apt-pkg/acquire.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: acquire.h,v 1.2 1998/10/20 02:39:16 jgg Exp $
   4 /* ######################################################################
   5
   6    Acquire - File Acquiration
   7
   8    This module contians the Acquire system. It is responsible for bringing
   9    files into the local pathname space. It deals with URIs for files and
  10    URI handlers responsible for downloading or finding the URIs.
  11
  12    Each file to download is represented by an Acquire::Item class subclassed
  13    into a specialization. The Item class can add itself to several URI
  14    acquire queues each prioritized by the download scheduler. When the
  15    system is run the proper URI handlers are spawned and the the acquire
  16    queues are fed into the handlers by the schedular until the queues are
  17    empty. This allows for an Item to be downloaded from an alternate source
  18    if the first try turns out to fail. It also alows concurrent downloading
  19    of multiple items from multiple sources as well as dynamic balancing
  20    of load between the sources.
  21
  22    Schedualing of downloads is done on a first ask first get basis. This
  23    preserves the order of the download as much as possible. And means the
  24    fastest source will tend to process the largest number of files.
  25
  26    Internal methods and queues for performing gzip decompression,
  27    md5sum hashing and file copying are provided to allow items to apply
  28    a number of transformations to the data files they are working with.
  29
  30    ##################################################################### */
  31                                                                         /*}}}*/
  32 #ifndef PKGLIB_ACQUIRE_H
  33 #define PKGLIB_ACQUIRE_H
  34
  35 #include <vector>
  36 #include <string>
  37
  38 #ifdef __GNUG__
  39 #pragma interface "apt-pkg/acquire.h"
  40 #endif
  41
  42 class pkgAcquire
  43 {
  44    public:
  45
  46    class Item;
  47    class Queue;
  48    class Worker;
  49    struct MethodConfig;
  50    friend Item;
  51
  52    protected:
  53
  54    vector<Item *> Items;
  55    Queue *Queues;
  56    MethodConfig *Configs;
  57
  58    void Add(Item *Item);
  59    void Remove(Item *Item);
  60    void Enqueue(Item *Item,string URI);
  61
  62    public:
  63
  64    const MethodConfig *GetConfig(string Access);
  65    string QueueName(string URI);
  66
  67    pkgAcquire();
  68    ~pkgAcquire();
  69 };
  70
  71 // List of possible items queued for download.
  72 class pkgAcquire::Queue
  73 {
  74    friend pkgAcquire;
  75    Queue *Next;
  76
  77    protected:
  78
  79    string URIMatch;
  80
  81    vector<Item *> Items;
  82
  83    public:
  84 };
  85
  86 // Configuration information from each method
  87 struct pkgAcquire::MethodConfig
  88 {
  89    MethodConfig *Next;
  90
  91    string Access;
  92
  93    string Version;
  94    bool SingleInstance;
  95    bool PreScan;
  96
  97    MethodConfig();
  98 };
  99
 100 #endif