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