methods/gzip.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: gzip.cc,v 1.14 2001/03/11 22:37:35 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       Args[0] = _config->Find(GzPathOption,Prog).c_str();
  72       Args[1] = "-d";
  73       Args[2] = 0;
  74       execvp(Args[0],(char **)Args);
  75       _exit(100);
  76    }
  77    From.Close();
  78    close(GzOut[1]);
  79
  80    FileFd FromGz(GzOut[0]);  // For autoclose
  81    FileFd To(Itm->DestFile,FileFd::WriteEmpty);
  82    To.EraseOnFailure();
  83    if (_error->PendingError() == true)
  84       return false;
  85
  86    // Read data from gzip, generate checksums and write
  87    Hashes Hash;
  88    bool Failed = false;
  89    while (1)
  90    {
  91       unsigned char Buffer[4*1024];
  92       unsigned long Count;
  93
  94       Count = read(GzOut[0],Buffer,sizeof(Buffer));
  95       if (Count < 0 && errno == EINTR)
  96          continue;
  97
  98       if (Count < 0)
  99       {
 100          _error->Errno("read", "Read error from %s process",Prog);
 101          Failed = true;
 102          break;
 103       }
 104
 105       if (Count == 0)
 106          break;
 107
 108       Hash.Add(Buffer,Count);
 109       if (To.Write(Buffer,Count) == false)
 110       {
 111          Failed = true;
 112          break;
 113       }
 114    }
 115
 116    // Wait for gzip to finish
 117    if (ExecWait(Process,_config->Find(GzPathOption,Prog).c_str(),false) == false)
 118    {
 119       To.OpFail();
 120       return false;
 121    }
 122
 123    To.Close();
 124
 125    if (Failed == true)
 126       return false;
 127
 128    // Transfer the modification times
 129    struct stat Buf;
 130    if (stat(Path.c_str(),&Buf) != 0)
 131       return _error->Errno("stat","Failed to stat");
 132
 133    struct utimbuf TimeBuf;
 134    TimeBuf.actime = Buf.st_atime;
 135    TimeBuf.modtime = Buf.st_mtime;
 136    if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
 137       return _error->Errno("utime","Failed to set modification time");
 138
 139    if (stat(Itm->DestFile.c_str(),&Buf) != 0)
 140       return _error->Errno("stat","Failed to stat");
 141
 142    // Return a Done response
 143    Res.LastModified = Buf.st_mtime;
 144    Res.Size = Buf.st_size;
 145    Res.MD5Sum = Hash.MD5.Result();
 146
 147    URIDone(Res);
 148
 149    return true;
 150 }
 151                                                                         /*}}}*/
 152
 153 int main(int argc, char *argv[])
 154 {
 155    GzipMethod Mth;
 156
 157    Prog = strrchr(argv[0],'/');
 158    Prog++;
 159
 160    return Mth.Run();
 161 }