methods/gzip.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: gzip.cc,v 1.16 2001/05/27 04:29:30 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 #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                                                                         /*}}}*/
  24
  25 const char *Prog;
  26
  27 class GzipMethod : public pkgAcqMethod
  28 {
  29    virtual bool Fetch(FetchItem *Itm);
  30
  31    public:
  32
  33    GzipMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {};
  34 };
  35
  36
  37 // GzipMethod::Fetch - Decompress the passed URI                        /*{{{*/
  38 // ---------------------------------------------------------------------
  39 /* */
  40 bool GzipMethod::Fetch(FetchItem *Itm)
  41 {
  42    URI Get = Itm->Uri;
  43    string Path = Get.Host + Get.Path; // To account for relative paths
  44
  45    string GzPathOption = "Dir::bin::"+string(Prog);
  46
  47    FetchResult Res;
  48    Res.Filename = Itm->DestFile;
  49    URIStart(Res);
  50
  51    // Open the source and destination files
  52    FileFd From(Path,FileFd::ReadOnly);
  53
  54    int GzOut[2];
  55    if (pipe(GzOut) < 0)
  56       return _error->Errno("pipe","Couldn't open pipe for %s",Prog);
  57
  58    // Fork gzip
  59    int Process = ExecFork();
  60    if (Process == 0)
  61    {
  62       close(GzOut[0]);
  63       dup2(From.Fd(),STDIN_FILENO);
  64       dup2(GzOut[1],STDOUT_FILENO);
  65       From.Close();
  66       close(GzOut[1]);
  67       SetCloseExec(STDIN_FILENO,false);
  68       SetCloseExec(STDOUT_FILENO,false);
  69
  70       const char *Args[3];
  71       string Tmp = _config->Find(GzPathOption,Prog);
  72       Args[0] = Tmp.c_str();
  73       Args[1] = "-d";
  74       Args[2] = 0;
  75       execvp(Args[0],(char **)Args);
  76       _exit(100);
  77    }
  78    From.Close();
  79    close(GzOut[1]);
  80
  81    FileFd FromGz(GzOut[0]);  // For autoclose
  82    FileFd To(Itm->DestFile,FileFd::WriteEmpty);
  83    To.EraseOnFailure();
  84    if (_error->PendingError() == true)
  85       return false;
  86
  87    // Read data from gzip, generate checksums and write
  88    Hashes Hash;
  89    bool Failed = false;
  90    while (1)
  91    {
  92       unsigned char Buffer[4*1024];
  93       unsigned long Count;
  94
  95       Count = read(GzOut[0],Buffer,sizeof(Buffer));
  96       if (Count < 0 && errno == EINTR)
  97          continue;
  98
  99       if (Count < 0)
 100       {
 101          _error->Errno("read", "Read error from %s process",Prog);
 102          Failed = true;
 103          break;
 104       }
 105
 106       if (Count == 0)
 107          break;
 108
 109       Hash.Add(Buffer,Count);
 110       if (To.Write(Buffer,Count) == false)
 111       {
 112          Failed = true;
 113          break;
 114       }
 115    }
 116
 117    // Wait for gzip to finish
 118    if (ExecWait(Process,_config->Find(GzPathOption,Prog).c_str(),false) == false)
 119    {
 120       To.OpFail();
 121       return false;
 122    }
 123
 124    To.Close();
 125
 126    if (Failed == true)
 127       return false;
 128
 129    // Transfer the modification times
 130    struct stat Buf;
 131    if (stat(Path.c_str(),&Buf) != 0)
 132       return _error->Errno("stat","Failed to stat");
 133
 134    struct utimbuf TimeBuf;
 135    TimeBuf.actime = Buf.st_atime;
 136    TimeBuf.modtime = Buf.st_mtime;
 137    if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
 138       return _error->Errno("utime","Failed to set modification time");
 139
 140    if (stat(Itm->DestFile.c_str(),&Buf) != 0)
 141       return _error->Errno("stat","Failed to stat");
 142
 143    // Return a Done response
 144    Res.LastModified = Buf.st_mtime;
 145    Res.Size = Buf.st_size;
 146    Res.TakeHashes(Hash);
 147
 148    URIDone(Res);
 149
 150    return true;
 151 }
 152                                                                         /*}}}*/
 153
 154 int main(int argc, char *argv[])
 155 {
 156    GzipMethod Mth;
 157
 158    Prog = strrchr(argv[0],'/');
 159    Prog++;
 160
 161    return Mth.Run();
 162 }