]> git.saurik.com Git - apt.git/blobdiff - apt-pkg/acquire-item.cc
* apt-pkg/indexrecords.{cc,h}:
[apt.git] / apt-pkg / acquire-item.cc
index bc6d8cead6e1416644df03b401cd7ddc11ae8e1d..9e29f81893f0f51be3e66ad62691afb19bcaef72 100644 (file)
    ##################################################################### */
                                                                        /*}}}*/
 // Include Files                                                       /*{{{*/
-#ifdef __GNUG__
-#pragma implementation "apt-pkg/acquire-item.h"
-#endif
 #include <apt-pkg/acquire-item.h>
 #include <apt-pkg/configuration.h>
+#include <apt-pkg/aptconfiguration.h>
 #include <apt-pkg/sourcelist.h>
 #include <apt-pkg/vendorlist.h>
 #include <apt-pkg/error.h>
 #include <apt-pkg/strutl.h>
 #include <apt-pkg/fileutl.h>
 #include <apt-pkg/md5.h>
+#include <apt-pkg/sha1.h>
+#include <apt-pkg/tagfile.h>
 
 #include <apti18n.h>
     
@@ -31,6 +31,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <string>
+#include <sstream>
 #include <stdio.h>
                                                                        /*}}}*/
 
@@ -95,12 +96,13 @@ void pkgAcquire::Item::Start(string /*Message*/,unsigned long Size)
 // Acquire::Item::Done - Item downloaded OK                            /*{{{*/
 // ---------------------------------------------------------------------
 /* */
-void pkgAcquire::Item::Done(string Message,unsigned long Size,string,
+void pkgAcquire::Item::Done(string Message,unsigned long Size,string Hash,
                            pkgAcquire::MethodConfig *Cnf)
 {
    // We just downloaded something..
    string FileName = LookupTag(Message,"Filename");
-   if (Complete == false && FileName == DestFile)
+   // we only inform the Log class if it was actually not a local thing
+   if (Complete == false && !Local && FileName == DestFile)
    {
       if (Owner->Log != 0)
         Owner->Log->Fetched(Size,atoi(LookupTag(Message,"Resume-Point","0").c_str()));
@@ -130,15 +132,460 @@ void pkgAcquire::Item::Rename(string From,string To)
    }   
 }
                                                                        /*}}}*/
+// AcqDiffIndex::AcqDiffIndex - Constructor                            /*{{{*/
+// ---------------------------------------------------------------------
+/* Get the DiffIndex file first and see if there are patches availabe 
+ * If so, create a pkgAcqIndexDiffs fetcher that will get and apply the
+ * patches. If anything goes wrong in that process, it will fall back to
+ * the original packages file
+ */
+pkgAcqDiffIndex::pkgAcqDiffIndex(pkgAcquire *Owner,
+                                string URI,string URIDesc,string ShortDesc,
+                                HashString ExpectedHash)
+   : Item(Owner), RealURI(URI), ExpectedHash(ExpectedHash),
+     Description(URIDesc)
+{
+   
+   Debug = _config->FindB("Debug::pkgAcquire::Diffs",false);
+
+   Desc.Description = URIDesc + "/DiffIndex";
+   Desc.Owner = this;
+   Desc.ShortDesc = ShortDesc;
+   Desc.URI = URI + ".diff/Index";
+
+   DestFile = _config->FindDir("Dir::State::lists") + "partial/";
+   DestFile += URItoFileName(URI) + string(".DiffIndex");
+
+   if(Debug)
+      std::clog << "pkgAcqDiffIndex: " << Desc.URI << std::endl;
+
+   // look for the current package file
+   CurrentPackagesFile = _config->FindDir("Dir::State::lists");
+   CurrentPackagesFile += URItoFileName(RealURI);
+
+   // FIXME: this file:/ check is a hack to prevent fetching
+   //        from local sources. this is really silly, and
+   //        should be fixed cleanly as soon as possible
+   if(!FileExists(CurrentPackagesFile) || 
+      Desc.URI.substr(0,strlen("file:/")) == "file:/")
+   {
+      // we don't have a pkg file or we don't want to queue
+      if(Debug)
+        std::clog << "No index file, local or canceld by user" << std::endl;
+      Failed("", NULL);
+      return;
+   }
+
+   if(Debug) 
+      std::clog << "pkgAcqIndexDiffs::pkgAcqIndexDiffs(): " 
+               << CurrentPackagesFile << std::endl;
+   
+   QueueURI(Desc);
+
+}
+                                                                       /*}}}*/
+// AcqIndex::Custom600Headers - Insert custom request headers          /*{{{*/
+// ---------------------------------------------------------------------
+/* The only header we use is the last-modified header. */
+string pkgAcqDiffIndex::Custom600Headers()
+{
+   string Final = _config->FindDir("Dir::State::lists");
+   Final += URItoFileName(RealURI) + string(".IndexDiff");
+   
+   if(Debug)
+      std::clog << "Custom600Header-IMS: " << Final << std::endl;
+
+   struct stat Buf;
+   if (stat(Final.c_str(),&Buf) != 0)
+      return "\nIndex-File: true";
+   
+   return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
+}
+                                                                       /*}}}*/
+bool pkgAcqDiffIndex::ParseDiffIndex(string IndexDiffFile)             /*{{{*/
+{
+   if(Debug)
+      std::clog << "pkgAcqIndexDiffs::ParseIndexDiff() " << IndexDiffFile 
+               << std::endl;
+
+   pkgTagSection Tags;
+   string ServerSha1;
+   vector<DiffInfo> available_patches;
+   
+   FileFd Fd(IndexDiffFile,FileFd::ReadOnly);
+   pkgTagFile TF(&Fd);
+   if (_error->PendingError() == true)
+      return false;
+
+   if(TF.Step(Tags) == true)
+   {
+      bool found = false;
+      DiffInfo d;
+      string size;
+
+      string const tmp = Tags.FindS("SHA1-Current");
+      std::stringstream ss(tmp);
+      ss >> ServerSha1 >> size;
+      unsigned long const ServerSize = atol(size.c_str());
+
+      FileFd fd(CurrentPackagesFile, FileFd::ReadOnly);
+      SHA1Summation SHA1;
+      SHA1.AddFD(fd.Fd(), fd.Size());
+      string const local_sha1 = SHA1.Result();
+
+      if(local_sha1 == ServerSha1) 
+      {
+        // we have the same sha1 as the server
+        if(Debug)
+           std::clog << "Package file is up-to-date" << std::endl;
+        // set found to true, this will queue a pkgAcqIndexDiffs with
+        // a empty availabe_patches
+        found = true;
+      } 
+      else 
+      {
+        if(Debug)
+           std::clog << "SHA1-Current: " << ServerSha1 << std::endl;
+
+        // check the historie and see what patches we need
+        string const history = Tags.FindS("SHA1-History");
+        std::stringstream hist(history);
+        while(hist >> d.sha1 >> size >> d.file)
+        {
+           // read until the first match is found
+           // from that point on, we probably need all diffs
+           if(d.sha1 == local_sha1) 
+              found=true;
+           else if (found == false)
+              continue;
+
+           if(Debug)
+              std::clog << "Need to get diff: " << d.file << std::endl;
+           available_patches.push_back(d);
+        }
+
+        if (available_patches.empty() == false)
+        {
+           // patching with too many files is rather slow compared to a fast download
+           unsigned long const fileLimit = _config->FindI("Acquire::PDiffs::FileLimit", 0);
+           if (fileLimit != 0 && fileLimit < available_patches.size())
+           {
+              if (Debug)
+                 std::clog << "Need " << available_patches.size() << " diffs (Limit is " << fileLimit
+                       << ") so fallback to complete download" << std::endl;
+              return false;
+           }
+
+           // see if the patches are too big
+           found = false; // it was true and it will be true again at the end
+           d = *available_patches.begin();
+           string const firstPatch = d.file;
+           unsigned long patchesSize = 0;
+           std::stringstream patches(Tags.FindS("SHA1-Patches"));
+           while(patches >> d.sha1 >> size >> d.file)
+           {
+              if (firstPatch == d.file)
+                 found = true;
+              else if (found == false)
+                 continue;
+
+              patchesSize += atol(size.c_str());
+           }
+           unsigned long const sizeLimit = ServerSize * _config->FindI("Acquire::PDiffs::SizeLimit", 100);
+           if (sizeLimit > 0 && (sizeLimit/100) < patchesSize)
+           {
+              if (Debug)
+                 std::clog << "Need " << patchesSize << " bytes (Limit is " << sizeLimit/100
+                       << ") so fallback to complete download" << std::endl;
+              return false;
+           }
+        }
+      }
+
+      // we have something, queue the next diff
+      if(found) 
+      {
+        // queue the diffs
+        string::size_type const last_space = Description.rfind(" ");
+        if(last_space != string::npos)
+           Description.erase(last_space, Description.size()-last_space);
+        new pkgAcqIndexDiffs(Owner, RealURI, Description, Desc.ShortDesc,
+                             ExpectedHash, ServerSha1, available_patches);
+        Complete = false;
+        Status = StatDone;
+        Dequeue();
+        return true;
+      }
+   }
+   
+   // Nothing found, report and return false
+   // Failing here is ok, if we return false later, the full
+   // IndexFile is queued
+   if(Debug)
+      std::clog << "Can't find a patch in the index file" << std::endl;
+   return false;
+}
+                                                                       /*}}}*/
+void pkgAcqDiffIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)     /*{{{*/
+{
+   if(Debug)
+      std::clog << "pkgAcqDiffIndex failed: " << Desc.URI << std::endl
+               << "Falling back to normal index file aquire" << std::endl;
+
+   new pkgAcqIndex(Owner, RealURI, Description, Desc.ShortDesc, 
+                  ExpectedHash);
+
+   Complete = false;
+   Status = StatDone;
+   Dequeue();
+}
+                                                                       /*}}}*/
+void pkgAcqDiffIndex::Done(string Message,unsigned long Size,string Md5Hash,   /*{{{*/
+                          pkgAcquire::MethodConfig *Cnf)
+{
+   if(Debug)
+      std::clog << "pkgAcqDiffIndex::Done(): " << Desc.URI << std::endl;
+
+   Item::Done(Message,Size,Md5Hash,Cnf);
+
+   string FinalFile;
+   FinalFile = _config->FindDir("Dir::State::lists")+URItoFileName(RealURI);
+
+   // sucess in downloading the index
+   // rename the index
+   FinalFile += string(".IndexDiff");
+   if(Debug)
+      std::clog << "Renaming: " << DestFile << " -> " << FinalFile 
+               << std::endl;
+   Rename(DestFile,FinalFile);
+   chmod(FinalFile.c_str(),0644);
+   DestFile = FinalFile;
+
+   if(!ParseDiffIndex(DestFile))
+      return Failed("", NULL);
+
+   Complete = true;
+   Status = StatDone;
+   Dequeue();
+   return;
+}
+                                                                       /*}}}*/
+// AcqIndexDiffs::AcqIndexDiffs - Constructor                          /*{{{*/
+// ---------------------------------------------------------------------
+/* The package diff is added to the queue. one object is constructed
+ * for each diff and the index
+ */
+pkgAcqIndexDiffs::pkgAcqIndexDiffs(pkgAcquire *Owner,
+                                  string URI,string URIDesc,string ShortDesc,
+                                  HashString ExpectedHash, 
+                                  string ServerSha1,
+                                  vector<DiffInfo> diffs)
+   : Item(Owner), RealURI(URI), ExpectedHash(ExpectedHash), 
+     available_patches(diffs), ServerSha1(ServerSha1)
+{
+   
+   DestFile = _config->FindDir("Dir::State::lists") + "partial/";
+   DestFile += URItoFileName(URI);
+
+   Debug = _config->FindB("Debug::pkgAcquire::Diffs",false);
+
+   Description = URIDesc;
+   Desc.Owner = this;
+   Desc.ShortDesc = ShortDesc;
+
+   if(available_patches.size() == 0) 
+   {
+      // we are done (yeah!)
+      Finish(true);
+   }
+   else
+   {
+      // get the next diff
+      State = StateFetchDiff;
+      QueueNextDiff();
+   }
+}
+                                                                       /*}}}*/
+void pkgAcqIndexDiffs::Failed(string Message,pkgAcquire::MethodConfig *Cnf)    /*{{{*/
+{
+   if(Debug)
+      std::clog << "pkgAcqIndexDiffs failed: " << Desc.URI << std::endl
+               << "Falling back to normal index file aquire" << std::endl;
+   new pkgAcqIndex(Owner, RealURI, Description,Desc.ShortDesc, 
+                  ExpectedHash);
+   Finish();
+}
+                                                                       /*}}}*/
+// Finish - helper that cleans the item out of the fetcher queue       /*{{{*/
+void pkgAcqIndexDiffs::Finish(bool allDone)
+{
+   // we restore the original name, this is required, otherwise
+   // the file will be cleaned
+   if(allDone) 
+   {
+      DestFile = _config->FindDir("Dir::State::lists");
+      DestFile += URItoFileName(RealURI);
+
+      if(!ExpectedHash.empty() && !ExpectedHash.VerifyFile(DestFile))
+      {
+        Status = StatAuthError;
+        ErrorText = _("MD5Sum mismatch");
+        Rename(DestFile,DestFile + ".FAILED");
+        Dequeue();
+        return;
+      }
+
+      // this is for the "real" finish
+      Complete = true;
+      Status = StatDone;
+      Dequeue();
+      if(Debug)
+        std::clog << "\n\nallDone: " << DestFile << "\n" << std::endl;
+      return;
+   }
+
+   if(Debug)
+      std::clog << "Finishing: " << Desc.URI << std::endl;
+   Complete = false;
+   Status = StatDone;
+   Dequeue();
+   return;
+}
+                                                                       /*}}}*/
+bool pkgAcqIndexDiffs::QueueNextDiff()                                 /*{{{*/
+{
+
+   // calc sha1 of the just patched file
+   string FinalFile = _config->FindDir("Dir::State::lists");
+   FinalFile += URItoFileName(RealURI);
+
+   FileFd fd(FinalFile, FileFd::ReadOnly);
+   SHA1Summation SHA1;
+   SHA1.AddFD(fd.Fd(), fd.Size());
+   string local_sha1 = string(SHA1.Result());
+   if(Debug)
+      std::clog << "QueueNextDiff: " 
+               << FinalFile << " (" << local_sha1 << ")"<<std::endl;
+
+   // final file reached before all patches are applied
+   if(local_sha1 == ServerSha1)
+   {
+      Finish(true);
+      return true;
+   }
+
+   // remove all patches until the next matching patch is found
+   // this requires the Index file to be ordered
+   for(vector<DiffInfo>::iterator I=available_patches.begin();
+       available_patches.size() > 0 && 
+         I != available_patches.end() &&
+         (*I).sha1 != local_sha1; 
+       I++) 
+   {
+      available_patches.erase(I);
+   }
+
+   // error checking and falling back if no patch was found
+   if(available_patches.size() == 0) 
+   { 
+      Failed("", NULL);
+      return false;
+   }
+
+   // queue the right diff
+   Desc.URI = string(RealURI) + ".diff/" + available_patches[0].file + ".gz";
+   Desc.Description = Description + " " + available_patches[0].file + string(".pdiff");
+   DestFile = _config->FindDir("Dir::State::lists") + "partial/";
+   DestFile += URItoFileName(RealURI + ".diff/" + available_patches[0].file);
+
+   if(Debug)
+      std::clog << "pkgAcqIndexDiffs::QueueNextDiff(): " << Desc.URI << std::endl;
+   
+   QueueURI(Desc);
+
+   return true;
+}
+                                                                       /*}}}*/
+void pkgAcqIndexDiffs::Done(string Message,unsigned long Size,string Md5Hash,  /*{{{*/
+                           pkgAcquire::MethodConfig *Cnf)
+{
+   if(Debug)
+      std::clog << "pkgAcqIndexDiffs::Done(): " << Desc.URI << std::endl;
+
+   Item::Done(Message,Size,Md5Hash,Cnf);
+
+   string FinalFile;
+   FinalFile = _config->FindDir("Dir::State::lists")+URItoFileName(RealURI);
+
+   // sucess in downloading a diff, enter ApplyDiff state
+   if(State == StateFetchDiff) 
+   {
+
+      if(Debug)
+        std::clog << "Sending to gzip method: " << FinalFile << std::endl;
+
+      string FileName = LookupTag(Message,"Filename");
+      State = StateUnzipDiff;
+      Local = true;
+      Desc.URI = "gzip:" + FileName;
+      DestFile += ".decomp";
+      QueueURI(Desc);
+      Mode = "gzip";
+      return;
+   } 
+
+   // sucess in downloading a diff, enter ApplyDiff state
+   if(State == StateUnzipDiff) 
+   {
+
+      // rred excepts the patch as $FinalFile.ed
+      Rename(DestFile,FinalFile+".ed");
 
+      if(Debug)
+        std::clog << "Sending to rred method: " << FinalFile << std::endl;
+
+      State = StateApplyDiff;
+      Local = true;
+      Desc.URI = "rred:" + FinalFile;
+      QueueURI(Desc);
+      Mode = "rred";
+      return;
+   } 
+
+
+   // success in download/apply a diff, queue next (if needed)
+   if(State == StateApplyDiff)
+   {
+      // remove the just applied patch
+      available_patches.erase(available_patches.begin());
+
+      // move into place
+      if(Debug) 
+      {
+        std::clog << "Moving patched file in place: " << std::endl
+                  << DestFile << " -> " << FinalFile << std::endl;
+      }
+      Rename(DestFile,FinalFile);
+      chmod(FinalFile.c_str(),0644);
+
+      // see if there is more to download
+      if(available_patches.size() > 0) {
+        new pkgAcqIndexDiffs(Owner, RealURI, Description, Desc.ShortDesc,
+                             ExpectedHash, ServerSha1, available_patches);
+        return Finish();
+      } else 
+        return Finish(true);
+   }
+}
+                                                                       /*}}}*/
 // AcqIndex::AcqIndex - Constructor                                    /*{{{*/
 // ---------------------------------------------------------------------
 /* The package file is added to the queue and a second class is 
    instantiated to fetch the revision file */   
 pkgAcqIndex::pkgAcqIndex(pkgAcquire *Owner,
                         string URI,string URIDesc,string ShortDesc,
-                        string ExpectedMD5, string comprExt) :
-   Item(Owner), RealURI(URI), ExpectedMD5(ExpectedMD5)
+                        HashString ExpectedHash, string comprExt)
+   : Item(Owner), RealURI(URI), ExpectedHash(ExpectedHash)
 {
    Decompression = false;
    Erase = false;
@@ -149,14 +596,15 @@ pkgAcqIndex::pkgAcqIndex(pkgAcquire *Owner,
    if(comprExt.empty()) 
    {
       // autoselect the compression method
-      if(FileExists("/bin/bzip2")) 
-        CompressionExtension = ".bz2";
-      else 
-        CompressionExtension = ".gz";
-   } else {
-      CompressionExtension = comprExt;
+      std::vector<std::string> types = APT::Configuration::getCompressionTypes();
+      if (types.empty() == true)
+        comprExt = "plain";
+      else
+        comprExt = "." + types[0];
    }
-   Desc.URI = URI + CompressionExtension; 
+   CompressionExtension = ((comprExt == "plain" || comprExt == ".") ? "" : comprExt);
+
+   Desc.URI = URI + CompressionExtension;
 
    Desc.Description = URIDesc;
    Desc.Owner = this;
@@ -180,27 +628,45 @@ string pkgAcqIndex::Custom600Headers()
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
 }
                                                                        /*}}}*/
-
-void pkgAcqIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
+void pkgAcqIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf) /*{{{*/
 {
-   // no .bz2 found, retry with .gz
-   if(Desc.URI.substr(Desc.URI.size()-3) == "bz2") {
-      Desc.URI = Desc.URI.substr(0,Desc.URI.size()-3) + "gz"; 
+   std::vector<std::string> types = APT::Configuration::getCompressionTypes();
+
+   for (std::vector<std::string>::const_iterator t = types.begin();
+       t != types.end(); t++)
+   {
+      // jump over all already tried compression types
+      const unsigned int nameLen = Desc.URI.size() - (*t).size();
+      if(Desc.URI.substr(nameLen) != *t)
+        continue;
 
-      // retry with a gzip one 
-      new pkgAcqIndex(Owner, RealURI, Desc.Description,Desc.ShortDesc, 
-                     ExpectedMD5, string(".gz"));
+      // we want to try it with the next extension (and make sure to 
+      // not skip over the end)
+      t++;
+      if (t == types.end())
+        break;
+
+      // queue new download
+      Desc.URI = Desc.URI.substr(0, nameLen) + *t;
+      new pkgAcqIndex(Owner, RealURI, Desc.Description, Desc.ShortDesc,
+      ExpectedHash, string(".").append(*t));
+      
       Status = StatDone;
       Complete = false;
       Dequeue();
       return;
    }
 
-   
+   // on decompression failure, remove bad versions in partial/
+   if(Decompression && Erase) {
+      string s = _config->FindDir("Dir::State::lists") + "partial/";
+      s += URItoFileName(RealURI);
+      unlink(s.c_str());
+   }
+
    Item::Failed(Message,Cnf);
 }
-
-
+                                                                       /*}}}*/
 // AcqIndex::Done - Finished a fetch                                   /*{{{*/
 // ---------------------------------------------------------------------
 /* This goes through a number of states.. On the initial fetch the
@@ -208,32 +674,23 @@ void pkgAcqIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    to the uncompressed version of the file. If this is so the file
    is copied into the partial directory. In all other cases the file
    is decompressed with a gzip uri. */
-void pkgAcqIndex::Done(string Message,unsigned long Size,string MD5,
+void pkgAcqIndex::Done(string Message,unsigned long Size,string Hash,
                       pkgAcquire::MethodConfig *Cfg)
 {
-   Item::Done(Message,Size,MD5,Cfg);
+   Item::Done(Message,Size,Hash,Cfg);
 
    if (Decompression == true)
    {
       if (_config->FindB("Debug::pkgAcquire::Auth", false))
       {
-         std::cerr << std::endl << RealURI << ": Computed MD5: " << MD5;
-         std::cerr << "  Expected MD5: " << ExpectedMD5 << std::endl;
-      }
-
-      if (MD5.empty())
-      {
-         MD5Summation sum;
-         FileFd Fd(DestFile, FileFd::ReadOnly);
-         sum.AddFD(Fd.Fd(), Fd.Size());
-         Fd.Close();
-         MD5 = (string)sum.Result();
+         std::cerr << std::endl << RealURI << ": Computed Hash: " << Hash;
+         std::cerr << "  Expected Hash: " << ExpectedHash.toStr() << std::endl;
       }
 
-      if (!ExpectedMD5.empty() && MD5 != ExpectedMD5)
+      if (!ExpectedHash.empty() && ExpectedHash.toStr() != Hash)
       {
          Status = StatAuthError;
-         ErrorText = _("MD5Sum mismatch");
+         ErrorText = _("Hash Sum mismatch");
          Rename(DestFile,DestFile + ".FAILED");
          return;
       }
@@ -263,10 +720,7 @@ void pkgAcqIndex::Done(string Message,unsigned long Size,string MD5,
    {
       // The files timestamp matches
       if (StringToBool(LookupTag(Message,"Alt-IMS-Hit"),false) == true)
-      {
-        unlink(FileName.c_str());
         return;
-      }
       Decompression = true;
       Local = true;
       DestFile += ".decomp";
@@ -285,22 +739,26 @@ void pkgAcqIndex::Done(string Message,unsigned long Size,string MD5,
    
    // The files timestamp matches
    if (StringToBool(LookupTag(Message,"IMS-Hit"),false) == true)
-   {
-      unlink(FileName.c_str());
       return;
-   }
 
    if (FileName == DestFile)
       Erase = true;
    else
       Local = true;
    
-   string compExt = Desc.URI.substr(Desc.URI.size()-3);
-   char *decompProg;
-   if(compExt == "bz2") 
-      decompProg = "bzip2";
-   else if(compExt == ".gz") 
-      decompProg = "gzip";
+   string compExt = flExtension(flNotDir(URI(Desc.URI).Path));
+   string decompProg;
+
+   // get the binary name for your used compression type
+   decompProg = _config->Find(string("Acquire::CompressionTypes::").append(compExt),"");
+   if(decompProg.empty() == false);
+   // flExtensions returns the full name if no extension is found
+   // this is why we have this complicated compare operation here
+   // FIMXE: add a new flJustExtension() that return "" if no
+   //        extension is found and use that above so that it can
+   //        be tested against ""
+   else if(compExt == flNotDir(URI(Desc.URI).Path))
+      decompProg = "copy";
    else {
       _error->Error("Unsupported extension: %s", compExt.c_str());
       return;
@@ -308,12 +766,39 @@ void pkgAcqIndex::Done(string Message,unsigned long Size,string MD5,
 
    Decompression = true;
    DestFile += ".decomp";
-   Desc.URI = string(decompProg) + ":" + FileName;
+   Desc.URI = decompProg + ":" + FileName;
    QueueURI(Desc);
-   Mode = decompProg;
+   Mode = decompProg.c_str();
 }
-
-pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,
+                                                                       /*}}}*/
+// AcqIndexTrans::pkgAcqIndexTrans - Constructor                       /*{{{*/
+// ---------------------------------------------------------------------
+/* The Translation file is added to the queue */
+pkgAcqIndexTrans::pkgAcqIndexTrans(pkgAcquire *Owner,
+                           string URI,string URIDesc,string ShortDesc) 
+  : pkgAcqIndex(Owner, URI, URIDesc, ShortDesc, HashString(), "")
+{
+}
+                                                                       /*}}}*/
+// AcqIndexTrans::Failed - Silence failure messages for missing files  /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+void pkgAcqIndexTrans::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
+{
+   if (Cnf->LocalOnly == true || 
+       StringToBool(LookupTag(Message,"Transient-Failure"),false) == false)
+   {      
+      // Ignore this
+      Status = StatDone;
+      Complete = false;
+      Dequeue();
+      return;
+   }
+   
+   Item::Failed(Message,Cnf);
+}
+                                                                       /*}}}*/
+pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,                                /*{{{*/
                             string URI,string URIDesc,string ShortDesc,
                             string MetaIndexURI, string MetaIndexURIDesc,
                             string MetaIndexShortDesc,
@@ -326,8 +811,9 @@ pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,
    DestFile = _config->FindDir("Dir::State::lists") + "partial/";
    DestFile += URItoFileName(URI);
 
-   // remove any partial downloaded sig-file. it may confuse proxies
-   // and is too small to warrant a partial download anyway
+   // remove any partial downloaded sig-file in partial/. 
+   // it may confuse proxies and is too small to warrant a 
+   // partial download anyway
    unlink(DestFile.c_str());
 
    // Create the item
@@ -335,16 +821,19 @@ pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,
    Desc.Owner = this;
    Desc.ShortDesc = ShortDesc;
    Desc.URI = URI;
-   
       
    string Final = _config->FindDir("Dir::State::lists");
    Final += URItoFileName(RealURI);
    struct stat Buf;
    if (stat(Final.c_str(),&Buf) == 0)
    {
-      // File was already in place.  It needs to be re-verified
-      // because Release might have changed, so Move it into partial
-      Rename(Final,DestFile);
+      // File was already in place.  It needs to be re-downloaded/verified
+      // because Release might have changed, we do give it a differnt
+      // name than DestFile because otherwise the http method will
+      // send If-Range requests and there are too many broken servers
+      // out there that do not understand them
+      LastGoodSig = DestFile+".reverify";
+      Rename(Final,LastGoodSig);
    }
 
    QueueURI(Desc);
@@ -356,7 +845,7 @@ pkgAcqMetaSig::pkgAcqMetaSig(pkgAcquire *Owner,
 string pkgAcqMetaSig::Custom600Headers()
 {
    struct stat Buf;
-   if (stat(DestFile.c_str(),&Buf) != 0)
+   if (stat(LastGoodSig.c_str(),&Buf) != 0)
       return "\nIndex-File: true";
 
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
@@ -386,25 +875,36 @@ void pkgAcqMetaSig::Done(string Message,unsigned long Size,string MD5,
 
    Complete = true;
 
+   // put the last known good file back on i-m-s hit (it will
+   // be re-verified again)
+   // Else do nothing, we have the new file in DestFile then
+   if(StringToBool(LookupTag(Message,"IMS-Hit"),false) == true)
+      Rename(LastGoodSig, DestFile);
+
    // queue a pkgAcqMetaIndex to be verified against the sig we just retrieved
    new pkgAcqMetaIndex(Owner, MetaIndexURI, MetaIndexURIDesc, MetaIndexShortDesc,
                       DestFile, IndexTargets, MetaIndexParser);
 
 }
                                                                        /*}}}*/
-void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
+void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)/*{{{*/
 {
+   string Final = _config->FindDir("Dir::State::lists") + URItoFileName(RealURI);
 
    // if we get a network error we fail gracefully
-   if(LookupTag(Message,"FailReason") == "Timeout" || 
-      LookupTag(Message,"FailReason") == "TmpResolveFailure" ||
-      LookupTag(Message,"FailReason") == "ConnectionRefused") {
+   if(Status == StatTransientNetworkError)
+   {
       Item::Failed(Message,Cnf);
+      // move the sigfile back on transient network failures 
+      if(FileExists(DestFile))
+        Rename(LastGoodSig,Final);
+
+      // set the status back to , Item::Failed likes to reset it
+      Status = pkgAcquire::Item::StatTransientNetworkError;
       return;
    }
 
    // Delete any existing sigfile when the acquire failed
-   string Final = _config->FindDir("Dir::State::lists") + URItoFileName(RealURI);
    unlink(Final.c_str());
 
    // queue a pkgAcqMetaIndex with no sigfile
@@ -423,14 +923,14 @@ void pkgAcqMetaSig::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    
    Item::Failed(Message,Cnf);
 }
-
-pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire *Owner,
+                                                                       /*}}}*/
+pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire *Owner,                    /*{{{*/
                                 string URI,string URIDesc,string ShortDesc,
                                 string SigFile,
                                 const vector<struct IndexTarget*>* IndexTargets,
                                 indexRecords* MetaIndexParser) :
-   Item(Owner), RealURI(URI), SigFile(SigFile), AuthPass(false),
-   MetaIndexParser(MetaIndexParser), IndexTargets(IndexTargets), IMSHit(false)
+   Item(Owner), RealURI(URI), SigFile(SigFile), IndexTargets(IndexTargets),
+   MetaIndexParser(MetaIndexParser), AuthPass(false), IMSHit(false)
 {
    DestFile = _config->FindDir("Dir::State::lists") + "partial/";
    DestFile += URItoFileName(URI);
@@ -443,7 +943,6 @@ pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire *Owner,
 
    QueueURI(Desc);
 }
-
                                                                        /*}}}*/
 // pkgAcqMetaIndex::Custom600Headers - Insert custom request headers   /*{{{*/
 // ---------------------------------------------------------------------
@@ -459,11 +958,11 @@ string pkgAcqMetaIndex::Custom600Headers()
    
    return "\nIndex-File: true\nLast-Modified: " + TimeRFC1123(Buf.st_mtime);
 }
-
-void pkgAcqMetaIndex::Done(string Message,unsigned long Size,string MD5,
+                                                                       /*}}}*/
+void pkgAcqMetaIndex::Done(string Message,unsigned long Size,string Hash,      /*{{{*/
                           pkgAcquire::MethodConfig *Cfg)
 {
-   Item::Done(Message,Size,MD5,Cfg);
+   Item::Done(Message,Size,Hash,Cfg);
 
    // MetaIndexes are done in two passes: one to download the
    // metaindex with an appropriate method, and a second to verify it
@@ -501,8 +1000,8 @@ void pkgAcqMetaIndex::Done(string Message,unsigned long Size,string MD5,
       }
    }
 }
-
-void pkgAcqMetaIndex::RetrievalDone(string Message)
+                                                                       /*}}}*/
+void pkgAcqMetaIndex::RetrievalDone(string Message)                    /*{{{*/
 {
    // We have just finished downloading a Release file (it is not
    // verified yet)
@@ -540,8 +1039,8 @@ void pkgAcqMetaIndex::RetrievalDone(string Message)
    chmod(FinalFile.c_str(),0644);
    DestFile = FinalFile;
 }
-
-void pkgAcqMetaIndex::AuthDone(string Message)
+                                                                       /*}}}*/
+void pkgAcqMetaIndex::AuthDone(string Message)                         /*{{{*/
 {
    // At this point, the gpgv method has succeeded, so there is a
    // valid signature from a key in the trusted keyring.  We
@@ -574,14 +1073,14 @@ void pkgAcqMetaIndex::AuthDone(string Message)
    Rename(SigFile,VerifiedSigFile);
    chmod(VerifiedSigFile.c_str(),0644);
 }
-
-void pkgAcqMetaIndex::QueueIndexes(bool verify)
+                                                                       /*}}}*/
+void pkgAcqMetaIndex::QueueIndexes(bool verify)                                /*{{{*/
 {
    for (vector <struct IndexTarget*>::const_iterator Target = IndexTargets->begin();
         Target != IndexTargets->end();
         Target++)
    {
-      string ExpectedIndexMD5;
+      HashString ExpectedIndexHash;
       if (verify)
       {
          const indexRecords::checkSum *Record = MetaIndexParser->Lookup((*Target)->MetaKey);
@@ -592,28 +1091,36 @@ void pkgAcqMetaIndex::QueueIndexes(bool verify)
                + (*Target)->MetaKey + " in Meta-index file (malformed Release file?)";
             return;
          }
-         ExpectedIndexMD5 = Record->MD5Hash;
+         ExpectedIndexHash = Record->Hash;
          if (_config->FindB("Debug::pkgAcquire::Auth", false))
          {
             std::cerr << "Queueing: " << (*Target)->URI << std::endl;
-            std::cerr << "Expected MD5: " << ExpectedIndexMD5 << std::endl;
+            std::cerr << "Expected Hash: " << ExpectedIndexHash.toStr() << std::endl;
          }
-         if (ExpectedIndexMD5.empty())
+         if (ExpectedIndexHash.empty())
          {
             Status = StatAuthError;
-            ErrorText = "Unable to find MD5 sum for "
+            ErrorText = "Unable to find hash sum for "
                + (*Target)->MetaKey + " in Meta-index file";
             return;
          }
       }
-      
-      // Queue Packages file
-      new pkgAcqIndex(Owner, (*Target)->URI, (*Target)->Description,
-                      (*Target)->ShortDesc, ExpectedIndexMD5);
+
+      /* Queue Packages file (either diff or full packages files, depending
+         on the users option) - we also check if the PDiff Index file is listed
+         in the Meta-Index file. Ideal would be if pkgAcqDiffIndex would test this
+         instead, but passing the required info to it is to much hassle */
+      if(_config->FindB("Acquire::PDiffs",true) == true && (verify == false ||
+         MetaIndexParser->Exists(string((*Target)->MetaKey).append(".diff/Index")) == true))
+        new pkgAcqDiffIndex(Owner, (*Target)->URI, (*Target)->Description,
+                            (*Target)->ShortDesc, ExpectedIndexHash);
+      else
+        new pkgAcqIndex(Owner, (*Target)->URI, (*Target)->Description,
+                           (*Target)->ShortDesc, ExpectedIndexHash);
    }
 }
-
-bool pkgAcqMetaIndex::VerifyVendor(string Message)
+                                                                       /*}}}*/
+bool pkgAcqMetaIndex::VerifyVendor(string Message)                     /*{{{*/
 {
 //    // Maybe this should be made available from above so we don't have
 //    // to read and parse it every time?
@@ -699,9 +1206,8 @@ bool pkgAcqMetaIndex::VerifyVendor(string Message)
 
    return true;
 }
-                                                                       /*}}}*/
-// pkgAcqMetaIndex::Failed - no Release file present or no signature
-//      file present                                           /*{{{*/
+                                                                       /*}}}*/
+// pkgAcqMetaIndex::Failed - no Release file present or no signature file present      /*{{{*/
 // ---------------------------------------------------------------------
 /* */
 void pkgAcqMetaIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
@@ -738,9 +1244,7 @@ void pkgAcqMetaIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    // back to queueing Packages files without verification
    QueueIndexes(false);
 }
-
                                                                        /*}}}*/
-
 // AcqArchive::AcqArchive - Constructor                                        /*{{{*/
 // ---------------------------------------------------------------------
 /* This just sets up the initial fetch environment and queues the first
@@ -826,7 +1330,8 @@ pkgAcqArchive::pkgAcqArchive(pkgAcquire *Owner,pkgSourceList *Sources,
    the archive is already available in the cache and stashs the MD5 for
    checking later. */
 bool pkgAcqArchive::QueueNext()
-{   
+{
+   string const ForceHash = _config->Find("Acquire::ForceHash");
    for (; Vf.end() == false; Vf++)
    {
       // Ignore not source sources
@@ -849,7 +1354,25 @@ bool pkgAcqArchive::QueueNext()
         return false;
       
       string PkgFile = Parse.FileName();
-      MD5 = Parse.MD5Hash();
+      if (ForceHash.empty() == false)
+      {
+        if(stringcasecmp(ForceHash, "sha256") == 0)
+           ExpectedHash = HashString("SHA256", Parse.SHA256Hash());
+        else if (stringcasecmp(ForceHash, "sha1") == 0)
+           ExpectedHash = HashString("SHA1", Parse.SHA1Hash());
+        else
+           ExpectedHash = HashString("MD5Sum", Parse.MD5Hash());
+      }
+      else
+      {
+        string Hash;
+        if ((Hash = Parse.SHA256Hash()).empty() == false)
+           ExpectedHash = HashString("SHA256", Hash);
+        else if ((Hash = Parse.SHA1Hash()).empty() == false)
+           ExpectedHash = HashString("SHA1", Hash);
+        else
+           ExpectedHash = HashString("MD5Sum", Parse.MD5Hash());
+      }
       if (PkgFile.empty() == true)
         return _error->Error(_("The package index files are corrupted. No Filename: "
                              "field for package %s."),
@@ -929,10 +1452,10 @@ bool pkgAcqArchive::QueueNext()
 // AcqArchive::Done - Finished fetching                                        /*{{{*/
 // ---------------------------------------------------------------------
 /* */
-void pkgAcqArchive::Done(string Message,unsigned long Size,string Md5Hash,
+void pkgAcqArchive::Done(string Message,unsigned long Size,string CalcHash,
                         pkgAcquire::MethodConfig *Cfg)
 {
-   Item::Done(Message,Size,Md5Hash,Cfg);
+   Item::Done(Message,Size,CalcHash,Cfg);
    
    // Check the size
    if (Size != Version->Size)
@@ -942,17 +1465,14 @@ void pkgAcqArchive::Done(string Message,unsigned long Size,string Md5Hash,
       return;
    }
    
-   // Check the md5
-   if (Md5Hash.empty() == false && MD5.empty() == false)
+   // Check the hash
+   if(ExpectedHash.toStr() != CalcHash)
    {
-      if (Md5Hash != MD5)
-      {
-        Status = StatError;
-        ErrorText = _("MD5Sum mismatch");
-        if(FileExists(DestFile))
-           Rename(DestFile,DestFile + ".FAILED");
-        return;
-      }
+      Status = StatError;
+      ErrorText = _("Hash Sum mismatch");
+      if(FileExists(DestFile))
+        Rename(DestFile,DestFile + ".FAILED");
+      return;
    }
 
    // Grab the output filename
@@ -1021,14 +1541,13 @@ void pkgAcqArchive::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    }
 }
                                                                        /*}}}*/
-// AcqArchive::IsTrusted - Determine whether this archive comes from a
-// trusted source                                                      /*{{{*/
+// AcqArchive::IsTrusted - Determine whether this archive comes from a trusted source /*{{{*/
 // ---------------------------------------------------------------------
 bool pkgAcqArchive::IsTrusted()
 {
    return Trusted;
 }
-
+                                                                       /*}}}*/
 // AcqArchive::Finished - Fetching has finished, tidy up               /*{{{*/
 // ---------------------------------------------------------------------
 /* */
@@ -1040,14 +1559,14 @@ void pkgAcqArchive::Finished()
    StoreFilename = string();
 }
                                                                        /*}}}*/
-
 // AcqFile::pkgAcqFile - Constructor                                   /*{{{*/
 // ---------------------------------------------------------------------
 /* The file is added to the queue */
-pkgAcqFile::pkgAcqFile(pkgAcquire *Owner,string URI,string MD5,
+pkgAcqFile::pkgAcqFile(pkgAcquire *Owner,string URI,string Hash,
                       unsigned long Size,string Dsc,string ShortDesc,
-                      const string &DestDir, const string &DestFilename) :
-                       Item(Owner), Md5Hash(MD5)
+                      const string &DestDir, const string &DestFilename,
+                       bool IsIndexFile) :
+                       Item(Owner), ExpectedHash(Hash), IsIndexFile(IsIndexFile)
 {
    Retries = _config->FindI("Acquire::Retries",0);
    
@@ -1084,23 +1603,20 @@ pkgAcqFile::pkgAcqFile(pkgAcquire *Owner,string URI,string MD5,
 // AcqFile::Done - Item downloaded OK                                  /*{{{*/
 // ---------------------------------------------------------------------
 /* */
-void pkgAcqFile::Done(string Message,unsigned long Size,string MD5,
+void pkgAcqFile::Done(string Message,unsigned long Size,string CalcHash,
                      pkgAcquire::MethodConfig *Cnf)
 {
-   // Check the md5
-   if (Md5Hash.empty() == false && MD5.empty() == false)
+   Item::Done(Message,Size,CalcHash,Cnf);
+
+   // Check the hash
+   if(!ExpectedHash.empty() && ExpectedHash.toStr() != CalcHash)
    {
-      if (Md5Hash != MD5)
-      {
-        Status = StatError;
-        ErrorText = "MD5Sum mismatch";
-        Rename(DestFile,DestFile + ".FAILED");
-        return;
-      }
+      Status = StatError;
+      ErrorText = "Hash Sum mismatch";
+      Rename(DestFile,DestFile + ".FAILED");
+      return;
    }
    
-   Item::Done(Message,Size,MD5,Cnf);
-
    string FileName = LookupTag(Message,"Filename");
    if (FileName.empty() == true)
    {
@@ -1165,3 +1681,13 @@ void pkgAcqFile::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
    Item::Failed(Message,Cnf);
 }
                                                                        /*}}}*/
+// AcqIndex::Custom600Headers - Insert custom request headers          /*{{{*/
+// ---------------------------------------------------------------------
+/* The only header we use is the last-modified header. */
+string pkgAcqFile::Custom600Headers()
+{
+   if (IsIndexFile)
+      return "\nIndex-File: true";
+   return "";
+}
+                                                                       /*}}}*/