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
 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 Hash The HashSum 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 Hash,
 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 HashSum
 234     *
 235     *  \return the HashSum of this object, if applicable; otherwise, an
 236     *  empty string.
 237     */
 238    virtual string HashSum() {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 Hash that the real index file should have after
 301     *  all patches have been applied.
 302     */
 303    HashString ExpectedHash;
 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 ExpectedHash The list file's MD5 signature.
 347     */
 348    pkgAcqDiffIndex(pkgAcquire *Owner,string URI,string URIDesc,
 349                    string ShortDesc, HashString ExpectedHash);
 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 ExpectedHash 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 HashSum of the package index file that is being
 409     *  reconstructed.
 410     */
 411    HashString ExpectedHash;
 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
 426    /** Stop applying patches when reaching that sha1 */
 427    string ServerSha1;
 428
 429    /** The current status of this patch. */
 430    enum DiffState
 431      {
 432         /** \brief The diff is in an unknown state. */
 433          StateFetchUnkown,
 434
 435          /** \brief The diff is currently being fetched. */
 436          StateFetchDiff,
 437
 438          /** \brief The diff is currently being uncompressed. */
 439          StateUnzipDiff,
 440
 441          /** \brief The diff is currently being applied. */
 442          StateApplyDiff
 443    } State;
 444
 445    public:
 446
 447    /** \brief Called when the patch file failed to be downloaded.
 448     *
 449     *  This method will fall back to downloading the whole index file
 450     *  outright; its arguments are ignored.
 451     */
 452    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 453
 454    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 455                      pkgAcquire::MethodConfig *Cnf);
 456    virtual string DescURI() {return RealURI + "Index";};
 457
 458    /** \brief Create an index diff item.
 459     *
 460     *  After filling in its basic fields, this invokes Finish(true) if
 461     *  #diffs is empty, or QueueNextDiff() otherwise.
 462     *
 463     *  \param Owner The pkgAcquire object that owns this item.
 464     *
 465     *  \param URI The URI of the package index file being
 466     *  reconstructed.
 467     *
 468     *  \param URIDesc A long description of this item.
 469     *
 470     *  \param ShortDesc A brief description of this item.
 471     *
 472     *  \param ExpectedHash The expected md5sum of the completely
 473     *  reconstructed package index file; the index file will be tested
 474     *  against this value when it is entirely reconstructed.
 475     *
 476     *  \param diffs The remaining diffs from the index of diffs.  They
 477     *  should be ordered so that each diff appears before any diff
 478     *  that depends on it.
 479     */
 480    pkgAcqIndexDiffs(pkgAcquire *Owner,string URI,string URIDesc,
 481                     string ShortDesc, HashString ExpectedHash,
 482                     string ServerSha1,
 483                     vector<DiffInfo> diffs=vector<DiffInfo>());
 484 };
 485                                                                         /*}}}*/
 486 /** \brief An acquire item that is responsible for fetching an index    {{{
 487  *  file (e.g., Packages or Sources).
 488  *
 489  *  \sa pkgAcqDiffIndex, pkgAcqIndexDiffs, pkgAcqIndexTrans
 490  *
 491  *  \todo Why does pkgAcqIndex have protected members?
 492  */
 493 class pkgAcqIndex : public pkgAcquire::Item
 494 {
 495    protected:
 496
 497    /** \brief If \b true, the index file has been decompressed. */
 498    bool Decompression;
 499
 500    /** \brief If \b true, the partially downloaded file will be
 501     *  removed when the download completes.
 502     */
 503    bool Erase;
 504
 505    /** \brief The download request that is currently being
 506     *   processed.
 507     */
 508    pkgAcquire::ItemDesc Desc;
 509
 510    /** \brief The object that is actually being fetched (minus any
 511     *  compression-related extensions).
 512     */
 513    string RealURI;
 514
 515    /** \brief The expected hashsum of the decompressed index file. */
 516    HashString ExpectedHash;
 517
 518    /** \brief The compression-related file extension that is being
 519     *  added to the downloaded file (e.g., ".gz" or ".bz2").
 520     */
 521    string CompressionExtension;
 522
 523    public:
 524
 525    // Specialized action members
 526    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 527    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 528                      pkgAcquire::MethodConfig *Cnf);
 529    virtual string Custom600Headers();
 530    virtual string DescURI() {return RealURI + CompressionExtension;};
 531    virtual string HashSum() {return ExpectedHash.toStr(); };
 532
 533    /** \brief Create a pkgAcqIndex.
 534     *
 535     *  \param Owner The pkgAcquire object with which this item is
 536     *  associated.
 537     *
 538     *  \param URI The URI of the index file that is to be downloaded.
 539     *
 540     *  \param URIDesc A "URI-style" description of this index file.
 541     *
 542     *  \param ShortDesc A brief description of this index file.
 543     *
 544     *  \param ExpectedHash The expected hashsum of this index file.
 545     *
 546     *  \param compressExt The compression-related extension with which
 547     *  this index file should be downloaded, or "" to autodetect
 548     *  Compression types can be set with config Acquire::CompressionTypes,
 549     *  default is ".lzma" or ".bz2" (if the needed binaries are present)
 550     *  fallback is ".gz" or none.
 551     */
 552    pkgAcqIndex(pkgAcquire *Owner,string URI,string URIDesc,
 553                string ShortDesc, HashString ExpectedHash, string compressExt="");
 554 };
 555                                                                         /*}}}*/
 556 /** \brief An acquire item that is responsible for fetching a           {{{
 557  *  translated index file.
 558  *
 559  *  The only difference from pkgAcqIndex is that transient failures
 560  *  are suppressed: no error occurs if the translated index file is
 561  *  missing.
 562  */
 563 class pkgAcqIndexTrans : public pkgAcqIndex
 564 {
 565    public:
 566
 567    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 568
 569    /** \brief Create a pkgAcqIndexTrans.
 570     *
 571     *  \param Owner The pkgAcquire object with which this item is
 572     *  associated.
 573     *
 574     *  \param URI The URI of the index file that is to be downloaded.
 575     *
 576     *  \param URIDesc A "URI-style" description of this index file.
 577     *
 578     *  \param ShortDesc A brief description of this index file.
 579     */
 580    pkgAcqIndexTrans(pkgAcquire *Owner,string URI,string URIDesc,
 581                     string ShortDesc);
 582 };
 583                                                                         /*}}}*/
 584 /** \brief Information about an index file. */                          /*{{{*/
 585 struct IndexTarget
 586 {
 587    /** \brief A URI from which the index file can be downloaded. */
 588    string URI;
 589
 590    /** \brief A description of the index file. */
 591    string Description;
 592
 593    /** \brief A shorter description of the index file. */
 594    string ShortDesc;
 595
 596    /** \brief The key by which this index file should be
 597     *  looked up within the meta signature file.
 598     */
 599    string MetaKey;
 600 };
 601                                                                         /*}}}*/
 602 /** \brief An acquire item that downloads the detached signature        {{{
 603  *  of a meta-index (Release) file, then queues up the release
 604  *  file itself.
 605  *
 606  *  \todo Why protected members?
 607  *
 608  *  \sa pkgAcqMetaIndex
 609  */
 610 class pkgAcqMetaSig : public pkgAcquire::Item
 611 {
 612    protected:
 613    /** \brief The last good signature file */
 614    string LastGoodSig;
 615
 616
 617    /** \brief The fetch request that is currently being processed. */
 618    pkgAcquire::ItemDesc Desc;
 619
 620    /** \brief The URI of the signature file.  Unlike Desc.URI, this is
 621     *  never modified; it is used to determine the file that is being
 622     *  downloaded.
 623     */
 624    string RealURI;
 625
 626    /** \brief The URI of the meta-index file to be fetched after the signature. */
 627    string MetaIndexURI;
 628
 629    /** \brief A "URI-style" description of the meta-index file to be
 630     *  fetched after the signature.
 631     */
 632    string MetaIndexURIDesc;
 633
 634    /** \brief A brief description of the meta-index file to be fetched
 635     *  after the signature.
 636     */
 637    string MetaIndexShortDesc;
 638
 639    /** \brief A package-system-specific parser for the meta-index file. */
 640    indexRecords* MetaIndexParser;
 641
 642    /** \brief The index files which should be looked up in the meta-index
 643     *  and then downloaded.
 644     *
 645     *  \todo Why a list of pointers instead of a list of structs?
 646     */
 647    const vector<struct IndexTarget*>* IndexTargets;
 648
 649    public:
 650
 651    // Specialized action members
 652    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 653    virtual void Done(string Message,unsigned long Size,string Md5Hash,
 654                      pkgAcquire::MethodConfig *Cnf);
 655    virtual string Custom600Headers();
 656    virtual string DescURI() {return RealURI; };
 657
 658    /** \brief Create a new pkgAcqMetaSig. */
 659    pkgAcqMetaSig(pkgAcquire *Owner,string URI,string URIDesc, string ShortDesc,
 660                  string MetaIndexURI, string MetaIndexURIDesc, string MetaIndexShortDesc,
 661                  const vector<struct IndexTarget*>* IndexTargets,
 662                  indexRecords* MetaIndexParser);
 663 };
 664                                                                         /*}}}*/
 665 /** \brief An item that is responsible for downloading the meta-index   {{{
 666  *  file (i.e., Release) itself and verifying its signature.
 667  *
 668  *  Once the download and verification are complete, the downloads of
 669  *  the individual index files are queued up using pkgAcqDiffIndex.
 670  *  If the meta-index file had a valid signature, the expected hashsums
 671  *  of the index files will be the md5sums listed in the meta-index;
 672  *  otherwise, the expected hashsums will be "" (causing the
 673  *  authentication of the index files to be bypassed).
 674  */
 675 class pkgAcqMetaIndex : public pkgAcquire::Item
 676 {
 677    protected:
 678    /** \brief The fetch command that is currently being processed. */
 679    pkgAcquire::ItemDesc Desc;
 680
 681    /** \brief The URI that is actually being downloaded; never
 682     *  modified by pkgAcqMetaIndex.
 683     */
 684    string RealURI;
 685
 686    /** \brief The file in which the signature for this index was stored.
 687     *
 688     *  If empty, the signature and the md5sums of the individual
 689     *  indices will not be checked.
 690     */
 691    string SigFile;
 692
 693    /** \brief The index files to download. */
 694    const vector<struct IndexTarget*>* IndexTargets;
 695
 696    /** \brief The parser for the meta-index file. */
 697    indexRecords* MetaIndexParser;
 698
 699    /** \brief If \b true, the index's signature is currently being verified.
 700     */
 701    bool AuthPass;
 702    // required to deal gracefully with problems caused by incorrect ims hits
 703    bool IMSHit;
 704
 705    /** \brief Check that the release file is a release file for the
 706     *  correct distribution.
 707     *
 708     *  \return \b true if no fatal errors were encountered.
 709     */
 710    bool VerifyVendor(string Message);
 711
 712    /** \brief Called when a file is finished being retrieved.
 713     *
 714     *  If the file was not downloaded to DestFile, a copy process is
 715     *  set up to copy it to DestFile; otherwise, Complete is set to \b
 716     *  true and the file is moved to its final location.
 717     *
 718     *  \param Message The message block received from the fetch
 719     *  subprocess.
 720     */
 721    void RetrievalDone(string Message);
 722
 723    /** \brief Called when authentication succeeded.
 724     *
 725     *  Sanity-checks the authenticated file, queues up the individual
 726     *  index files for download, and saves the signature in the lists
 727     *  directory next to the authenticated list file.
 728     *
 729     *  \param Message The message block received from the fetch
 730     *  subprocess.
 731     */
 732    void AuthDone(string Message);
 733
 734    /** \brief Starts downloading the individual index files.
 735     *
 736     *  \param verify If \b true, only indices whose expected hashsum
 737     *  can be determined from the meta-index will be downloaded, and
 738     *  the hashsums of indices will be checked (reporting
 739     *  #StatAuthError if there is a mismatch).  If verify is \b false,
 740     *  no hashsum checking will be performed.
 741     */
 742    void QueueIndexes(bool verify);
 743
 744    public:
 745
 746    // Specialized action members
 747    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 748    virtual void Done(string Message,unsigned long Size, string Hash,
 749                      pkgAcquire::MethodConfig *Cnf);
 750    virtual string Custom600Headers();
 751    virtual string DescURI() {return RealURI; };
 752
 753    /** \brief Create a new pkgAcqMetaIndex. */
 754    pkgAcqMetaIndex(pkgAcquire *Owner,
 755                    string URI,string URIDesc, string ShortDesc,
 756                    string SigFile,
 757                    const vector<struct IndexTarget*>* IndexTargets,
 758                    indexRecords* MetaIndexParser);
 759 };
 760                                                                         /*}}}*/
 761 /** \brief An item that is responsible for fetching a package file.     {{{
 762  *
 763  *  If the package file already exists in the cache, nothing will be
 764  *  done.
 765  */
 766 class pkgAcqArchive : public pkgAcquire::Item
 767 {
 768    protected:
 769    /** \brief The package version being fetched. */
 770    pkgCache::VerIterator Version;
 771
 772    /** \brief The fetch command that is currently being processed. */
 773    pkgAcquire::ItemDesc Desc;
 774
 775    /** \brief The list of sources from which to pick archives to
 776     *  download this package from.
 777     */
 778    pkgSourceList *Sources;
 779
 780    /** \brief A package records object, used to look up the file
 781     *  corresponding to each version of the package.
 782     */
 783    pkgRecords *Recs;
 784
 785    /** \brief The hashsum of this package. */
 786    HashString ExpectedHash;
 787
 788    /** \brief A location in which the actual filename of the package
 789     *  should be stored.
 790     */
 791    string &StoreFilename;
 792
 793    /** \brief The next file for this version to try to download. */
 794    pkgCache::VerFileIterator Vf;
 795
 796    /** \brief How many (more) times to try to find a new source from
 797     *  which to download this package version if it fails.
 798     *
 799     *  Set from Acquire::Retries.
 800     */
 801    unsigned int Retries;
 802
 803    /** \brief \b true if this version file is being downloaded from a
 804     *  trusted source.
 805     */
 806    bool Trusted;
 807
 808    /** \brief Queue up the next available file for this version. */
 809    bool QueueNext();
 810
 811    public:
 812
 813    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 814    virtual void Done(string Message,unsigned long Size,string Hash,
 815                      pkgAcquire::MethodConfig *Cnf);
 816    virtual string DescURI() {return Desc.URI;};
 817    virtual string ShortDesc() {return Desc.ShortDesc;};
 818    virtual void Finished();
 819    virtual string HashSum() {return ExpectedHash.toStr(); };
 820    virtual bool IsTrusted();
 821
 822    /** \brief Create a new pkgAcqArchive.
 823     *
 824     *  \param Owner The pkgAcquire object with which this item is
 825     *  associated.
 826     *
 827     *  \param Sources The sources from which to download version
 828     *  files.
 829     *
 830     *  \param Recs A package records object, used to look up the file
 831     *  corresponding to each version of the package.
 832     *
 833     *  \param Version The package version to download.
 834     *
 835     *  \param StoreFilename A location in which the actual filename of
 836     *  the package should be stored.  It will be set to a guessed
 837     *  basename in the constructor, and filled in with a fully
 838     *  qualified filename once the download finishes.
 839     */
 840    pkgAcqArchive(pkgAcquire *Owner,pkgSourceList *Sources,
 841                  pkgRecords *Recs,pkgCache::VerIterator const &Version,
 842                  string &StoreFilename);
 843 };
 844                                                                         /*}}}*/
 845 /** \brief Retrieve an arbitrary file to the current directory.         {{{
 846  *
 847  *  The file is retrieved even if it is accessed via a URL type that
 848  *  normally is a NOP, such as "file".  If the download fails, the
 849  *  partial file is renamed to get a ".FAILED" extension.
 850  */
 851 class pkgAcqFile : public pkgAcquire::Item
 852 {
 853    /** \brief The currently active download process. */
 854    pkgAcquire::ItemDesc Desc;
 855
 856    /** \brief The hashsum of the file to download, if it is known. */
 857    HashString ExpectedHash;
 858
 859    /** \brief How many times to retry the download, set from
 860     *  Acquire::Retries.
 861     */
 862    unsigned int Retries;
 863
 864    public:
 865
 866    // Specialized action members
 867    virtual void Failed(string Message,pkgAcquire::MethodConfig *Cnf);
 868    virtual void Done(string Message,unsigned long Size,string CalcHash,
 869                      pkgAcquire::MethodConfig *Cnf);
 870    virtual string DescURI() {return Desc.URI;};
 871    virtual string HashSum() {return ExpectedHash.toStr(); };
 872
 873    /** \brief Create a new pkgAcqFile object.
 874     *
 875     *  \param Owner The pkgAcquire object with which this object is
 876     *  associated.
 877     *
 878     *  \param URI The URI to download.
 879     *
 880     *  \param Hash The hashsum of the file to download, if it is known;
 881     *  otherwise "".
 882     *
 883     *  \param Size The size of the file to download, if it is known;
 884     *  otherwise 0.
 885     *
 886     *  \param Desc A description of the file being downloaded.
 887     *
 888     *  \param ShortDesc A brief description of the file being
 889     *  downloaded.
 890     *
 891     *  \param DestDir The directory the file should be downloaded into.
 892     *
 893     *  \param DestFilename The filename+path the file is downloaded to.
 894     *
 895     *
 896     * If DestFilename is empty, download to DestDir/<basename> if
 897     * DestDir is non-empty, $CWD/<basename> otherwise.  If
 898     * DestFilename is NOT empty, DestDir is ignored and DestFilename
 899     * is the absolute name to which the file should be downloaded.
 900     */
 901
 902    pkgAcqFile(pkgAcquire *Owner, string URI, string Hash, unsigned long Size,
 903               string Desc, string ShortDesc,
 904               const string &DestDir="", const string &DestFilename="");
 905 };
 906                                                                         /*}}}*/
 907 /** @} */
 908
 909 #endif