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 #if APT_PKG_ABI >= 413
  89 // storing file sizes of indexes, which are way below 4 GB for now
  90 typedef uint32_t map_filesize_t;
  91 typedef map_filesize_t should_be_map_filesize_t;
  92 #else
  93 typedef unsigned long map_filesize_t;
  94 typedef unsigned int should_be_map_filesize_t;
  95 #endif
  96 #if APT_PKG_ABI >= 413
  97 // each package/group/dependency gets an id
  98 typedef uint32_t map_id_t;
  99 typedef map_id_t should_be_map_id_t;
 100 #else
 101 typedef unsigned long map_id_t;
 102 typedef unsigned int should_be_map_id_t;
 103 #endif
 104 #if APT_PKG_ABI >= 413
 105 // some files get an id, too, but in far less absolute numbers
 106 typedef uint16_t map_fileid_t;
 107 typedef map_fileid_t should_be_map_fileid_t;
 108 #else
 109 typedef unsigned long map_fileid_t;
 110 typedef unsigned int should_be_map_fileid_t;
 111 #endif
 112 #if APT_PKG_ABI >= 413
 113 // relative pointer from cache start
 114 typedef uint32_t map_pointer_t;
 115 #else
 116 typedef unsigned int map_pointer_t;
 117 #endif
 118 // same as the previous, but documented to be to a string item
 119 typedef map_pointer_t map_stringitem_t;
 120 #if APT_PKG_ABI >= 413
 121 typedef uint64_t should_be_uint64_t;
 122 typedef uint64_t should_be_uint64_small_t;
 123 #else
 124 typedef unsigned long long should_be_uint64_t;
 125 typedef unsigned long should_be_uint64_small_t;
 126 #endif
 127
 128 class pkgVersioningSystem;
 129 class pkgCache                                                          /*{{{*/
 130 {
 131    public:
 132    // Cache element predeclarations
 133    struct Header;
 134    struct Group;
 135    struct Package;
 136    struct ReleaseFile;
 137    struct PackageFile;
 138    struct Version;
 139    struct Description;
 140    struct Provides;
 141    struct Dependency;
 142    struct StringItem;
 143    struct VerFile;
 144    struct DescFile;
 145
 146    // Iterators
 147    template<typename Str, typename Itr> class Iterator;
 148    class GrpIterator;
 149    class PkgIterator;
 150    class VerIterator;
 151    class DescIterator;
 152    class DepIterator;
 153    class PrvIterator;
 154    class RlsFileIterator;
 155    class PkgFileIterator;
 156    class VerFileIterator;
 157    class DescFileIterator;
 158
 159    class Namespace;
 160
 161    // These are all the constants used in the cache structures
 162
 163    // WARNING - if you change these lists you must also edit
 164    // the stringification in pkgcache.cc and also consider whether
 165    // the cache file will become incompatible.
 166    struct Dep
 167    {
 168       enum DepType {Depends=1,PreDepends=2,Suggests=3,Recommends=4,
 169          Conflicts=5,Replaces=6,Obsoletes=7,DpkgBreaks=8,Enhances=9};
 170       /** \brief available compare operators
 171
 172           The lower 4 bits are used to indicate what operator is being specified and
 173           the upper 4 bits are flags. OR indicates that the next package is
 174           or'd with the current package. */
 175       enum DepCompareOp {Or=0x10,NoOp=0,LessEq=0x1,GreaterEq=0x2,Less=0x3,
 176          Greater=0x4,Equals=0x5,NotEquals=0x6};
 177    };
 178
 179    struct State
 180    {
 181       /** \brief priority of a package version
 182
 183           Zero is used for unparsable or absent Priority fields. */
 184       enum VerPriority {Required=1,Important=2,Standard=3,Optional=4,Extra=5};
 185       enum PkgSelectedState {Unknown=0,Install=1,Hold=2,DeInstall=3,Purge=4};
 186       enum PkgInstState {Ok=0,ReInstReq=1,HoldInst=2,HoldReInstReq=3};
 187       enum PkgCurrentState {NotInstalled=0,UnPacked=1,HalfConfigured=2,
 188            HalfInstalled=4,ConfigFiles=5,Installed=6,
 189            TriggersAwaited=7,TriggersPending=8};
 190    };
 191
 192    struct Flag
 193    {
 194       enum PkgFlags {Auto=(1<<0),Essential=(1<<3),Important=(1<<4)};
 195       enum PkgFFlags {
 196          NotSource=(1<<0), /*!< packages can't be fetched from here, e.g. dpkg/status file */
 197          LocalSource=(1<<1), /*!< local sources can't and will not be verified by hashes */
 198          NoPackages=(1<<2), /*!< the file includes no package records itself, but additions like Translations */
 199       };
 200       enum ReleaseFileFlags {
 201          NotAutomatic=(1<<0), /*!< archive has a default pin of 1 */
 202          ButAutomaticUpgrades=(1<<1), /*!< (together with the previous) archive has a default pin of 100 */
 203       };
 204    };
 205
 206    protected:
 207
 208    // Memory mapped cache file
 209    std::string CacheFile;
 210    MMap &Map;
 211
 212    map_id_t sHash(const std::string &S) const APT_PURE;
 213    map_id_t sHash(const char *S) const APT_PURE;
 214
 215    public:
 216
 217    // Pointers to the arrays of items
 218    Header *HeaderP;
 219    Group *GrpP;
 220    Package *PkgP;
 221    VerFile *VerFileP;
 222    DescFile *DescFileP;
 223    ReleaseFile *RlsFileP;
 224    PackageFile *PkgFileP;
 225    Version *VerP;
 226    Description *DescP;
 227    Provides *ProvideP;
 228    Dependency *DepP;
 229    APT_DEPRECATED StringItem *StringItemP;
 230    char *StrP;
 231
 232    virtual bool ReMap(bool const &Errorchecks = true);
 233    inline bool Sync() {return Map.Sync();}
 234    inline MMap &GetMap() {return Map;}
 235    inline void *DataEnd() {return ((unsigned char *)Map.Data()) + Map.Size();}
 236
 237    // String hashing function (512 range)
 238    inline map_id_t Hash(const std::string &S) const {return sHash(S);}
 239    inline map_id_t Hash(const char *S) const {return sHash(S);}
 240
 241    // Useful transformation things
 242    const char *Priority(unsigned char Priority);
 243
 244    // Accessors
 245    GrpIterator FindGrp(const std::string &Name);
 246    PkgIterator FindPkg(const std::string &Name);
 247    PkgIterator FindPkg(const std::string &Name, const std::string &Arch);
 248
 249    Header &Head() {return *HeaderP;}
 250    inline GrpIterator GrpBegin();
 251    inline GrpIterator GrpEnd();
 252    inline PkgIterator PkgBegin();
 253    inline PkgIterator PkgEnd();
 254    inline PkgFileIterator FileBegin();
 255    inline PkgFileIterator FileEnd();
 256    inline RlsFileIterator RlsFileBegin();
 257    inline RlsFileIterator RlsFileEnd();
 258
 259    inline bool MultiArchCache() const { return MultiArchEnabled; }
 260    inline char const * NativeArch();
 261
 262    // Make me a function
 263    pkgVersioningSystem *VS;
 264
 265    // Converters
 266    static const char *CompTypeDeb(unsigned char Comp) APT_CONST;
 267    static const char *CompType(unsigned char Comp) APT_CONST;
 268    static const char *DepType(unsigned char Dep);
 269
 270    pkgCache(MMap *Map,bool DoMap = true);
 271    virtual ~pkgCache() {}
 272
 273 private:
 274    bool MultiArchEnabled;
 275    APT_HIDDEN PkgIterator SingleArchFindPkg(const std::string &Name);
 276 };
 277                                                                         /*}}}*/
 278 // Header structure                                                     /*{{{*/
 279 struct pkgCache::Header
 280 {
 281    /** \brief Signature information
 282
 283        This must contain the hex value 0x98FE76DC which is designed to
 284        verify that the system loading the image has the same byte order
 285        and byte size as the system saving the image */
 286    unsigned long Signature;
 287    /** These contain the version of the cache file */
 288    short MajorVersion;
 289    short MinorVersion;
 290    /** \brief indicates if the cache should be erased
 291
 292        Dirty is true if the cache file was opened for reading, the client
 293        expects to have written things to it and have not fully synced it.
 294        The file should be erased and rebuilt if it is true. */
 295    bool Dirty;
 296
 297    /** \brief Size of structure values
 298
 299        All *Sz variables contains the sizeof() that particular structure.
 300        It is used as an extra consistency check on the structure of the file.
 301
 302        If any of the size values do not exactly match what the client expects
 303        then the client should refuse the load the file. */
 304    unsigned short HeaderSz;
 305    unsigned short GroupSz;
 306    unsigned short PackageSz;
 307    unsigned short ReleaseFileSz;
 308    unsigned short PackageFileSz;
 309    unsigned short VersionSz;
 310    unsigned short DescriptionSz;
 311    unsigned short DependencySz;
 312    unsigned short ProvidesSz;
 313    unsigned short VerFileSz;
 314    unsigned short DescFileSz;
 315
 316    /** \brief Structure counts
 317
 318        These indicate the number of each structure contained in the cache.
 319        PackageCount is especially useful for generating user state structures.
 320        See Package::Id for more info. */
 321    map_id_t GroupCount;
 322    map_id_t PackageCount;
 323    map_id_t VersionCount;
 324    map_id_t DescriptionCount;
 325    map_id_t DependsCount;
 326    map_fileid_t ReleaseFileCount;
 327    map_fileid_t PackageFileCount;
 328    map_fileid_t VerFileCount;
 329    map_fileid_t DescFileCount;
 330    map_id_t ProvidesCount;
 331
 332    /** \brief index of the first PackageFile structure
 333
 334        The PackageFile structures are singly linked lists that represent
 335        all package files that have been merged into the cache. */
 336    map_pointer_t FileList;
 337    /** \brief index of the first ReleaseFile structure */
 338    map_pointer_t RlsFileList;
 339
 340 #if APT_PKG_ABI < 413
 341    APT_DEPRECATED map_pointer_t StringList;
 342 #endif
 343    /** \brief String representing the version system used */
 344    map_pointer_t VerSysName;
 345    /** \brief native architecture the cache was built against */
 346    map_pointer_t Architecture;
 347 #if APT_PKG_ABI >= 413
 348    /** \brief all architectures the cache was built against */
 349    map_pointer_t Architectures;
 350 #endif
 351    /** \brief The maximum size of a raw entry from the original Package file */
 352    map_filesize_t MaxVerFileSize;
 353    /** \brief The maximum size of a raw entry from the original Translation file */
 354    map_filesize_t MaxDescFileSize;
 355
 356    /** \brief The Pool structures manage the allocation pools that the generator uses
 357
 358        Start indicates the first byte of the pool, Count is the number of objects
 359        remaining in the pool and ItemSize is the structure size (alignment factor)
 360        of the pool. An ItemSize of 0 indicates the pool is empty. There should be
 361        the same number of pools as there are structure types. The generator
 362        stores this information so future additions can make use of any unused pool
 363        blocks. */
 364    DynamicMMap::Pool Pools[9];
 365
 366    /** \brief hash tables providing rapid group/package name lookup
 367
 368        Each group/package name is inserted into a hash table using pkgCache::Hash(const &string)
 369        By iterating over each entry in the hash table it is possible to iterate over
 370        the entire list of packages. Hash Collisions are handled with a singly linked
 371        list of packages based at the hash item. The linked list contains only
 372        packages that match the hashing function.
 373        In the PkgHashTable is it possible that multiple packages have the same name -
 374        these packages are stored as a sequence in the list.
 375        The size of both tables is the same. */
 376 #if APT_PKG_ABI >= 413
 377    unsigned int HashTableSize;
 378    unsigned int GetHashTableSize() const { return HashTableSize; }
 379    void SetHashTableSize(unsigned int const sz) { HashTableSize = sz; }
 380    map_pointer_t GetArchitectures() const { return Architectures; }
 381    void SetArchitectures(map_pointer_t const idx) { Architectures = idx; }
 382 #else
 383    // BEWARE: these tables are pretty much empty and just here for abi compat
 384    map_ptrloc PkgHashTable[2*1048];
 385    map_ptrloc GrpHashTable[2*1048];
 386    unsigned int GetHashTableSize() const { return PkgHashTable[0]; }
 387    void SetHashTableSize(unsigned int const sz) { PkgHashTable[0] = sz; }
 388    map_pointer_t GetArchitectures() const { return PkgHashTable[1]; }
 389    void SetArchitectures(map_pointer_t const idx) { PkgHashTable[1] = idx; }
 390 #endif
 391    map_pointer_t * PkgHashTableP() const { return (map_pointer_t*) (this + 1); }
 392    map_pointer_t * GrpHashTableP() const { return PkgHashTableP() + GetHashTableSize(); }
 393
 394    /** \brief Size of the complete cache file */
 395    should_be_uint64_small_t CacheFileSize;
 396
 397    bool CheckSizes(Header &Against) const APT_PURE;
 398    Header();
 399 };
 400                                                                         /*}}}*/
 401 // Group structure                                                      /*{{{*/
 402 /** \brief groups architecture depending packages together
 403
 404     On or more packages with the same name form a group, so we have
 405     a simple way to access a package built for different architectures
 406     Group exists in a singly linked list of group records starting at
 407     the hash index of the name in the pkgCache::Header::GrpHashTable */
 408 struct pkgCache::Group
 409 {
 410    /** \brief Name of the group */
 411    map_stringitem_t Name;
 412
 413    // Linked List
 414    /** \brief Link to the first package which belongs to the group */
 415    map_pointer_t FirstPackage;  // Package
 416    /** \brief Link to the last package which belongs to the group */
 417    map_pointer_t LastPackage;   // Package
 418    /** \brief Link to the next Group */
 419    map_pointer_t Next;          // Group
 420    /** \brief unique sequel ID */
 421    should_be_map_id_t ID;
 422
 423 };
 424                                                                         /*}}}*/
 425 // Package structure                                                    /*{{{*/
 426 /** \brief contains information for a single unique package
 427
 428     There can be any number of versions of a given package.
 429     Package exists in a singly linked list of package records starting at
 430     the hash index of the name in the pkgCache::Header::PkgHashTable
 431
 432     A package can be created for every architecture so package names are
 433     not unique, but it is guaranteed that packages with the same name
 434     are sequencel ordered in the list. Packages with the same name can be
 435     accessed with the Group.
 436 */
 437 struct pkgCache::Package
 438 {
 439    /** \brief Name of the package
 440     * Note that the access method Name() will remain. It is just this data member
 441     * deprecated as this information is already stored and available via the
 442     * associated Group – so it is wasting precious binary cache space */
 443    APT_DEPRECATED map_stringitem_t Name;
 444    /** \brief Architecture of the package */
 445    map_stringitem_t Arch;
 446    /** \brief Base of a singly linked list of versions
 447
 448        Each structure represents a unique version of the package.
 449        The version structures contain links into PackageFile and the
 450        original text file as well as detailed information about the size
 451        and dependencies of the specific package. In this way multiple
 452        versions of a package can be cleanly handled by the system.
 453        Furthermore, this linked list is guaranteed to be sorted
 454        from Highest version to lowest version with no duplicate entries. */
 455    map_pointer_t VersionList;       // Version
 456    /** \brief index to the installed version */
 457    map_pointer_t CurrentVer;        // Version
 458    /** \brief indicates nothing (consistently)
 459        This field used to contain ONE section the package belongs to,
 460        if those differs between versions it is a RANDOM one.
 461        The Section() method tries to reproduce it, but the only sane
 462        thing to do is use the Section field from the version! */
 463    APT_DEPRECATED map_ptrloc Section; // StringItem
 464    /** \brief index of the group this package belongs to */
 465    map_pointer_t Group;             // Group the Package belongs to
 466
 467    // Linked list
 468    /** \brief Link to the next package in the same bucket */
 469    map_pointer_t NextPackage;       // Package
 470    /** \brief List of all dependencies on this package */
 471    map_pointer_t RevDepends;        // Dependency
 472    /** \brief List of all "packages" this package provide */
 473    map_pointer_t ProvidesList;      // Provides
 474
 475    // Install/Remove/Purge etc
 476    /** \brief state that the user wishes the package to be in */
 477    unsigned char SelectedState;     // What
 478    /** \brief installation state of the package
 479
 480        This should be "ok" but in case the installation failed
 481        it will be different.
 482    */
 483    unsigned char InstState;         // Flags
 484    /** \brief indicates if the package is installed */
 485    unsigned char CurrentState;      // State
 486
 487    /** \brief unique sequel ID
 488
 489        ID is a unique value from 0 to Header->PackageCount assigned by the generator.
 490        This allows clients to create an array of size PackageCount and use it to store
 491        state information for the package map. For instance the status file emitter uses
 492        this to track which packages have been emitted already. */
 493    should_be_map_id_t ID;
 494    /** \brief some useful indicators of the package's state */
 495    unsigned long Flags;
 496 };
 497                                                                         /*}}}*/
 498 // Release File structure                                               /*{{{*/
 499 /** \brief stores information about the release files used to generate the cache
 500
 501     PackageFiles reference ReleaseFiles as we need to keep record of which
 502     version belongs to which release e.g. for pinning. */
 503 struct pkgCache::ReleaseFile
 504 {
 505    /** \brief physical disk file that this ReleaseFile represents */
 506    map_stringitem_t FileName;
 507    /** \brief the release information
 508
 509        Please see the files document for a description of what the
 510        release information means. */
 511    map_stringitem_t Archive;
 512    map_stringitem_t Codename;
 513    map_stringitem_t Version;
 514    map_stringitem_t Origin;
 515    map_stringitem_t Label;
 516    /** \brief The site the index file was fetched from */
 517    map_stringitem_t Site;
 518
 519    /** \brief Size of the file
 520
 521        Used together with the modification time as a
 522        simple check to ensure that the Packages
 523        file has not been altered since Cache generation. */
 524    map_filesize_t Size;
 525    /** \brief Modification time for the file */
 526    time_t mtime;
 527
 528    /** @TODO document PackageFile::Flags */
 529    unsigned long Flags;
 530
 531    // Linked list
 532    /** \brief Link to the next ReleaseFile in the Cache */
 533    map_pointer_t NextFile;
 534    /** \brief unique sequel ID */
 535    should_be_map_fileid_t ID;
 536 };
 537                                                                         /*}}}*/
 538 // Package File structure                                               /*{{{*/
 539 /** \brief stores information about the files used to generate the cache
 540
 541     Package files are referenced by Version structures to be able to know
 542     after the generation still from which Packages file includes this Version
 543     as we need this information later on e.g. for pinning. */
 544 struct pkgCache::PackageFile
 545 {
 546    /** \brief physical disk file that this PackageFile represents */
 547    map_stringitem_t FileName;
 548    /** \brief the release information */
 549    map_pointer_t Release;
 550
 551    map_stringitem_t Component;
 552    map_stringitem_t Architecture;
 553
 554    /** \brief indicates what sort of index file this is
 555
 556        @TODO enumerate at least the possible indexes */
 557    map_stringitem_t IndexType;
 558    /** \brief Size of the file
 559
 560        Used together with the modification time as a
 561        simple check to ensure that the Packages
 562        file has not been altered since Cache generation. */
 563    map_filesize_t Size;
 564    /** \brief Modification time for the file */
 565    time_t mtime;
 566
 567    /** @TODO document PackageFile::Flags */
 568    unsigned long Flags;
 569
 570    // Linked list
 571    /** \brief Link to the next PackageFile in the Cache */
 572    map_pointer_t NextFile;        // PackageFile
 573    /** \brief unique sequel ID */
 574    should_be_map_fileid_t ID;
 575 };
 576                                                                         /*}}}*/
 577 // VerFile structure                                                    /*{{{*/
 578 /** \brief associates a version with a PackageFile
 579
 580     This allows a full description of all Versions in all files
 581     (and hence all sources) under consideration. */
 582 struct pkgCache::VerFile
 583 {
 584    /** \brief index of the package file that this version was found in */
 585    map_pointer_t File;           // PackageFile
 586    /** \brief next step in the linked list */
 587    map_pointer_t NextFile;       // PkgVerFile
 588    /** \brief position in the package file */
 589    should_be_map_filesize_t Offset;         // File offset
 590    /** @TODO document pkgCache::VerFile::Size */
 591    map_filesize_t Size;
 592 };
 593                                                                         /*}}}*/
 594 // DescFile structure                                                   /*{{{*/
 595 /** \brief associates a description with a Translation file */
 596 struct pkgCache::DescFile
 597 {
 598    /** \brief index of the file that this description was found in */
 599    map_pointer_t File;           // PackageFile
 600    /** \brief next step in the linked list */
 601    map_pointer_t NextFile;       // PkgVerFile
 602    /** \brief position in the file */
 603    should_be_map_filesize_t Offset;         // File offset
 604    /** @TODO document pkgCache::DescFile::Size */
 605    map_filesize_t Size;
 606 };
 607                                                                         /*}}}*/
 608 // Version structure                                                    /*{{{*/
 609 /** \brief information for a single version of a package
 610
 611     The version list is always sorted from highest version to lowest
 612     version by the generator. Equal version numbers are either merged
 613     or handled as separate versions based on the Hash value. */
 614 struct pkgCache::Version
 615 {
 616    /** \brief complete version string */
 617    map_stringitem_t VerStr;
 618    /** \brief section this version is filled in */
 619    map_stringitem_t Section;
 620 #if APT_PKG_ABI >= 413
 621    /** \brief source package name this version comes from
 622       Always contains the name, even if it is the same as the binary name */
 623    map_stringitem_t SourcePkgName;
 624    /** \brief source version this version comes from
 625       Always contains the version string, even if it is the same as the binary version */
 626    map_stringitem_t SourceVerStr;
 627 #endif
 628
 629    /** \brief Multi-Arch capabilities of a package version */
 630    enum VerMultiArch { None = 0, /*!< is the default and doesn't trigger special behaviour */
 631                        All = (1<<0), /*!< will cause that Ver.Arch() will report "all" */
 632                        Foreign = (1<<1), /*!< can satisfy dependencies in another architecture */
 633                        Same = (1<<2), /*!< can be co-installed with itself from other architectures */
 634                        Allowed = (1<<3), /*!< other packages are allowed to depend on thispkg:any */
 635                        AllForeign = All | Foreign,
 636                        AllAllowed = All | Allowed };
 637    /** \brief stores the MultiArch capabilities of this version
 638
 639        Flags used are defined in pkgCache::Version::VerMultiArch
 640    */
 641    unsigned char MultiArch;
 642
 643    /** \brief references all the PackageFile's that this version came from
 644
 645        FileList can be used to determine what distribution(s) the Version
 646        applies to. If FileList is 0 then this is a blank version.
 647        The structure should also have a 0 in all other fields excluding
 648        pkgCache::Version::VerStr and Possibly pkgCache::Version::NextVer. */
 649    map_pointer_t FileList;          // VerFile
 650    /** \brief next (lower or equal) version in the linked list */
 651    map_pointer_t NextVer;           // Version
 652    /** \brief next description in the linked list */
 653    map_pointer_t DescriptionList;   // Description
 654    /** \brief base of the dependency list */
 655    map_pointer_t DependsList;       // Dependency
 656    /** \brief links to the owning package
 657
 658        This allows reverse dependencies to determine the package */
 659    map_pointer_t ParentPkg;         // Package
 660    /** \brief list of pkgCache::Provides */
 661    map_pointer_t ProvidesList;      // Provides
 662
 663    /** \brief archive size for this version
 664
 665        For Debian this is the size of the .deb file. */
 666    should_be_uint64_t Size; // These are the .deb size
 667    /** \brief uncompressed size for this version */
 668    should_be_uint64_t InstalledSize;
 669    /** \brief characteristic value representing this version
 670
 671        No two packages in existence should have the same VerStr
 672        and Hash with different contents. */
 673    unsigned short Hash;
 674    /** \brief unique sequel ID */
 675    should_be_map_id_t ID;
 676    /** \brief parsed priority value */
 677    unsigned char Priority;
 678 };
 679                                                                         /*}}}*/
 680 // Description structure                                                /*{{{*/
 681 /** \brief datamember of a linked list of available description for a version */
 682 struct pkgCache::Description
 683 {
 684    /** \brief Language code of this description (translation)
 685
 686        If the value has a 0 length then this is read using the Package
 687        file else the Translation-CODE file is used. */
 688    map_stringitem_t language_code;
 689    /** \brief MD5sum of the original description
 690
 691        Used to map Translations of a description to a version
 692        and to check that the Translation is up-to-date. */
 693    map_stringitem_t md5sum;
 694
 695    /** @TODO document pkgCache::Description::FileList */
 696    map_pointer_t FileList;          // DescFile
 697    /** \brief next translation for this description */
 698    map_pointer_t NextDesc;          // Description
 699    /** \brief the text is a description of this package */
 700    map_pointer_t ParentPkg;         // Package
 701
 702    /** \brief unique sequel ID */
 703    should_be_map_id_t ID;
 704 };
 705                                                                         /*}}}*/
 706 // Dependency structure                                                 /*{{{*/
 707 /** \brief information for a single dependency record
 708
 709     The records are split up like this to ease processing by the client.
 710     The base of the linked list is pkgCache::Version::DependsList.
 711     All forms of dependencies are recorded here including Depends,
 712     Recommends, Suggests, Enhances, Conflicts, Replaces and Breaks. */
 713 struct pkgCache::Dependency
 714 {
 715    /** \brief string of the version the dependency is applied against */
 716    map_stringitem_t Version;
 717    /** \brief index of the package this depends applies to
 718
 719        The generator will - if the package does not already exist -
 720        create a blank (no version records) package. */
 721    map_pointer_t Package;         // Package
 722    /** \brief next dependency of this version */
 723    map_pointer_t NextDepends;     // Dependency
 724    /** \brief next reverse dependency of this package */
 725    map_pointer_t NextRevDepends;  // Dependency
 726    /** \brief version of the package which has the reverse depends */
 727    map_pointer_t ParentVer;       // Version
 728
 729    /** \brief unique sequel ID */
 730    should_be_map_id_t ID;
 731    /** \brief Dependency type - Depends, Recommends, Conflicts, etc */
 732    unsigned char Type;
 733    /** \brief comparison operator specified on the depends line
 734
 735        If the high bit is set then it is a logical OR with the previous record. */
 736    unsigned char CompareOp;
 737 };
 738                                                                         /*}}}*/
 739 // Provides structure                                                   /*{{{*/
 740 /** \brief handles virtual packages
 741
 742     When a Provides: line is encountered a new provides record is added
 743     associating the package with a virtual package name.
 744     The provides structures are linked off the package structures.
 745     This simplifies the analysis of dependencies and other aspects A provides
 746     refers to a specific version of a specific package, not all versions need to
 747     provide that provides.*/
 748 struct pkgCache::Provides
 749 {
 750    /** \brief index of the package providing this */
 751    map_pointer_t ParentPkg;        // Package
 752    /** \brief index of the version this provide line applies to */
 753    map_pointer_t Version;          // Version
 754    /** \brief version in the provides line (if any)
 755
 756        This version allows dependencies to depend on specific versions of a
 757        Provides, as well as allowing Provides to override existing packages.
 758        This is experimental. Note that Debian doesn't allow versioned provides */
 759    map_stringitem_t ProvideVersion;
 760    /** \brief next provides (based of package) */
 761    map_pointer_t NextProvides;     // Provides
 762    /** \brief next provides (based of version) */
 763    map_pointer_t NextPkgProv;      // Provides
 764 };
 765                                                                         /*}}}*/
 766 // UNUSED StringItem structure                                          /*{{{*/
 767 struct APT_DEPRECATED  pkgCache::StringItem
 768 {
 769    /** \brief string this refers to */
 770    map_ptrloc String;        // StringItem
 771    /** \brief Next link in the chain */
 772    map_ptrloc NextItem;      // StringItem
 773 };
 774                                                                         /*}}}*/
 775
 776 inline char const * pkgCache::NativeArch()
 777         { return StrP + HeaderP->Architecture; }
 778
 779 #include <apt-pkg/cacheiterators.h>
 780
 781 inline pkgCache::GrpIterator pkgCache::GrpBegin()
 782        {return GrpIterator(*this);}
 783 inline pkgCache::GrpIterator pkgCache::GrpEnd()
 784        {return GrpIterator(*this,GrpP);}
 785 inline pkgCache::PkgIterator pkgCache::PkgBegin()
 786        {return PkgIterator(*this);}
 787 inline pkgCache::PkgIterator pkgCache::PkgEnd()
 788        {return PkgIterator(*this,PkgP);}
 789 inline pkgCache::PkgFileIterator pkgCache::FileBegin()
 790        {return PkgFileIterator(*this,PkgFileP + HeaderP->FileList);}
 791 inline pkgCache::PkgFileIterator pkgCache::FileEnd()
 792        {return PkgFileIterator(*this,PkgFileP);}
 793 inline pkgCache::RlsFileIterator pkgCache::RlsFileBegin()
 794        {return RlsFileIterator(*this,RlsFileP + HeaderP->RlsFileList);}
 795 inline pkgCache::RlsFileIterator pkgCache::RlsFileEnd()
 796        {return RlsFileIterator(*this,RlsFileP);}
 797
 798
 799 // Oh I wish for Real Name Space Support
 800 class pkgCache::Namespace                                               /*{{{*/
 801 {
 802    public:
 803    typedef pkgCache::GrpIterator GrpIterator;
 804    typedef pkgCache::PkgIterator PkgIterator;
 805    typedef pkgCache::VerIterator VerIterator;
 806    typedef pkgCache::DescIterator DescIterator;
 807    typedef pkgCache::DepIterator DepIterator;
 808    typedef pkgCache::PrvIterator PrvIterator;
 809    typedef pkgCache::RlsFileIterator RlsFileIterator;
 810    typedef pkgCache::PkgFileIterator PkgFileIterator;
 811    typedef pkgCache::VerFileIterator VerFileIterator;
 812    typedef pkgCache::Version Version;
 813    typedef pkgCache::Description Description;
 814    typedef pkgCache::Package Package;
 815    typedef pkgCache::Header Header;
 816    typedef pkgCache::Dep Dep;
 817    typedef pkgCache::Flag Flag;
 818 };
 819                                                                         /*}}}*/
 820 #endif