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 Hash
  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 #include <apt-pkg/hashes.h>
  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    string UsedMirror;
 146
 147    /** \brief The number of fetch queues into which this item has been
 148     *  inserted.
 149     *
 150     *  There is one queue for each source from which an item could be
 151     *  downloaded.
 152     *
 153     *  \sa pkgAcquire
 154     */
 155    unsigned int QueueCounter;
 156
 157    /** \brief The name of the file into which the retrieved object
 158     *  will be written.
 159     */
 160    string DestFile;
 161
 162    /** \brief Invoked by the acquire worker when the object couldn't
 163     *  be fetched.
 164     *
 165     *  This is a branch of the continuation of the fetch process.
 166     *
 167     *  \param Message An RFC822-formatted message from the acquire
 168     *  method describing what went wrong.  Use LookupTag() to parse
 169     *  it.
 170     *
 171     *  \param Cnf The method via which the worker tried to fetch this object.
 172     *
 173     *  \sa pkgAcqMethod
 174     */
 175    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 176
 177    /** \brief Invoked by the acquire worker when the object was
 178     *  fetched successfully.
 179     *
 180     *  Note that the object might \e not have been written to
 181     *  DestFile; check for the presence of an Alt-Filename entry in
 182     *  Message to find the file to which it was really written.
 183     *
 184     *  Done is often used to switch from one stage of the processing
 185     *  to the next (e.g. fetching, unpacking, copying).  It is one
 186     *  branch of the continuation of the fetch process.
 187     *
 188     *  \param Message Data from the acquire method.  Use LookupTag()
 189     *  to parse it.
 190     *  \param Size The size of the object that was fetched.
 191     *  \param Hash The HashSum of the object that was fetched.
 192     *  \param Cnf The method via which the object was fetched.
 193     *
 194     *  \sa pkgAcqMethod
 195     */
 196    virtual void Done(string Message,unsigned long Size,string Hash,
 197                      pkgAcquire::MethodConfig *Cnf);
 198
 199    /** \brief Invoked when the worker starts to fetch this object.
 200     *
 201     *  \param Message RFC822-formatted data from the worker process.
 202     *  Use LookupTag() to parse it.
 203     *
 204     *  \param Size The size of the object being fetched.
 205     *
 206     *  \sa pkgAcqMethod
 207     */
 208    virtual void Start(string Message,unsigned long Size);
 209
 210    /** \brief Custom headers to be sent to the fetch process.
 211     *
 212     *  \return a string containing RFC822-style headers that are to be
 213     *  inserted into the 600 URI Acquire message sent to the fetch
 214     *  subprocess.  The headers are inserted after a newline-less
 215     *  line, so they should (if nonempty) have a leading newline and
 216     *  no trailing newline.
 217     */
 218    virtual string Custom600Headers() {return string();};
 219
 220    /** \brief A "descriptive" URI-like string.
 221     *
 222     *  \return a URI that should be used to describe what is being fetched.
 223     */
 224    virtual string DescURI() = 0;
 225    /** \brief Short item description.
 226     *
 227     *  \return a brief description of the object being fetched.
 228     */
 229    virtual string ShortDesc() {return DescURI();}
 230
 231    /** \brief Invoked by the worker when the download is completely done. */
 232    virtual void Finished() {};
 233
 234    /** \brief HashSum
 235     *
 236     *  \return the HashSum of this object, if applicable; otherwise, an
 237     *  empty string.
 238     */
 239    virtual string HashSum() {return string();};
 240
 241    /** \return the acquire process with which this item is associated. */
 242    pkgAcquire *GetOwner() {return Owner;};
 243
 244    /** \return \b true if this object is being fetched from a trusted source. */
 245    virtual bool IsTrusted() {return false;};
 246
 247    // report mirror problems
 248    /** \brief Report mirror problem
 249     *
 250     *  This allows reporting mirror failures back to a centralized
 251     *  server. The apt-report-mirror-failure script is called for this
 252     *
 253     *  \param FailCode A short failure string that is send
 254     */
 255    void ReportMirrorFailure(string FailCode);
 256
 257
 258    /** \brief Initialize an item.
 259     *
 260     *  Adds the item to the list of items known to the acquire
 261     *  process, but does not place it into any fetch queues (you must
 262     *  manually invoke QueueURI() to do so).
 263     *
 264     *  Initializes all fields of the item other than Owner to 0,
 265     *  false, or the empty string.
 266     *
 267     *  \param Owner The new owner of this item.
 268     */
 269    Item(pkgAcquire *Owner);
 270
 271    /** \brief Remove this item from its owner's queue by invoking
 272     *  pkgAcquire::Remove.
 273     */
 274    virtual ~Item();
 275 };
 276
 277 /** \brief Information about an index patch (aka diff). */
 278 struct DiffInfo {
 279    /** The filename of the diff. */
 280    string file;
 281
 282    /** The sha1 hash of the diff. */
 283    string sha1;
 284
 285    /** The size of the diff. */
 286    unsigned long size;
 287 };
 288
 289 /** \brief An item that is responsible for fetching an index file of
 290  *  package list diffs and starting the package list's download.
 291  *
 292  *  This item downloads the Index file and parses it, then enqueues
 293  *  additional downloads of either the individual patches (using
 294  *  pkgAcqIndexDiffs) or the entire Packages file (using pkgAcqIndex).
 295  *
 296  *  \sa pkgAcqIndexDiffs, pkgAcqIndex
 297  */
 298 class pkgAcqDiffIndex : public pkgAcquire::Item
 299 {
 300  protected:
 301    /** \brief If \b true, debugging information will be written to std::clog. */
 302    bool Debug;
 303
 304    /** \brief The item that is currently being downloaded. */
 305    pkgAcquire::ItemDesc Desc;
 306
 307    /** \brief The URI of the index file to recreate at our end (either
 308     *  by downloading it or by applying partial patches).
 309     */
 310    string RealURI;
 311
 312    /** \brief The Hash that the real index file should have after
 313     *  all patches have been applied.
 314     */
 315    HashString ExpectedHash;
 316
 317    /** \brief The index file which will be patched to generate the new
 318     *  file.
 319     */
 320    string CurrentPackagesFile;
 321
 322    /** \brief A description of the Packages file (stored in
 323     *  pkgAcquire::ItemDesc::Description).
 324     */
 325    string Description;
 326
 327  public:
 328    // Specialized action members
 329    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 330    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 331                      pkgAcquire::MethodConfig *Cnf);
 332    virtual string DescURI() {return RealURI + "Index";};
 333    virtual string Custom600Headers();
 334
 335    /** \brief Parse the Index file for a set of Packages diffs.
 336     *
 337     *  Parses the Index file and creates additional download items as
 338     *  necessary.
 339     *
 340     *  \param IndexDiffFile The name of the Index file.
 341     *
 342     *  \return \b true if the Index file was successfully parsed, \b
 343     *  false otherwise.
 344     */
 345    bool ParseDiffIndex(string IndexDiffFile);
 346
 347
 348    /** \brief Create a new pkgAcqDiffIndex.
 349     *
 350     *  \param Owner The Acquire object that owns this item.
 351     *
 352     *  \param URI The URI of the list file to download.
 353     *
 354     *  \param URIDesc A long description of the list file to download.
 355     *
 356     *  \param ShortDesc A short description of the list file to download.
 357     *
 358     *  \param ExpectedHash The list file's MD5 signature.
 359     */
 360    pkgAcqDiffIndex(pkgAcquire *Owner,string URI,string URIDesc,
 361                    string ShortDesc, HashString ExpectedHash);
 362 };
 363
 364 /** \brief An item that is responsible for fetching all the patches
 365  *  that need to be applied to a given package index file.
 366  *
 367  *  After downloading and applying a single patch, this item will
 368  *  enqueue a new pkgAcqIndexDiffs to download and apply the remaining
 369  *  patches.  If no patch can be found that applies to an intermediate
 370  *  file or if one of the patches cannot be downloaded, falls back to
 371  *  downloading the entire package index file using pkgAcqIndex.
 372  *
 373  *  \sa pkgAcqDiffIndex, pkgAcqIndex
 374  */
 375 class pkgAcqIndexDiffs : public pkgAcquire::Item
 376 {
 377    private:
 378
 379    /** \brief Queue up the next diff download.
 380     *
 381     *  Search for the next available diff that applies to the file
 382     *  that currently exists on disk, and enqueue it by calling
 383     *  QueueURI().
 384     *
 385     *  \return \b true if an applicable diff was found, \b false
 386     *  otherwise.
 387     */
 388    bool QueueNextDiff();
 389
 390    /** \brief Handle tasks that must be performed after the item
 391     *  finishes downloading.
 392     *
 393     *  Dequeues the item and checks the resulting file's md5sum
 394     *  against ExpectedHash after the last patch was applied.
 395     *  There is no need to check the md5/sha1 after a "normal"
 396     *  patch because QueueNextDiff() will check the sha1 later.
 397     *
 398     *  \param allDone If \b true, the file was entirely reconstructed,
 399     *  and its md5sum is verified.
 400     */
 401    void Finish(bool allDone=false);
 402
 403    protected:
 404
 405    /** \brief If \b true, debugging output will be written to
 406     *  std::clog.
 407     */
 408    bool Debug;
 409
 410    /** \brief A description of the item that is currently being
 411     *  downloaded.
 412     */
 413    pkgAcquire::ItemDesc Desc;
 414
 415    /** \brief The URI of the package index file that is being
 416     *  reconstructed.
 417     */
 418    string RealURI;
 419
 420    /** \brief The HashSum of the package index file that is being
 421     *  reconstructed.
 422     */
 423    HashString ExpectedHash;
 424
 425    /** A description of the file being downloaded. */
 426    string Description;
 427
 428    /** The patches that remain to be downloaded, including the patch
 429     *  being downloaded right now.  This list should be ordered so
 430     *  that each diff appears before any diff that depends on it.
 431     *
 432     *  \todo These are indexed by sha1sum; why not use some sort of
 433     *  dictionary instead of relying on ordering and stripping them
 434     *  off the front?
 435     */
 436    vector<DiffInfo> available_patches;
 437    /** The current status of this patch. */
 438    enum DiffState
 439      {
 440         /** \brief The diff is in an unknown state. */
 441          StateFetchUnkown,
 442
 443          /** \brief The diff is currently being fetched. */
 444          StateFetchDiff,
 445
 446          /** \brief The diff is currently being uncompressed. */
 447          StateUnzipDiff,
 448
 449          /** \brief The diff is currently being applied. */
 450          StateApplyDiff
 451    } State;
 452
 453    public:
 454
 455    /** \brief Called when the patch file failed to be downloaded.
 456     *
 457     *  This method will fall back to downloading the whole index file
 458     *  outright; its arguments are ignored.
 459     */
 460    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 461
 462    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 463                      pkgAcquire::MethodConfig *Cnf);
 464    virtual string DescURI() {return RealURI + "Index";};
 465
 466    /** \brief Create an index diff item.
 467     *
 468     *  After filling in its basic fields, this invokes Finish(true) if
 469     *  #diffs is empty, or QueueNextDiff() otherwise.
 470     *
 471     *  \param Owner The pkgAcquire object that owns this item.
 472     *
 473     *  \param URI The URI of the package index file being
 474     *  reconstructed.
 475     *
 476     *  \param URIDesc A long description of this item.
 477     *
 478     *  \param ShortDesc A brief description of this item.
 479     *
 480     *  \param ExpectedHash The expected md5sum of the completely
 481     *  reconstructed package index file; the index file will be tested
 482     *  against this value when it is entirely reconstructed.
 483     *
 484     *  \param diffs The remaining diffs from the index of diffs.  They
 485     *  should be ordered so that each diff appears before any diff
 486     *  that depends on it.
 487     */
 488    pkgAcqIndexDiffs(pkgAcquire *Owner,string URI,string URIDesc,
 489                     string ShortDesc, HashString ExpectedHash,
 490                     vector<DiffInfo> diffs=vector<DiffInfo>());
 491 };
 492
 493 /** \brief An acquire item that is responsible for fetching an index
 494  *  file (e.g., Packages or Sources).
 495  *
 496  *  \sa pkgAcqDiffIndex, pkgAcqIndexDiffs, pkgAcqIndexTrans
 497  *
 498  *  \todo Why does pkgAcqIndex have protected members?
 499  */
 500 class pkgAcqIndex : public pkgAcquire::Item
 501 {
 502    protected:
 503
 504    /** \brief If \b true, the index file has been decompressed. */
 505    bool Decompression;
 506
 507    /** \brief If \b true, the partially downloaded file will be
 508     *  removed when the download completes.
 509     */
 510    bool Erase;
 511
 512    /** \brief The download request that is currently being
 513     *   processed.
 514     */
 515    pkgAcquire::ItemDesc Desc;
 516
 517    /** \brief The object that is actually being fetched (minus any
 518     *  compression-related extensions).
 519     */
 520    string RealURI;
 521
 522    /** \brief The expected hashsum of the decompressed index file. */
 523    HashString ExpectedHash;
 524
 525    /** \brief The compression-related file extension that is being
 526     *  added to the downloaded file (e.g., ".gz" or ".bz2").
 527     */
 528    string CompressionExtension;
 529
 530    public:
 531
 532    // Specialized action members
 533    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 534    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 535                      pkgAcquire::MethodConfig *Cnf);
 536    virtual string Custom600Headers();
 537    virtual string DescURI() {return RealURI + CompressionExtension;};
 538    virtual string HashSum() {return ExpectedHash.toStr(); };
 539
 540    /** \brief Create a pkgAcqIndex.
 541     *
 542     *  \param Owner The pkgAcquire object with which this item is
 543     *  associated.
 544     *
 545     *  \param URI The URI of the index file that is to be downloaded.
 546     *
 547     *  \param URIDesc A "URI-style" description of this index file.
 548     *
 549     *  \param ShortDesc A brief description of this index file.
 550     *
 551     *  \param ExpectedHash The expected hashsum of this index file.
 552     *
 553     *  \param compressExt The compression-related extension with which
 554     *  this index file should be downloaded, or "" to autodetect
 555     *  (".bz2" is used if bzip2 is installed, ".gz" otherwise).
 556     */
 557    pkgAcqIndex(pkgAcquire *Owner,string URI,string URIDesc,
 558                string ShortDesc, HashString ExpectedHash,
 559                string compressExt="");
 560 };
 561
 562 /** \brief An acquire item that is responsible for fetching a
 563  *  translated index file.
 564  *
 565  *  The only difference from pkgAcqIndex is that transient failures
 566  *  are suppressed: no error occurs if the translated index file is
 567  *  missing.
 568  */
 569 class pkgAcqIndexTrans : public pkgAcqIndex
 570 {
 571    public:
 572
 573    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 574
 575    /** \brief Create a pkgAcqIndexTrans.
 576     *
 577     *  \param Owner The pkgAcquire object with which this item is
 578     *  associated.
 579     *
 580     *  \param URI The URI of the index file that is to be downloaded.
 581     *
 582     *  \param URIDesc A "URI-style" description of this index file.
 583     *
 584     *  \param ShortDesc A brief description of this index file.
 585     *
 586     *  \param ExpectedHash The expected hashsum of this index file.
 587     *
 588     *  \param compressExt The compression-related extension with which
 589     *  this index file should be downloaded, or "" to autodetect
 590     *  (".bz2" is used if bzip2 is installed, ".gz" otherwise).
 591     */
 592    pkgAcqIndexTrans(pkgAcquire *Owner,string URI,string URIDesc,
 593                     string ShortDesc);
 594 };
 595
 596 /** \brief Information about an index file. */
 597 struct IndexTarget
 598 {
 599    /** \brief A URI from which the index file can be downloaded. */
 600    string URI;
 601
 602    /** \brief A description of the index file. */
 603    string Description;
 604
 605    /** \brief A shorter description of the index file. */
 606    string ShortDesc;
 607
 608    /** \brief The key by which this index file should be
 609     *  looked up within the meta signature file.
 610     */
 611    string MetaKey;
 612 };
 613
 614 /** \brief An acquire item that downloads the detached signature
 615  *  of a meta-index (Release) file, then queues up the release
 616  *  file itself.
 617  *
 618  *  \todo Why protected members?
 619  *
 620  *  \sa pkgAcqMetaIndex
 621  */
 622 class pkgAcqMetaSig : public pkgAcquire::Item
 623 {
 624    protected:
 625    /** \brief The fetch request that is currently being processed. */
 626    pkgAcquire::ItemDesc Desc;
 627
 628    /** \brief The URI of the signature file.  Unlike Desc.URI, this is
 629     *  never modified; it is used to determine the file that is being
 630     *  downloaded.
 631     */
 632    string RealURI;
 633
 634    /** \brief The URI of the meta-index file to be fetched after the signature. */
 635    string MetaIndexURI;
 636
 637    /** \brief A "URI-style" description of the meta-index file to be
 638     *  fetched after the signature.
 639     */
 640    string MetaIndexURIDesc;
 641
 642    /** \brief A brief description of the meta-index file to be fetched
 643     *  after the signature.
 644     */
 645    string MetaIndexShortDesc;
 646
 647    /** \brief A package-system-specific parser for the meta-index file. */
 648    indexRecords* MetaIndexParser;
 649
 650    /** \brief The index files which should be looked up in the meta-index
 651     *  and then downloaded.
 652     *
 653     *  \todo Why a list of pointers instead of a list of structs?
 654     */
 655    const vector<struct IndexTarget*>* IndexTargets;
 656
 657    public:
 658
 659    // Specialized action members
 660    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 661    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 662                      pkgAcquire::MethodConfig *Cnf);
 663    virtual string Custom600Headers();
 664    virtual string DescURI() {return RealURI; };
 665
 666    /** \brief Create a new pkgAcqMetaSig. */
 667    pkgAcqMetaSig(pkgAcquire *Owner,string URI,string URIDesc, string ShortDesc,
 668                  string MetaIndexURI, string MetaIndexURIDesc, string MetaIndexShortDesc,
 669                  const vector<struct IndexTarget*>* IndexTargets,
 670                  indexRecords* MetaIndexParser);
 671 };
 672
 673 /** \brief An item that is responsible for downloading the meta-index
 674  *  file (i.e., Release) itself and verifying its signature.
 675  *
 676  *  Once the download and verification are complete, the downloads of
 677  *  the individual index files are queued up using pkgAcqDiffIndex.
 678  *  If the meta-index file had a valid signature, the expected hashsums
 679  *  of the index files will be the md5sums listed in the meta-index;
 680  *  otherwise, the expected hashsums will be "" (causing the
 681  *  authentication of the index files to be bypassed).
 682  */
 683 class pkgAcqMetaIndex : public pkgAcquire::Item
 684 {
 685    protected:
 686    /** \brief The fetch command that is currently being processed. */
 687    pkgAcquire::ItemDesc Desc;
 688
 689    /** \brief The URI that is actually being downloaded; never
 690     *  modified by pkgAcqMetaIndex.
 691     */
 692    string RealURI;
 693
 694    /** \brief The file in which the signature for this index was stored.
 695     *
 696     *  If empty, the signature and the md5sums of the individual
 697     *  indices will not be checked.
 698     */
 699    string SigFile;
 700
 701    /** \brief The index files to download. */
 702    const vector<struct IndexTarget*>* IndexTargets;
 703
 704    /** \brief The parser for the meta-index file. */
 705    indexRecords* MetaIndexParser;
 706
 707    /** \brief If \b true, the index's signature is currently being verified.
 708     */
 709    bool AuthPass;
 710    // required to deal gracefully with problems caused by incorrect ims hits
 711    bool IMSHit;
 712
 713    /** \brief Check that the release file is a release file for the
 714     *  correct distribution.
 715     *
 716     *  \return \b true if no fatal errors were encountered.
 717     */
 718    bool VerifyVendor(string Message);
 719
 720    /** \brief Called when a file is finished being retrieved.
 721     *
 722     *  If the file was not downloaded to DestFile, a copy process is
 723     *  set up to copy it to DestFile; otherwise, Complete is set to \b
 724     *  true and the file is moved to its final location.
 725     *
 726     *  \param Message The message block received from the fetch
 727     *  subprocess.
 728     */
 729    void RetrievalDone(string Message);
 730
 731    /** \brief Called when authentication succeeded.
 732     *
 733     *  Sanity-checks the authenticated file, queues up the individual
 734     *  index files for download, and saves the signature in the lists
 735     *  directory next to the authenticated list file.
 736     *
 737     *  \param Message The message block received from the fetch
 738     *  subprocess.
 739     */
 740    void AuthDone(string Message);
 741
 742    /** \brief Starts downloading the individual index files.
 743     *
 744     *  \param verify If \b true, only indices whose expected hashsum
 745     *  can be determined from the meta-index will be downloaded, and
 746     *  the hashsums of indices will be checked (reporting
 747     *  #StatAuthError if there is a mismatch).  If verify is \b false,
 748     *  no hashsum checking will be performed.
 749     */
 750    void QueueIndexes(bool verify);
 751
 752    public:
 753
 754    // Specialized action members
 755    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 756    virtual void Done(string Message,unsigned long Size, string Hash,
 757                      pkgAcquire::MethodConfig *Cnf);
 758    virtual string Custom600Headers();
 759    virtual string DescURI() {return RealURI; };
 760
 761    /** \brief Create a new pkgAcqMetaIndex. */
 762    pkgAcqMetaIndex(pkgAcquire *Owner,
 763                    string URI,string URIDesc, string ShortDesc,
 764                    string SigFile,
 765                    const vector<struct IndexTarget*>* IndexTargets,
 766                    indexRecords* MetaIndexParser);
 767 };
 768
 769 /** \brief An item that is responsible for fetching a package file.
 770  *
 771  *  If the package file already exists in the cache, nothing will be
 772  *  done.
 773  */
 774 class pkgAcqArchive : public pkgAcquire::Item
 775 {
 776    protected:
 777    /** \brief The package version being fetched. */
 778    pkgCache::VerIterator Version;
 779
 780    /** \brief The fetch command that is currently being processed. */
 781    pkgAcquire::ItemDesc Desc;
 782
 783    /** \brief The list of sources from which to pick archives to
 784     *  download this package from.
 785     */
 786    pkgSourceList *Sources;
 787
 788    /** \brief A package records object, used to look up the file
 789     *  corresponding to each version of the package.
 790     */
 791    pkgRecords *Recs;
 792
 793    /** \brief The hashsum of this package. */
 794    HashString ExpectedHash;
 795
 796    /** \brief A location in which the actual filename of the package
 797     *  should be stored.
 798     */
 799    string &StoreFilename;
 800
 801    /** \brief The next file for this version to try to download. */
 802    pkgCache::VerFileIterator Vf;
 803
 804    /** \brief How many (more) times to try to find a new source from
 805     *  which to download this package version if it fails.
 806     *
 807     *  Set from Acquire::Retries.
 808     */
 809    unsigned int Retries;
 810
 811    /** \brief \b true if this version file is being downloaded from a
 812     *  trusted source.
 813     */
 814    bool Trusted;
 815
 816    /** \brief Queue up the next available file for this version. */
 817    bool QueueNext();
 818
 819    public:
 820
 821    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 822    virtual void Done(string Message,unsigned long Size,string Hash,
 823                      pkgAcquire::MethodConfig *Cnf);
 824    virtual string DescURI() {return Desc.URI;};
 825    virtual string ShortDesc() {return Desc.ShortDesc;};
 826    virtual void Finished();
 827    virtual string HashSum() {return ExpectedHash.toStr(); };
 828    virtual bool IsTrusted();
 829
 830    /** \brief Create a new pkgAcqArchive.
 831     *
 832     *  \param Owner The pkgAcquire object with which this item is
 833     *  associated.
 834     *
 835     *  \param Sources The sources from which to download version
 836     *  files.
 837     *
 838     *  \param Recs A package records object, used to look up the file
 839     *  corresponding to each version of the package.
 840     *
 841     *  \param Version The package version to download.
 842     *
 843     *  \param StoreFilename A location in which the actual filename of
 844     *  the package should be stored.  It will be set to a guessed
 845     *  basename in the constructor, and filled in with a fully
 846     *  qualified filename once the download finishes.
 847     */
 848    pkgAcqArchive(pkgAcquire *Owner,pkgSourceList *Sources,
 849                  pkgRecords *Recs,pkgCache::VerIterator const &Version,
 850                  string &StoreFilename);
 851 };
 852
 853 /** \brief Retrieve an arbitrary file to the current directory.
 854  *
 855  *  The file is retrieved even if it is accessed via a URL type that
 856  *  normally is a NOP, such as "file".  If the download fails, the
 857  *  partial file is renamed to get a ".FAILED" extension.
 858  */
 859 class pkgAcqFile : public pkgAcquire::Item
 860 {
 861    /** \brief The currently active download process. */
 862    pkgAcquire::ItemDesc Desc;
 863
 864    /** \brief The hashsum of the file to download, if it is known. */
 865    HashString ExpectedHash;
 866
 867    /** \brief How many times to retry the download, set from
 868     *  Acquire::Retries.
 869     */
 870    unsigned int Retries;
 871
 872    public:
 873
 874    // Specialized action members
 875    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 876    virtual void Done(string Message,unsigned long Size,string CalcHash,
 877                      pkgAcquire::MethodConfig *Cnf);
 878    virtual string DescURI() {return Desc.URI;};
 879    virtual string HashSum() {return ExpectedHash.toStr(); };
 880
 881    /** \brief Create a new pkgAcqFile object.
 882     *
 883     *  \param Owner The pkgAcquire object with which this object is
 884     *  associated.
 885     *
 886     *  \param URI The URI to download.
 887     *
 888     *  \param Hash The hashsum of the file to download, if it is known;
 889     *  otherwise "".
 890     *
 891     *  \param Size The size of the file to download, if it is known;
 892     *  otherwise 0.
 893     *
 894     *  \param Desc A description of the file being downloaded.
 895     *
 896     *  \param ShortDesc A brief description of the file being
 897     *  downloaded.
 898     *
 899     *  \param DestDir The directory the file should be downloaded into.
 900     *
 901     *  \param DestFilename The filename+path the file is downloaded to.
 902     *
 903     *
 904     * If DestFilename is empty, download to DestDir/<basename> if
 905     * DestDir is non-empty, $CWD/<basename> otherwise.  If
 906     * DestFilename is NOT empty, DestDir is ignored and DestFilename
 907     * is the absolute name to which the file should be downloaded.
 908     */
 909
 910    pkgAcqFile(pkgAcquire *Owner, string URI, string Hash, unsigned long Size,
 911               string Desc, string ShortDesc,
 912               const string &DestDir="", const string &DestFilename="");
 913 };
 914
 915 /** @} */
 916
 917 #endif