methods/mirror.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: mirror.cc,v 1.59 2004/05/08 19:42:35 mdz Exp $
   4 /* ######################################################################
   5
   6    Mirror Aquire Method - This is the Mirror aquire method for APT.
   7
   8    ##################################################################### */
   9                                                                         /*}}}*/
  10 // Include Files                                                        /*{{{*/
  11 #include <apt-pkg/fileutl.h>
  12 #include <apt-pkg/acquire-method.h>
  13 #include <apt-pkg/acquire-item.h>
  14 #include <apt-pkg/acquire.h>
  15 #include <apt-pkg/error.h>
  16 #include <apt-pkg/hashes.h>
  17 #include <apt-pkg/sourcelist.h>
  18
  19 #include <fstream>
  20 #include <algorithm>
  21 #include <iostream>
  22 #include <stdarg.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <dirent.h>
  26
  27 using namespace std;
  28
  29 #include<sstream>
  30
  31 #include "mirror.h"
  32 #include "http.h"
  33 #include "apti18n.h"
  34                                                                         /*}}}*/
  35
  36 /* Done:
  37  * - works with http (only!)
  38  * - always picks the first mirror from the list
  39  * - call out to problem reporting script
  40  * - supports "deb mirror://host/path/to/mirror-list/// dist component"
  41  * - uses pkgAcqMethod::FailReason() to have a string representation
  42  *   of the failure that is also send to LP
  43  *
  44  * TODO:
  45  * - deal with runing as non-root because we can't write to the lists
  46      dir then -> use the cached mirror file
  47  * - better method to download than having a pkgAcquire interface here
  48  *   and better error handling there!
  49  * - support more than http
  50  * - testing :)
  51  */
  52
  53 MirrorMethod::MirrorMethod()
  54    : HttpMethod(), DownloadedMirrorFile(false)
  55 {
  56 };
  57
  58 // HttpMethod::Configuration - Handle a configuration message           /*{{{*/
  59 // ---------------------------------------------------------------------
  60 /* We stash the desired pipeline depth */
  61 bool MirrorMethod::Configuration(string Message)
  62 {
  63    if (pkgAcqMethod::Configuration(Message) == false)
  64       return false;
  65    Debug = _config->FindB("Debug::Acquire::mirror",false);
  66
  67    return true;
  68 }
  69                                                                         /*}}}*/
  70
  71 // clean the mirrors dir based on ttl information
  72 bool MirrorMethod::Clean(string Dir)
  73 {
  74    vector<metaIndex *>::const_iterator I;
  75
  76    if(Debug)
  77       clog << "MirrorMethod::Clean(): " << Dir << endl;
  78
  79    if(Dir == "/")
  80       return _error->Error("will not clean: '/'");
  81
  82    // read sources.list
  83    pkgSourceList list;
  84    list.ReadMainList();
  85
  86    DIR *D = opendir(Dir.c_str());
  87    if (D == 0)
  88       return _error->Errno("opendir",_("Unable to read %s"),Dir.c_str());
  89
  90    string StartDir = SafeGetCWD();
  91    if (chdir(Dir.c_str()) != 0)
  92    {
  93       closedir(D);
  94       return _error->Errno("chdir",_("Unable to change to %s"),Dir.c_str());
  95    }
  96
  97    for (struct dirent *Dir = readdir(D); Dir != 0; Dir = readdir(D))
  98    {
  99       // Skip some files..
 100       if (strcmp(Dir->d_name,"lock") == 0 ||
 101           strcmp(Dir->d_name,"partial") == 0 ||
 102           strcmp(Dir->d_name,".") == 0 ||
 103           strcmp(Dir->d_name,"..") == 0)
 104          continue;
 105
 106       // see if we have that uri
 107       for(I=list.begin(); I != list.end(); I++)
 108       {
 109          string uri = (*I)->GetURI();
 110          if(uri.find("mirror://") != 0)
 111             continue;
 112          string BaseUri = uri.substr(0,uri.size()-1);
 113          if (URItoFileName(BaseUri) == Dir->d_name)
 114             break;
 115       }
 116       // nothing found, nuke it
 117       if (I == list.end())
 118          unlink(Dir->d_name);
 119    };
 120
 121    chdir(StartDir.c_str());
 122    closedir(D);
 123    return true;
 124 }
 125
 126
 127 bool MirrorMethod::DownloadMirrorFile(string mirror_uri_str)
 128 {
 129    // not that great to use pkgAcquire here, but we do not have
 130    // any other way right now
 131    string fetch = BaseUri;
 132    fetch.replace(0,strlen("mirror://"),"http://");
 133
 134    if(Debug)
 135       clog << "MirrorMethod::DownloadMirrorFile(): '" << fetch << "'"
 136            << " to " << MirrorFile << endl;
 137
 138    pkgAcquire Fetcher;
 139    new pkgAcqFile(&Fetcher, fetch, "", 0, "", "", "", MirrorFile);
 140    bool res = (Fetcher.Run() == pkgAcquire::Continue);
 141    if(res)
 142       DownloadedMirrorFile = true;
 143    Fetcher.Shutdown();
 144
 145    if(Debug)
 146       clog << "MirrorMethod::DownloadMirrorFile() success: " << res << endl;
 147
 148    return res;
 149 }
 150
 151 // Randomizes the lines in the mirror file, this is used so that
 152 // we spread the load on the mirrors evenly
 153 bool MirrorMethod::RandomizeMirrorFile(string mirror_file)
 154 {
 155    vector<string> content;
 156    string line;
 157
 158    // read
 159    ifstream in(mirror_file.c_str());
 160    while ( !in.eof() ) {
 161       getline(in, line);
 162       content.push_back(line);
 163    }
 164
 165    // randomize
 166    random_shuffle(content.begin(), content.end());
 167
 168    // write
 169    ofstream out(mirror_file.c_str());
 170    while ( !content.empty()) {
 171       line = content.back();
 172       content.pop_back();
 173       out << line << "\n";
 174    }
 175
 176    return true;
 177 }
 178
 179 /* convert a the Queue->Uri back to the mirror base uri and look
 180  * at all mirrors we have for this, this is needed as queue->uri
 181  * may point to different mirrors (if TryNextMirror() was run)
 182  */
 183 void MirrorMethod::CurrentQueueUriToMirror()
 184 {
 185    // already in mirror:// style so nothing to do
 186    if(Queue->Uri.find("mirror://") == 0)
 187       return;
 188
 189    // find current mirror and select next one
 190    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 191         mirror != AllMirrors.end(); ++mirror)
 192    {
 193       if (Queue->Uri.find(*mirror) == 0)
 194       {
 195          Queue->Uri.replace(0, mirror->length(), BaseUri);
 196          return;
 197       }
 198    }
 199    _error->Error("Internal error: Failed to convert %s back to %s",
 200                  Queue->Uri.c_str(), BaseUri.c_str());
 201 }
 202
 203 bool MirrorMethod::TryNextMirror()
 204 {
 205    // find current mirror and select next one
 206    for (vector<string>::const_iterator mirror = AllMirrors.begin();
 207         mirror != AllMirrors.end(); ++mirror)
 208    {
 209       if (Queue->Uri.find(*mirror) != 0)
 210          continue;
 211
 212       vector<string>::const_iterator nextmirror = mirror + 1;
 213       if (nextmirror == AllMirrors.end())
 214          break;
 215       Queue->Uri.replace(0, mirror->length(), *nextmirror);
 216       if (Debug)
 217          clog << "TryNextMirror: " << Queue->Uri << endl;
 218
 219       // inform parent
 220       UsedMirror = *nextmirror;
 221       Log("Switching mirror");
 222       return true;
 223    }
 224
 225    if (Debug)
 226       clog << "TryNextMirror could not find another mirror to try" << endl;
 227
 228    return false;
 229 }
 230
 231 bool MirrorMethod::InitMirrors()
 232 {
 233    // if we do not have a MirrorFile, fallback
 234    if(!FileExists(MirrorFile))
 235    {
 236       // FIXME: fallback to a default mirror here instead
 237       //        and provide a config option to define that default
 238       return _error->Error(_("No mirror file '%s' found "), MirrorFile.c_str());
 239    }
 240
 241    // FIXME: make the mirror selection more clever, do not
 242    //        just use the first one!
 243    // BUT: we can not make this random, the mirror has to be
 244    //      stable accross session, because otherwise we can
 245    //      get into sync issues (got indexfiles from mirror A,
 246    //      but packages from mirror B - one might be out of date etc)
 247    ifstream in(MirrorFile.c_str());
 248    string s;
 249    while (!in.eof())
 250    {
 251       getline(in, s);
 252       if (s.size() > 0)
 253          AllMirrors.push_back(s);
 254    }
 255    Mirror = AllMirrors[0];
 256    UsedMirror = Mirror;
 257    return true;
 258 }
 259
 260 string MirrorMethod::GetMirrorFileName(string mirror_uri_str)
 261 {
 262    /*
 263     - a mirror_uri_str looks like this:
 264     mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors/dists/feisty/Release.gpg
 265
 266     - the matching source.list entry
 267     deb mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors feisty main
 268
 269     - we actually want to go after:
 270     http://people.ubuntu.com/~mvo/apt/mirror/mirrors
 271
 272     And we need to save the BaseUri for later:
 273     - mirror://people.ubuntu.com/~mvo/apt/mirror/mirrors
 274
 275    FIXME: what if we have two similar prefixes?
 276      mirror://people.ubuntu.com/~mvo/mirror
 277      mirror://people.ubuntu.com/~mvo/mirror2
 278    then mirror_uri_str looks like:
 279      mirror://people.ubuntu.com/~mvo/apt/mirror/dists/feisty/Release.gpg
 280      mirror://people.ubuntu.com/~mvo/apt/mirror2/dists/feisty/Release.gpg
 281    we search sources.list and find:
 282      mirror://people.ubuntu.com/~mvo/apt/mirror
 283    in both cases! So we need to apply some domain knowledge here :( and
 284    check for /dists/ or /Release.gpg as suffixes
 285    */
 286    string name;
 287    if(Debug)
 288       std::cerr << "GetMirrorFileName: " << mirror_uri_str << std::endl;
 289
 290    // read sources.list and find match
 291    vector<metaIndex *>::const_iterator I;
 292    pkgSourceList list;
 293    list.ReadMainList();
 294    for(I=list.begin(); I != list.end(); I++)
 295    {
 296       string uristr = (*I)->GetURI();
 297       if(Debug)
 298          std::cerr << "Checking: " << uristr << std::endl;
 299       if(uristr.substr(0,strlen("mirror://")) != string("mirror://"))
 300          continue;
 301       // find matching uri in sources.list
 302       if(mirror_uri_str.substr(0,uristr.size()) == uristr)
 303       {
 304          if(Debug)
 305             std::cerr << "found BaseURI: " << uristr << std::endl;
 306          BaseUri = uristr.substr(0,uristr.size()-1);
 307       }
 308    }
 309    // get new file
 310    name = _config->FindDir("Dir::State::mirrors") + URItoFileName(BaseUri);
 311
 312    if(Debug)
 313    {
 314       cerr << "base-uri: " << BaseUri << endl;
 315       cerr << "mirror-file: " << name << endl;
 316    }
 317    return name;
 318 }
 319
 320 // MirrorMethod::Fetch - Fetch an item                                  /*{{{*/
 321 // ---------------------------------------------------------------------
 322 /* This adds an item to the pipeline. We keep the pipeline at a fixed
 323    depth. */
 324 bool MirrorMethod::Fetch(FetchItem *Itm)
 325 {
 326    if(Debug)
 327       clog << "MirrorMethod::Fetch()" << endl;
 328
 329    // the http method uses Fetch(0) as a way to update the pipeline,
 330    // just let it do its work in this case - Fetch() with a valid
 331    // Itm will always run before the first Fetch(0)
 332    if(Itm == NULL)
 333       return HttpMethod::Fetch(Itm);
 334
 335    // if we don't have the name of the mirror file on disk yet,
 336    // calculate it now (can be derived from the uri)
 337    if(MirrorFile.empty())
 338       MirrorFile = GetMirrorFileName(Itm->Uri);
 339
 340   // download mirror file once (if we are after index files)
 341    if(Itm->IndexFile && !DownloadedMirrorFile)
 342    {
 343       Clean(_config->FindDir("Dir::State::mirrors"));
 344       DownloadMirrorFile(Itm->Uri);
 345       RandomizeMirrorFile(MirrorFile);
 346    }
 347
 348    if(AllMirrors.empty()) {
 349       if(!InitMirrors()) {
 350          // no valid mirror selected, something went wrong downloading
 351          // from the master mirror site most likely and there is
 352          // no old mirror file availalbe
 353          return false;
 354       }
 355    }
 356
 357    if(Itm->Uri.find("mirror://") != string::npos)
 358       Itm->Uri.replace(0,BaseUri.size(), Mirror);
 359
 360    if(Debug)
 361       clog << "Fetch: " << Itm->Uri << endl << endl;
 362
 363    // now run the real fetcher
 364    return HttpMethod::Fetch(Itm);
 365 };
 366
 367 void MirrorMethod::Fail(string Err,bool Transient)
 368 {
 369    // FIXME: TryNextMirror is not ideal for indexfile as we may
 370    //        run into auth issues
 371
 372    if (Debug)
 373       clog << "Failure to get " << Queue->Uri << endl;
 374
 375    // try the next mirror on fail (if its not a expected failure,
 376    // e.g. translations are ok to ignore)
 377    if (!Queue->FailIgnore && TryNextMirror())
 378       return;
 379
 380    // all mirrors failed, so bail out
 381    string s;
 382    strprintf(s, _("[Mirror: %s]"), Mirror.c_str());
 383    SetIP(s);
 384
 385    CurrentQueueUriToMirror();
 386    pkgAcqMethod::Fail(Err, Transient);
 387 }
 388
 389 void MirrorMethod::URIStart(FetchResult &Res)
 390 {
 391    CurrentQueueUriToMirror();
 392    pkgAcqMethod::URIStart(Res);
 393 }
 394
 395 void MirrorMethod::URIDone(FetchResult &Res,FetchResult *Alt)
 396 {
 397    CurrentQueueUriToMirror();
 398    pkgAcqMethod::URIDone(Res, Alt);
 399 }
 400
 401
 402 int main()
 403 {
 404    setlocale(LC_ALL, "");
 405
 406    srand ( time(NULL) );
 407
 408    MirrorMethod Mth;
 409
 410    return Mth.Loop();
 411 }
 412
 413