apt-pkg/pkgcache.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 /**\file pkgcache.h
   4    \brief pkgCache - Structure definitions for the cache file
   5
   6    The goal of the cache file is two fold:
   7    Firstly to speed loading and processing of the package file array and
   8    secondly to reduce memory consumption of the package file array.
   9
  10    The implementation is aimed at an environment with many primary package
  11    files, for instance someone that has a Package file for their CD-ROM, a
  12    Package file for the latest version of the distribution on the CD-ROM and a
  13    package file for the development version. Always present is the information
  14    contained in the status file which might be considered a separate package
  15    file.
  16
  17    Please understand, this is designed as a <b>Cache file</b> it is not meant to be
  18    used on any system other than the one it was created for. It is not meant to
  19    be authoritative either, i.e. if a system crash or software failure occurs it
  20    must be perfectly acceptable for the cache file to be in an inconsistent
  21    state. Furthermore at any time the cache file may be erased without losing
  22    any information.
  23
  24    Also the structures and storage layout is optimized for use by the APT
  25    and may not be suitable for all purposes. However it should be possible
  26    to extend it with associate cache files that contain other information.
  27
  28    To keep memory use down the cache file only contains often used fields and
  29    fields that are inexpensive to store, the Package file has a full list of
  30    fields. Also the client may assume that all items are perfectly valid and
  31    need not perform checks against their correctness. Removal of information
  32    from the cache is possible, but blanks will be left in the file, and
  33    unused strings will also be present. The recommended implementation is to
  34    simply rebuild the cache each time any of the data files change. It is
  35    possible to add a new package file to the cache without any negative side
  36    effects.
  37
  38    <b>Note on Pointer access</b>
  39    Clients should always use the CacheIterators classes for access to the
  40    cache and the data in it. They also provide a simple STL-like method for
  41    traversing the links of the datastructure.
  42
  43    Every item in every structure is stored as the index to that structure.
  44    What this means is that once the files is mmaped every data access has to
  45    go through a fix up stage to get a real memory pointer. This is done
  46    by taking the index, multiplying it by the type size and then adding
  47    it to the start address of the memory block. This sounds complex, but
  48    in C it is a single array dereference. Because all items are aligned to
  49    their size and indexes are stored as multiples of the size of the structure
  50    the format is immediately portable to all possible architectures - BUT the
  51    generated files are -NOT-.
  52
  53    This scheme allows code like this to be written:
  54    <example>
  55      void *Map = mmap(...);
  56      Package *PkgList = (Package *)Map;
  57      Header *Head = (Header *)Map;
  58      char *Strings = (char *)Map;
  59      cout << (Strings + PkgList[Head->HashTable[0]]->Name) << endl;
  60    </example>
  61    Notice the lack of casting or multiplication. The net result is to return
  62    the name of the first package in the first hash bucket, without error
  63    checks.
  64
  65    The generator uses allocation pools to group similarly sized structures in
  66    large blocks to eliminate any alignment overhead. The generator also
  67    assures that no structures overlap and all indexes are unique. Although
  68    at first glance it may seem like there is the potential for two structures
  69    to exist at the same point the generator never allows this to happen.
  70    (See the discussion of free space pools)
  71
  72    See \ref pkgcachegen.h for more information about generating cache structures. */
  73                                                                         /*}}}*/
  74 #ifndef PKGLIB_PKGCACHE_H
  75 #define PKGLIB_PKGCACHE_H
  76
  77 #include <apt-pkg/mmap.h>
  78 #include <apt-pkg/macros.h>
  79
  80 #include <string>
  81 #include <time.h>
  82 #include <stdint.h>
  83
  84 #ifndef APT_8_CLEANER_HEADERS
  85 using std::string;
  86 #endif
  87
  88 // size of (potentially big) files like debs or the install size of them
  89 typedef uint64_t map_filesize_t;
  90 // storing file sizes of indexes, which are way below 4 GB for now
  91 typedef uint32_t map_filesize_small_t;
  92 // each package/group/dependency gets an id
  93 typedef uint32_t map_id_t;
  94 // some files get an id, too, but in far less absolute numbers
  95 typedef uint16_t map_fileid_t;
  96 // relative pointer from cache start
  97 typedef uint32_t map_pointer_t;
  98 // same as the previous, but documented to be to a string item
  99 typedef map_pointer_t map_stringitem_t;
 100 // we have only a small amount of flags for each item
 101 typedef uint8_t map_flags_t;
 102 typedef uint8_t map_number_t;
 103
 104 class pkgVersioningSystem;
 105 class pkgCache                                                          /*{{{*/
 106 {
 107    public:
 108    // Cache element predeclarations
 109    struct Header;
 110    struct Group;
 111    struct Package;
 112    struct ReleaseFile;
 113    struct PackageFile;
 114    struct Version;
 115    struct Description;
 116    struct Provides;
 117    struct Dependency;
 118    struct DependencyData;
 119    struct StringItem;
 120    struct VerFile;
 121    struct DescFile;
 122
 123    // Iterators
 124    template<typename Str, typename Itr> class Iterator;
 125    class GrpIterator;
 126    class PkgIterator;
 127    class VerIterator;
 128    class DescIterator;
 129    class DepIterator;
 130    class PrvIterator;
 131    class RlsFileIterator;
 132    class PkgFileIterator;
 133    class VerFileIterator;
 134    class DescFileIterator;
 135
 136    class Namespace;
 137
 138    // These are all the constants used in the cache structures
 139
 140    // WARNING - if you change these lists you must also edit
 141    // the stringification in pkgcache.cc and also consider whether
 142    // the cache file will become incompatible.
 143    struct Dep
 144    {
 145       enum DepType {Depends=1,PreDepends=2,Suggests=3,Recommends=4,
 146          Conflicts=5,Replaces=6,Obsoletes=7,DpkgBreaks=8,Enhances=9};
 147       /** \brief available compare operators
 148
 149           The lower 4 bits are used to indicate what operator is being specified and
 150           the upper 4 bits are flags. OR indicates that the next package is
 151           or'd with the current package. */
 152       enum DepCompareOp {NoOp=0,LessEq=0x1,GreaterEq=0x2,Less=0x3,
 153          Greater=0x4,Equals=0x5,NotEquals=0x6,
 154          Or=0x10, /*!< or'ed with the next dependency */
 155          MultiArchImplicit=0x20, /*!< generated internally, not spelled out in the index */
 156          ArchSpecific=0x40 /*!< was decorated with an explicit architecture in index */
 157       };
 158    };
 159
 160    struct State
 161    {
 162       /** \brief priority of a package version
 163
 164           Zero is used for unparsable or absent Priority fields. */
 165       enum VerPriority {Required=1,Important=2,Standard=3,Optional=4,Extra=5};
 166       enum PkgSelectedState {Unknown=0,Install=1,Hold=2,DeInstall=3,Purge=4};
 167       enum PkgInstState {Ok=0,ReInstReq=1,HoldInst=2,HoldReInstReq=3};
 168       enum PkgCurrentState {NotInstalled=0,UnPacked=1,HalfConfigured=2,
 169            HalfInstalled=4,ConfigFiles=5,Installed=6,
 170            TriggersAwaited=7,TriggersPending=8};
 171    };
 172
 173    struct Flag
 174    {
 175       enum PkgFlags {Auto=(1<<0),Essential=(1<<3),Important=(1<<4)};
 176       enum PkgFFlags {
 177          NotSource=(1<<0), /*!< packages can't be fetched from here, e.g. dpkg/status file */
 178          LocalSource=(1<<1), /*!< local sources can't and will not be verified by hashes */
 179          NoPackages=(1<<2), /*!< the file includes no package records itself, but additions like Translations */
 180       };
 181       enum ReleaseFileFlags {
 182          NotAutomatic=(1<<0), /*!< archive has a default pin of 1 */
 183          ButAutomaticUpgrades=(1<<1), /*!< (together with the previous) archive has a default pin of 100 */
 184       };
 185       enum ProvidesFlags {
 186          MultiArchImplicit=pkgCache::Dep::MultiArchImplicit, /*!< generated internally, not spelled out in the index */
 187          ArchSpecific=pkgCache::Dep::ArchSpecific /*!< was decorated with an explicit architecture in index */
 188       };
 189    };
 190
 191    protected:
 192
 193    // Memory mapped cache file
 194    std::string CacheFile;
 195    MMap &Map;
 196
 197    map_id_t sHash(const std::string &S) const APT_PURE;
 198    map_id_t sHash(const char *S) const APT_PURE;
 199
 200    public:
 201
 202    // Pointers to the arrays of items
 203    Header *HeaderP;
 204    Group *GrpP;
 205    Package *PkgP;
 206    VerFile *VerFileP;
 207    DescFile *DescFileP;
 208    ReleaseFile *RlsFileP;
 209    PackageFile *PkgFileP;
 210    Version *VerP;
 211    Description *DescP;
 212    Provides *ProvideP;
 213    Dependency *DepP;
 214    DependencyData *DepDataP;
 215    APT_DEPRECATED_MSG("Not used anymore in cache generation and without a replacement") StringItem *StringItemP;
 216    char *StrP;
 217
 218    virtual bool ReMap(bool const &Errorchecks = true);
 219    inline bool Sync() {return Map.Sync();}
 220    inline MMap &GetMap() {return Map;}
 221    inline void *DataEnd() {return ((unsigned char *)Map.Data()) + Map.Size();}
 222
 223    // String hashing function (512 range)
 224    inline map_id_t Hash(const std::string &S) const {return sHash(S);}
 225    inline map_id_t Hash(const char *S) const {return sHash(S);}
 226
 227    APT_HIDDEN uint32_t CacheHash();
 228
 229    // Useful transformation things
 230    static const char *Priority(unsigned char Priority);
 231
 232    // Accessors
 233    GrpIterator FindGrp(const std::string &Name);
 234    PkgIterator FindPkg(const std::string &Name);
 235    PkgIterator FindPkg(const std::string &Name, const std::string &Arch);
 236
 237    Header &Head() {return *HeaderP;}
 238    inline GrpIterator GrpBegin();
 239    inline GrpIterator GrpEnd();
 240    inline PkgIterator PkgBegin();
 241    inline PkgIterator PkgEnd();
 242    inline PkgFileIterator FileBegin();
 243    inline PkgFileIterator FileEnd();
 244    inline RlsFileIterator RlsFileBegin();
 245    inline RlsFileIterator RlsFileEnd();
 246
 247    inline bool MultiArchCache() const { return MultiArchEnabled; }
 248    inline char const * NativeArch();
 249
 250    // Make me a function
 251    pkgVersioningSystem *VS;
 252
 253    // Converters
 254    static const char *CompTypeDeb(unsigned char Comp) APT_CONST;
 255    static const char *CompType(unsigned char Comp) APT_CONST;
 256    static const char *DepType(unsigned char Dep);
 257
 258    pkgCache(MMap *Map,bool DoMap = true);
 259    virtual ~pkgCache();
 260
 261 private:
 262    void * const d;
 263    bool MultiArchEnabled;
 264 };
 265                                                                         /*}}}*/
 266 // Header structure                                                     /*{{{*/
 267 struct pkgCache::Header
 268 {
 269    /** \brief Signature information
 270
 271        This must contain the hex value 0x98FE76DC which is designed to
 272        verify that the system loading the image has the same byte order
 273        and byte size as the system saving the image */
 274    uint32_t Signature;
 275    /** These contain the version of the cache file */
 276    map_number_t MajorVersion;
 277    map_number_t MinorVersion;
 278    /** \brief indicates if the cache should be erased
 279
 280        Dirty is true if the cache file was opened for reading, the client
 281        expects to have written things to it and have not fully synced it.
 282        The file should be erased and rebuilt if it is true. */
 283    bool Dirty;
 284
 285    /** \brief Size of structure values
 286
 287        All *Sz variables contains the sizeof() that particular structure.
 288        It is used as an extra consistency check on the structure of the file.
 289
 290        If any of the size values do not exactly match what the client expects
 291        then the client should refuse the load the file. */
 292    uint16_t HeaderSz;
 293    map_number_t GroupSz;
 294    map_number_t PackageSz;
 295    map_number_t ReleaseFileSz;
 296    map_number_t PackageFileSz;
 297    map_number_t VersionSz;
 298    map_number_t DescriptionSz;
 299    map_number_t DependencySz;
 300    map_number_t DependencyDataSz;
 301    map_number_t ProvidesSz;
 302    map_number_t VerFileSz;
 303    map_number_t DescFileSz;
 304
 305    /** \brief Structure counts
 306
 307        These indicate the number of each structure contained in the cache.
 308        PackageCount is especially useful for generating user state structures.
 309        See Package::Id for more info. */
 310    map_id_t GroupCount;
 311    map_id_t PackageCount;
 312    map_id_t VersionCount;
 313    map_id_t DescriptionCount;
 314    map_id_t DependsCount;
 315    map_id_t DependsDataCount;
 316    map_fileid_t ReleaseFileCount;
 317    map_fileid_t PackageFileCount;
 318    map_fileid_t VerFileCount;
 319    map_fileid_t DescFileCount;
 320    map_id_t ProvidesCount;
 321
 322    /** \brief index of the first PackageFile structure
 323
 324        The PackageFile structures are singly linked lists that represent
 325        all package files that have been merged into the cache. */
 326    map_pointer_t FileList;
 327    /** \brief index of the first ReleaseFile structure */
 328    map_pointer_t RlsFileList;
 329
 330    /** \brief String representing the version system used */
 331    map_pointer_t VerSysName;
 332    /** \brief native architecture the cache was built against */
 333    map_pointer_t Architecture;
 334    /** \brief all architectures the cache was built against */
 335    map_pointer_t Architectures;
 336    /** \brief The maximum size of a raw entry from the original Package file */
 337    map_filesize_t MaxVerFileSize;
 338    /** \brief The maximum size of a raw entry from the original Translation file */
 339    map_filesize_t MaxDescFileSize;
 340
 341    /** \brief The Pool structures manage the allocation pools that the generator uses
 342
 343        Start indicates the first byte of the pool, Count is the number of objects
 344        remaining in the pool and ItemSize is the structure size (alignment factor)
 345        of the pool. An ItemSize of 0 indicates the pool is empty. There should be
 346        the same number of pools as there are structure types. The generator
 347        stores this information so future additions can make use of any unused pool
 348        blocks. */
 349    DynamicMMap::Pool Pools[12];
 350
 351    /** \brief hash tables providing rapid group/package name lookup
 352
 353        Each group/package name is inserted into a hash table using pkgCache::Hash(const &string)
 354        By iterating over each entry in the hash table it is possible to iterate over
 355        the entire list of packages. Hash Collisions are handled with a singly linked
 356        list of packages based at the hash item. The linked list contains only
 357        packages that match the hashing function.
 358        In the PkgHashTable is it possible that multiple packages have the same name -
 359        these packages are stored as a sequence in the list.
 360        The size of both tables is the same. */
 361    uint32_t HashTableSize;
 362    uint32_t GetHashTableSize() const { return HashTableSize; }
 363    void SetHashTableSize(unsigned int const sz) { HashTableSize = sz; }
 364    map_pointer_t GetArchitectures() const { return Architectures; }
 365    void SetArchitectures(map_pointer_t const idx) { Architectures = idx; }
 366    map_pointer_t * PkgHashTableP() const { return (map_pointer_t*) (this + 1); }
 367    map_pointer_t * GrpHashTableP() const { return PkgHashTableP() + GetHashTableSize(); }
 368
 369    /** \brief Hash of the file (TODO: Rename) */
 370    map_filesize_small_t CacheFileSize;
 371
 372    bool CheckSizes(Header &Against) const APT_PURE;
 373    Header();
 374 };
 375                                                                         /*}}}*/
 376 // Group structure                                                      /*{{{*/
 377 /** \brief groups architecture depending packages together
 378
 379     On or more packages with the same name form a group, so we have
 380     a simple way to access a package built for different architectures
 381     Group exists in a singly linked list of group records starting at
 382     the hash index of the name in the pkgCache::Header::GrpHashTable */
 383 struct pkgCache::Group
 384 {
 385    /** \brief Name of the group */
 386    map_stringitem_t Name;
 387
 388    // Linked List
 389    /** \brief Link to the first package which belongs to the group */
 390    map_pointer_t FirstPackage;  // Package
 391    /** \brief Link to the last package which belongs to the group */
 392    map_pointer_t LastPackage;   // Package
 393    /** \brief Link to the next Group */
 394    map_pointer_t Next;          // Group
 395    /** \brief unique sequel ID */
 396    map_id_t ID;
 397
 398 };
 399                                                                         /*}}}*/
 400 // Package structure                                                    /*{{{*/
 401 /** \brief contains information for a single unique package
 402
 403     There can be any number of versions of a given package.
 404     Package exists in a singly linked list of package records starting at
 405     the hash index of the name in the pkgCache::Header::PkgHashTable
 406
 407     A package can be created for every architecture so package names are
 408     not unique, but it is guaranteed that packages with the same name
 409     are sequencel ordered in the list. Packages with the same name can be
 410     accessed with the Group.
 411 */
 412 struct pkgCache::Package
 413 {
 414    /** \brief Name of the package
 415     * Note that the access method Name() will remain. It is just this data member
 416     * deprecated as this information is already stored and available via the
 417     * associated Group – so it is wasting precious binary cache space */
 418    APT_DEPRECATED_MSG("Use the .Name() method instead of accessing the member directly") map_stringitem_t Name;
 419    /** \brief Architecture of the package */
 420    map_stringitem_t Arch;
 421    /** \brief Base of a singly linked list of versions
 422
 423        Each structure represents a unique version of the package.
 424        The version structures contain links into PackageFile and the
 425        original text file as well as detailed information about the size
 426        and dependencies of the specific package. In this way multiple
 427        versions of a package can be cleanly handled by the system.
 428        Furthermore, this linked list is guaranteed to be sorted
 429        from Highest version to lowest version with no duplicate entries. */
 430    map_pointer_t VersionList;       // Version
 431    /** \brief index to the installed version */
 432    map_pointer_t CurrentVer;        // Version
 433    /** \brief index of the group this package belongs to */
 434    map_pointer_t Group;             // Group the Package belongs to
 435
 436    // Linked list
 437    /** \brief Link to the next package in the same bucket */
 438    map_pointer_t NextPackage;       // Package
 439    /** \brief List of all dependencies on this package */
 440    map_pointer_t RevDepends;        // Dependency
 441    /** \brief List of all "packages" this package provide */
 442    map_pointer_t ProvidesList;      // Provides
 443
 444    // Install/Remove/Purge etc
 445    /** \brief state that the user wishes the package to be in */
 446    map_number_t SelectedState;     // What
 447    /** \brief installation state of the package
 448
 449        This should be "ok" but in case the installation failed
 450        it will be different.
 451    */
 452    map_number_t InstState;         // Flags
 453    /** \brief indicates if the package is installed */
 454    map_number_t CurrentState;      // State
 455
 456    /** \brief unique sequel ID
 457
 458        ID is a unique value from 0 to Header->PackageCount assigned by the generator.
 459        This allows clients to create an array of size PackageCount and use it to store
 460        state information for the package map. For instance the status file emitter uses
 461        this to track which packages have been emitted already. */
 462    map_id_t ID;
 463    /** \brief some useful indicators of the package's state */
 464    map_flags_t Flags;
 465 };
 466                                                                         /*}}}*/
 467 // Release File structure                                               /*{{{*/
 468 /** \brief stores information about the release files used to generate the cache
 469
 470     PackageFiles reference ReleaseFiles as we need to keep record of which
 471     version belongs to which release e.g. for pinning. */
 472 struct pkgCache::ReleaseFile
 473 {
 474    /** \brief physical disk file that this ReleaseFile represents */
 475    map_stringitem_t FileName;
 476    /** \brief the release information
 477
 478        Please see the files document for a description of what the
 479        release information means. */
 480    map_stringitem_t Archive;
 481    map_stringitem_t Codename;
 482    map_stringitem_t Version;
 483    map_stringitem_t Origin;
 484    map_stringitem_t Label;
 485    /** \brief The site the index file was fetched from */
 486    map_stringitem_t Site;
 487
 488    /** \brief Size of the file
 489
 490        Used together with the modification time as a
 491        simple check to ensure that the Packages
 492        file has not been altered since Cache generation. */
 493    map_filesize_t Size;
 494    /** \brief Modification time for the file */
 495    time_t mtime;
 496
 497    /** @TODO document PackageFile::Flags */
 498    map_flags_t Flags;
 499
 500    // Linked list
 501    /** \brief Link to the next ReleaseFile in the Cache */
 502    map_pointer_t NextFile;
 503    /** \brief unique sequel ID */
 504    map_fileid_t ID;
 505 };
 506                                                                         /*}}}*/
 507 // Package File structure                                               /*{{{*/
 508 /** \brief stores information about the files used to generate the cache
 509
 510     Package files are referenced by Version structures to be able to know
 511     after the generation still from which Packages file includes this Version
 512     as we need this information later on e.g. for pinning. */
 513 struct pkgCache::PackageFile
 514 {
 515    /** \brief physical disk file that this PackageFile represents */
 516    map_stringitem_t FileName;
 517    /** \brief the release information */
 518    map_pointer_t Release;
 519
 520    map_stringitem_t Component;
 521    map_stringitem_t Architecture;
 522
 523    /** \brief indicates what sort of index file this is
 524
 525        @TODO enumerate at least the possible indexes */
 526    map_stringitem_t IndexType;
 527    /** \brief Size of the file
 528
 529        Used together with the modification time as a
 530        simple check to ensure that the Packages
 531        file has not been altered since Cache generation. */
 532    map_filesize_t Size;
 533    /** \brief Modification time for the file */
 534    time_t mtime;
 535
 536    /** @TODO document PackageFile::Flags */
 537    map_flags_t Flags;
 538
 539    // Linked list
 540    /** \brief Link to the next PackageFile in the Cache */
 541    map_pointer_t NextFile;        // PackageFile
 542    /** \brief unique sequel ID */
 543    map_fileid_t ID;
 544 };
 545                                                                         /*}}}*/
 546 // VerFile structure                                                    /*{{{*/
 547 /** \brief associates a version with a PackageFile
 548
 549     This allows a full description of all Versions in all files
 550     (and hence all sources) under consideration. */
 551 struct pkgCache::VerFile
 552 {
 553    /** \brief index of the package file that this version was found in */
 554    map_pointer_t File;           // PackageFile
 555    /** \brief next step in the linked list */
 556    map_pointer_t NextFile;       // PkgVerFile
 557    /** \brief position in the package file */
 558    map_filesize_t Offset;         // File offset
 559    /** @TODO document pkgCache::VerFile::Size */
 560    map_filesize_t Size;
 561 };
 562                                                                         /*}}}*/
 563 // DescFile structure                                                   /*{{{*/
 564 /** \brief associates a description with a Translation file */
 565 struct pkgCache::DescFile
 566 {
 567    /** \brief index of the file that this description was found in */
 568    map_pointer_t File;           // PackageFile
 569    /** \brief next step in the linked list */
 570    map_pointer_t NextFile;       // PkgVerFile
 571    /** \brief position in the file */
 572    map_filesize_t Offset;         // File offset
 573    /** @TODO document pkgCache::DescFile::Size */
 574    map_filesize_t Size;
 575 };
 576                                                                         /*}}}*/
 577 // Version structure                                                    /*{{{*/
 578 /** \brief information for a single version of a package
 579
 580     The version list is always sorted from highest version to lowest
 581     version by the generator. Equal version numbers are either merged
 582     or handled as separate versions based on the Hash value. */
 583 APT_IGNORE_DEPRECATED_PUSH
 584 struct pkgCache::Version
 585 {
 586    /** \brief complete version string */
 587    map_stringitem_t VerStr;
 588    /** \brief section this version is filled in */
 589    map_stringitem_t Section;
 590    /** \brief source package name this version comes from
 591       Always contains the name, even if it is the same as the binary name */
 592    map_stringitem_t SourcePkgName;
 593    /** \brief source version this version comes from
 594       Always contains the version string, even if it is the same as the binary version */
 595    map_stringitem_t SourceVerStr;
 596
 597    /** \brief Multi-Arch capabilities of a package version */
 598    enum VerMultiArch { No = 0, /*!< is the default and doesn't trigger special behaviour */
 599                        All = (1<<0), /*!< will cause that Ver.Arch() will report "all" */
 600                        Foreign = (1<<1), /*!< can satisfy dependencies in another architecture */
 601                        Same = (1<<2), /*!< can be co-installed with itself from other architectures */
 602                        Allowed = (1<<3), /*!< other packages are allowed to depend on thispkg:any */
 603                        AllForeign = All | Foreign,
 604                        AllAllowed = All | Allowed };
 605
 606    /** \brief deprecated variant of No */
 607    static const APT_DEPRECATED_MSG("The default value of the Multi-Arch field is no, not none") VerMultiArch None = No;
 608
 609    /** \brief stores the MultiArch capabilities of this version
 610
 611        Flags used are defined in pkgCache::Version::VerMultiArch
 612    */
 613    map_number_t MultiArch;
 614
 615    /** \brief references all the PackageFile's that this version came from
 616
 617        FileList can be used to determine what distribution(s) the Version
 618        applies to. If FileList is 0 then this is a blank version.
 619        The structure should also have a 0 in all other fields excluding
 620        pkgCache::Version::VerStr and Possibly pkgCache::Version::NextVer. */
 621    map_pointer_t FileList;          // VerFile
 622    /** \brief next (lower or equal) version in the linked list */
 623    map_pointer_t NextVer;           // Version
 624    /** \brief next description in the linked list */
 625    map_pointer_t DescriptionList;   // Description
 626    /** \brief base of the dependency list */
 627    map_pointer_t DependsList;       // Dependency
 628    /** \brief links to the owning package
 629
 630        This allows reverse dependencies to determine the package */
 631    map_pointer_t ParentPkg;         // Package
 632    /** \brief list of pkgCache::Provides */
 633    map_pointer_t ProvidesList;      // Provides
 634
 635    /** \brief archive size for this version
 636
 637        For Debian this is the size of the .deb file. */
 638    map_filesize_t Size; // These are the .deb size
 639    /** \brief uncompressed size for this version */
 640    map_filesize_t InstalledSize;
 641    /** \brief characteristic value representing this version
 642
 643        No two packages in existence should have the same VerStr
 644        and Hash with different contents. */
 645    unsigned short Hash;
 646    /** \brief unique sequel ID */
 647    map_id_t ID;
 648    /** \brief parsed priority value */
 649    map_number_t Priority;
 650 };
 651 APT_IGNORE_DEPRECATED_POP
 652                                                                         /*}}}*/
 653 // Description structure                                                /*{{{*/
 654 /** \brief datamember of a linked list of available description for a version */
 655 struct pkgCache::Description
 656 {
 657    /** \brief Language code of this description (translation)
 658
 659        If the value has a 0 length then this is read using the Package
 660        file else the Translation-CODE file is used. */
 661    map_stringitem_t language_code;
 662    /** \brief MD5sum of the original description
 663
 664        Used to map Translations of a description to a version
 665        and to check that the Translation is up-to-date. */
 666    map_stringitem_t md5sum;
 667
 668    /** @TODO document pkgCache::Description::FileList */
 669    map_pointer_t FileList;          // DescFile
 670    /** \brief next translation for this description */
 671    map_pointer_t NextDesc;          // Description
 672    /** \brief the text is a description of this package */
 673    map_pointer_t ParentPkg;         // Package
 674
 675    /** \brief unique sequel ID */
 676    map_id_t ID;
 677 };
 678                                                                         /*}}}*/
 679 // Dependency structure                                                 /*{{{*/
 680 /** \brief information for a single dependency record
 681
 682     The records are split up like this to ease processing by the client.
 683     The base of the linked list is pkgCache::Version::DependsList.
 684     All forms of dependencies are recorded here including Depends,
 685     Recommends, Suggests, Enhances, Conflicts, Replaces and Breaks. */
 686 struct pkgCache::DependencyData
 687 {
 688    /** \brief string of the version the dependency is applied against */
 689    map_stringitem_t Version;
 690    /** \brief index of the package this depends applies to
 691
 692        The generator will - if the package does not already exist -
 693        create a blank (no version records) package. */
 694    map_pointer_t Package;         // Package
 695
 696    /** \brief Dependency type - Depends, Recommends, Conflicts, etc */
 697    map_number_t Type;
 698    /** \brief comparison operator specified on the depends line
 699
 700        If the high bit is set then it is a logical OR with the previous record. */
 701    map_flags_t CompareOp;
 702
 703    map_pointer_t NextData;
 704 };
 705 struct pkgCache::Dependency
 706 {
 707    map_pointer_t DependencyData;  // DependencyData
 708    /** \brief version of the package which has the depends */
 709    map_pointer_t ParentVer;       // Version
 710    /** \brief next reverse dependency of this package */
 711    map_pointer_t NextRevDepends;  // Dependency
 712    /** \brief next dependency of this version */
 713    map_pointer_t NextDepends;     // Dependency
 714
 715    /** \brief unique sequel ID */
 716    map_id_t ID;
 717 };
 718                                                                         /*}}}*/
 719 // Provides structure                                                   /*{{{*/
 720 /** \brief handles virtual packages
 721
 722     When a Provides: line is encountered a new provides record is added
 723     associating the package with a virtual package name.
 724     The provides structures are linked off the package structures.
 725     This simplifies the analysis of dependencies and other aspects A provides
 726     refers to a specific version of a specific package, not all versions need to
 727     provide that provides.*/
 728 struct pkgCache::Provides
 729 {
 730    /** \brief index of the package providing this */
 731    map_pointer_t ParentPkg;        // Package
 732    /** \brief index of the version this provide line applies to */
 733    map_pointer_t Version;          // Version
 734    /** \brief version in the provides line (if any)
 735
 736        This version allows dependencies to depend on specific versions of a
 737        Provides, as well as allowing Provides to override existing packages. */
 738    map_stringitem_t ProvideVersion;
 739    map_flags_t Flags;
 740    /** \brief next provides (based of package) */
 741    map_pointer_t NextProvides;     // Provides
 742    /** \brief next provides (based of version) */
 743    map_pointer_t NextPkgProv;      // Provides
 744 };
 745                                                                         /*}}}*/
 746 // UNUSED StringItem structure                                          /*{{{*/
 747 struct APT_DEPRECATED_MSG("No longer used in cache generation without a replacement") pkgCache::StringItem
 748 {
 749    /** \brief string this refers to */
 750    map_ptrloc String;        // StringItem
 751    /** \brief Next link in the chain */
 752    map_ptrloc NextItem;      // StringItem
 753 };
 754                                                                         /*}}}*/
 755
 756 inline char const * pkgCache::NativeArch()
 757         { return StrP + HeaderP->Architecture; }
 758
 759 #include <apt-pkg/cacheiterators.h>
 760
 761 inline pkgCache::GrpIterator pkgCache::GrpBegin()
 762        {return GrpIterator(*this);}
 763 inline pkgCache::GrpIterator pkgCache::GrpEnd()
 764        {return GrpIterator(*this,GrpP);}
 765 inline pkgCache::PkgIterator pkgCache::PkgBegin()
 766        {return PkgIterator(*this);}
 767 inline pkgCache::PkgIterator pkgCache::PkgEnd()
 768        {return PkgIterator(*this,PkgP);}
 769 inline pkgCache::PkgFileIterator pkgCache::FileBegin()
 770        {return PkgFileIterator(*this,PkgFileP + HeaderP->FileList);}
 771 inline pkgCache::PkgFileIterator pkgCache::FileEnd()
 772        {return PkgFileIterator(*this,PkgFileP);}
 773 inline pkgCache::RlsFileIterator pkgCache::RlsFileBegin()
 774        {return RlsFileIterator(*this,RlsFileP + HeaderP->RlsFileList);}
 775 inline pkgCache::RlsFileIterator pkgCache::RlsFileEnd()
 776        {return RlsFileIterator(*this,RlsFileP);}
 777
 778
 779 // Oh I wish for Real Name Space Support
 780 class pkgCache::Namespace                                               /*{{{*/
 781 {
 782    public:
 783    typedef pkgCache::GrpIterator GrpIterator;
 784    typedef pkgCache::PkgIterator PkgIterator;
 785    typedef pkgCache::VerIterator VerIterator;
 786    typedef pkgCache::DescIterator DescIterator;
 787    typedef pkgCache::DepIterator DepIterator;
 788    typedef pkgCache::PrvIterator PrvIterator;
 789    typedef pkgCache::RlsFileIterator RlsFileIterator;
 790    typedef pkgCache::PkgFileIterator PkgFileIterator;
 791    typedef pkgCache::VerFileIterator VerFileIterator;
 792    typedef pkgCache::Version Version;
 793    typedef pkgCache::Description Description;
 794    typedef pkgCache::Package Package;
 795    typedef pkgCache::Header Header;
 796    typedef pkgCache::Dep Dep;
 797    typedef pkgCache::Flag Flag;
 798 };
 799                                                                         /*}}}*/
 800 #endif