apt-pkg/cachefile.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: cachefile.cc,v 1.8 2002/04/27 04:28:04 jgg Exp $
   4 /* ######################################################################
   5
   6    CacheFile - Simple wrapper class for opening, generating and whatnot
   7
   8    This class implements a simple 2 line mechanism to open various sorts
   9    of caches. It can operate as root, as not root, show progress and so on,
  10    it transparently handles everything necessary.
  11
  12    ##################################################################### */
  13                                                                         /*}}}*/
  14 // Include Files                                                        /*{{{*/
  15 #include <config.h>
  16
  17 #include <apt-pkg/cachefile.h>
  18 #include <apt-pkg/error.h>
  19 #include <apt-pkg/sourcelist.h>
  20 #include <apt-pkg/pkgcachegen.h>
  21 #include <apt-pkg/configuration.h>
  22 #include <apt-pkg/policy.h>
  23 #include <apt-pkg/pkgsystem.h>
  24 #include <apt-pkg/fileutl.h>
  25 #include <apt-pkg/progress.h>
  26 #include <apt-pkg/depcache.h>
  27 #include <apt-pkg/mmap.h>
  28 #include <apt-pkg/pkgcache.h>
  29 #include <apt-pkg/indexfile.h>
  30
  31 #include <string.h>
  32 #include <unistd.h>
  33 #include <string>
  34 #include <vector>
  35 #include <memory>
  36
  37 #include <apti18n.h>
  38                                                                         /*}}}*/
  39 // CacheFile::CacheFile - Constructor                                   /*{{{*/
  40 pkgCacheFile::pkgCacheFile() : d(NULL), ExternOwner(false), Map(NULL), Cache(NULL),
  41                                 DCache(NULL), SrcList(NULL), Policy(NULL)
  42 {
  43 }
  44 pkgCacheFile::pkgCacheFile(pkgDepCache * const Owner) : d(NULL), ExternOwner(true),
  45    Map(&Owner->GetCache().GetMap()), Cache(&Owner->GetCache()),
  46    DCache(Owner), SrcList(NULL), Policy(NULL)
  47 {
  48 }
  49                                                                         /*}}}*/
  50 // CacheFile::~CacheFile - Destructor                                   /*{{{*/
  51 // ---------------------------------------------------------------------
  52 /* */
  53 pkgCacheFile::~pkgCacheFile()
  54 {
  55    if (ExternOwner == false)
  56    {
  57       delete DCache;
  58       delete Cache;
  59       delete Map;
  60    }
  61    delete Policy;
  62    delete SrcList;
  63    if (ExternOwner == false)
  64       _system->UnLock(true);
  65 }
  66                                                                         /*}}}*/
  67 // CacheFile::BuildCaches - Open and build the cache files              /*{{{*/
  68 class APT_HIDDEN ScopedErrorMerge {
  69 public:
  70    ScopedErrorMerge() { _error->PushToStack(); }
  71    ~ScopedErrorMerge() { _error->MergeWithStack(); }
  72 };
  73
  74 bool pkgCacheFile::BuildCaches(OpProgress *Progress, bool WithLock)
  75 {
  76    std::unique_ptr<pkgCache> Cache;
  77    std::unique_ptr<MMap> Map;
  78
  79    if (this->Cache != NULL)
  80       return true;
  81
  82    ScopedErrorMerge sem;
  83    if (_config->FindB("pkgCacheFile::Generate", true) == false)
  84    {
  85       FileFd file(_config->FindFile("Dir::Cache::pkgcache"), FileFd::ReadOnly);
  86       if (file.IsOpen() == false || file.Failed())
  87          return false;
  88       Map.reset(new MMap(file, MMap::Public|MMap::ReadOnly));
  89       if (unlikely(Map->validData() == false))
  90          return false;
  91       Cache.reset(new pkgCache(Map.get()));
  92       if (_error->PendingError() == true)
  93          return _error->ReturnError();
  94
  95       this->Cache = Cache.release();
  96       this->Map = Map.release();
  97       return true;
  98    }
  99
 100    if (WithLock == true)
 101       if (_system->Lock() == false)
 102          return false;
 103
 104    if (_error->PendingError() == true)
 105       return _error->ReturnError();
 106
 107    if (BuildSourceList(Progress) == false)
 108       return false;
 109
 110    // Read the caches
 111    MMap *TmpMap = nullptr;
 112    pkgCache *TmpCache = nullptr;
 113    bool Res = pkgCacheGenerator::MakeStatusCache(*SrcList,Progress,&TmpMap, &TmpCache, true);
 114    Map.reset(TmpMap);
 115    Cache.reset(TmpCache);
 116    if (Progress != NULL)
 117       Progress->Done();
 118    if (Res == false)
 119       return _error->Error(_("The package lists or status file could not be parsed or opened."));
 120
 121    if (Cache == nullptr)
 122       Cache.reset(new pkgCache(Map.get()));
 123    this->Map = Map.release();
 124    this->Cache = Cache.release();
 125
 126    return true;
 127 }
 128                                                                         /*}}}*/
 129 // CacheFile::BuildSourceList - Open and build all relevant sources.list/*{{{*/
 130 // ---------------------------------------------------------------------
 131 /* */
 132 bool pkgCacheFile::BuildSourceList(OpProgress * /*Progress*/)
 133 {
 134    std::unique_ptr<pkgSourceList> SrcList;
 135    if (this->SrcList != NULL)
 136       return true;
 137
 138    SrcList.reset(new pkgSourceList());
 139    if (SrcList->ReadMainList() == false)
 140       return _error->Error(_("The list of sources could not be read."));
 141    this->SrcList = SrcList.release();
 142    return true;
 143 }
 144                                                                         /*}}}*/
 145 // CacheFile::BuildPolicy - Open and build all relevant preferences     /*{{{*/
 146 // ---------------------------------------------------------------------
 147 /* */
 148 bool pkgCacheFile::BuildPolicy(OpProgress * /*Progress*/)
 149 {
 150    std::unique_ptr<pkgPolicy> Policy;
 151    if (this->Policy != NULL)
 152       return true;
 153
 154    Policy.reset(new pkgPolicy(Cache));
 155    if (_error->PendingError() == true)
 156       return _error->ReturnError();
 157
 158    if (ReadPinFile(*Policy) == false || ReadPinDir(*Policy) == false)
 159       return false;
 160
 161    this->Policy = Policy.release();
 162    return true;
 163 }
 164                                                                         /*}}}*/
 165 // CacheFile::BuildDepCache - Open and build the dependency cache       /*{{{*/
 166 // ---------------------------------------------------------------------
 167 /* */
 168 bool pkgCacheFile::BuildDepCache(OpProgress *Progress)
 169 {
 170    if (BuildCaches(Progress, false) == false)
 171       return false;
 172
 173    std::unique_ptr<pkgDepCache> DCache;
 174    if (this->DCache != NULL)
 175       return true;
 176
 177    if (BuildPolicy(Progress) == false)
 178       return false;
 179
 180    DCache.reset(new pkgDepCache(Cache,Policy));
 181    if (_error->PendingError() == true)
 182       return _error->ReturnError();
 183    if (DCache->Init(Progress) == false)
 184       return false;
 185
 186    this->DCache = DCache.release();
 187    return true;
 188 }
 189                                                                         /*}}}*/
 190 // CacheFile::Open - Open the cache files, creating if necessary        /*{{{*/
 191 // ---------------------------------------------------------------------
 192 /* */
 193 bool pkgCacheFile::Open(OpProgress *Progress, bool WithLock)
 194 {
 195    if (BuildCaches(Progress,WithLock) == false)
 196       return false;
 197
 198    if (BuildPolicy(Progress) == false)
 199       return false;
 200
 201    if (BuildDepCache(Progress) == false)
 202       return false;
 203
 204    if (Progress != NULL)
 205       Progress->Done();
 206
 207    return true;
 208 }
 209                                                                         /*}}}*/
 210 bool pkgCacheFile::AddIndexFile(pkgIndexFile * const File)              /*{{{*/
 211 {
 212    if (SrcList == NULL)
 213       if (BuildSourceList() == false)
 214          return false;
 215    SrcList->AddVolatileFile(File);
 216
 217    if (Cache == nullptr || File->HasPackages() == false || File->Exists() == false)
 218       return true;
 219
 220    if (File->FindInCache(*Cache).end() == false)
 221       return _error->Warning("Duplicate sources.list entry %s",
 222             File->Describe().c_str());
 223
 224    if (ExternOwner == false)
 225    {
 226       delete DCache;
 227       delete Cache;
 228    }
 229    delete Policy;
 230    DCache = NULL;
 231    Policy = NULL;
 232    Cache = NULL;
 233
 234    if (ExternOwner == false)
 235    {
 236       // a dynamic mmap means that we have build at least parts of the cache
 237       // in memory – which we might or might not have written to disk.
 238       // Throwing away would therefore be a very costly operation we want to avoid
 239       DynamicMMap * dynmmap = dynamic_cast<DynamicMMap*>(Map);
 240       if (dynmmap != nullptr)
 241       {
 242          {
 243             pkgCacheGenerator Gen(dynmmap, nullptr);
 244             if (Gen.Start() == false || File->Merge(Gen, nullptr) == false)
 245                return false;
 246          }
 247          Cache = new pkgCache(Map);
 248          if (_error->PendingError() == true) {
 249             delete Cache;
 250             Cache = nullptr;
 251             return _error->ReturnError();
 252          }
 253          return true;
 254       }
 255       else
 256       {
 257          delete Map;
 258          Map = NULL;
 259       }
 260    }
 261    else
 262    {
 263       ExternOwner = false;
 264       Map = NULL;
 265    }
 266    _system->UnLock(true);
 267    return true;
 268 }
 269                                                                         /*}}}*/
 270 // CacheFile::RemoveCaches - remove all cache files from disk           /*{{{*/
 271 // ---------------------------------------------------------------------
 272 /* */
 273 void pkgCacheFile::RemoveCaches()
 274 {
 275    std::string const pkgcache = _config->FindFile("Dir::cache::pkgcache");
 276    std::string const srcpkgcache = _config->FindFile("Dir::cache::srcpkgcache");
 277
 278    if (pkgcache.empty() == false && RealFileExists(pkgcache) == true)
 279       RemoveFile("RemoveCaches", pkgcache);
 280    if (srcpkgcache.empty() == false && RealFileExists(srcpkgcache) == true)
 281       RemoveFile("RemoveCaches", srcpkgcache);
 282    if (pkgcache.empty() == false)
 283    {
 284       std::string cachedir = flNotFile(pkgcache);
 285       std::string cachefile = flNotDir(pkgcache);
 286       if (cachedir.empty() != true && cachefile.empty() != true && DirectoryExists(cachedir) == true)
 287       {
 288          cachefile.append(".");
 289          std::vector<std::string> caches = GetListOfFilesInDir(cachedir, false);
 290          for (std::vector<std::string>::const_iterator file = caches.begin(); file != caches.end(); ++file)
 291          {
 292             std::string nuke = flNotDir(*file);
 293             if (strncmp(cachefile.c_str(), nuke.c_str(), cachefile.length()) != 0)
 294                continue;
 295             RemoveFile("RemoveCaches", *file);
 296          }
 297       }
 298    }
 299
 300    if (srcpkgcache.empty() == true)
 301       return;
 302
 303    std::string cachedir = flNotFile(srcpkgcache);
 304    std::string cachefile = flNotDir(srcpkgcache);
 305    if (cachedir.empty() == true || cachefile.empty() == true || DirectoryExists(cachedir) == false)
 306       return;
 307    cachefile.append(".");
 308    std::vector<std::string> caches = GetListOfFilesInDir(cachedir, false);
 309    for (std::vector<std::string>::const_iterator file = caches.begin(); file != caches.end(); ++file)
 310    {
 311       std::string nuke = flNotDir(*file);
 312       if (strncmp(cachefile.c_str(), nuke.c_str(), cachefile.length()) != 0)
 313          continue;
 314       RemoveFile("RemoveCaches", *file);
 315    }
 316 }
 317                                                                         /*}}}*/
 318 // CacheFile::Close - close the cache files                             /*{{{*/
 319 // ---------------------------------------------------------------------
 320 /* */
 321 void pkgCacheFile::Close()
 322 {
 323    if (ExternOwner == false)
 324    {
 325       delete DCache;
 326       delete Cache;
 327       delete Map;
 328    }
 329    else
 330       ExternOwner = false;
 331    delete Policy;
 332    delete SrcList;
 333    _system->UnLock(true);
 334
 335    Map = NULL;
 336    DCache = NULL;
 337    Policy = NULL;
 338    Cache = NULL;
 339    SrcList = NULL;
 340 }
 341                                                                         /*}}}*/