methods/gzip.cc

   1 extern "C" {
   2     #include <mach-o/nlist.h>
   3 }
   4
   5 // -*- mode: cpp; mode: fold -*-
   6 // Description                                                          /*{{{*/
   7 // $Id: gzip.cc,v 1.17.2.1 2004/01/16 18:58:50 mdz Exp $
   8 /* ######################################################################
   9
  10    GZip method - Take a file URI in and decompress it into the target
  11    file.
  12
  13    ##################################################################### */
  14                                                                         /*}}}*/
  15 // Include Files                                                        /*{{{*/
  16 #include <apt-pkg/fileutl.h>
  17 #include <apt-pkg/error.h>
  18 #include <apt-pkg/acquire-method.h>
  19 #include <apt-pkg/strutl.h>
  20 #include <apt-pkg/hashes.h>
  21
  22 #include <sys/stat.h>
  23 #include <unistd.h>
  24 #include <utime.h>
  25 #include <stdio.h>
  26 #include <errno.h>
  27 #include <apti18n.h>
  28                                                                         /*}}}*/
  29
  30 const char *Prog;
  31
  32 class GzipMethod : public pkgAcqMethod
  33 {
  34    virtual bool Fetch(FetchItem *Itm);
  35
  36    public:
  37
  38    GzipMethod() : pkgAcqMethod("1.1",SingleInstance | SendConfig) {};
  39 };
  40
  41
  42 // GzipMethod::Fetch - Decompress the passed URI                        /*{{{*/
  43 // ---------------------------------------------------------------------
  44 /* */
  45 bool GzipMethod::Fetch(FetchItem *Itm)
  46 {
  47    URI Get = Itm->Uri;
  48    string Path = Get.Host + Get.Path; // To account for relative paths
  49
  50    string GzPathOption = "Dir::bin::"+string(Prog);
  51
  52    FetchResult Res;
  53    Res.Filename = Itm->DestFile;
  54    URIStart(Res);
  55
  56    // Open the source and destination files
  57    FileFd From(Path,FileFd::ReadOnly);
  58
  59    // if the file is empty, just rename it and return
  60    if(From.Size() == 0)
  61    {
  62       rename(Path.c_str(), Itm->DestFile.c_str());
  63       return true;
  64    }
  65
  66    int GzOut[2];
  67    if (pipe(GzOut) < 0)
  68       return _error->Errno("pipe",_("Couldn't open pipe for %s"),Prog);
  69
  70    // Fork gzip
  71    pid_t Process = ExecFork();
  72    if (Process == 0)
  73    {
  74       close(GzOut[0]);
  75       dup2(From.Fd(),STDIN_FILENO);
  76       dup2(GzOut[1],STDOUT_FILENO);
  77       From.Close();
  78       close(GzOut[1]);
  79       SetCloseExec(STDIN_FILENO,false);
  80       SetCloseExec(STDOUT_FILENO,false);
  81
  82       const char *Args[3];
  83       string Tmp = _config->Find(GzPathOption,Prog);
  84       Args[0] = Tmp.c_str();
  85       Args[1] = "-d";
  86       Args[2] = 0;
  87       execvp(Args[0],(char **)Args);
  88       _exit(100);
  89    }
  90    From.Close();
  91    close(GzOut[1]);
  92
  93    FileFd FromGz(GzOut[0]);  // For autoclose
  94    FileFd To(Itm->DestFile,FileFd::WriteEmpty);
  95    To.EraseOnFailure();
  96    if (_error->PendingError() == true)
  97       return false;
  98
  99    // Read data from gzip, generate checksums and write
 100    Hashes Hash;
 101    bool Failed = false;
 102    while (1)
 103    {
 104       unsigned char Buffer[4*1024];
 105       unsigned long Count;
 106
 107       Count = read(GzOut[0],Buffer,sizeof(Buffer));
 108       if (Count < 0 && errno == EINTR)
 109          continue;
 110
 111       if (Count < 0)
 112       {
 113          _error->Errno("read", _("Read error from %s process"),Prog);
 114          Failed = true;
 115          break;
 116       }
 117
 118       if (Count == 0)
 119          break;
 120
 121       Hash.Add(Buffer,Count);
 122       if (To.Write(Buffer,Count) == false)
 123       {
 124          Failed = true;
 125          FromGz.Close();
 126          break;
 127       }
 128    }
 129
 130    // Wait for gzip to finish
 131    if (ExecWait(Process,_config->Find(GzPathOption,Prog).c_str(),false) == false)
 132    {
 133       To.OpFail();
 134       return false;
 135    }
 136
 137    To.Close();
 138
 139    if (Failed == true)
 140       return false;
 141
 142    // Transfer the modification times
 143    struct stat Buf;
 144    if (stat(Path.c_str(),&Buf) != 0)
 145       return _error->Errno("stat",_("Failed to stat"));
 146
 147    struct utimbuf TimeBuf;
 148    TimeBuf.actime = Buf.st_atime;
 149    TimeBuf.modtime = Buf.st_mtime;
 150    if (utime(Itm->DestFile.c_str(),&TimeBuf) != 0)
 151       return _error->Errno("utime",_("Failed to set modification time"));
 152
 153    if (stat(Itm->DestFile.c_str(),&Buf) != 0)
 154       return _error->Errno("stat",_("Failed to stat"));
 155
 156    // Return a Done response
 157    Res.LastModified = Buf.st_mtime;
 158    Res.Size = Buf.st_size;
 159    Res.TakeHashes(Hash);
 160
 161    URIDone(Res);
 162
 163    return true;
 164 }
 165                                                                         /*}}}*/
 166
 167 int main(int argc, char *argv[])
 168 {
 169    struct nlist nl[2];
 170    memset(nl, 0, sizeof(nl));
 171    nl[0].n_un.n_name = "_useMDNSResponder";
 172    nlist("/usr/lib/libc.dylib", nl);
 173    if (nl[0].n_type != N_UNDF)
 174        *(int *) nl[0].n_value = 0;
 175
 176    setlocale(LC_ALL, "");
 177
 178    GzipMethod Mth;
 179
 180    Prog = strrchr(argv[0],'/');
 181    Prog++;
 182
 183    return Mth.Run();
 184 }