FileSize() == 0)
  64       return _error->Error(_("Empty files can't be valid archives"));
  65
  66    FileFd To(Itm->DestFile,FileFd::WriteAtomic);
  67    To.EraseOnFailure();
  68    if (_error->PendingError() == true)
  69       return false;
  70
  71    // Read data from source, generate checksums and write
  72    Hashes Hash;
  73    bool Failed = false;
  74    while (1)
  75    {
  76       unsigned char Buffer[4*1024];
  77       unsigned long long Count = 0;
  78
  79       if (!From.Read(Buffer,sizeof(Buffer),&Count))
  80       {
  81          To.OpFail();
  82          return false;
  83       }
  84       if (Count == 0)
  85          break;
  86
  87       Hash.Add(Buffer,Count);
  88       if (To.Write(Buffer,Count) == false)
  89       {
  90          Failed = true;
  91          break;
  92       }
  93    }
  94
  95    From.Close();
  96
  97    if (Failed == true)
  98       return false;
  99
 100    // Transfer the modification times
 101    struct stat Buf;
 102    if (stat(Path.c_str(),&Buf) != 0)
 103       return _error->Errno("stat",_("Failed to stat"));
 104
 105    struct timespec times[2];
 106    times[0].tv_sec = Buf.st_atime;
 107    times[1].tv_sec = Buf.st_mtime;
 108    times[0].tv_nsec = times[1].tv_nsec = 0;
 109    if (futimens(To.Fd(), times) != 0)
 110    {
 111       To.OpFail();
 112       return _error->Errno("futimens",_("Failed to set modification time"));
 113    }
 114    Res.Size = To.FileSize();
 115    To.Close();
 116
 117    if (stat(Itm->DestFile.c_str(),&Buf) != 0)
 118       return _error->Errno("stat",_("Failed to stat"));
 119
 120    // Return a Done response
 121    Res.LastModified = Buf.st_mtime;
 122    Res.TakeHashes(Hash);
 123
 124    URIDone(Res);
 125    return true;
 126 }
 127                                                                         /*}}}*/
 128
 129 int main(int argc, char *argv[])
 130 {
 131    setlocale(LC_ALL, "");
 132
 133    Prog = strrchr(argv[0],'/');
 134    ++Prog;
 135
 136    GzipMethod Mth;
 137    return Mth.Run();
 138 }