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 <apt-pkg/fileutl.h>
  13 #include <apt-pkg/error.h>
  14 #include <apt-pkg/acquire-method.h>
  15 #include <apt-pkg/strutl.h>
  16 #include <apt-pkg/hashes.h>
  17
  18 #include <sys/stat.h>
  19 #include <unistd.h>
  20 #include <utime.h>
  21 #include <stdio.h>
  22 #include <errno.h>
  23 #include <apti18n.h>
  24                                                                         /*}}}*/
  25
  26 const char *Prog;
  27
  28 class GzipMethod : public pkgAcqMethod
  29 {
  30    virtual bool Fetch(FetchItem *Itm);
  31
  32    public:
  33
  34    GzipMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {};
  35 };
  36
  37
  38 // GzipMethod::Fetch - Decompress the passed URI                        /*{{{*/
  39 // ---------------------------------------------------------------------
  40 /* */
  41 bool GzipMethod::Fetch(FetchItem *Itm)
  42 {
  43    URI Get = Itm->Uri;
  44    string Path = Get.Host + Get.Path; // To account for relative paths
  45
  46    string GzPathOption = "Dir::bin::"+string(Prog);
  47
  48    FetchResult Res;
  49    Res.Filename = Itm->DestFile;
  50    URIStart(Res);
  51
  52    // Open the source and destination files
  53    FileFd From(Path,FileFd::ReadOnly);
  54
  55    // if the file is empty, just rename it and return
  56    if(From.Size() == 0)
  57    {
  58       rename(Path.c_str(), Itm->DestFile.c_str());
  59       return true;
  60    }
  61
  62    int GzOut[2];
  63    if (pipe(GzOut) < 0)
  64       return _error->Errno("pipe",_("Couldn't open pipe for %s"),Prog);
  65
  66    // Fork gzip
  67    pid_t Process = ExecFork();
  68    if (Process == 0)
  69    {
  70       close(GzOut[0]);
  71       dup2(From.Fd(),STDIN_FILENO);
  72       dup2(GzOut[1],STDOUT_FILENO);
  73       From.Close();
  74       close(GzOut[1]);
  75       SetCloseExec(STDIN_FILENO,false);
  76       SetCloseExec(STDOUT_FILENO,false);
  77
  78       const char *Args[3];
  79       string Tmp = _config->Find(GzPathOption,Prog);
  80       Args[0] = Tmp.c_str();
  81       Args[1] = "-d";
  82       Args[2] = 0;
  83       execvp(Args[0],(char **)Args);
  84       _exit(100);
  85    }
  86    From.Close();
  87    close(GzOut[1]);
  88
  89    FileFd FromGz(GzOut[0]);  // For autoclose
  90    FileFd To(Itm->DestFile,FileFd::WriteEmpty);
  91    To.EraseOnFailure();
  92    if (_error->PendingError() == true)
  93       return false;
  94
  95    // Read data from gzip, generate checksums and write
  96    Hashes Hash;
  97    bool Failed = false;
  98    while (1)
  99    {
 100       unsigned char Buffer[4*1024];
 101       unsigned long Count;
 102
 103       Count = read(GzOut[0],Buffer,sizeof(Buffer));
 104       if (Count < 0 && errno == EINTR)
 105          continue;
 106
 107       if (Count < 0)
 108       {
 109          _error->Errno("read", _("Read error from %s process"),Prog);
 110          Failed = true;
 111          break;
 112       }
 113
 114       if (Count == 0)
 115          break;
 116
 117       Hash.Add(Buffer,Count);
 118       if (To.Write(Buffer,Count) == false)
 119       {
 120          Failed = true;
 121          FromGz.Close();
 122          break;
 123       }
 124    }
 125
 126    // Wait for gzip to finish
 127    if (ExecWait(Process,_config->Find(GzPathOption,Prog).c_str(),false) == false)
 128    {
 129       To.OpFail();
 130       return false;
 131    }
 132
 133    To.Close();
 134
 135    if (Failed == true)
 136       return false;
 137
 138    // Transfer the modification times
 139    struct stat Buf;
 140    if (stat(Path.c_str(),&Buf) != 0)
 141       return _error->Errno("stat",_("Failed to stat"));
 142
 143    struct utimbuf TimeBuf;
 144    TimeBuf.actime = Buf.st_atime;
 145    TimeBuf.modtime = Buf.st_mtime;
 146    if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
 147       return _error->Errno("utime",_("Failed to set modification time"));
 148
 149    if (stat(Itm->DestFile.c_str(),&Buf) != 0)
 150       return _error->Errno("stat",_("Failed to stat"));
 151
 152    // Return a Done response
 153    Res.LastModified = Buf.st_mtime;
 154    Res.Size = Buf.st_size;
 155    Res.TakeHashes(Hash);
 156
 157    URIDone(Res);
 158
 159    return true;
 160 }
 161                                                                         /*}}}*/
 162
 163 int main(int argc, char *argv[])
 164 {
 165    setlocale(LC_ALL, "");
 166
 167    GzipMethod Mth;
 168
 169    Prog = strrchr(argv[0],'/');
 170    Prog++;
 171
 172    return Mth.Run();
 173 }