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/configuration.h>
  15 #include <apt-pkg/acquire-method.h>
  16 #include <apt-pkg/error.h>
  17 #include <apt-pkg/fileutl.h>
  18 #include <apt-pkg/hashes.h>
  19 #include <apt-pkg/strutl.h>
  20 #include <apt-pkg/aptconfiguration.h>
  21
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/time.h>
  25 #include <string>
  26 #include <vector>
  27
  28 #include <apti18n.h>
  29                                                                         /*}}}*/
  30
  31 const char *Prog;
  32
  33 class GzipMethod : public pkgAcqMethod
  34 {
  35    virtual bool Fetch(FetchItem *Itm) APT_OVERRIDE;
  36    virtual bool Configuration(std::string Message) APT_OVERRIDE;
  37
  38    public:
  39
  40    GzipMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {};
  41 };
  42
  43 bool GzipMethod::Configuration(std::string Message)
  44 {
  45    if (pkgAcqMethod::Configuration(Message) == false)
  46       return false;
  47
  48    DropPrivsOrDie();
  49
  50    return true;
  51 }
  52
  53 // GzipMethod::Fetch - Decompress the passed URI                        /*{{{*/
  54 // ---------------------------------------------------------------------
  55 /* */
  56 bool GzipMethod::Fetch(FetchItem *Itm)
  57 {
  58    URI Get = Itm->Uri;
  59    std::string Path = Get.Host + Get.Path; // To account for relative paths
  60
  61    FetchResult Res;
  62    Res.Filename = Itm->DestFile;
  63    URIStart(Res);
  64
  65    std::vector<APT::Configuration::Compressor> const compressors = APT::Configuration::getCompressors();
  66    std::vector<APT::Configuration::Compressor>::const_iterator compressor = compressors.begin();
  67    for (; compressor != compressors.end(); ++compressor)
  68       if (compressor->Name == Prog)
  69          break;
  70    if (compressor == compressors.end())
  71       return _error->Error("Extraction of file %s requires unknown compressor %s", Path.c_str(), Prog);
  72
  73    // Open the source and destination files
  74    FileFd From;
  75    if (_config->FindB("Method::Compress", false) == false)
  76    {
  77       From.Open(Path, FileFd::ReadOnly, *compressor);
  78       if(From.FileSize() == 0)
  79          return _error->Error(_("Empty files can't be valid archives"));
  80    }
  81    else
  82       From.Open(Path, FileFd::ReadOnly);
  83    if (From.IsOpen() == false || From.Failed() == true)
  84       return false;
  85
  86    FileFd To;
  87    if (Itm->DestFile != "/dev/null")
  88    {
  89       if (_config->FindB("Method::Compress", false) == false)
  90          To.Open(Itm->DestFile, FileFd::WriteAtomic);
  91       else
  92          To.Open(Itm->DestFile, FileFd::WriteOnly | FileFd::Create | FileFd::Empty, *compressor);
  93
  94       if (To.IsOpen() == false || To.Failed() == true)
  95          return false;
  96       To.EraseOnFailure();
  97    }
  98
  99
 100    // Read data from source, generate checksums and write
 101    Hashes Hash(Itm->ExpectedHashes);
 102    bool Failed = false;
 103    Res.Size = 0;
 104    while (1)
 105    {
 106       unsigned char Buffer[4*1024];
 107       unsigned long long Count = 0;
 108
 109       if (!From.Read(Buffer,sizeof(Buffer),&Count))
 110       {
 111          if (To.IsOpen())
 112             To.OpFail();
 113          return false;
 114       }
 115       if (Count == 0)
 116          break;
 117       Res.Size += Count;
 118
 119       Hash.Add(Buffer,Count);
 120       if (To.IsOpen() && To.Write(Buffer,Count) == false)
 121       {
 122          Failed = true;
 123          break;
 124       }
 125    }
 126
 127    From.Close();
 128    To.Close();
 129
 130    if (Failed == true)
 131       return false;
 132
 133    // Transfer the modification times
 134    if (Itm->DestFile != "/dev/null")
 135    {
 136       struct stat Buf;
 137       if (stat(Path.c_str(),&Buf) != 0)
 138          return _error->Errno("stat",_("Failed to stat"));
 139
 140       struct timeval times[2];
 141       times[0].tv_sec = Buf.st_atime;
 142       Res.LastModified = times[1].tv_sec = Buf.st_mtime;
 143       times[0].tv_usec = times[1].tv_usec = 0;
 144       if (utimes(Itm->DestFile.c_str(), times) != 0)
 145          return _error->Errno("utimes",_("Failed to set modification time"));
 146    }
 147
 148    // Return a Done response
 149    Res.TakeHashes(Hash);
 150
 151    URIDone(Res);
 152    return true;
 153 }
 154                                                                         /*}}}*/
 155
 156 int main(int, char *argv[])
 157 {
 158    setlocale(LC_ALL, "");
 159
 160    Prog = strrchr(argv[0],'/');
 161    ++Prog;
 162
 163    GzipMethod Mth;
 164
 165    return Mth.Run();
 166 }