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    int GzOut[2];
  56    if (pipe(GzOut) < 0)
  57       return _error->Errno("pipe",_("Couldn't open pipe for %s"),Prog);
  58
  59    // Fork gzip
  60    pid_t Process = ExecFork();
  61    if (Process == 0)
  62    {
  63       close(GzOut[0]);
  64       dup2(From.Fd(),STDIN_FILENO);
  65       dup2(GzOut[1],STDOUT_FILENO);
  66       From.Close();
  67       close(GzOut[1]);
  68       SetCloseExec(STDIN_FILENO,false);
  69       SetCloseExec(STDOUT_FILENO,false);
  70
  71       const char *Args[3];
  72       string Tmp = _config->Find(GzPathOption,Prog);
  73       Args[0] = Tmp.c_str();
  74       Args[1] = "-d";
  75       Args[2] = 0;
  76       execvp(Args[0],(char **)Args);
  77       _exit(100);
  78    }
  79    From.Close();
  80    close(GzOut[1]);
  81
  82    FileFd FromGz(GzOut[0]);  // For autoclose
  83    FileFd To(Itm->DestFile,FileFd::WriteEmpty);
  84    To.EraseOnFailure();
  85    if (_error->PendingError() == true)
  86       return false;
  87
  88    // Read data from gzip, generate checksums and write
  89    Hashes Hash;
  90    bool Failed = false;
  91    while (1)
  92    {
  93       unsigned char Buffer[4*1024];
  94       unsigned long Count;
  95
  96       Count = read(GzOut[0],Buffer,sizeof(Buffer));
  97       if (Count < 0 && errno == EINTR)
  98          continue;
  99
 100       if (Count < 0)
 101       {
 102          _error->Errno("read", _("Read error from %s process"),Prog);
 103          Failed = true;
 104          break;
 105       }
 106
 107       if (Count == 0)
 108          break;
 109
 110       Hash.Add(Buffer,Count);
 111       if (To.Write(Buffer,Count) == false)
 112       {
 113          Failed = true;
 114          break;
 115       }
 116    }
 117
 118    // Wait for gzip to finish
 119    if (ExecWait(Process,_config->Find(GzPathOption,Prog).c_str(),false) == false)
 120    {
 121       To.OpFail();
 122       return false;
 123    }
 124
 125    To.Close();
 126
 127    if (Failed == true)
 128       return false;
 129
 130    // Transfer the modification times
 131    struct stat Buf;
 132    if (stat(Path.c_str(),&Buf) != 0)
 133       return _error->Errno("stat",_("Failed to stat"));
 134
 135    struct utimbuf TimeBuf;
 136    TimeBuf.actime = Buf.st_atime;
 137    TimeBuf.modtime = Buf.st_mtime;
 138    if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
 139       return _error->Errno("utime",_("Failed to set modification time"));
 140
 141    if (stat(Itm->DestFile.c_str(),&Buf) != 0)
 142       return _error->Errno("stat",_("Failed to stat"));
 143
 144    // Return a Done response
 145    Res.LastModified = Buf.st_mtime;
 146    Res.Size = Buf.st_size;
 147    Res.TakeHashes(Hash);
 148
 149    URIDone(Res);
 150
 151    return true;
 152 }
 153                                                                         /*}}}*/
 154
 155 int main(int argc, char *argv[])
 156 {
 157    setlocale(LC_ALL, "");
 158
 159    GzipMethod Mth;
 160
 161    Prog = strrchr(argv[0],'/');
 162    Prog++;
 163
 164    return Mth.Run();
 165 }