]> git.saurik.com Git - apt.git/blobdiff - apt-pkg/acquire-item.cc
* apt-pkg/acquire-item.cc:
[apt.git] / apt-pkg / acquire-item.cc
index f566b16b803775abfb54995a1d025331b5f4f6de..679f9cee7e0850a063872cc22c1c9bae9957d249 100644 (file)
@@ -13,9 +13,6 @@
    ##################################################################### */
                                                                        /*}}}*/
 // 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/sourcelist.h>
@@ -24,6 +21,8 @@
 #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 +30,7 @@
 #include <unistd.h>
 #include <errno.h>
 #include <string>
+#include <sstream>
 #include <stdio.h>
                                                                        /*}}}*/
 
@@ -95,12 +95,13 @@ 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()));
@@ -131,14 +132,427 @@ 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)
+   {
+      string local_sha1;
+      bool found = false;
+      DiffInfo d;
+      string size;
+
+      string tmp = Tags.FindS("SHA1-Current");
+      std::stringstream ss(tmp);
+      ss >> ServerSha1;
+
+      FileFd fd(CurrentPackagesFile, FileFd::ReadOnly);
+      SHA1Summation SHA1;
+      SHA1.AddFD(fd.Fd(), fd.Size());
+      local_sha1 = string(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 history = Tags.FindS("SHA1-History");     
+        std::stringstream hist(history);
+        while(hist >> d.sha1 >> size >> d.file) 
+        {
+           d.size = atoi(size.c_str());
+           // read until the first match is found
+           if(d.sha1 == local_sha1) 
+              found=true;
+           // from that point on, we probably need all diffs
+           if(found) 
+           {
+              if(Debug)
+                 std::clog << "Need to get diff: " << d.file << std::endl;
+              available_patches.push_back(d);
+           }
+        }
+      }
+
+      // we have something, queue the next diff
+      if(found) 
+      {
+        // queue the diffs
+        string::size_type 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, 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, 
+                                  vector<DiffInfo> diffs)
+   : Item(Owner), RealURI(URI), ExpectedHash(ExpectedHash), 
+     available_patches(diffs)
+{
+   
+   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();
+}
+
+
+// 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;
+
+   // 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, 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;
@@ -154,9 +568,9 @@ pkgAcqIndex::pkgAcqIndex(pkgAcquire *Owner,
       else 
         CompressionExtension = ".gz";
    } else {
-      CompressionExtension = comprExt;
+      CompressionExtension = (comprExt == "plain" ? "" : comprExt);
    }
-   Desc.URI = URI + CompressionExtension; 
+   Desc.URI = URI + CompressionExtension;
 
    Desc.Description = URIDesc;
    Desc.Owner = this;
@@ -183,20 +597,30 @@ string pkgAcqIndex::Custom600Headers()
 
 void pkgAcqIndex::Failed(string Message,pkgAcquire::MethodConfig *Cnf)
 {
-
+   bool descChanged = false;
    // 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"; 
+      Desc.URI = Desc.URI.substr(0,Desc.URI.size()-3) + "gz";
+
+      new pkgAcqIndex(Owner, RealURI, Desc.Description,Desc.ShortDesc,
+                     ExpectedHash, string(".gz"));
+         descChanged = true;
+   }
+   // no .gz found, retry with uncompressed
+   else if(Desc.URI.substr(Desc.URI.size()-2) == "gz") {
+      Desc.URI = Desc.URI.substr(0,Desc.URI.size()-2);
 
-      // retry with a gzip one 
-      new pkgAcqIndex(Owner, RealURI, Desc.Description,Desc.ShortDesc, 
-                     ExpectedMD5, string(".gz"));
+      new pkgAcqIndex(Owner, RealURI, Desc.Description,Desc.ShortDesc,
+                     ExpectedHash, string("plain"));
+         descChanged = true;
+   }
+   if (descChanged) {
       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/";
@@ -215,32 +639,23 @@ 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;
       }
@@ -271,7 +686,6 @@ void pkgAcqIndex::Done(string Message,unsigned long Size,string MD5,
       // The files timestamp matches
       if (StringToBool(LookupTag(Message,"Alt-IMS-Hit"),false) == true)
         return;
-
       Decompression = true;
       Local = true;
       DestFile += ".decomp";
@@ -297,12 +711,14 @@ void pkgAcqIndex::Done(string Message,unsigned long Size,string MD5,
    else
       Local = true;
    
-   string compExt = Desc.URI.substr(Desc.URI.size()-3);
-   char *decompProg;
+   string compExt = flExtension(URI(Desc.URI).Path);
+   const char *decompProg;
    if(compExt == "bz2") 
       decompProg = "bzip2";
    else if(compExt == ".gz") 
       decompProg = "gzip";
+   else if(compExt == "")
+      decompProg = "copy";
    else {
       _error->Error("Unsupported extension: %s", compExt.c_str());
       return;
@@ -315,6 +731,35 @@ void pkgAcqIndex::Done(string Message,unsigned long Size,string MD5,
    Mode = decompProg;
 }
 
+// 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,
@@ -328,8 +773,9 @@ 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
@@ -337,16 +783,19 @@ 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);
@@ -358,7 +807,7 @@ 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);
@@ -388,6 +837,12 @@ 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);
@@ -396,17 +851,22 @@ void pkgAcqMetaSig::Done(string Message,unsigned long Size,string MD5,
                                                                        /*}}}*/
 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
@@ -431,8 +891,8 @@ pkgAcqMetaIndex::pkgAcqMetaIndex(pkgAcquire *Owner,
                                 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);
@@ -462,10 +922,10 @@ 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
@@ -527,18 +987,19 @@ void pkgAcqMetaIndex::RetrievalDone(string Message)
 
    // see if the download was a IMSHit
    IMSHit = StringToBool(LookupTag(Message,"IMS-Hit"),false);
-
    Complete = true;
 
    string FinalFile = _config->FindDir("Dir::State::lists");
    FinalFile += URItoFileName(RealURI);
 
-   // The files timestamp matches
-   if (StringToBool(LookupTag(Message,"IMS-Hit"),false) == false)
-   {
-      // Move it into position
+   // If we get a IMS hit we can remove the empty file in partial
+   // othersie we move the file in place
+   if (IMSHit)
+      unlink(DestFile.c_str());
+   else
       Rename(DestFile,FinalFile);
-   }
+
+   chmod(FinalFile.c_str(),0644);
    DestFile = FinalFile;
 }
 
@@ -582,7 +1043,7 @@ void pkgAcqMetaIndex::QueueIndexes(bool verify)
         Target != IndexTargets->end();
         Target++)
    {
-      string ExpectedIndexMD5;
+      HashString ExpectedIndexHash;
       if (verify)
       {
          const indexRecords::checkSum *Record = MetaIndexParser->Lookup((*Target)->MetaKey);
@@ -593,24 +1054,29 @@ 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)
+      if(_config->FindB("Acquire::PDiffs",true) == true) 
+        new pkgAcqDiffIndex(Owner, (*Target)->URI, (*Target)->Description,
+                            (*Target)->ShortDesc, ExpectedIndexHash);
+      else 
+        new pkgAcqIndex(Owner, (*Target)->URI, (*Target)->Description,
+                           (*Target)->ShortDesc, ExpectedIndexHash);
    }
 }
 
@@ -850,7 +1316,12 @@ bool pkgAcqArchive::QueueNext()
         return false;
       
       string PkgFile = Parse.FileName();
-      MD5 = Parse.MD5Hash();
+      if(Parse.SHA256Hash() != "")
+        ExpectedHash = HashString("SHA256", Parse.SHA256Hash());
+      else if (Parse.SHA1Hash() != "")
+        ExpectedHash = HashString("SHA1", Parse.SHA1Hash());
+      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."),
@@ -930,10 +1401,10 @@ 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)
@@ -943,17 +1414,14 @@ 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
@@ -1045,10 +1513,10 @@ void pkgAcqArchive::Finished()
 // 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)
+                       Item(Owner), ExpectedHash(Hash)
 {
    Retries = _config->FindI("Acquire::Retries",0);
    
@@ -1085,23 +1553,20 @@ 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)
    {