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