apt-pkg/deb/debsystem.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: debsystem.cc,v 1.3 2001/04/29 05:13:51 jgg Exp $
   4 /* ######################################################################
   5
   6    System - Abstraction for running on different systems.
   7
   8    Basic general structure..
   9
  10    ##################################################################### */
  11                                                                         /*}}}*/
  12 // Include Files                                                        /*{{{*/
  13 #ifdef __GNUG__
  14 #pragma implementation "apt-pkg/debsystem.h"
  15 #endif
  16
  17 #include <apt-pkg/debsystem.h>
  18 #include <apt-pkg/debversion.h>
  19 #include <apt-pkg/debindexfile.h>
  20 #include <apt-pkg/dpkgpm.h>
  21 #include <apt-pkg/configuration.h>
  22 #include <apt-pkg/error.h>
  23 #include <apt-pkg/fileutl.h>
  24
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27 #include <dirent.h>
  28 #include <errno.h>
  29                                                                         /*}}}*/
  30
  31 debSystem debSys;
  32
  33 // System::debSystem - Constructor                                      /*{{{*/
  34 // ---------------------------------------------------------------------
  35 /* */
  36 debSystem::debSystem()
  37 {
  38    LockFD = -1;
  39    LockCount = 0;
  40
  41    Label = "Debian dpkg interface";
  42    VS = &debVS;
  43 }
  44                                                                         /*}}}*/
  45 // System::~debSystem - Destructor                                      /*{{{*/
  46 // ---------------------------------------------------------------------
  47 /* */
  48 debSystem::~debSystem()
  49 {
  50    delete StatusFile;
  51 }
  52                                                                         /*}}}*/
  53 // System::Lock - Get the lock                                          /*{{{*/
  54 // ---------------------------------------------------------------------
  55 /* This mirrors the operations dpkg does when it starts up. Note the
  56    checking of the updates directory. */
  57 bool debSystem::Lock()
  58 {
  59    // Disable file locking
  60    if (_config->FindB("Debug::NoLocking",false) == true || LockCount > 1)
  61    {
  62       LockCount++;
  63       return true;
  64    }
  65
  66    // Create the lockfile
  67    string AdminDir = flNotFile(_config->Find("Dir::State::status"));
  68    LockFD = GetLock(AdminDir + "lock");
  69    if (LockFD == -1)
  70    {
  71       if (errno == EACCES || errno == EAGAIN)
  72          return _error->Error("Unable to lock the administration directory (%s), "
  73                               "is another process using it?",AdminDir.c_str());
  74       else
  75          return _error->Error("Unable to lock the administration directory (%s), "
  76                               "are you root?",AdminDir.c_str());
  77    }
  78
  79    // See if we need to abort with a dirty journal
  80    if (CheckUpdates() == true)
  81    {
  82       close(LockFD);
  83       LockFD = -1;
  84       return _error->Error("dpkg was interrupted, you must manually "
  85                            "run 'dpkg --configure -a' to correct the problem. ");
  86    }
  87
  88          LockCount++;
  89
  90    return true;
  91 }
  92                                                                         /*}}}*/
  93 // System::UnLock - Drop a lock                                         /*{{{*/
  94 // ---------------------------------------------------------------------
  95 /* */
  96 bool debSystem::UnLock(bool NoErrors)
  97 {
  98    if (LockCount == 0 && NoErrors == true)
  99       return false;
 100
 101    if (LockCount < 1)
 102       return _error->Error("Not locked");
 103    if (--LockCount == 0)
 104    {
 105       close(LockFD);
 106       LockCount = 0;
 107    }
 108
 109    return true;
 110 }
 111                                                                         /*}}}*/
 112 // System::CheckUpdates - Check if the updates dir is dirty             /*{{{*/
 113 // ---------------------------------------------------------------------
 114 /* This does a check of the updates directory (dpkg journal) to see if it has
 115    any entries in it. */
 116 bool debSystem::CheckUpdates()
 117 {
 118    // Check for updates.. (dirty)
 119    string File = flNotFile(_config->Find("Dir::State::status")) + "updates/";
 120    DIR *DirP = opendir(File.c_str());
 121    if (DirP == 0)
 122       return false;
 123
 124    /* We ignore any files that are not all digits, this skips .,.. and
 125       some tmp files dpkg will leave behind.. */
 126    bool Damaged = false;
 127    for (struct dirent *Ent = readdir(DirP); Ent != 0; Ent = readdir(DirP))
 128    {
 129       Damaged = true;
 130       for (unsigned int I = 0; Ent->d_name[I] != 0; I++)
 131       {
 132          // Check if its not a digit..
 133          if (isdigit(Ent->d_name[I]) == 0)
 134          {
 135             Damaged = false;
 136             break;
 137          }
 138       }
 139       if (Damaged == true)
 140          break;
 141    }
 142    closedir(DirP);
 143
 144    return Damaged;
 145 }
 146                                                                         /*}}}*/
 147 // System::CreatePM - Create the underlying package manager             /*{{{*/
 148 // ---------------------------------------------------------------------
 149 /* */
 150 pkgPackageManager *debSystem::CreatePM(pkgDepCache *Cache) const
 151 {
 152    return new pkgDPkgPM(Cache);
 153 }
 154                                                                         /*}}}*/
 155 // System::Initialize - Setup the configuration space..                 /*{{{*/
 156 // ---------------------------------------------------------------------
 157 /* These are the Debian specific configuration variables.. */
 158 bool debSystem::Initialize(Configuration &Cnf)
 159 {
 160    /* These really should be jammed into a generic 'Local Database' engine
 161       which is yet to be determined. The functions in pkgcachegen should
 162       be the only users of these */
 163    Cnf.CndSet("Dir::State::userstatus","status.user"); // Defunct
 164    Cnf.CndSet("Dir::State::status","/var/lib/dpkg/status");
 165    Cnf.CndSet("Dir::Bin::dpkg","/usr/bin/dpkg");
 166
 167    return true;
 168 }
 169                                                                         /*}}}*/
 170 // System::ArchiveSupported - Is a file format supported                /*{{{*/
 171 // ---------------------------------------------------------------------
 172 /* The standard name for a deb is 'deb'.. There are no seperate versions
 173    of .deb to worry about.. */
 174 bool debSystem::ArchiveSupported(const char *Type)
 175 {
 176    if (strcmp(Type,"deb") == 0)
 177       return true;
 178    return false;
 179 }
 180                                                                         /*}}}*/
 181 // System::Score - Determine how 'Debiany' this sys is..                /*{{{*/
 182 // ---------------------------------------------------------------------
 183 /* We check some files that are sure tell signs of this being a Debian
 184    System.. */
 185 signed debSystem::Score(Configuration const &Cnf)
 186 {
 187    signed Score = 0;
 188    if (FileExists(Cnf.FindFile("Dir::State::status","/var/lib/dpkg/status")) == true)
 189        Score += 10;
 190    if (FileExists(Cnf.FindFile("Dir::Bin::dpkg","/usr/bin/dpkg")) == true)
 191       Score += 10;
 192    if (FileExists("/etc/debian_version") == true)
 193       Score += 10;
 194    return Score;
 195 }
 196                                                                         /*}}}*/
 197 // System::AddStatusFiles - Register the status files                   /*{{{*/
 198 // ---------------------------------------------------------------------
 199 /* */
 200 bool debSystem::AddStatusFiles(vector<pkgIndexFile *> &List)
 201 {
 202    if (StatusFile == 0)
 203       StatusFile = new debStatusIndex(_config->FindFile("Dir::State::status"));
 204    List.push_back(StatusFile);
 205    return true;
 206 }
 207                                                                         /*}}}*/
 208 // System::FindIndex - Get an index file for status files               /*{{{*/
 209 // ---------------------------------------------------------------------
 210 /* */
 211 bool debSystem::FindIndex(pkgCache::PkgFileIterator File,
 212                           pkgIndexFile *&Found) const
 213 {
 214    if (StatusFile == 0)
 215       return false;
 216    if (StatusFile->FindInCache(*File.Cache()) == File)
 217    {
 218       Found = StatusFile;
 219       return true;
 220    }
 221
 222    return false;
 223 }
 224                                                                         /*}}}*/