]> git.saurik.com Git - apt.git/blobdiff - apt-pkg/pkgcachegen.cc
merge MultiArch-ABI. We don't support MultiArch yet (as most other tools),
[apt.git] / apt-pkg / pkgcachegen.cc
index 397c198293a934331ef98c73796e3a61075fe313..8187b3950112be32e93a11820744c40986a30ed6 100644 (file)
 #include <apt-pkg/progress.h>
 #include <apt-pkg/sourcelist.h>
 #include <apt-pkg/configuration.h>
+#include <apt-pkg/aptconfiguration.h>
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/sptr.h>
 #include <apt-pkg/pkgsystem.h>
+#include <apt-pkg/macros.h>
 
 #include <apt-pkg/tagfile.h>
 
 #include <unistd.h>
 #include <errno.h>
 #include <stdio.h>
-#include <system.h>
                                                                        /*}}}*/
 typedef vector<pkgIndexFile *>::iterator FileIterator;
 
 // CacheGenerator::pkgCacheGenerator - Constructor                     /*{{{*/
 // ---------------------------------------------------------------------
-/* We set the diry flag and make sure that is written to the disk */
+/* We set the dirty flag and make sure that is written to the disk */
 pkgCacheGenerator::pkgCacheGenerator(DynamicMMap *pMap,OpProgress *Prog) :
                    Map(*pMap), Cache(pMap,false), Progress(Prog),
                    FoundFileDeps(0)
@@ -53,14 +54,16 @@ pkgCacheGenerator::pkgCacheGenerator(DynamicMMap *pMap,OpProgress *Prog) :
    {
       // Setup the map interface..
       Cache.HeaderP = (pkgCache::Header *)Map.Data();
-      Map.RawAllocate(sizeof(pkgCache::Header));
+      if (Map.RawAllocate(sizeof(pkgCache::Header)) == 0 && _error->PendingError() == true)
+        return;
+
       Map.UsePools(*Cache.HeaderP->Pools,sizeof(Cache.HeaderP->Pools)/sizeof(Cache.HeaderP->Pools[0]));
-      
+
       // Starting header
       *Cache.HeaderP = pkgCache::Header();
       Cache.HeaderP->VerSysName = Map.WriteString(_system->VS->Label);
       Cache.HeaderP->Architecture = Map.WriteString(_config->Find("APT::Architecture"));
-      Cache.ReMap(); 
+      Cache.ReMap();
    }
    else
    {
@@ -105,13 +108,26 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
    unsigned int Counter = 0;
    while (List.Step() == true)
    {
-      // Get a pointer to the package structure
-      string PackageName = List.Package();
+      string const PackageName = List.Package();
       if (PackageName.empty() == true)
         return false;
-      
+
+      /* As we handle Arch all packages as architecture bounded
+         we add all information to every (simulated) arch package */
+      std::vector<string> genArch;
+      if (List.ArchitectureAll() == true) {
+        genArch = APT::Configuration::getArchitectures();
+        if (genArch.size() != 1)
+           genArch.push_back("all");
+      } else
+        genArch.push_back(List.Architecture());
+
+      for (std::vector<string>::const_iterator arch = genArch.begin();
+          arch != genArch.end(); ++arch)
+      {
+      // Get a pointer to the package structure
       pkgCache::PkgIterator Pkg;
-      if (NewPackage(Pkg,PackageName) == false)
+      if (NewPackage(Pkg, PackageName, *arch) == false)
         return _error->Error(_("Error occurred while processing %s (NewPackage)"),PackageName.c_str());
       Counter++;
       if (Counter % 100 == 0 && Progress != 0)
@@ -135,7 +151,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
         pkgCache::VerIterator Ver = Pkg.VersionList();
         map_ptrloc *LastVer = &Pkg->VersionList;
 
-        for (; Ver.end() == false; LastVer = &Ver->NextVer, Ver++) 
+        for (; Ver.end() == false; LastVer = &Ver->NextVer, Ver++)
         {
            pkgCache::DescIterator Desc = Ver.DescriptionList();
            map_ptrloc *LastDesc = &Ver->DescriptionList;
@@ -143,7 +159,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
 
            // don't add a new description if we have one for the given
            // md5 && language
-           for ( ; Desc.end() == false; Desc++)
+           for ( ; Desc.end() == false; Desc++)
               if (MD5SumValue(Desc.md5()) == CurMd5 && 
                   Desc.LanguageCode() == List.DescriptionLanguage())
                  duplicate=true;
@@ -151,7 +167,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
               continue;
            
            for (Desc = Ver.DescriptionList();
-                Desc.end() == false; 
+                Desc.end() == false;
                 LastDesc = &Desc->NextDesc, Desc++)
            {
               if (MD5SumValue(Desc.md5()) == CurMd5) 
@@ -160,7 +176,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
                  *LastDesc = NewDescription(Desc, List.DescriptionLanguage(), CurMd5, *LastDesc);
                  Desc->ParentPkg = Pkg.Index();
                  
-                 if (NewFileDesc(Desc,List) == false)
+                 if ((*LastDesc == 0 && _error->PendingError()) || NewFileDesc(Desc,List) == false)
                     return _error->Error(_("Error occurred while processing %s (NewFileDesc1)"),PackageName.c_str());
                  break;
               }
@@ -173,17 +189,22 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
       pkgCache::VerIterator Ver = Pkg.VersionList();
       map_ptrloc *LastVer = &Pkg->VersionList;
       int Res = 1;
+      unsigned long const Hash = List.VersionHash();
       for (; Ver.end() == false; LastVer = &Ver->NextVer, Ver++)
       {
         Res = Cache.VS->CmpVersion(Version,Ver.VerStr());
-        if (Res >= 0)
+        // Version is higher as current version - insert here
+        if (Res > 0)
+           break;
+        // Versionstrings are equal - is hash also equal?
+        if (Res == 0 && Ver->Hash == Hash)
            break;
+        // proceed with the next till we have either the right
+        // or we found another version (which will be lower)
       }
-      
-      /* We already have a version for this item, record that we
-         saw it */
-      unsigned long Hash = List.VersionHash();
-      if (Res == 0 && Ver->Hash == Hash)
+
+      /* We already have a version for this item, record that we saw it */
+      if (Res == 0 && Ver.end() == false && Ver->Hash == Hash)
       {
         if (List.UsePackage(Pkg,Ver) == false)
            return _error->Error(_("Error occurred while processing %s (UsePackage2)"),
@@ -202,17 +223,6 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
         }
         
         continue;
-      }      
-
-      // Skip to the end of the same version set.
-      if (Res == 0)
-      {
-        for (; Ver.end() == false; LastVer = &Ver->NextVer, Ver++)
-        {
-           Res = Cache.VS->CmpVersion(Version,Ver.VerStr());
-           if (Res != 0)
-              break;
-        }
       }
 
       // Add a new version
@@ -220,7 +230,7 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
       Ver->ParentPkg = Pkg.Index();
       Ver->Hash = Hash;
 
-      if (List.NewVersion(Ver) == false)
+      if ((*LastVer == 0 && _error->PendingError()) || List.NewVersion(Ver) == false)
         return _error->Error(_("Error occurred while processing %s (NewVersion1)"),
                              PackageName.c_str());
 
@@ -252,8 +262,9 @@ bool pkgCacheGenerator::MergeList(ListParser &List,
       *LastDesc = NewDescription(Desc, List.DescriptionLanguage(), List.Description_md5(), *LastDesc);
       Desc->ParentPkg = Pkg.Index();
 
-      if (NewFileDesc(Desc,List) == false)
+      if ((*LastDesc == 0 && _error->PendingError()) || NewFileDesc(Desc,List) == false)
         return _error->Error(_("Error occurred while processing %s (NewFileDesc2)"),PackageName.c_str());
+      }
    }
 
    FoundFileDeps |= List.HasFileDeps();
@@ -321,33 +332,71 @@ bool pkgCacheGenerator::MergeFileProvides(ListParser &List)
    return true;
 }
                                                                        /*}}}*/
+// CacheGenerator::NewGroup - Add a new group                          /*{{{*/
+// ---------------------------------------------------------------------
+/* This creates a new group structure and adds it to the hash table */
+bool pkgCacheGenerator::NewGroup(pkgCache::GrpIterator &Grp, const string &Name) {
+       Grp = Cache.FindGrp(Name);
+       if (Grp.end() == false)
+               return true;
+
+       // Get a structure
+       unsigned long const Group = Map.Allocate(sizeof(pkgCache::Group));
+       if (unlikely(Group == 0))
+               return false;
+
+       Grp = pkgCache::GrpIterator(Cache, Cache.GrpP + Group);
+       Grp->Name = Map.WriteString(Name);
+       if (unlikely(Grp->Name == 0))
+               return false;
+
+       // Insert it into the hash table
+       unsigned long const Hash = Cache.Hash(Name);
+       Grp->Next = Cache.HeaderP->GrpHashTable[Hash];
+       Cache.HeaderP->GrpHashTable[Hash] = Group;
+
+       Cache.HeaderP->GroupCount++;
+
+       return true;
+}
+                                                                       /*}}}*/
 // CacheGenerator::NewPackage - Add a new package                      /*{{{*/
 // ---------------------------------------------------------------------
 /* This creates a new package structure and adds it to the hash table */
-bool pkgCacheGenerator::NewPackage(pkgCache::PkgIterator &Pkg,const string &Name)
-{
-   Pkg = Cache.FindPkg(Name);
-   if (Pkg.end() == false)
-      return true;
+bool pkgCacheGenerator::NewPackage(pkgCache::PkgIterator &Pkg,const string &Name,
+                                       const string &Arch) {
+   pkgCache::GrpIterator Grp;
+   if (unlikely(NewGroup(Grp, Name) == false))
+      return false;
+
+   Pkg = Grp.FindPkg(Arch);
+      if (Pkg.end() == false)
+        return true;
 
    // Get a structure
-   unsigned long Package = Map.Allocate(sizeof(pkgCache::Package));
-   if (Package == 0)
+   unsigned long const Package = Map.Allocate(sizeof(pkgCache::Package));
+   if (unlikely(Package == 0))
       return false;
-   
    Pkg = pkgCache::PkgIterator(Cache,Cache.PkgP + Package);
-   
+
    // Insert it into the hash table
-   unsigned long Hash = Cache.Hash(Name);
-   Pkg->NextPackage = Cache.HeaderP->HashTable[Hash];
-   Cache.HeaderP->HashTable[Hash] = Package;
-   
-   // Set the name and the ID
-   Pkg->Name = Map.WriteString(Name);
-   if (Pkg->Name == 0)
+   unsigned long const Hash = Cache.Hash(Name);
+   Pkg->NextPackage = Cache.HeaderP->PkgHashTable[Hash];
+   Cache.HeaderP->PkgHashTable[Hash] = Package;
+
+   // remember the packages in the group
+   Grp->FirstPackage = Package;
+   if (Grp->LastPackage == 0)
+      Grp->LastPackage = Package;
+
+   // Set the name, arch and the ID
+   Pkg->Name = Grp->Name;
+   Pkg->Group = Grp.Index();
+   Pkg->Arch = WriteUniqString(Arch.c_str());
+   if (unlikely(Pkg->Arch == 0))
       return false;
    Pkg->ID = Cache.HeaderP->PackageCount++;
-   
+
    return true;
 }
                                                                        /*}}}*/
@@ -419,7 +468,7 @@ bool pkgCacheGenerator::NewFileDesc(pkgCache::DescIterator &Desc,
    // Get a structure
    unsigned long DescFile = Map.Allocate(sizeof(pkgCache::DescFile));
    if (DescFile == 0)
-      return 0;
+      return false;
 
    pkgCache::DescFileIterator DF(Cache,Cache.DescFileP + DescFile);
    DF->File = CurrentFile - Cache.PkgFileP;
@@ -460,25 +509,93 @@ map_ptrloc pkgCacheGenerator::NewDescription(pkgCache::DescIterator &Desc,
    Desc->ID = Cache.HeaderP->DescriptionCount++;
    Desc->language_code = Map.WriteString(Lang);
    Desc->md5sum = Map.WriteString(md5sum.Value());
+   if (Desc->language_code == 0 || Desc->md5sum == 0)
+      return 0;
 
    return Description;
 }
                                                                        /*}}}*/
-// ListParser::NewDepends - Create a dependency element                        /*{{{*/
+// CacheGenerator::FinishCache - do various finish operations          /*{{{*/
+// ---------------------------------------------------------------------
+/* This prepares the Cache for delivery */
+bool pkgCacheGenerator::FinishCache(OpProgress &Progress) {
+       // FIXME: add progress reporting for this operation
+       // Do we have different architectures in your groups ?
+       vector<string> archs = APT::Configuration::getArchitectures();
+       if (archs.size() > 1) {
+               // Create Conflicts in between the group
+               for (pkgCache::GrpIterator G = GetCache().GrpBegin(); G.end() != true; G++) {
+                       string const PkgName = G.Name();
+                       for (pkgCache::PkgIterator P = G.PackageList(); P.end() != true; P = G.NextPkg(P)) {
+                               if (strcmp(P.Arch(),"all") == 0)
+                                       continue;
+                               pkgCache::PkgIterator allPkg;
+                               for (pkgCache::VerIterator V = P.VersionList(); V.end() != true; V++) {
+                                       string const Arch = V.Arch(true);
+                                       map_ptrloc *OldDepLast = NULL;
+                                       /* MultiArch handling introduces a lot of implicit Dependencies:
+                                          - MultiArch: same → Co-Installable if they have the same version
+                                          - Architecture: all → Need to be Co-Installable for internal reasons
+                                          - All others conflict with all other group members */
+                                       bool const coInstall = (V->MultiArch == pkgCache::Version::All ||
+                                                               V->MultiArch == pkgCache::Version::Same);
+                                       if (V->MultiArch == pkgCache::Version::All && allPkg.end() == true)
+                                               allPkg = G.FindPkg("all");
+                                       for (vector<string>::const_iterator A = archs.begin(); A != archs.end(); ++A) {
+                                               if (*A == Arch)
+                                                       continue;
+                                               /* We allow only one installed arch at the time
+                                                  per group, therefore each group member conflicts
+                                                  with all other group members */
+                                               pkgCache::PkgIterator D = G.FindPkg(*A);
+                                               if (D.end() == true)
+                                                       continue;
+                                               if (coInstall == true) {
+                                                       // Replaces: ${self}:other ( << ${binary:Version})
+                                                       NewDepends(D, V, V.VerStr(),
+                                                                  pkgCache::Dep::Less, pkgCache::Dep::Replaces,
+                                                                  OldDepLast);
+                                                       // Breaks: ${self}:other (!= ${binary:Version})
+                                                       NewDepends(D, V, V.VerStr(),
+                                                                  pkgCache::Dep::Less, pkgCache::Dep::DpkgBreaks,
+                                                                  OldDepLast);
+                                                       NewDepends(D, V, V.VerStr(),
+                                                                  pkgCache::Dep::Greater, pkgCache::Dep::DpkgBreaks,
+                                                                  OldDepLast);
+                                                       if (V->MultiArch == pkgCache::Version::All) {
+                                                               // Depend on ${self}:all which does depend on nothing
+                                                               NewDepends(allPkg, V, V.VerStr(),
+                                                                          pkgCache::Dep::Equals, pkgCache::Dep::Depends,
+                                                                          OldDepLast);
+                                                       }
+                                               } else {
+                                                       // Conflicts: ${self}:other
+                                                       NewDepends(D, V, "",
+                                                                  pkgCache::Dep::NoOp, pkgCache::Dep::Conflicts,
+                                                                  OldDepLast);
+                                               }
+                                       }
+                               }
+                       }
+               }
+       }
+       return true;
+}
+                                                                       /*}}}*/
+// CacheGenerator::NewDepends - Create a dependency element            /*{{{*/
 // ---------------------------------------------------------------------
 /* This creates a dependency element in the tree. It is linked to the
    version and to the package that it is pointing to. */
-bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator Ver,
-                                              const string &PackageName,
-                                              const string &Version,
-                                              unsigned int Op,
-                                              unsigned int Type)
+bool pkgCacheGenerator::NewDepends(pkgCache::PkgIterator &Pkg,
+                                  pkgCache::VerIterator &Ver,
+                                  string const &Version,
+                                  unsigned int const &Op,
+                                  unsigned int const &Type,
+                                  map_ptrloc *OldDepLast)
 {
-   pkgCache &Cache = Owner->Cache;
-   
    // Get a structure
-   unsigned long Dependency = Owner->Map.Allocate(sizeof(pkgCache::Dependency));
-   if (Dependency == 0)
+   unsigned long const Dependency = Map.Allocate(sizeof(pkgCache::Dependency));
+   if (unlikely(Dependency == 0))
       return false;
    
    // Fill it in
@@ -487,12 +604,7 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator Ver,
    Dep->Type = Type;
    Dep->CompareOp = Op;
    Dep->ID = Cache.HeaderP->DependsCount++;
-   
-   // Locate the target package
-   pkgCache::PkgIterator Pkg;
-   if (Owner->NewPackage(Pkg,PackageName) == false)
-      return false;
-   
+
    // Probe the reverse dependency list for a version string that matches
    if (Version.empty() == false)
    {
@@ -500,29 +612,23 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator Ver,
         if (I->Version != 0 && I.TargetVer() == Version)
            Dep->Version = I->Version;*/
       if (Dep->Version == 0)
-        if ((Dep->Version = WriteString(Version)) == 0)
+        if (unlikely((Dep->Version = Map.WriteString(Version)) == 0))
            return false;
    }
-      
+
    // Link it to the package
    Dep->Package = Pkg.Index();
    Dep->NextRevDepends = Pkg->RevDepends;
    Pkg->RevDepends = Dep.Index();
-   
-   /* Link it to the version (at the end of the list)
-      Caching the old end point speeds up generation substantially */
-   if (OldDepVer != Ver)
+
+   // Do we know where to link the Dependency to?
+   if (OldDepLast == NULL)
    {
       OldDepLast = &Ver->DependsList;
       for (pkgCache::DepIterator D = Ver.DependsList(); D.end() == false; D++)
         OldDepLast = &D->NextDepends;
-      OldDepVer = Ver;
    }
 
-   // Is it a file dependency?
-   if (PackageName[0] == '/')
-      FoundFileDeps = true;
-   
    Dep->NextDepends = *OldDepLast;
    *OldDepLast = Dep.Index();
    OldDepLast = &Dep->NextDepends;
@@ -530,22 +636,58 @@ bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator Ver,
    return true;
 }
                                                                        /*}}}*/
+// ListParser::NewDepends - Create the environment for a new dependency        /*{{{*/
+// ---------------------------------------------------------------------
+/* This creates a Group and the Package to link this dependency to if
+   needed and handles also the caching of the old endpoint */
+bool pkgCacheGenerator::ListParser::NewDepends(pkgCache::VerIterator Ver,
+                                              const string &PackageName,
+                                              const string &Arch,
+                                              const string &Version,
+                                              unsigned int Op,
+                                              unsigned int Type)
+{
+   pkgCache::GrpIterator Grp;
+   if (unlikely(Owner->NewGroup(Grp, PackageName) == false))
+      return false;
+
+   // Locate the target package
+   pkgCache::PkgIterator Pkg = Grp.FindPkg(Arch);
+   if (Pkg.end() == true) {
+      if (unlikely(Owner->NewPackage(Pkg, PackageName, Arch) == false))
+        return false;
+   }
+
+   // Is it a file dependency?
+   if (unlikely(PackageName[0] == '/'))
+      FoundFileDeps = true;
+
+   /* Caching the old end point speeds up generation substantially */
+   if (OldDepVer != Ver) {
+      OldDepLast = NULL;
+      OldDepVer = Ver;
+   }
+
+   return Owner->NewDepends(Pkg, Ver, Version, Op, Type, OldDepLast);
+}
+                                                                       /*}}}*/
 // ListParser::NewProvides - Create a Provides element                 /*{{{*/
 // ---------------------------------------------------------------------
 /* */
 bool pkgCacheGenerator::ListParser::NewProvides(pkgCache::VerIterator Ver,
-                                               const string &PackageName,
+                                               const string &PkgName,
+                                               const string &PkgArch,
                                                const string &Version)
 {
    pkgCache &Cache = Owner->Cache;
 
    // We do not add self referencing provides
-   if (Ver.ParentPkg().Name() == PackageName)
+   if (Ver.ParentPkg().Name() == PkgName && PkgArch == Ver.Arch(true))
       return true;
    
    // Get a structure
-   unsigned long Provides = Owner->Map.Allocate(sizeof(pkgCache::Provides));
-   if (Provides == 0)
+   unsigned long const Provides = Owner->Map.Allocate(sizeof(pkgCache::Provides));
+   if (unlikely(Provides == 0))
       return false;
    Cache.HeaderP->ProvidesCount++;
    
@@ -554,12 +696,12 @@ bool pkgCacheGenerator::ListParser::NewProvides(pkgCache::VerIterator Ver,
    Prv->Version = Ver.Index();
    Prv->NextPkgProv = Ver->ProvidesList;
    Ver->ProvidesList = Prv.Index();
-   if (Version.empty() == false && (Prv->ProvideVersion = WriteString(Version)) == 0)
+   if (Version.empty() == false && unlikely((Prv->ProvideVersion = WriteString(Version)) == 0))
       return false;
    
    // Locate the target package
    pkgCache::PkgIterator Pkg;
-   if (Owner->NewPackage(Pkg,PackageName) == false)
+   if (unlikely(Owner->NewPackage(Pkg,PkgName, PkgArch) == false))
       return false;
    
    // Link it to the package
@@ -652,7 +794,6 @@ unsigned long pkgCacheGenerator::WriteUniqString(const char *S,
    return ItemP->String;
 }
                                                                        /*}}}*/
-
 // CheckValidity - Check that a cache is up-to-date                    /*{{{*/
 // ---------------------------------------------------------------------
 /* This just verifies that each file in the list of index files exists,
@@ -661,16 +802,23 @@ unsigned long pkgCacheGenerator::WriteUniqString(const char *S,
 static bool CheckValidity(const string &CacheFile, FileIterator Start, 
                           FileIterator End,MMap **OutMap = 0)
 {
+   bool const Debug = _config->FindB("Debug::pkgCacheGen", false);
    // No file, certainly invalid
    if (CacheFile.empty() == true || FileExists(CacheFile) == false)
+   {
+      if (Debug == true)
+        std::clog << "CacheFile doesn't exist" << std::endl;
       return false;
-   
+   }
+
    // Map it
    FileFd CacheF(CacheFile,FileFd::ReadOnly);
-   SPtr<MMap> Map = new MMap(CacheF,MMap::Public | MMap::ReadOnly);
+   SPtr<MMap> Map = new MMap(CacheF,0);
    pkgCache Cache(Map);
    if (_error->PendingError() == true || Map->Size() == 0)
    {
+      if (Debug == true)
+        std::clog << "Errors are pending or Map is empty()" << std::endl;
       _error->Discard();
       return false;
    }
@@ -680,9 +828,15 @@ static bool CheckValidity(const string &CacheFile, FileIterator Start,
    SPtrArray<bool> Visited = new bool[Cache.HeaderP->PackageFileCount];
    memset(Visited,0,sizeof(*Visited)*Cache.HeaderP->PackageFileCount);
    for (; Start != End; Start++)
-   {      
+   {
+      if (Debug == true)
+        std::clog << "Checking PkgFile " << (*Start)->Describe() << ": ";
       if ((*Start)->HasPackages() == false)
+      {
+         if (Debug == true)
+           std::clog << "Has NO packages" << std::endl;
         continue;
+      }
     
       if ((*Start)->Exists() == false)
       {
@@ -690,23 +844,40 @@ static bool CheckValidity(const string &CacheFile, FileIterator Start,
         _error->WarningE("stat",_("Couldn't stat source package list %s"),
                          (*Start)->Describe().c_str());
 #endif
+         if (Debug == true)
+           std::clog << "file doesn't exist" << std::endl;
         continue;
       }
 
       // FindInCache is also expected to do an IMS check.
       pkgCache::PkgFileIterator File = (*Start)->FindInCache(Cache);
       if (File.end() == true)
+      {
+        if (Debug == true)
+           std::clog << "FindInCache returned end-Pointer" << std::endl;
         return false;
+      }
 
       Visited[File->ID] = true;
+      if (Debug == true)
+        std::clog << "with ID " << File->ID << " is valid" << std::endl;
    }
    
    for (unsigned I = 0; I != Cache.HeaderP->PackageFileCount; I++)
       if (Visited[I] == false)
+      {
+        if (Debug == true)
+           std::clog << "File with ID" << I << " wasn't visited" << std::endl;
         return false;
+      }
    
    if (_error->PendingError() == true)
    {
+      if (Debug == true)
+      {
+        std::clog << "Validity failed because of pending errors:" << std::endl;
+        _error->DumpErrors();
+      }
       _error->Discard();
       return false;
    }
@@ -793,7 +964,8 @@ static bool BuildCache(pkgCacheGenerator &Gen,
 bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
                        MMap **OutMap,bool AllowMem)
 {
-   unsigned long MapSize = _config->FindI("APT::Cache-Limit",24*1024*1024);
+   bool const Debug = _config->FindB("Debug::pkgCacheGen", false);
+   unsigned long const MapSize = _config->FindI("APT::Cache-Limit",24*1024*1024);
    
    vector<pkgIndexFile *> Files;
    for (vector<metaIndex *>::const_iterator i = List.begin();
@@ -807,13 +979,13 @@ bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
          Files.push_back (*j);
    }
    
-   unsigned long EndOfSource = Files.size();
+   unsigned long const EndOfSource = Files.size();
    if (_system->AddStatusFiles(Files) == false)
       return false;
-   
+
    // Decide if we can write to the files..
-   string CacheFile = _config->FindFile("Dir::Cache::pkgcache");
-   string SrcCacheFile = _config->FindFile("Dir::Cache::srcpkgcache");
+   string const CacheFile = _config->FindFile("Dir::Cache::pkgcache");
+   string const SrcCacheFile = _config->FindFile("Dir::Cache::srcpkgcache");
    
    // Decide if we can write to the cache
    bool Writeable = false;
@@ -822,7 +994,9 @@ bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
    else
       if (SrcCacheFile.empty() == false)
         Writeable = access(flNotFile(SrcCacheFile).c_str(),W_OK) == 0;
-   
+   if (Debug == true)
+      std::clog << "Do we have write-access to the cache files? " << (Writeable ? "YES" : "NO") << std::endl;
+
    if (Writeable == false && AllowMem == false && CacheFile.empty() == false)
       return _error->Error(_("Unable to write to %s"),flNotFile(CacheFile).c_str());
    
@@ -832,8 +1006,12 @@ bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
    if (CheckValidity(CacheFile,Files.begin(),Files.end(),OutMap) == true)
    {
       Progress.OverallProgress(1,1,1,_("Reading package lists"));
+      if (Debug == true)
+        std::clog << "pkgcache.bin is valid - no need to build anything" << std::endl;
       return true;
    }
+   else if (Debug == true)
+        std::clog << "pkgcache.bin is NOT valid" << std::endl;
    
    /* At this point we know we need to reconstruct the package cache,
       begin. */
@@ -847,11 +1025,15 @@ bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
       Map = new DynamicMMap(*CacheF,MMap::Public,MapSize);
       if (_error->PendingError() == true)
         return false;
+      if (Debug == true)
+        std::clog << "Open filebased MMap" << std::endl;
    }
    else
    {
       // Just build it in memory..
-      Map = new DynamicMMap(MMap::Public,MapSize);
+      Map = new DynamicMMap(0,MapSize);
+      if (Debug == true)
+        std::clog << "Open memory Map (not filebased)" << std::endl;
    }
    
    // Lets try the source cache.
@@ -860,14 +1042,18 @@ bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
    if (CheckValidity(SrcCacheFile,Files.begin(),
                     Files.begin()+EndOfSource) == true)
    {
+      if (Debug == true)
+        std::clog << "srcpkgcache.bin is valid - populate MMap with it." << std::endl;
       // Preload the map with the source cache
       FileFd SCacheF(SrcCacheFile,FileFd::ReadOnly);
-      if (SCacheF.Read((unsigned char *)Map->Data() + Map->RawAllocate(SCacheF.Size()),
-                      SCacheF.Size()) == false)
+      unsigned long const alloc = Map->RawAllocate(SCacheF.Size());
+      if ((alloc == 0 && _error->PendingError())
+               || SCacheF.Read((unsigned char *)Map->Data() + alloc,
+                               SCacheF.Size()) == false)
         return false;
 
       TotalSize = ComputeSize(Files.begin()+EndOfSource,Files.end());
-      
+
       // Build the status cache
       pkgCacheGenerator Gen(Map.Get(),&Progress);
       if (_error->PendingError() == true)
@@ -875,9 +1061,14 @@ bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
       if (BuildCache(Gen,Progress,CurrentSize,TotalSize,
                     Files.begin()+EndOfSource,Files.end()) == false)
         return false;
+
+      // FIXME: move me to a better place
+      Gen.FinishCache(Progress);
    }
    else
    {
+      if (Debug == true)
+        std::clog << "srcpkgcache.bin is NOT valid - rebuild" << std::endl;
       TotalSize = ComputeSize(Files.begin(),Files.end());
       
       // Build the source cache
@@ -915,7 +1106,12 @@ bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
       if (BuildCache(Gen,Progress,CurrentSize,TotalSize,
                     Files.begin()+EndOfSource,Files.end()) == false)
         return false;
+
+      // FIXME: move me to a better place
+      Gen.FinishCache(Progress);
    }
+   if (Debug == true)
+      std::clog << "Caches are ready for shipping" << std::endl;
 
    if (_error->PendingError() == true)
       return false;
@@ -924,7 +1120,7 @@ bool pkgMakeStatusCache(pkgSourceList &List,OpProgress &Progress,
       if (CacheF != 0)
       {
         delete Map.UnGuard();
-        *OutMap = new MMap(*CacheF,MMap::Public | MMap::ReadOnly);
+        *OutMap = new MMap(*CacheF,0);
       }
       else
       {
@@ -946,8 +1142,7 @@ bool pkgMakeOnlyStatusCache(OpProgress &Progress,DynamicMMap **OutMap)
    if (_system->AddStatusFiles(Files) == false)
       return false;
    
-   SPtr<DynamicMMap> Map;   
-   Map = new DynamicMMap(MMap::Public,MapSize);
+   SPtr<DynamicMMap> Map = new DynamicMMap(0,MapSize);
    unsigned long CurrentSize = 0;
    unsigned long TotalSize = 0;
    
@@ -961,7 +1156,10 @@ bool pkgMakeOnlyStatusCache(OpProgress &Progress,DynamicMMap **OutMap)
    if (BuildCache(Gen,Progress,CurrentSize,TotalSize,
                  Files.begin()+EndOfSource,Files.end()) == false)
       return false;
-   
+
+   // FIXME: move me to a better place
+   Gen.FinishCache(Progress);
+
    if (_error->PendingError() == true)
       return false;
    *OutMap = Map.UnGuard();