acquire.h

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// -*- mode: cpp; mode: fold -*-
// Description                                                          /*{{{*/
// $Id: acquire.h,v 1.29.2.1 2003/12/24 23:09:17 mdz Exp $
/* ######################################################################

   Acquire - File Acquiration
   
   This module contians the Acquire system. It is responsible for bringing
   files into the local pathname space. It deals with URIs for files and
   URI handlers responsible for downloading or finding the URIs.
   
   Each file to download is represented by an Acquire::Item class subclassed
   into a specialization. The Item class can add itself to several URI
   acquire queues each prioritized by the download scheduler. When the 
   system is run the proper URI handlers are spawned and the the acquire 
   queues are fed into the handlers by the schedular until the queues are
   empty. This allows for an Item to be downloaded from an alternate source
   if the first try turns out to fail. It also alows concurrent downloading
   of multiple items from multiple sources as well as dynamic balancing
   of load between the sources.
   
   Schedualing of downloads is done on a first ask first get basis. This
   preserves the order of the download as much as possible. And means the
   fastest source will tend to process the largest number of files.
   
   Internal methods and queues for performing gzip decompression,
   md5sum hashing and file copying are provided to allow items to apply
   a number of transformations to the data files they are working with.
   
   ##################################################################### */
                                                                        /*}}}*/
                                                                        /*}}}*/

#ifndef PKGLIB_ACQUIRE_H
#define PKGLIB_ACQUIRE_H

#include <apt-pkg/macros.h>
#include <apt-pkg/weakptr.h>

#include <vector>
#include <string>

using std::vector;
using std::string;


#include <sys/time.h>
#include <unistd.h>

class pkgAcquireStatus;

class pkgAcquire
{   
   public:
   
   class Item;
   class Queue;
   class Worker;
   struct MethodConfig;
   struct ItemDesc;
   friend class Item;
   friend class Queue;

   typedef vector<Item *>::iterator ItemIterator;
   typedef vector<Item *>::const_iterator ItemCIterator;

   protected:
   
   vector<Item *> Items;
   
   Queue *Queues;

   Worker *Workers;

   MethodConfig *Configs;

   pkgAcquireStatus *Log;

   unsigned long ToFetch;

   // Configurable parameters for the scheduler

   enum QueueStrategy {
     QueueHost,
     QueueAccess} QueueMode;

   bool const Debug;
   bool Running;

   void Add(Item *Item);

   void Remove(Item *Item);

   void Add(Worker *Work);

   void Remove(Worker *Work);
   
   void Enqueue(ItemDesc &Item);

   void Dequeue(Item *Item);

   string QueueName(string URI,MethodConfig const *&Config);

   virtual void SetFds(int &Fd,fd_set *RSet,fd_set *WSet);

   virtual void RunFds(fd_set *RSet,fd_set *WSet);   

   void Bump();
   
   public:

   MethodConfig *GetConfig(string Access);

   enum RunResult {
     Continue,

     Failed,

     Cancelled};

   RunResult Run(int PulseInterval=500000);

   void Shutdown();
   
   inline Worker *WorkersBegin() {return Workers;};

   Worker *WorkerStep(Worker *I);

   inline ItemIterator ItemsBegin() {return Items.begin();};

   inline ItemIterator ItemsEnd() {return Items.end();};
   
   // Iterate over queued Item URIs
   class UriIterator;
   UriIterator UriBegin();
   UriIterator UriEnd();
   
   bool Clean(string Dir);

   unsigned long long TotalNeeded();

   unsigned long long FetchNeeded();

   unsigned long long PartialPresent();

   bool Setup(pkgAcquireStatus *Progress = NULL, string const &Lock = "");

   void SetLog(pkgAcquireStatus *Progress) { Log = Progress; }

   pkgAcquire(pkgAcquireStatus *Log) __deprecated;
   pkgAcquire();

   virtual ~pkgAcquire();

   private:
   int LockFD;
};

struct pkgAcquire::ItemDesc : public WeakPointable
{
   string URI;
   string Description;
   string ShortDesc;
   Item *Owner;
};
                                                                        /*}}}*/
class pkgAcquire::Queue
{
   friend class pkgAcquire;
   friend class pkgAcquire::UriIterator;
   friend class pkgAcquire::Worker;

   Queue *Next;
   
   protected:

   struct QItem : pkgAcquire::ItemDesc
   {
      QItem *Next;
      pkgAcquire::Worker *Worker;

      void operator =(pkgAcquire::ItemDesc const &I)
      {
         URI = I.URI;
         Description = I.Description;
         ShortDesc = I.ShortDesc;
         Owner = I.Owner;
      };
   };
   
   string Name;

   QItem *Items;

   pkgAcquire::Worker *Workers;

   pkgAcquire *Owner;

   signed long PipeDepth;

   unsigned long MaxPipeDepth;
   
   public:
   
   bool Enqueue(ItemDesc &Item);

   bool Dequeue(Item *Owner);

   QItem *FindItem(string URI,pkgAcquire::Worker *Owner);

   bool ItemStart(QItem *Itm,unsigned long Size);

   bool ItemDone(QItem *Itm);
   
   bool Startup();

   bool Shutdown(bool Final);

   bool Cycle();

   void Bump();
   
   Queue(string Name,pkgAcquire *Owner);

   ~Queue();
};
                                                                        /*}}}*/
class pkgAcquire::UriIterator
{
   pkgAcquire::Queue *CurQ;
   pkgAcquire::Queue::QItem *CurItem;
   
   public:
   
   inline void operator ++() {operator ++(0);};

   void operator ++(int)
   {
      CurItem = CurItem->Next;
      while (CurItem == 0 && CurQ != 0)
      {
         CurItem = CurQ->Items;
         CurQ = CurQ->Next;
      }
   };
   
   inline pkgAcquire::ItemDesc const *operator ->() const {return CurItem;};
   inline bool operator !=(UriIterator const &rhs) const {return rhs.CurQ != CurQ || rhs.CurItem != CurItem;};
   inline bool operator ==(UriIterator const &rhs) const {return rhs.CurQ == CurQ && rhs.CurItem == CurItem;};
   
   UriIterator(pkgAcquire::Queue *Q) : CurQ(Q), CurItem(0)
   {
      while (CurItem == 0 && CurQ != 0)
      {
         CurItem = CurQ->Items;
         CurQ = CurQ->Next;
      }
   }   
};
                                                                        /*}}}*/
struct pkgAcquire::MethodConfig
{
   MethodConfig *Next;
   
   string Access;

   string Version;

   bool SingleInstance;

   bool Pipeline;

   bool SendConfig;

   bool LocalOnly;

   bool NeedsCleanup;

   bool Removable;
   
   MethodConfig();
};
                                                                        /*}}}*/
class pkgAcquireStatus
{
   protected:
   
   struct timeval Time;

   struct timeval StartTime;

   double LastBytes;

   double CurrentCPS;

   double CurrentBytes;

   double TotalBytes;

   double FetchedBytes;

   unsigned long ElapsedTime;

   unsigned long TotalItems;

   unsigned long CurrentItems;
   
   public:

   bool Update;

   bool MorePulses;
      
   virtual void Fetched(unsigned long Size,unsigned long ResumePoint);
   
   virtual bool MediaChange(string Media,string Drive) = 0;
   
   virtual void IMSHit(pkgAcquire::ItemDesc &/*Itm*/) {};

   virtual void Fetch(pkgAcquire::ItemDesc &/*Itm*/) {};

   virtual void Done(pkgAcquire::ItemDesc &/*Itm*/) {};

   virtual void Fail(pkgAcquire::ItemDesc &/*Itm*/) {};

   virtual bool Pulse(pkgAcquire *Owner);

   virtual void Start();

   virtual void Stop();
   
   pkgAcquireStatus();
   virtual ~pkgAcquireStatus() {};
};
                                                                        /*}}}*/
#endif