methods/gzip.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: gzip.cc,v 1.3 1998/10/30 07:53:53 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 <strutl.h>
  16
  17 #include <sys/stat.h>
  18 #include <unistd.h>
  19 #include <utime.h>
  20 #include <wait.h>
  21 #include <stdio.h>
  22                                                                         /*}}}*/
  23
  24 class GzipMethod : public pkgAcqMethod
  25 {
  26    virtual bool Fetch(string Message,URI Get);
  27
  28    public:
  29
  30    GzipMethod() : pkgAcqMethod("1.0",SingleInstance | SendConfig) {};
  31 };
  32
  33 // GzipMethod::Fetch - Decompress the passed URI                        /*{{{*/
  34 // ---------------------------------------------------------------------
  35 /* */
  36 bool GzipMethod::Fetch(string Message,URI Get)
  37 {
  38    // Open the source and destintation files
  39    FileFd From(Get.Path,FileFd::ReadOnly);
  40    FileFd To(DestFile,FileFd::WriteEmpty);
  41    To.EraseOnFailure();
  42    if (_error->PendingError() == true)
  43       return false;
  44
  45    // Fork gzip
  46    int Process = fork();
  47    if (Process < 0)
  48       return _error->Errno("fork","Couldn't fork gzip");
  49
  50    // The child
  51    if (Process == 0)
  52    {
  53       dup2(From.Fd(),STDIN_FILENO);
  54       dup2(To.Fd(),STDOUT_FILENO);
  55       From.Close();
  56       To.Close();
  57       SetCloseExec(STDIN_FILENO,false);
  58       SetCloseExec(STDOUT_FILENO,false);
  59
  60       const char *Args[3];
  61       Args[0] = _config->Find("Dir::bin::gzip","gzip").c_str();
  62       Args[1] = "-d";
  63       Args[2] = 0;
  64       execvp(Args[0],(char **)Args);
  65       exit(100);
  66    }
  67    From.Close();
  68
  69    // Wait for gzip to finish
  70    int Status;
  71    if (waitpid(Process,&Status,0) != Process)
  72    {
  73       To.OpFail();
  74       return _error->Errno("wait","Waiting for gzip failed");
  75    }
  76
  77    if (WIFEXITED(Status) == 0 || WEXITSTATUS(Status) != 0)
  78    {
  79       To.OpFail();
  80       return _error->Error("gzip failed, perhaps the disk is full or the directory permissions are wrong.");
  81    }
  82
  83    To.Close();
  84
  85    // Transfer the modification times
  86    struct stat Buf;
  87    if (stat(Get.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(DestFile.c_str(),&TimeBuf) != 0)
  94       return _error->Errno("utime","Failed to set modification time");
  95
  96    // Return a Done response
  97    FetchResult Res;
  98    Res.LastModified = Buf.st_mtime;
  99    Res.Filename = DestFile;
 100    URIDone(Res);
 101
 102    return true;
 103 }
 104                                                                         /*}}}*/
 105
 106 int main()
 107 {
 108    GzipMethod Mth;
 109    return Mth.Run();
 110 }