apt-pkg/acquire-item.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: acquire-item.h,v 1.26.2.3 2004/01/02 18:51:00 mdz Exp $
   4 /* ######################################################################
   5
   6    Acquire Item - Item to acquire
   7
   8    When an item is instantiated it will add it self to the local list in
   9    the Owner Acquire class. Derived classes will then call QueueURI to
  10    register all the URI's they wish to fetch at the initial moment.
  11
  12    Three item classes are provided to provide functionality for
  13    downloading of Index, Translation and Packages files.
  14
  15    A Archive class is provided for downloading .deb files. It does Md5
  16    checking and source location as well as a retry algorithm.
  17
  18    ##################################################################### */
  19                                                                         /*}}}*/
  20 #ifndef PKGLIB_ACQUIRE_ITEM_H
  21 #define PKGLIB_ACQUIRE_ITEM_H
  22
  23 #include <apt-pkg/acquire.h>
  24 #include <apt-pkg/indexfile.h>
  25 #include <apt-pkg/vendor.h>
  26 #include <apt-pkg/sourcelist.h>
  27 #include <apt-pkg/pkgrecords.h>
  28 #include <apt-pkg/indexrecords.h>
  29
  30
  31 /** \addtogroup acquire
  32  *  @{
  33  *
  34  *  \file acquire-item.h
  35  */
  36
  37 /** \brief Represents the process by which a pkgAcquire object should
  38  *  retrieve a file or a collection of files.
  39  *
  40  *  By convention, Item subclasses should insert themselves into the
  41  *  acquire queue when they are created by calling QueueURI(), and
  42  *  remove themselves by calling Dequeue() when either Done() or
  43  *  Failed() is invoked.  Item objects are also responsible for
  44  *  notifying the download progress indicator (accessible via
  45  *  #Owner->Log) of their status.
  46  *
  47  *  \see pkgAcquire
  48  */
  49 class pkgAcquire::Item
  50 {
  51    protected:
  52
  53    /** \brief The acquire object with which this item is associated. */
  54    pkgAcquire *Owner;
  55
  56    /** \brief Insert this item into its owner's queue.
  57     *
  58     *  \param ItemDesc Metadata about this item (its URI and
  59     *  description).
  60     */
  61    inline void QueueURI(ItemDesc &Item)
  62                  {Owner->Enqueue(Item);};
  63
  64    /** \brief Remove this item from its owner's queue. */
  65    inline void Dequeue() {Owner->Dequeue(this);};
  66
  67    /** \brief Rename a file without modifying its timestamp.
  68     *
  69     *  Many item methods call this as their final action.
  70     *
  71     *  \param From The file to be renamed.
  72     *
  73     *  \param To The new name of #From.  If #To exists it will be
  74     *  overwritten.
  75     */
  76    void Rename(string From,string To);
  77
  78    public:
  79
  80    /** \brief The current status of this item. */
  81    enum ItemState
  82      {
  83        /** \brief The item is waiting to be downloaded. */
  84        StatIdle,
  85
  86        /** \brief The item is currently being downloaded. */
  87        StatFetching,
  88
  89        /** \brief The item has been successfully downloaded. */
  90        StatDone,
  91
  92        /** \brief An error was encountered while downloading this
  93         *  item.
  94         */
  95        StatError,
  96
  97        /** \brief The item was downloaded but its authenticity could
  98         *  not be verified.
  99         */
 100        StatAuthError,
 101
 102        /** \brief The item was could not be downloaded because of
 103         *  a transient network error (e.g. network down)
 104         */
 105        StatTransientNetworkError
 106      } Status;
 107
 108    /** \brief Contains a textual description of the error encountered
 109     *  if #Status is #StatError or #StatAuthError.
 110     */
 111    string ErrorText;
 112
 113    /** \brief The size of the object to fetch. */
 114    unsigned long FileSize;
 115
 116    /** \brief How much of the object was already fetched. */
 117    unsigned long PartialSize;
 118
 119    /** \brief If not \b NULL, contains the name of a subprocess that
 120     *  is operating on this object (for instance, "gzip" or "gpgv").
 121     */
 122    const char *Mode;
 123
 124    /** \brief A client-supplied unique identifier.
 125     *
 126     *  This field is initalized to 0; it is meant to be filled in by
 127     *  clients that wish to use it to uniquely identify items.
 128     *
 129     *  \todo it's unused in apt itself
 130     */
 131    unsigned long ID;
 132
 133    /** \brief If \b true, the entire object has been successfully fetched.
 134     *
 135     *  Subclasses should set this to \b true when appropriate.
 136     */
 137    bool Complete;
 138
 139    /** \brief If \b true, the URI of this object is "local".
 140     *
 141     *  The only effect of this field is to exclude the object from the
 142     *  download progress indicator's overall statistics.
 143     */
 144    bool Local;
 145
 146    /** \brief The number of fetch queues into which this item has been
 147     *  inserted.
 148     *
 149     *  There is one queue for each source from which an item could be
 150     *  downloaded.
 151     *
 152     *  \sa pkgAcquire
 153     */
 154    unsigned int QueueCounter;
 155
 156    /** \brief The name of the file into which the retrieved object
 157     *  will be written.
 158     */
 159    string DestFile;
 160
 161    /** \brief Invoked by the acquire worker when the object couldn't
 162     *  be fetched.
 163     *
 164     *  This is a branch of the continuation of the fetch process.
 165     *
 166     *  \param Message An RFC822-formatted message from the acquire
 167     *  method describing what went wrong.  Use LookupTag() to parse
 168     *  it.
 169     *
 170     *  \param Cnf The method via which the worker tried to fetch this object.
 171     *
 172     *  \sa pkgAcqMethod
 173     */
 174    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 175
 176    /** \brief Invoked by the acquire worker when the object was
 177     *  fetched successfully.
 178     *
 179     *  Note that the object might \e not have been written to
 180     *  DestFile; check for the presence of an Alt-Filename entry in
 181     *  Message to find the file to which it was really written.
 182     *
 183     *  Done is often used to switch from one stage of the processing
 184     *  to the next (e.g. fetching, unpacking, copying).  It is one
 185     *  branch of the continuation of the fetch process.
 186     *
 187     *  \param Message Data from the acquire method.  Use LookupTag()
 188     *  to parse it.
 189     *  \param Size The size of the object that was fetched.
 190     *  \param Md5Hash The MD5Sum of the object that was fetched.
 191     *  \param Cnf The method via which the object was fetched.
 192     *
 193     *  \sa pkgAcqMethod
 194     */
 195    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 196                      pkgAcquire::MethodConfig *Cnf);
 197
 198    /** \brief Invoked when the worker starts to fetch this object.
 199     *
 200     *  \param Message RFC822-formatted data from the worker process.
 201     *  Use LookupTag() to parse it.
 202     *
 203     *  \param Size The size of the object being fetched.
 204     *
 205     *  \sa pkgAcqMethod
 206     */
 207    virtual void Start(string Message,unsigned long Size);
 208
 209    /** \brief Custom headers to be sent to the fetch process.
 210     *
 211     *  \return a string containing RFC822-style headers that are to be
 212     *  inserted into the 600 URI Acquire message sent to the fetch
 213     *  subprocess.  The headers are inserted after a newline-less
 214     *  line, so they should (if nonempty) have a leading newline and
 215     *  no trailing newline.
 216     */
 217    virtual string Custom600Headers() {return string();};
 218
 219    /** \brief A "descriptive" URI-like string.
 220     *
 221     *  \return a URI that should be used to describe what is being fetched.
 222     */
 223    virtual string DescURI() = 0;
 224    /** \brief Short item description.
 225     *
 226     *  \return a brief description of the object being fetched.
 227     */
 228    virtual string ShortDesc() {return DescURI();}
 229
 230    /** \brief Invoked by the worker when the download is completely done. */
 231    virtual void Finished() {};
 232
 233    /** \brief MD5Sum.
 234     *
 235     *  \return the MD5Sum of this object, if applicable; otherwise, an
 236     *  empty string.
 237     */
 238    virtual string MD5Sum() {return string();};
 239
 240    /** \return the acquire process with which this item is associated. */
 241    pkgAcquire *GetOwner() {return Owner;};
 242
 243    /** \return \b true if this object is being fetched from a trusted source. */
 244    virtual bool IsTrusted() {return false;};
 245
 246    /** \brief Initialize an item.
 247     *
 248     *  Adds the item to the list of items known to the acquire
 249     *  process, but does not place it into any fetch queues (you must
 250     *  manually invoke QueueURI() to do so).
 251     *
 252     *  Initializes all fields of the item other than Owner to 0,
 253     *  false, or the empty string.
 254     *
 255     *  \param Owner The new owner of this item.
 256     */
 257    Item(pkgAcquire *Owner);
 258
 259    /** \brief Remove this item from its owner's queue by invoking
 260     *  pkgAcquire::Remove.
 261     */
 262    virtual ~Item();
 263 };
 264
 265 /** \brief Information about an index patch (aka diff). */
 266 struct DiffInfo {
 267    /** The filename of the diff. */
 268    string file;
 269
 270    /** The sha1 hash of the diff. */
 271    string sha1;
 272
 273    /** The size of the diff. */
 274    unsigned long size;
 275 };
 276
 277 /** \brief An item that is responsible for fetching an index file of
 278  *  package list diffs and starting the package list's download.
 279  *
 280  *  This item downloads the Index file and parses it, then enqueues
 281  *  additional downloads of either the individual patches (using
 282  *  pkgAcqIndexDiffs) or the entire Packages file (using pkgAcqIndex).
 283  *
 284  *  \sa pkgAcqIndexDiffs, pkgAcqIndex
 285  */
 286 class pkgAcqDiffIndex : public pkgAcquire::Item
 287 {
 288  protected:
 289    /** \brief If \b true, debugging information will be written to std::clog. */
 290    bool Debug;
 291
 292    /** \brief The item that is currently being downloaded. */
 293    pkgAcquire::ItemDesc Desc;
 294
 295    /** \brief The URI of the index file to recreate at our end (either
 296     *  by downloading it or by applying partial patches).
 297     */
 298    string RealURI;
 299
 300    /** \brief The MD5Sum that the real index file should have after
 301     *  all patches have been applied.
 302     */
 303    string ExpectedMD5;
 304
 305    /** \brief The index file which will be patched to generate the new
 306     *  file.
 307     */
 308    string CurrentPackagesFile;
 309
 310    /** \brief A description of the Packages file (stored in
 311     *  pkgAcquire::ItemDesc::Description).
 312     */
 313    string Description;
 314
 315  public:
 316    // Specialized action members
 317    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 318    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 319                      pkgAcquire::MethodConfig *Cnf);
 320    virtual string DescURI() {return RealURI + "Index";};
 321    virtual string Custom600Headers();
 322
 323    /** \brief Parse the Index file for a set of Packages diffs.
 324     *
 325     *  Parses the Index file and creates additional download items as
 326     *  necessary.
 327     *
 328     *  \param IndexDiffFile The name of the Index file.
 329     *
 330     *  \return \b true if the Index file was successfully parsed, \b
 331     *  false otherwise.
 332     */
 333    bool ParseDiffIndex(string IndexDiffFile);
 334
 335
 336    /** \brief Create a new pkgAcqDiffIndex.
 337     *
 338     *  \param Owner The Acquire object that owns this item.
 339     *
 340     *  \param URI The URI of the list file to download.
 341     *
 342     *  \param URIDesc A long description of the list file to download.
 343     *
 344     *  \param ShortDesc A short description of the list file to download.
 345     *
 346     *  \param ExpectedMD5 The list file's MD5 signature.
 347     */
 348    pkgAcqDiffIndex(pkgAcquire *Owner,string URI,string URIDesc,
 349                    string ShortDesc, string ExpectedMD5);
 350 };
 351
 352 /** \brief An item that is responsible for fetching all the patches
 353  *  that need to be applied to a given package index file.
 354  *
 355  *  After downloading and applying a single patch, this item will
 356  *  enqueue a new pkgAcqIndexDiffs to download and apply the remaining
 357  *  patches.  If no patch can be found that applies to an intermediate
 358  *  file or if one of the patches cannot be downloaded, falls back to
 359  *  downloading the entire package index file using pkgAcqIndex.
 360  *
 361  *  \sa pkgAcqDiffIndex, pkgAcqIndex
 362  */
 363 class pkgAcqIndexDiffs : public pkgAcquire::Item
 364 {
 365    private:
 366
 367    /** \brief Queue up the next diff download.
 368     *
 369     *  Search for the next available diff that applies to the file
 370     *  that currently exists on disk, and enqueue it by calling
 371     *  QueueURI().
 372     *
 373     *  \return \b true if an applicable diff was found, \b false
 374     *  otherwise.
 375     */
 376    bool QueueNextDiff();
 377
 378    /** \brief Handle tasks that must be performed after the item
 379     *  finishes downloading.
 380     *
 381     *  Dequeues the item and checks the resulting file's md5sum
 382     *  against ExpectedMD5 after the last patch was applied.
 383     *  There is no need to check the md5/sha1 after a "normal"
 384     *  patch because QueueNextDiff() will check the sha1 later.
 385     *
 386     *  \param allDone If \b true, the file was entirely reconstructed,
 387     *  and its md5sum is verified.
 388     */
 389    void Finish(bool allDone=false);
 390
 391    protected:
 392
 393    /** \brief If \b true, debugging output will be written to
 394     *  std::clog.
 395     */
 396    bool Debug;
 397
 398    /** \brief A description of the item that is currently being
 399     *  downloaded.
 400     */
 401    pkgAcquire::ItemDesc Desc;
 402
 403    /** \brief The URI of the package index file that is being
 404     *  reconstructed.
 405     */
 406    string RealURI;
 407
 408    /** \brief The MD5Sum of the package index file that is being
 409     *  reconstructed.
 410     */
 411    string ExpectedMD5;
 412
 413    /** A description of the file being downloaded. */
 414    string Description;
 415
 416    /** The patches that remain to be downloaded, including the patch
 417     *  being downloaded right now.  This list should be ordered so
 418     *  that each diff appears before any diff that depends on it.
 419     *
 420     *  \todo These are indexed by sha1sum; why not use some sort of
 421     *  dictionary instead of relying on ordering and stripping them
 422     *  off the front?
 423     */
 424    vector<DiffInfo> available_patches;
 425    /** The current status of this patch. */
 426    enum DiffState
 427      {
 428         /** \brief The diff is in an unknown state. */
 429          StateFetchUnkown,
 430
 431          /** \brief The diff is currently being fetched. */
 432          StateFetchDiff,
 433
 434          /** \brief The diff is currently being uncompressed. */
 435          StateUnzipDiff,
 436
 437          /** \brief The diff is currently being applied. */
 438          StateApplyDiff
 439    } State;
 440
 441    public:
 442
 443    /** \brief Called when the patch file failed to be downloaded.
 444     *
 445     *  This method will fall back to downloading the whole index file
 446     *  outright; its arguments are ignored.
 447     */
 448    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 449
 450    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 451                      pkgAcquire::MethodConfig *Cnf);
 452    virtual string DescURI() {return RealURI + "Index";};
 453
 454    /** \brief Create an index diff item.
 455     *
 456     *  After filling in its basic fields, this invokes Finish(true) if
 457     *  #diffs is empty, or QueueNextDiff() otherwise.
 458     *
 459     *  \param Owner The pkgAcquire object that owns this item.
 460     *
 461     *  \param URI The URI of the package index file being
 462     *  reconstructed.
 463     *
 464     *  \param URIDesc A long description of this item.
 465     *
 466     *  \param ShortDesc A brief description of this item.
 467     *
 468     *  \param ExpectedMD5 The expected md5sum of the completely
 469     *  reconstructed package index file; the index file will be tested
 470     *  against this value when it is entirely reconstructed.
 471     *
 472     *  \param diffs The remaining diffs from the index of diffs.  They
 473     *  should be ordered so that each diff appears before any diff
 474     *  that depends on it.
 475     */
 476    pkgAcqIndexDiffs(pkgAcquire *Owner,string URI,string URIDesc,
 477                     string ShortDesc, string ExpectedMD5,
 478                     vector<DiffInfo> diffs=vector<DiffInfo>());
 479 };
 480
 481 /** \brief An acquire item that is responsible for fetching an index
 482  *  file (e.g., Packages or Sources).
 483  *
 484  *  \sa pkgAcqDiffIndex, pkgAcqIndexDiffs, pkgAcqIndexTrans
 485  *
 486  *  \todo Why does pkgAcqIndex have protected members?
 487  */
 488 class pkgAcqIndex : public pkgAcquire::Item
 489 {
 490    protected:
 491
 492    /** \brief If \b true, the index file has been decompressed. */
 493    bool Decompression;
 494
 495    /** \brief If \b true, the partially downloaded file will be
 496     *  removed when the download completes.
 497     */
 498    bool Erase;
 499
 500    /** \brief The download request that is currently being
 501     *   processed.
 502     */
 503    pkgAcquire::ItemDesc Desc;
 504
 505    /** \brief The object that is actually being fetched (minus any
 506     *  compression-related extensions).
 507     */
 508    string RealURI;
 509
 510    /** \brief The expected md5sum of the decompressed index file. */
 511    string ExpectedMD5;
 512
 513    /** \brief The compression-related file extension that is being
 514     *  added to the downloaded file (e.g., ".gz" or ".bz2").
 515     */
 516    string CompressionExtension;
 517
 518    public:
 519
 520    // Specialized action members
 521    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 522    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 523                      pkgAcquire::MethodConfig *Cnf);
 524    virtual string Custom600Headers();
 525    virtual string DescURI() {return RealURI + CompressionExtension;};
 526
 527    /** \brief Create a pkgAcqIndex.
 528     *
 529     *  \param Owner The pkgAcquire object with which this item is
 530     *  associated.
 531     *
 532     *  \param URI The URI of the index file that is to be downloaded.
 533     *
 534     *  \param URIDesc A "URI-style" description of this index file.
 535     *
 536     *  \param ShortDesc A brief description of this index file.
 537     *
 538     *  \param ExpectedMD5 The expected md5sum of this index file.
 539     *
 540     *  \param compressExt The compression-related extension with which
 541     *  this index file should be downloaded, or "" to autodetect
 542     *  (".bz2" is used if bzip2 is installed, ".gz" otherwise).
 543     */
 544    pkgAcqIndex(pkgAcquire *Owner,string URI,string URIDesc,
 545                string ShortDesc, string ExpectedMD5, string compressExt="");
 546 };
 547
 548 /** \brief An acquire item that is responsible for fetching a
 549  *  translated index file.
 550  *
 551  *  The only difference from pkgAcqIndex is that transient failures
 552  *  are suppressed: no error occurs if the translated index file is
 553  *  missing.
 554  */
 555 class pkgAcqIndexTrans : public pkgAcqIndex
 556 {
 557    public:
 558
 559    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 560
 561    /** \brief Create a pkgAcqIndexTrans.
 562     *
 563     *  \param Owner The pkgAcquire object with which this item is
 564     *  associated.
 565     *
 566     *  \param URI The URI of the index file that is to be downloaded.
 567     *
 568     *  \param URIDesc A "URI-style" description of this index file.
 569     *
 570     *  \param ShortDesc A brief description of this index file.
 571     *
 572     *  \param ExpectedMD5 The expected md5sum of this index file.
 573     *
 574     *  \param compressExt The compression-related extension with which
 575     *  this index file should be downloaded, or "" to autodetect
 576     *  (".bz2" is used if bzip2 is installed, ".gz" otherwise).
 577     */
 578    pkgAcqIndexTrans(pkgAcquire *Owner,string URI,string URIDesc,
 579                     string ShortDesc);
 580 };
 581
 582 /** \brief Information about an index file. */
 583 struct IndexTarget
 584 {
 585    /** \brief A URI from which the index file can be downloaded. */
 586    string URI;
 587
 588    /** \brief A description of the index file. */
 589    string Description;
 590
 591    /** \brief A shorter description of the index file. */
 592    string ShortDesc;
 593
 594    /** \brief The key by which this index file should be
 595     *  looked up within the meta signature file.
 596     */
 597    string MetaKey;
 598 };
 599
 600 /** \brief An acquire item that downloads the detached signature
 601  *  of a meta-index (Release) file, then queues up the release
 602  *  file itself.
 603  *
 604  *  \todo Why protected members?
 605  *
 606  *  \sa pkgAcqMetaIndex
 607  */
 608 class pkgAcqMetaSig : public pkgAcquire::Item
 609 {
 610    protected:
 611    /** \brief The fetch request that is currently being processed. */
 612    pkgAcquire::ItemDesc Desc;
 613
 614    /** \brief The URI of the signature file.  Unlike Desc.URI, this is
 615     *  never modified; it is used to determine the file that is being
 616     *  downloaded.
 617     */
 618    string RealURI;
 619
 620    /** \brief The URI of the meta-index file to be fetched after the signature. */
 621    string MetaIndexURI;
 622
 623    /** \brief A "URI-style" description of the meta-index file to be
 624     *  fetched after the signature.
 625     */
 626    string MetaIndexURIDesc;
 627
 628    /** \brief A brief description of the meta-index file to be fetched
 629     *  after the signature.
 630     */
 631    string MetaIndexShortDesc;
 632
 633    /** \brief A package-system-specific parser for the meta-index file. */
 634    indexRecords* MetaIndexParser;
 635
 636    /** \brief The index files which should be looked up in the meta-index
 637     *  and then downloaded.
 638     *
 639     *  \todo Why a list of pointers instead of a list of structs?
 640     */
 641    const vector<struct IndexTarget*>* IndexTargets;
 642
 643    public:
 644
 645    // Specialized action members
 646    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 647    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 648                      pkgAcquire::MethodConfig *Cnf);
 649    virtual string Custom600Headers();
 650    virtual string DescURI() {return RealURI; };
 651
 652    /** \brief Create a new pkgAcqMetaSig. */
 653    pkgAcqMetaSig(pkgAcquire *Owner,string URI,string URIDesc, string ShortDesc,
 654                  string MetaIndexURI, string MetaIndexURIDesc, string MetaIndexShortDesc,
 655                  const vector<struct IndexTarget*>* IndexTargets,
 656                  indexRecords* MetaIndexParser);
 657 };
 658
 659 /** \brief An item that is responsible for downloading the meta-index
 660  *  file (i.e., Release) itself and verifying its signature.
 661  *
 662  *  Once the download and verification are complete, the downloads of
 663  *  the individual index files are queued up using pkgAcqDiffIndex.
 664  *  If the meta-index file had a valid signature, the expected md5sums
 665  *  of the index files will be the md5sums listed in the meta-index;
 666  *  otherwise, the expected md5sums will be "" (causing the
 667  *  authentication of the index files to be bypassed).
 668  */
 669 class pkgAcqMetaIndex : public pkgAcquire::Item
 670 {
 671    protected:
 672    /** \brief The fetch command that is currently being processed. */
 673    pkgAcquire::ItemDesc Desc;
 674
 675    /** \brief The URI that is actually being downloaded; never
 676     *  modified by pkgAcqMetaIndex.
 677     */
 678    string RealURI;
 679
 680    /** \brief The file in which the signature for this index was stored.
 681     *
 682     *  If empty, the signature and the md5sums of the individual
 683     *  indices will not be checked.
 684     */
 685    string SigFile;
 686
 687    /** \brief The index files to download. */
 688    const vector<struct IndexTarget*>* IndexTargets;
 689
 690    /** \brief The parser for the meta-index file. */
 691    indexRecords* MetaIndexParser;
 692
 693    /** \brief If \b true, the index's signature is currently being verified.
 694     */
 695    bool AuthPass;
 696    // required to deal gracefully with problems caused by incorrect ims hits
 697    bool IMSHit;
 698
 699    /** \brief Check that the release file is a release file for the
 700     *  correct distribution.
 701     *
 702     *  \return \b true if no fatal errors were encountered.
 703     */
 704    bool VerifyVendor(string Message);
 705
 706    /** \brief Called when a file is finished being retrieved.
 707     *
 708     *  If the file was not downloaded to DestFile, a copy process is
 709     *  set up to copy it to DestFile; otherwise, Complete is set to \b
 710     *  true and the file is moved to its final location.
 711     *
 712     *  \param Message The message block received from the fetch
 713     *  subprocess.
 714     */
 715    void RetrievalDone(string Message);
 716
 717    /** \brief Called when authentication succeeded.
 718     *
 719     *  Sanity-checks the authenticated file, queues up the individual
 720     *  index files for download, and saves the signature in the lists
 721     *  directory next to the authenticated list file.
 722     *
 723     *  \param Message The message block received from the fetch
 724     *  subprocess.
 725     */
 726    void AuthDone(string Message);
 727
 728    /** \brief Starts downloading the individual index files.
 729     *
 730     *  \param verify If \b true, only indices whose expected md5sum
 731     *  can be determined from the meta-index will be downloaded, and
 732     *  the md5sums of indices will be checked (reporting
 733     *  #StatAuthError if there is a mismatch).  If verify is \b false,
 734     *  no md5sum checking will be performed.
 735     */
 736    void QueueIndexes(bool verify);
 737
 738    public:
 739
 740    // Specialized action members
 741    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 742    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 743                      pkgAcquire::MethodConfig *Cnf);
 744    virtual string Custom600Headers();
 745    virtual string DescURI() {return RealURI; };
 746
 747    /** \brief Create a new pkgAcqMetaIndex. */
 748    pkgAcqMetaIndex(pkgAcquire *Owner,
 749                    string URI,string URIDesc, string ShortDesc,
 750                    string SigFile,
 751                    const vector<struct IndexTarget*>* IndexTargets,
 752                    indexRecords* MetaIndexParser);
 753 };
 754
 755 /** \brief An item that is responsible for fetching a package file.
 756  *
 757  *  If the package file already exists in the cache, nothing will be
 758  *  done.
 759  */
 760 class pkgAcqArchive : public pkgAcquire::Item
 761 {
 762    protected:
 763    /** \brief The package version being fetched. */
 764    pkgCache::VerIterator Version;
 765
 766    /** \brief The fetch command that is currently being processed. */
 767    pkgAcquire::ItemDesc Desc;
 768
 769    /** \brief The list of sources from which to pick archives to
 770     *  download this package from.
 771     */
 772    pkgSourceList *Sources;
 773
 774    /** \brief A package records object, used to look up the file
 775     *  corresponding to each version of the package.
 776     */
 777    pkgRecords *Recs;
 778
 779    /** \brief The md5sum of this package. */
 780    string MD5;
 781
 782    /** \brief A location in which the actual filename of the package
 783     *  should be stored.
 784     */
 785    string &StoreFilename;
 786
 787    /** \brief The next file for this version to try to download. */
 788    pkgCache::VerFileIterator Vf;
 789
 790    /** \brief How many (more) times to try to find a new source from
 791     *  which to download this package version if it fails.
 792     *
 793     *  Set from Acquire::Retries.
 794     */
 795    unsigned int Retries;
 796
 797    /** \brief \b true if this version file is being downloaded from a
 798     *  trusted source.
 799     */
 800    bool Trusted;
 801
 802    /** \brief Queue up the next available file for this version. */
 803    bool QueueNext();
 804
 805    public:
 806
 807    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 808    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 809                      pkgAcquire::MethodConfig *Cnf);
 810    virtual string MD5Sum() {return MD5;};
 811    virtual string DescURI() {return Desc.URI;};
 812    virtual string ShortDesc() {return Desc.ShortDesc;};
 813    virtual void Finished();
 814
 815    virtual bool IsTrusted();
 816
 817    /** \brief Create a new pkgAcqArchive.
 818     *
 819     *  \param Owner The pkgAcquire object with which this item is
 820     *  associated.
 821     *
 822     *  \param Sources The sources from which to download version
 823     *  files.
 824     *
 825     *  \param Recs A package records object, used to look up the file
 826     *  corresponding to each version of the package.
 827     *
 828     *  \param Version The package version to download.
 829     *
 830     *  \param StoreFilename A location in which the actual filename of
 831     *  the package should be stored.  It will be set to a guessed
 832     *  basename in the constructor, and filled in with a fully
 833     *  qualified filename once the download finishes.
 834     */
 835    pkgAcqArchive(pkgAcquire *Owner,pkgSourceList *Sources,
 836                  pkgRecords *Recs,pkgCache::VerIterator const &Version,
 837                  string &StoreFilename);
 838 };
 839
 840 /** \brief Retrieve an arbitrary file to the current directory.
 841  *
 842  *  The file is retrieved even if it is accessed via a URL type that
 843  *  normally is a NOP, such as "file".  If the download fails, the
 844  *  partial file is renamed to get a ".FAILED" extension.
 845  */
 846 class pkgAcqFile : public pkgAcquire::Item
 847 {
 848    /** \brief The currently active download process. */
 849    pkgAcquire::ItemDesc Desc;
 850
 851    /** \brief The md5sum of the file to download, if it is known. */
 852    string Md5Hash;
 853
 854    /** \brief How many times to retry the download, set from
 855     *  Acquire::Retries.
 856     */
 857    unsigned int Retries;
 858
 859    public:
 860
 861    // Specialized action members
 862    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 863    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 864                      pkgAcquire::MethodConfig *Cnf);
 865    virtual string MD5Sum() {return Md5Hash;};
 866    virtual string DescURI() {return Desc.URI;};
 867
 868    /** \brief Create a new pkgAcqFile object.
 869     *
 870     *  \param Owner The pkgAcquire object with which this object is
 871     *  associated.
 872     *
 873     *  \param URI The URI to download.
 874     *
 875     *  \param MD5 The md5sum of the file to download, if it is known;
 876     *  otherwise "".
 877     *
 878     *  \param Size The size of the file to download, if it is known;
 879     *  otherwise 0.
 880     *
 881     *  \param Desc A description of the file being downloaded.
 882     *
 883     *  \param ShortDesc A brief description of the file being
 884     *  downloaded.
 885     *
 886     *  \param DestDir The directory the file should be downloaded into.
 887     *
 888     *  \param DestFilename The filename+path the file is downloaded to.
 889     *
 890     *
 891     * If DestFilename is empty, download to DestDir/<basename> if
 892     * DestDir is non-empty, $CWD/<basename> otherwise.  If
 893     * DestFilename is NOT empty, DestDir is ignored and DestFilename
 894     * is the absolute name to which the file should be downloaded.
 895     */
 896
 897    pkgAcqFile(pkgAcquire *Owner, string URI, string MD5, unsigned long Size,
 898               string Desc, string ShortDesc,
 899               const string &DestDir="", const string &DestFilename="");
 900 };
 901
 902 /** @} */
 903
 904 #endif