move the detection for installed versions up as it is the easiest case

[apt.git] / methods / mirror.cc

diff --git a/methods/mirror.cc b/methods/mirror.cc
index b2b6b2ecf3e6692773c6a09eca4640a09ead17cd..713dc211a1c8ecd103502ad4f419645749126c1c 100644 (file)
--- a/methods/mirror.cc
+++ b/methods/mirror.cc
@@ -16,11 +16,15 @@
 #include <apt-pkg/hashes.h>
 #include <apt-pkg/sourcelist.h>
 
+
+#include <algorithm>
 #include <fstream>
 #include <iostream>
+
 #include <stdarg.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <sys/utsname.h>
 #include <dirent.h>
 
 using namespace std;
@@ -125,23 +129,75 @@ bool MirrorMethod::Clean(string Dir)
 
 bool MirrorMethod::DownloadMirrorFile(string mirror_uri_str)
 {
-   if(Debug)
-      clog << "MirrorMethod::DownloadMirrorFile(): " << endl;
-
    // not that great to use pkgAcquire here, but we do not have 
    // any other way right now
    string fetch = BaseUri;
    fetch.replace(0,strlen("mirror://"),"http://");
 
+   // append the dist as a query string
+   if (Dist != "")
+      fetch += "?dist=" + Dist;
+
+   if(Debug)
+      clog << "MirrorMethod::DownloadMirrorFile(): '" << fetch << "'"
+           << " to " << MirrorFile << endl;
+
    pkgAcquire Fetcher;
    new pkgAcqFile(&Fetcher, fetch, "", 0, "", "", "", MirrorFile);
    bool res = (Fetcher.Run() == pkgAcquire::Continue);
-   if(res)
+   if(res) {
       DownloadedMirrorFile = true;
+      chmod(MirrorFile.c_str(), 0644);
+   }
    Fetcher.Shutdown();
+
+   if(Debug)
+      clog << "MirrorMethod::DownloadMirrorFile() success: " << res << endl;
+   
    return res;
 }
 
+// Randomizes the lines in the mirror file, this is used so that
+// we spread the load on the mirrors evenly
+bool MirrorMethod::RandomizeMirrorFile(string mirror_file)
+{
+   vector<string> content;
+   string line;
+
+   if (!FileExists(mirror_file))
+      return false;
+
+   // read 
+   ifstream in(mirror_file.c_str());
+   while ( !in.eof() ) {
+      getline(in, line);
+      content.push_back(line);
+   }
+   
+   // we want the file to be random for each different machine, but also
+   // "stable" on the same machine. this is to avoid running into out-of-sync
+   // issues (i.e. Release/Release.gpg different on each mirror)
+   struct utsname buf;
+   int seed=1, i;
+   if(uname(&buf) == 0) {
+      for(i=0,seed=1; buf.nodename[i] != 0; i++) {
+         seed = seed * 31 + buf.nodename[i];
+      }
+   }
+   srand( seed );
+   random_shuffle(content.begin(), content.end());
+
+   // write
+   ofstream out(mirror_file.c_str());
+   while ( !content.empty()) {
+      line = content.back();
+      content.pop_back();
+      out << line << "\n";
+   }
+
+   return true;
+}
+
 /* convert a the Queue->Uri back to the mirror base uri and look
  * at all mirrors we have for this, this is needed as queue->uri
  * may point to different mirrors (if TryNextMirror() was run)
@@ -153,11 +209,12 @@ void MirrorMethod::CurrentQueueUriToMirror()
       return;
 
    // find current mirror and select next one
-   for (int i=0; i < AllMirrors.size(); i++) 
+   for (vector<string>::const_iterator mirror = AllMirrors.begin();
+       mirror != AllMirrors.end(); ++mirror)
    {
-      if (Queue->Uri.find(AllMirrors[i]) == 0)
+      if (Queue->Uri.find(*mirror) == 0)
       {
-        Queue->Uri.replace(0, AllMirrors[i].size(), BaseUri);
+        Queue->Uri.replace(0, mirror->length(), BaseUri);
         return;
       }
    }
@@ -168,15 +225,23 @@ void MirrorMethod::CurrentQueueUriToMirror()
 bool MirrorMethod::TryNextMirror()
 {
    // find current mirror and select next one
-   for (int i=0; i < AllMirrors.size()-1; i++) 
+   for (vector<string>::const_iterator mirror = AllMirrors.begin();
+       mirror != AllMirrors.end(); ++mirror)
    {
-      if (Queue->Uri.find(AllMirrors[i]) == 0)
-      {
-        Queue->Uri.replace(0, AllMirrors[i].size(), AllMirrors[i+1]);
-        if (Debug)
-           clog << "TryNextMirror: " << Queue->Uri << endl;
-        return true;
-      }
+      if (Queue->Uri.find(*mirror) != 0)
+        continue;
+
+      vector<string>::const_iterator nextmirror = mirror + 1;
+      if (nextmirror == AllMirrors.end())
+        break;
+      Queue->Uri.replace(0, mirror->length(), *nextmirror);
+      if (Debug)
+        clog << "TryNextMirror: " << Queue->Uri << endl;
+
+      // inform parent
+      UsedMirror = *nextmirror;
+      Log("Switching mirror");
+      return true;
    }
 
    if (Debug)
@@ -195,6 +260,13 @@ bool MirrorMethod::InitMirrors()
       return _error->Error(_("No mirror file '%s' found "), MirrorFile.c_str());
    }
 
+   if (access(MirrorFile.c_str(), R_OK) != 0)
+   {
+      // FIXME: fallback to a default mirror here instead 
+      //        and provide a config option to define that default
+      return _error->Error(_("Can not read mirror file '%s'"), MirrorFile.c_str());
+   }  
+
    // FIXME: make the mirror selection more clever, do not 
    //        just use the first one!
    // BUT: we can not make this random, the mirror has to be
@@ -206,8 +278,18 @@ bool MirrorMethod::InitMirrors()
    while (!in.eof()) 
    {
       getline(in, s);
-      if (s.size() > 0)
-        AllMirrors.push_back(s);
+
+      // ignore lines that start with #
+      if (s.find("#") == 0)
+         continue;
+      // ignore empty lines
+      if (s.size() == 0)
+         continue;
+      // ignore non http lines
+      if (s.find("http://") != 0)
+         continue;
+
+      AllMirrors.push_back(s);
    }
    Mirror = AllMirrors[0];
    UsedMirror = Mirror;
@@ -261,6 +343,7 @@ string MirrorMethod::GetMirrorFileName(string mirror_uri_str)
         if(Debug)
            std::cerr << "found BaseURI: " << uristr << std::endl;
         BaseUri = uristr.substr(0,uristr.size()-1);
+         Dist = (*I)->GetDist();
       }
    }
    // get new file
@@ -298,7 +381,8 @@ bool MirrorMethod::Fetch(FetchItem *Itm)
    if(Itm->IndexFile && !DownloadedMirrorFile)
    {
       Clean(_config->FindDir("Dir::State::mirrors"));
-      DownloadMirrorFile(Itm->Uri);
+      if (DownloadMirrorFile(Itm->Uri))
+         RandomizeMirrorFile(MirrorFile);
    }
 
    if(AllMirrors.empty()) {