apt-pkg/acquire.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: acquire.cc,v 1.27 1999/03/13 23:30:04 jgg Exp $
   4 /* ######################################################################
   5
   6    Acquire - File Acquiration
   7
   8    The core element for the schedual system is the concept of a named
   9    queue. Each queue is unique and each queue has a name derived from the
  10    URI. The degree of paralization can be controled by how the queue
  11    name is derived from the URI.
  12
  13    ##################################################################### */
  14                                                                         /*}}}*/
  15 // Include Files                                                        /*{{{*/
  16 #ifdef __GNUG__
  17 #pragma implementation "apt-pkg/acquire.h"
  18 #endif
  19 #include <apt-pkg/acquire.h>
  20 #include <apt-pkg/acquire-item.h>
  21 #include <apt-pkg/acquire-worker.h>
  22 #include <apt-pkg/configuration.h>
  23 #include <apt-pkg/error.h>
  24 #include <apt-pkg/strutl.h>
  25
  26 #include <dirent.h>
  27 #include <sys/time.h>
  28                                                                         /*}}}*/
  29
  30 // Acquire::pkgAcquire - Constructor                                    /*{{{*/
  31 // ---------------------------------------------------------------------
  32 /* We grab some runtime state from the configuration space */
  33 pkgAcquire::pkgAcquire(pkgAcquireStatus *Log) : Log(Log)
  34 {
  35    Queues = 0;
  36    Configs = 0;
  37    Workers = 0;
  38    ToFetch = 0;
  39    Running = false;
  40
  41    string Mode = _config->Find("Acquire::Queue-Mode","host");
  42    if (strcasecmp(Mode.c_str(),"host") == 0)
  43       QueueMode = QueueHost;
  44    if (strcasecmp(Mode.c_str(),"access") == 0)
  45       QueueMode = QueueAccess;
  46
  47    Debug = _config->FindB("Debug::pkgAcquire",false);
  48 }
  49                                                                         /*}}}*/
  50 // Acquire::~pkgAcquire - Destructor                                    /*{{{*/
  51 // ---------------------------------------------------------------------
  52 /* Free our memory, clean up the queues (destroy the workers) */
  53 pkgAcquire::~pkgAcquire()
  54 {
  55    while (Items.size() != 0)
  56       delete Items[0];
  57
  58    while (Configs != 0)
  59    {
  60       MethodConfig *Jnk = Configs;
  61       Configs = Configs->Next;
  62       delete Jnk;
  63    }
  64
  65    while (Queues != 0)
  66    {
  67       Queue *Jnk = Queues;
  68       Queues = Queues->Next;
  69       delete Jnk;
  70    }
  71 }
  72                                                                         /*}}}*/
  73 // Acquire::Add - Add a new item                                        /*{{{*/
  74 // ---------------------------------------------------------------------
  75 /* This puts an item on the acquire list. This list is mainly for tracking
  76    item status */
  77 void pkgAcquire::Add(Item *Itm)
  78 {
  79    Items.push_back(Itm);
  80 }
  81                                                                         /*}}}*/
  82 // Acquire::Remove - Remove a item                                      /*{{{*/
  83 // ---------------------------------------------------------------------
  84 /* Remove an item from the acquire list. This is usually not used.. */
  85 void pkgAcquire::Remove(Item *Itm)
  86 {
  87    for (vector<Item *>::iterator I = Items.begin(); I < Items.end(); I++)
  88    {
  89       if (*I == Itm)
  90          Items.erase(I);
  91    }
  92 }
  93                                                                         /*}}}*/
  94 // Acquire::Add - Add a worker                                          /*{{{*/
  95 // ---------------------------------------------------------------------
  96 /* A list of workers is kept so that the select loop can direct their FD
  97    usage. */
  98 void pkgAcquire::Add(Worker *Work)
  99 {
 100    Work->NextAcquire = Workers;
 101    Workers = Work;
 102 }
 103                                                                         /*}}}*/
 104 // Acquire::Remove - Remove a worker                                    /*{{{*/
 105 // ---------------------------------------------------------------------
 106 /* A worker has died. This can not be done while the select loop is running
 107    as it would require that RunFds could handling a changing list state and
 108    it cant.. */
 109 void pkgAcquire::Remove(Worker *Work)
 110 {
 111    if (Running == true)
 112       abort();
 113
 114    Worker **I = &Workers;
 115    for (; *I != 0;)
 116    {
 117       if (*I == Work)
 118          *I = (*I)->NextAcquire;
 119       else
 120          I = &(*I)->NextAcquire;
 121    }
 122 }
 123                                                                         /*}}}*/
 124 // Acquire::Enqueue - Queue an URI for fetching                         /*{{{*/
 125 // ---------------------------------------------------------------------
 126 /* This is the entry point for an item. An item calls this function when
 127    it is construction which creates a queue (based on the current queue
 128    mode) and puts the item in that queue. If the system is running then
 129    the queue might be started. */
 130 void pkgAcquire::Enqueue(ItemDesc &Item)
 131 {
 132    // Determine which queue to put the item in
 133    const MethodConfig *Config;
 134    string Name = QueueName(Item.URI,Config);
 135    if (Name.empty() == true)
 136       return;
 137
 138    // Find the queue structure
 139    Queue *I = Queues;
 140    for (; I != 0 && I->Name != Name; I = I->Next);
 141    if (I == 0)
 142    {
 143       I = new Queue(Name,this);
 144       I->Next = Queues;
 145       Queues = I;
 146
 147       if (Running == true)
 148          I->Startup();
 149    }
 150
 151    // See if this is a local only URI
 152    if (Config->LocalOnly == true && Item.Owner->Complete == false)
 153       Item.Owner->Local = true;
 154    Item.Owner->Status = Item::StatIdle;
 155
 156    // Queue it into the named queue
 157    I->Enqueue(Item);
 158    ToFetch++;
 159
 160    // Some trace stuff
 161    if (Debug == true)
 162    {
 163       clog << "Fetching " << Item.URI << endl;
 164       clog << " to " << Item.Owner->DestFile << endl;
 165       clog << " Queue is: " << Name << endl;
 166    }
 167 }
 168                                                                         /*}}}*/
 169 // Acquire::Dequeue - Remove an item from all queues                    /*{{{*/
 170 // ---------------------------------------------------------------------
 171 /* This is called when an item is finished being fetched. It removes it
 172    from all the queues */
 173 void pkgAcquire::Dequeue(Item *Itm)
 174 {
 175    Queue *I = Queues;
 176    bool Res = false;
 177    for (; I != 0; I = I->Next)
 178       Res |= I->Dequeue(Itm);
 179
 180    if (Debug == true)
 181       clog << "Dequeuing " << Itm->DestFile << endl;
 182    if (Res == true)
 183       ToFetch--;
 184 }
 185                                                                         /*}}}*/
 186 // Acquire::QueueName - Return the name of the queue for this URI       /*{{{*/
 187 // ---------------------------------------------------------------------
 188 /* The string returned depends on the configuration settings and the
 189    method parameters. Given something like http://foo.org/bar it can
 190    return http://foo.org or http */
 191 string pkgAcquire::QueueName(string Uri,MethodConfig const *&Config)
 192 {
 193    URI U(Uri);
 194
 195    Config = GetConfig(U.Access);
 196    if (Config == 0)
 197       return string();
 198
 199    /* Single-Instance methods get exactly one queue per URI. This is
 200       also used for the Access queue method  */
 201    if (Config->SingleInstance == true || QueueMode == QueueAccess)
 202        return U.Access;
 203
 204    return U.Access + ':' + U.Host;
 205 }
 206                                                                         /*}}}*/
 207 // Acquire::GetConfig - Fetch the configuration information             /*{{{*/
 208 // ---------------------------------------------------------------------
 209 /* This locates the configuration structure for an access method. If
 210    a config structure cannot be found a Worker will be created to
 211    retrieve it */
 212 pkgAcquire::MethodConfig *pkgAcquire::GetConfig(string Access)
 213 {
 214    // Search for an existing config
 215    MethodConfig *Conf;
 216    for (Conf = Configs; Conf != 0; Conf = Conf->Next)
 217       if (Conf->Access == Access)
 218          return Conf;
 219
 220    // Create the new config class
 221    Conf = new MethodConfig;
 222    Conf->Access = Access;
 223    Conf->Next = Configs;
 224    Configs = Conf;
 225
 226    // Create the worker to fetch the configuration
 227    Worker Work(Conf);
 228    if (Work.Start() == false)
 229       return 0;
 230
 231    return Conf;
 232 }
 233                                                                         /*}}}*/
 234 // Acquire::SetFds - Deal with readable FDs                             /*{{{*/
 235 // ---------------------------------------------------------------------
 236 /* Collect FDs that have activity monitors into the fd sets */
 237 void pkgAcquire::SetFds(int &Fd,fd_set *RSet,fd_set *WSet)
 238 {
 239    for (Worker *I = Workers; I != 0; I = I->NextAcquire)
 240    {
 241       if (I->InReady == true && I->InFd >= 0)
 242       {
 243          if (Fd < I->InFd)
 244             Fd = I->InFd;
 245          FD_SET(I->InFd,RSet);
 246       }
 247       if (I->OutReady == true && I->OutFd >= 0)
 248       {
 249          if (Fd < I->OutFd)
 250             Fd = I->OutFd;
 251          FD_SET(I->OutFd,WSet);
 252       }
 253    }
 254 }
 255                                                                         /*}}}*/
 256 // Acquire::RunFds - Deal with active FDs                               /*{{{*/
 257 // ---------------------------------------------------------------------
 258 /* Dispatch active FDs over to the proper workers. It is very important
 259    that a worker never be erased while this is running! The queue class
 260    should never erase a worker except during shutdown processing. */
 261 void pkgAcquire::RunFds(fd_set *RSet,fd_set *WSet)
 262 {
 263    for (Worker *I = Workers; I != 0; I = I->NextAcquire)
 264    {
 265       if (I->InFd >= 0 && FD_ISSET(I->InFd,RSet) != 0)
 266          I->InFdReady();
 267       if (I->OutFd >= 0 && FD_ISSET(I->OutFd,WSet) != 0)
 268          I->OutFdReady();
 269    }
 270 }
 271                                                                         /*}}}*/
 272 // Acquire::Run - Run the fetch sequence                                /*{{{*/
 273 // ---------------------------------------------------------------------
 274 /* This runs the queues. It manages a select loop for all of the
 275    Worker tasks. The workers interact with the queues and items to
 276    manage the actual fetch. */
 277 bool pkgAcquire::Run()
 278 {
 279    Running = true;
 280
 281    for (Queue *I = Queues; I != 0; I = I->Next)
 282       I->Startup();
 283
 284    if (Log != 0)
 285       Log->Start();
 286
 287    // Run till all things have been acquired
 288    struct timeval tv;
 289    tv.tv_sec = 0;
 290    tv.tv_usec = 500000;
 291    while (ToFetch > 0)
 292    {
 293       fd_set RFds;
 294       fd_set WFds;
 295       int Highest = 0;
 296       FD_ZERO(&RFds);
 297       FD_ZERO(&WFds);
 298       SetFds(Highest,&RFds,&WFds);
 299
 300       int Res = select(Highest+1,&RFds,&WFds,0,&tv);
 301       if (Res < 0)
 302       {
 303          _error->Errno("select","Select has failed");
 304          break;
 305       }
 306
 307       RunFds(&RFds,&WFds);
 308       if (_error->PendingError() == true)
 309          break;
 310
 311       // Timeout, notify the log class
 312       if (Res == 0 || (Log != 0 && Log->Update == true))
 313       {
 314          tv.tv_usec = 500000;
 315          for (Worker *I = Workers; I != 0; I = I->NextAcquire)
 316             I->Pulse();
 317          if (Log != 0)
 318             Log->Pulse(this);
 319       }
 320    }
 321
 322    if (Log != 0)
 323       Log->Stop();
 324
 325    // Shut down the acquire bits
 326    Running = false;
 327    for (Queue *I = Queues; I != 0; I = I->Next)
 328       I->Shutdown();
 329
 330    return !_error->PendingError();
 331 }
 332                                                                         /*}}}*/
 333 // Acquire::Bump - Called when an item is dequeued                      /*{{{*/
 334 // ---------------------------------------------------------------------
 335 /* This routine bumps idle queues in hopes that they will be able to fetch
 336    the dequeued item */
 337 void pkgAcquire::Bump()
 338 {
 339    for (Queue *I = Queues; I != 0; I = I->Next)
 340       I->Bump();
 341 }
 342                                                                         /*}}}*/
 343 // Acquire::WorkerStep - Step to the next worker                        /*{{{*/
 344 // ---------------------------------------------------------------------
 345 /* Not inlined to advoid including acquire-worker.h */
 346 pkgAcquire::Worker *pkgAcquire::WorkerStep(Worker *I)
 347 {
 348    return I->NextAcquire;
 349 };
 350                                                                         /*}}}*/
 351 // Acquire::Clean - Cleans a directory                                  /*{{{*/
 352 // ---------------------------------------------------------------------
 353 /* This is a bit simplistic, it looks at every file in the dir and sees
 354    if it is part of the download set. */
 355 bool pkgAcquire::Clean(string Dir)
 356 {
 357    DIR *D = opendir(Dir.c_str());
 358    if (D == 0)
 359       return _error->Errno("opendir","Unable to read %s",Dir.c_str());
 360
 361    string StartDir = SafeGetCWD();
 362    if (chdir(Dir.c_str()) != 0)
 363    {
 364       closedir(D);
 365       return _error->Errno("chdir","Unable to change to ",Dir.c_str());
 366    }
 367
 368    for (struct dirent *Dir = readdir(D); Dir != 0; Dir = readdir(D))
 369    {
 370       // Skip some files..
 371       if (strcmp(Dir->d_name,"lock") == 0 ||
 372           strcmp(Dir->d_name,"partial") == 0 ||
 373           strcmp(Dir->d_name,".") == 0 ||
 374           strcmp(Dir->d_name,"..") == 0)
 375          continue;
 376
 377       // Look in the get list
 378       vector<Item *>::iterator I = Items.begin();
 379       for (; I != Items.end(); I++)
 380          if (flNotDir((*I)->DestFile) == Dir->d_name)
 381             break;
 382
 383       // Nothing found, nuke it
 384       if (I == Items.end())
 385          unlink(Dir->d_name);
 386    };
 387
 388    chdir(StartDir.c_str());
 389    closedir(D);
 390    return true;
 391 }
 392                                                                         /*}}}*/
 393 // Acquire::TotalNeeded - Number of bytes to fetch                      /*{{{*/
 394 // ---------------------------------------------------------------------
 395 /* This is the total number of bytes needed */
 396 unsigned long pkgAcquire::TotalNeeded()
 397 {
 398    unsigned long Total = 0;
 399    for (pkgAcquire::Item **I = ItemsBegin(); I != ItemsEnd(); I++)
 400       Total += (*I)->FileSize;
 401    return Total;
 402 }
 403                                                                         /*}}}*/
 404 // Acquire::FetchNeeded - Number of bytes needed to get                 /*{{{*/
 405 // ---------------------------------------------------------------------
 406 /* This is the number of bytes that is not local */
 407 unsigned long pkgAcquire::FetchNeeded()
 408 {
 409    unsigned long Total = 0;
 410    for (pkgAcquire::Item **I = ItemsBegin(); I != ItemsEnd(); I++)
 411       if ((*I)->Local == false)
 412          Total += (*I)->FileSize;
 413    return Total;
 414 }
 415                                                                         /*}}}*/
 416 // pkgAcquire::UriBegin - Start iterator for the uri list               /*{{{*/
 417 // ---------------------------------------------------------------------
 418 /* */
 419 pkgAcquire::UriIterator pkgAcquire::UriBegin()
 420 {
 421    return UriIterator(Queues);
 422 }
 423                                                                         /*}}}*/
 424 // pkgAcquire::UriEnd - End iterator for the uri list                   /*{{{*/
 425 // ---------------------------------------------------------------------
 426 /* */
 427 pkgAcquire::UriIterator pkgAcquire::UriEnd()
 428 {
 429    return UriIterator(0);
 430 }
 431                                                                         /*}}}*/
 432
 433 // Acquire::MethodConfig::MethodConfig - Constructor                    /*{{{*/
 434 // ---------------------------------------------------------------------
 435 /* */
 436 pkgAcquire::MethodConfig::MethodConfig()
 437 {
 438    SingleInstance = false;
 439    Pipeline = false;
 440    SendConfig = false;
 441    LocalOnly = false;
 442    Next = 0;
 443 }
 444                                                                         /*}}}*/
 445
 446 // Queue::Queue - Constructor                                           /*{{{*/
 447 // ---------------------------------------------------------------------
 448 /* */
 449 pkgAcquire::Queue::Queue(string Name,pkgAcquire *Owner) : Name(Name),
 450             Owner(Owner)
 451 {
 452    Items = 0;
 453    Next = 0;
 454    Workers = 0;
 455    MaxPipeDepth = 1;
 456    PipeDepth = 0;
 457 }
 458                                                                         /*}}}*/
 459 // Queue::~Queue - Destructor                                           /*{{{*/
 460 // ---------------------------------------------------------------------
 461 /* */
 462 pkgAcquire::Queue::~Queue()
 463 {
 464    Shutdown();
 465
 466    while (Items != 0)
 467    {
 468       QItem *Jnk = Items;
 469       Items = Items->Next;
 470       delete Jnk;
 471    }
 472 }
 473                                                                         /*}}}*/
 474 // Queue::Enqueue - Queue an item to the queue                          /*{{{*/
 475 // ---------------------------------------------------------------------
 476 /* */
 477 void pkgAcquire::Queue::Enqueue(ItemDesc &Item)
 478 {
 479    QItem **I = &Items;
 480    for (; *I != 0; I = &(*I)->Next);
 481
 482    // Create a new item
 483    QItem *Itm = new QItem;
 484    *Itm = Item;
 485    Itm->Next = 0;
 486    *I = Itm;
 487
 488    Item.Owner->QueueCounter++;
 489    if (Items->Next == 0)
 490       Cycle();
 491 }
 492                                                                         /*}}}*/
 493 // Queue::Dequeue - Remove an item from the queue                       /*{{{*/
 494 // ---------------------------------------------------------------------
 495 /* We return true if we hit something */
 496 bool pkgAcquire::Queue::Dequeue(Item *Owner)
 497 {
 498    if (Owner->Status == pkgAcquire::Item::StatFetching)
 499       return _error->Error("Tried to dequeue a fetching object");
 500
 501    bool Res = false;
 502
 503    QItem **I = &Items;
 504    for (; *I != 0;)
 505    {
 506       if ((*I)->Owner == Owner)
 507       {
 508          QItem *Jnk= *I;
 509          *I = (*I)->Next;
 510          Owner->QueueCounter--;
 511          delete Jnk;
 512          Res = true;
 513       }
 514       else
 515          I = &(*I)->Next;
 516    }
 517
 518    return Res;
 519 }
 520                                                                         /*}}}*/
 521 // Queue::Startup - Start the worker processes                          /*{{{*/
 522 // ---------------------------------------------------------------------
 523 /* */
 524 bool pkgAcquire::Queue::Startup()
 525 {
 526    Shutdown();
 527
 528    URI U(Name);
 529    pkgAcquire::MethodConfig *Cnf = Owner->GetConfig(U.Access);
 530    if (Cnf == 0)
 531       return false;
 532
 533    Workers = new Worker(this,Cnf,Owner->Log);
 534    Owner->Add(Workers);
 535    if (Workers->Start() == false)
 536       return false;
 537
 538    /* When pipelining we commit 10 items. This needs to change when we
 539       added other source retry to have cycle maintain a pipeline depth
 540       on its own. */
 541    if (Cnf->Pipeline == true)
 542       MaxPipeDepth = 10;
 543    else
 544       MaxPipeDepth = 1;
 545
 546    return Cycle();
 547 }
 548                                                                         /*}}}*/
 549 // Queue::Shutdown - Shutdown the worker processes                      /*{{{*/
 550 // ---------------------------------------------------------------------
 551 /* */
 552 bool pkgAcquire::Queue::Shutdown()
 553 {
 554    // Delete all of the workers
 555    while (Workers != 0)
 556    {
 557       pkgAcquire::Worker *Jnk = Workers;
 558       Workers = Workers->NextQueue;
 559       Owner->Remove(Jnk);
 560       delete Jnk;
 561    }
 562
 563    return true;
 564 }
 565                                                                         /*}}}*/
 566 // Queue::FindItem - Find a URI in the item list                        /*{{{*/
 567 // ---------------------------------------------------------------------
 568 /* */
 569 pkgAcquire::Queue::QItem *pkgAcquire::Queue::FindItem(string URI,pkgAcquire::Worker *Owner)
 570 {
 571    for (QItem *I = Items; I != 0; I = I->Next)
 572       if (I->URI == URI && I->Worker == Owner)
 573          return I;
 574    return 0;
 575 }
 576                                                                         /*}}}*/
 577 // Queue::ItemDone - Item has been completed                            /*{{{*/
 578 // ---------------------------------------------------------------------
 579 /* The worker signals this which causes the item to be removed from the
 580    queue. If this is the last queue instance then it is removed from the
 581    main queue too.*/
 582 bool pkgAcquire::Queue::ItemDone(QItem *Itm)
 583 {
 584    PipeDepth--;
 585    if (Itm->Owner->Status == pkgAcquire::Item::StatFetching)
 586       Itm->Owner->Status = pkgAcquire::Item::StatDone;
 587
 588    if (Itm->Owner->QueueCounter <= 1)
 589       Owner->Dequeue(Itm->Owner);
 590    else
 591    {
 592       Dequeue(Itm->Owner);
 593       Owner->Bump();
 594    }
 595
 596    return Cycle();
 597 }
 598                                                                         /*}}}*/
 599 // Queue::Cycle - Queue new items into the method                       /*{{{*/
 600 // ---------------------------------------------------------------------
 601 /* This locates a new idle item and sends it to the worker. If pipelining
 602    is enabled then it keeps the pipe full. */
 603 bool pkgAcquire::Queue::Cycle()
 604 {
 605    if (Items == 0 || Workers == 0)
 606       return true;
 607
 608    if (PipeDepth < 0)
 609       return _error->Error("Pipedepth failure");
 610
 611    // Look for a queable item
 612    QItem *I = Items;
 613    while (PipeDepth < (signed)MaxPipeDepth)
 614    {
 615       for (; I != 0; I = I->Next)
 616          if (I->Owner->Status == pkgAcquire::Item::StatIdle)
 617             break;
 618
 619       // Nothing to do, queue is idle.
 620       if (I == 0)
 621          return true;
 622
 623       I->Worker = Workers;
 624       I->Owner->Status = pkgAcquire::Item::StatFetching;
 625       PipeDepth++;
 626       if (Workers->QueueItem(I) == false)
 627          return false;
 628    }
 629
 630    return true;
 631 }
 632                                                                         /*}}}*/
 633 // Queue::Bump - Fetch any pending objects if we are idle               /*{{{*/
 634 // ---------------------------------------------------------------------
 635 /* This is called when an item in multiple queues is dequeued */
 636 void pkgAcquire::Queue::Bump()
 637 {
 638    Cycle();
 639 }
 640                                                                         /*}}}*/
 641
 642 // AcquireStatus::pkgAcquireStatus - Constructor                        /*{{{*/
 643 // ---------------------------------------------------------------------
 644 /* */
 645 pkgAcquireStatus::pkgAcquireStatus()
 646 {
 647    Start();
 648 }
 649                                                                         /*}}}*/
 650 // AcquireStatus::Pulse - Called periodically                           /*{{{*/
 651 // ---------------------------------------------------------------------
 652 /* This computes some internal state variables for the derived classes to
 653    use. It generates the current downloaded bytes and total bytes to download
 654    as well as the current CPS estimate. */
 655 void pkgAcquireStatus::Pulse(pkgAcquire *Owner)
 656 {
 657    TotalBytes = 0;
 658    CurrentBytes = 0;
 659    TotalItems = 0;
 660    CurrentItems = 0;
 661
 662    // Compute the total number of bytes to fetch
 663    unsigned int Unknown = 0;
 664    unsigned int Count = 0;
 665    for (pkgAcquire::Item **I = Owner->ItemsBegin(); I != Owner->ItemsEnd();
 666         I++, Count++)
 667    {
 668       TotalItems++;
 669       if ((*I)->Status == pkgAcquire::Item::StatDone)
 670          CurrentItems++;
 671
 672       // Totally ignore local items
 673       if ((*I)->Local == true)
 674          continue;
 675
 676       TotalBytes += (*I)->FileSize;
 677       if ((*I)->Complete == true)
 678          CurrentBytes += (*I)->FileSize;
 679       if ((*I)->FileSize == 0 && (*I)->Complete == false)
 680          Unknown++;
 681    }
 682
 683    // Compute the current completion
 684    for (pkgAcquire::Worker *I = Owner->WorkersBegin(); I != 0;
 685         I = Owner->WorkerStep(I))
 686       if (I->CurrentItem != 0 && I->CurrentItem->Owner->Complete == false)
 687          CurrentBytes += I->CurrentSize;
 688
 689    // Normalize the figures and account for unknown size downloads
 690    if (TotalBytes <= 0)
 691       TotalBytes = 1;
 692    if (Unknown == Count)
 693       TotalBytes = Unknown;
 694    else
 695       TotalBytes += TotalBytes/(Count - Unknown)*Unknown;
 696
 697    // Compute the CPS
 698    struct timeval NewTime;
 699    gettimeofday(&NewTime,0);
 700    if (NewTime.tv_sec - Time.tv_sec == 6 && NewTime.tv_usec > Time.tv_usec ||
 701        NewTime.tv_sec - Time.tv_sec > 6)
 702    {
 703       double Delta = NewTime.tv_sec - Time.tv_sec +
 704                      (NewTime.tv_usec - Time.tv_usec)/1000000.0;
 705
 706       // Compute the CPS value
 707       if (Delta < 0.01)
 708          CurrentCPS = 0;
 709       else
 710          CurrentCPS = (CurrentBytes - LastBytes)/Delta;
 711       LastBytes = CurrentBytes;
 712       ElapsedTime = Delta;
 713       Time = NewTime;
 714    }
 715 }
 716                                                                         /*}}}*/
 717 // AcquireStatus::Start - Called when the download is started           /*{{{*/
 718 // ---------------------------------------------------------------------
 719 /* We just reset the counters */
 720 void pkgAcquireStatus::Start()
 721 {
 722    gettimeofday(&Time,0);
 723    gettimeofday(&StartTime,0);
 724    LastBytes = 0;
 725    CurrentCPS = 0;
 726    CurrentBytes = 0;
 727    TotalBytes = 0;
 728    FetchedBytes = 0;
 729    ElapsedTime = 0;
 730    TotalItems = 0;
 731    CurrentItems = 0;
 732 }
 733                                                                         /*}}}*/
 734 // AcquireStatus::Stop - Finished downloading                           /*{{{*/
 735 // ---------------------------------------------------------------------
 736 /* This accurately computes the elapsed time and the total overall CPS. */
 737 void pkgAcquireStatus::Stop()
 738 {
 739    // Compute the CPS and elapsed time
 740    struct timeval NewTime;
 741    gettimeofday(&NewTime,0);
 742
 743    // Compute the delta time with full accuracy
 744    long usdiff = NewTime.tv_usec - StartTime.tv_usec;
 745    long sdiff = NewTime.tv_sec - StartTime.tv_sec;
 746
 747    // Borrow
 748    if (usdiff < 0)
 749    {
 750       usdiff += 1000000;
 751       sdiff--;
 752    }
 753
 754    // Compute the CPS value
 755    if (sdiff == 0 && usdiff == 0)
 756       CurrentCPS = 0;
 757    else
 758       CurrentCPS = FetchedBytes/(sdiff + usdiff/1000000.0);
 759    LastBytes = CurrentBytes;
 760    ElapsedTime = sdiff;
 761 }
 762                                                                         /*}}}*/
 763 // AcquireStatus::Fetched - Called when a byte set has been fetched     /*{{{*/
 764 // ---------------------------------------------------------------------
 765 /* This is used to get accurate final transfer rate reporting. */
 766 void pkgAcquireStatus::Fetched(unsigned long Size,unsigned long Resume)
 767 {
 768    FetchedBytes += Size - Resume;
 769 }
 770                                                                         /*}}}*/