methods/gzip.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: gzip.cc,v 1.11 2001/03/06 03:11:22 jgg 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
  17 #include <sys/stat.h>
  18 #include <unistd.h>
  19 #include <utime.h>
  20 #include <stdio.h>
  21                                                                         /*}}}*/
  22
  23 class GzipMethod : public pkgAcqMethod
  24 {
  25    virtual bool Fetch(FetchItem *Itm);
  26
  27    public:
  28
  29    GzipMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {};
  30 };
  31
  32 // GzipMethod::Fetch - Decompress the passed URI                        /*{{{*/
  33 // ---------------------------------------------------------------------
  34 /* */
  35 bool GzipMethod::Fetch(FetchItem *Itm)
  36 {
  37    URI Get = Itm->Uri;
  38    string Path = Get.Host + Get.Path; // To account for relative paths
  39    string GzipPath = _config->Find("Dir::bin::gzip","gzip");
  40
  41    FetchResult Res;
  42    Res.Filename = Itm->DestFile;
  43    URIStart(Res);
  44
  45    // Open the source and destintation files
  46    FileFd From(Path,FileFd::ReadOnly);
  47    FileFd To(Itm->DestFile,FileFd::WriteEmpty);
  48    To.EraseOnFailure();
  49    if (_error->PendingError() == true)
  50       return false;
  51
  52    // Fork gzip
  53    int Process = fork();
  54    if (Process < 0)
  55       return _error->Errno("fork",string("Couldn't fork "+GzipPath).c_str());
  56
  57    // The child
  58    if (Process == 0)
  59    {
  60       dup2(From.Fd(),STDIN_FILENO);
  61       dup2(To.Fd(),STDOUT_FILENO);
  62       From.Close();
  63       To.Close();
  64       SetCloseExec(STDIN_FILENO,false);
  65       SetCloseExec(STDOUT_FILENO,false);
  66
  67       const char *Args[3];
  68       Args[0] = GzipPath.c_str();
  69       Args[1] = "-d";
  70       Args[2] = 0;
  71       execvp(Args[0],(char **)Args);
  72       exit(100);
  73    }
  74    From.Close();
  75
  76    // Wait for gzip to finish
  77    if (ExecWait(Process,GzipPath.c_str(),false) == false)
  78    {
  79       To.OpFail();
  80       return false;
  81    }
  82
  83    To.Close();
  84
  85    // Transfer the modification times
  86    struct stat Buf;
  87    if (stat(Path.c_str(),&Buf) != 0)
  88       return _error->Errno("stat","Failed to stat");
  89
  90    struct utimbuf TimeBuf;
  91    TimeBuf.actime = Buf.st_atime;
  92    TimeBuf.modtime = Buf.st_mtime;
  93    if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
  94       return _error->Errno("utime","Failed to set modification time");
  95
  96    if (stat(Itm->DestFile.c_str(),&Buf) != 0)
  97       return _error->Errno("stat","Failed to stat");
  98
  99    // Return a Done response
 100    Res.LastModified = Buf.st_mtime;
 101    Res.Size = Buf.st_size;
 102    URIDone(Res);
 103
 104    return true;
 105 }
 106                                                                         /*}}}*/
 107
 108 int main()
 109 {
 110    GzipMethod Mth;
 111    return Mth.Run();
 112 }